Great work! Returning to pottery after 20+ years and want to get back into the swing of things. Thank you for the classes. #Keepupthegreatwork I will certainly stay tuned.
Thank you do much for your very calm, clear and helpful instructions. Also enjoyed and related to your freedom of play with the brushstrokes. Lookd forward to more.
Thank you for this great video Richard. I’ve been looking for information on how to mix up and apply oxides. This is super helpful for the home potter. 🤗
I'm so glad I found you! I'm setting up my 2nd studio (new 2nd home in pacific northwest) I don't have much of my chemical supply, but I did bring some bits of oxides, so with your help I'm going to have enough to test. I've tried to find a recipe for satin matte clear or satin white cone 6 electric for years, with no success. I've got a waxy white, I think it has tin in the recipe, also have some clear. Thanks again, wonderful information!
Thank you so much for this good and informative tutorial. It's so nice to listen and watch you working. I will absolutely come back and subscribe for sure.
Thank you for your kind comment. I am always learning and experimenting. One of the best ways to get better is to teach it which forces you to understand it better.
Excelente me encantan los oxides en la ceramica, yo usaba chromium, cobalt, oxido de hierro, agabe o engabe rojo ladrillo y blanco , el blanco era porcelain fina blanca
This video is the bomb! First of all, thank you for sharing your knowledge in such an exciting way. I am not clear on the proportion between oxide and water. In the tests I performed, they came out too concentrated. thank you for your work. Greetings from Berlin
Hi Lorenzo, Thank you for watching and your great comment. I will thin the oxides to an ink consistency, on the watery side. The proportions will vary with the strength of the oxides you are using, for example cobalt is very strong and needs to be thin and Iron tends to look strong but is in reality quite weak in its coloring ability. It is better to apply the oxides too thin than too thick. The solution needs to be stirred frequently to keep the oxides in suspension. I had a friend who did beautiful cobalt blue painting on her work who would let the oxide settle and when she used it the deeper she dipped the brush the stronger the color. Be aware that cobalt carbonate is pinkish when in the raw state and is sometimes difficult to see when applied. I fix this by adding a small amount of either Iron Oxide or Manganese Dioxide to darken the oxide mix and it also softens the intense blue color after firing to a more pleasing shade. Both Chrome Oxide and Rutile are refractory (they don't like to melt) so it is important particularly with these to apply thinner and even flux the solution with a little glaze or gerstley borate or frit to help it melt. Rutile, when it is applied too thickly will be crusty and rough. Iron when it is applied too thickly actually will melt at a lower temperature and run. Also when too thick, Iron turns black and rough. Good luck, I hope this helps you.
What a helpful video! You gave me enough information to make washes that I can really use as well as a demonstration of how you use them. I really appreciate that. I would be interested to know if you fire gas or electric, and, if gas, how some of the colors would come out in a cone 6 electric firing. Again, thank you. I have subscribed to your channel and look forward to more really helpful videos from you.
Thank you for your kind comment. I fire to cone 10 in a reduction atmosphere in a gas kiln. The colors do come out differently from an oxidation (electric) firing particularly copper which depending on the base glaze that it is applied to. In a reduction firing reds and pinks are possible while in an oxidation firing you can expect turquoise to green to black depending on the glaze and application thickness. Good luck and be sure that you test your ideas before committing them to an important piece of work.
Richard - What can I say that so many others have already stated? Your 2 videos around Oxide Washes are simply excellent. Your delivery, demonstration and pace are all spot on for truly grasping a difficult topic. Most pottery videos are about process or recipes,, but yours included actually demo’ing the the subject title. This is what makes your videos stand out from others. My ask to you is: can you produce more videos of just your decoration and artistry approach on a blank plate using washes? I found that watching you just perform the deco process; your color choice, brush saturation & stroke, it’s placement, etc made all the difference in learning “how” to use the oxide wash, not just making it & hoping. You said it yourself: it’s hard to visualize your deco with washes. Don’t I know it. So why not continue with follow-up videos with a format even more terse: An Overhead camera view, very little dialogue, maybe state the oxide wash you choose, brush out a decoration, then show the final fired piece so a direct correlation can be made for the viewer. The focus of it is you performing your artistry using a tool we all have come to love and are showing great perseverance to master. I hope you can consider my request. Thank you for your contribution to the pottery world. Hats off to you!
Thank you for your kind words. I made my living as a potter with a shop in Playa del Rey California for 6 years and found that I could create the variety of colors and surface decorations using oxides. I taught it for about 40 years to all of my students and the video was produced for my last classes at Glendale Community College before retiring. I have published the videos that I produced for my classes on RUclips and have had wonderful feedback from potters like you. My studio is currently changing into my personal creative space and once I am ready I will probably create some more videos for you. Thank you for your good ideas and thank you for watching. Be safe and creative, Richard
@@richardmccoll9297 Your career has served you well. I am in a similar transition into pottery here in Oakland, CA although a bit late in the game. Nonetheless. I look forward to your future knowledge sharing as you have much to give. We are fortunate to have teachers like you in the world. Cheers
@@damonmanni It is never too late to squeeze clay. Learning something new that has so much depth, such as ceramics, is a joy and will keep you going like Harrison Macintosh, Beatrice Wood, Warren Mackenzie, Otto Heino, and many others. Cheers to you too
@@richardmccoll9297 thank you for your encouragement. I am constantly amazed at how complex pottery/glazes can be. Now I know you mentioned that oxide washes can also go UNDER a final glaze layer. Should I assume that the final glaze would be a clear glaze (so it does not obscure/block the deco beauty from the wash)?
@@damonmanni Be careful putting oxide under a glaze because it is like putting dust on your piece which will resist the glaze leaving bare spots. Think of the oxide washes as a way to add the oxide of your choice to an existing glaze. The Chinese blue and white ware like Ming, is painted under a clear glaze. If you use another glaze the oxide will mix with the glaze in the firing and change the color of the glaze you put over it. I will often "stain" a textured piece with oxides and wipe the high points off to enhance the texture. Beware of refractory oxides like chrome oxide and Rutile because it will change the surface texture of the glaze and firing temperature of the glaze you put over them. They don't melt well at even cone 10 without the addition of a flux.
Thank you. My dad was a rocket scientist and my daughter is a brain scientist so it only makes sense that I have to combine science and art in my clay work. I have a sweet lair. Random chemicals Bad hair (at times) MU-AH HA HA HA!
Thank you for the video! So soothing to listen to you patiently show us your technique :) I am wondering about copper oxide black which I brush over some work. Sometimes it comes out coppery turquoise, other times jet black. What ratio of Gerstley Borate would you use with the oxide, and would you add Frit 3124 to it as well? If I didn't want it to go jet black, would mixing 50/50 Copper Oxide Black and Copper Carb do the trick?
Thank you for your kind words. Copper behaves like a flux so more flux like a frit is not necessary. Copper is very sensitive to thickness and will go black when it is applied too thickly. Copper carbonate oxidizes early in the firing creating copper oxide so mixing oxide and carbonate will do little. An advantage to copper oxide is it is easier to see than copper carbonate when you apply it. Copper carbonate disperses better in a glaze than copper oxide which can produce specs. A little goes a long way. I will often band an area and the copper will volatilize in the firing and in reduction will create a pink to red halo much like it was airbrushed. I like it when the kiln helps me decorate.
Thank you very much for the video! If I apply these oxides on the glaze, will the piece be food-safe? If yes, it has to be a stoneware or can be also a low fire clay? Thank you in advance!
You are very welcome, thanks for watching. That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods.
As someone whose English isnt very good, this is after glaze is applied on biscuit or after glaze is fired to be fired again? Thank you so much for any help! Great video by the way!
Yes they can be used together and the result will vary depending on the glaze, firing temperature and atmosphere of the kiln. I often will put a fine accent line of copper next to another oxide and with luck it will blush pink in cone 10 reduction. The picture at the front of the video has just dots of copper on my glaze which after firing were green in the center and blushed pink around the copper dots.
Great video Richard. Thank you! Which white glaze do you recommend? I have used Laguna white and clear experienced that cobalt isn’t stable - runs a bit. Is this the potential nature of cobalt or this a matter of doing the drip test you demonstrated?
I recommend a stiff white glaze which should be high in calcium for durability. I have taken a four part celadon and added up to 12% zircopax to opacify it. The old Choinard Celadon, Cone 10, base is excellent. Custer Feldspar 27% Whiting 19% EPK 19% Silica 35% Add: 10-12% Zircopax (any zirconium opacifier will do) I am not familiar with pre-mixed glazes so cannot recommend any at this time.
Thank you so much! Was most of your talk in the context of a reduction or an oxidation environment in the kiln? You refer to a wash on a celadon glaze, which I assume is a reduction kiln. But at other times I think you may be talking of an oxidation kiln.
I produced the video for my students at Glendale College where most of the firing is done in gas kilns in reduction. All of the oxides and techniques will work in oxidation except the colors will be generally warmer and copper will not go pink to red. My mantra is always test, test and test again in your situation, with your glazes and kilns. I hope this helps and inspires you to try something that I discussed in the video. Best of luck and have fun at it, Richard
Hi, The oxides are best on top of the glaze. The colors are not as strong and if you put them on under a glaze it sometimes is like putting dust on the piece and the glaze will crawl. The famous Ming ware from China did paint cobalt under the glaze with great success. In a reply to another comment asking about safety I said: "That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods." We are dealing with complex chemistry in our craft with many variables so I can only answer you generally without having control of the making of the object from beginning to end." Take care and be safe, Best wishes, Richard
Some oxides will work in low fire: cobalt, iron, copper. Rutile and chrome are refractory, they melt at a high temperature, so you need to add a flux so they will not be dry. A natural one is Gerstley Borate or you could add a frit like Ferro 3134, and test to get the correct proportions for your glaze. Gerstley will help suspend the wash while the frit will settle unless either a little macaloid or bentonite is added before adding water.
Richard, very clear and detailed. But as a novice in pottery, what is the next step? Firing for sure but any finish on the oxide wash? Cover glaze, cone etc. Thanks
Hi Bob, Thank you for watching! This is one of the simplest and oldest ways to decorate pottery. Just brush the oxides on the unfired glaze and fire. The oxides melt into and become one with the glaze. The challenges are to find a glaze where the oxides don't run too much (unless that is what you want) and to get the application right. I hope you get some great results. Richard
Water is fine. I have found a little (teaspoon) of clear glaze works well to help keep the oxide suspended. Some oxides like cobalt carbonate are very fine and can settle so in the dry form you can add a little bit of bentonite, just do not add when wet or it will clump and not go into suspension.
The color that you get with cobalt will vary depending on the glaze that you apply it to. If you use a high magnesium glaze, which is waxy or a buttery matt, a little cobalt will go purple. What is unusual is that if you add rutile it can go green. The best way to get a lighter purple is simply to use less cobalt. Some cone 10 glazes that will work are MG2, waxy, eggshell and Stoney matte. Check out Glazy.org for glaze recipes and look for ones that contain dolomite and or talc which provide magnesium as a flux.
I use cobalt carbonate which is finer than cobalt oxide and does not spot like the oxide can. I also add a little Iron oxide and Manganese dioxide to darken the cobalt which makes it easier to see when brushing. We get almost pure cobalt which is, in my opinion a bit too intense a blue when fired so the iron/manganese softens the color a little bit. In historical ceramics the cobalt was naturally mixed and not as pure as ours.
I use volume. Be aware that rutile and chrome oxide melt at high temperatures and need the addition of Gerstley Borate or a flux to keep the surface smooth not dry and textured. Gerstley Borate has the added benefits of helping to suspend the wash and helps with the brushability. Good luck and be sure to test your mixes on your glazes before using them on a special piece. Good luck and have fun.
Hi, I use Tom Coleman's black wash recipe. This is by weight: Red Iron Oxide 25 Cobalt Carbonate 15 Manganese Dioxide 10 Chrome Oxide 5 Gerstley Borate 10 Add water to the consistency of your choice. Enjoy!
That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods.
@@beverlywilson5788 The oxides will melt and bond at cone 6 which is only about 150 degrees F less than cone 10. The best thing to do is to test them in your kiln on your glazes. The ones which can cause problems are the refractory oxides, chrome and rutile. To melt them a bit more just add some gerstley borate to the mix which will flux them. You can also add a bit (1 to 2 oxide) of a clear glaze to the oxide to help them melt. I learned this from an amazing Potter, John Glick.
I've been looking for a video on this subject...THANK YOU :^)....Question....Can you use these washes on pieces fired to cone 6? or will some of them not melt well enough?
The oxides will melt and bond at cone 6 which is only about 150 degrees F less than cone 10. The best thing to do is to test them in your kiln on your glazes. The ones which can cause problems are the refractory oxides, chrome and rutile. To melt them a bit more just add some gerstley borate to the mix which will flux them. You can also add a bit (1 to 2 oxide) of a clear glaze to the oxide to help them melt. I learned this from an amazing Potter, John Glick.
Hi Mike, You are correct that burnt umber contains about 11.5% Manganese Oxide so when using it in dry form you should always wear a mask (n95) and also be careful to make sure it is fired in a well ventilated kiln. When Manganese is fired it will give off dangerous fumes which is why we are cautious with it. The main people who were harmed were steel workers which is why we know to be careful when using it. Umber is calcined at a low temperature (burnt) which drives out organics and leaves just calcium, alumina, silica, a lot of iron and some manganese. The proportions vary depending on the source and you can even buy it to color concrete. My black wash contains some manganese dioxide and I will put some with cobalt carbonate to soften the intensity of the blue.
Hi Elizabeth, I believe it is Rutile wash on a high alumina cone 10 reduction glaze. The glaze you paint on will determine the colors that the oxides produce. The application thickness will also change the colors which I really enjoy. For example a brush stroke will be stronger at the beginning and lighter at the end of the stroke. The glaze is porous in the raw state when the oxides are applied so the color will bleed to the edges of the brush stroke and be thinner there creating (if you are lucky) another color.
The oxides are food safe when applied to the right glaze and fired to the right temperature. Applying too thickly can saturate the glaze creating a dry spot with some oxides which could cause problems. If in doubt have it tested or just do not apply any oxides where they can come in contact with food. I have answered this question several times in the comments below in more detail for your viewing pleasure. Have fun!
tY for sharing this knowledge! are you using cobalt carb or oxide in your wash - specifically the cobalt & rutile one? also, is it only to the chrome wash you add gerstley borate?
Hi Alex, Thank you for watching and the good questions. I use cobalt carbonate because it is finer, does not spot like the oxide and is less expensive. I do add a bit of either Iron oxide or manganese dioxide to color the wash and tone down the intensity of the blue. These oxide additions are also to allow me to see my brush work better when I apply it because the carbonate is a very light pinkish color in the raw state. I add the gerstley borate to the two refractory oxides, chrome and rutile, to lower their melting temperature and prevent a rough dry surface if too much is applied.
@@alexchouinard3384 To melt them a bit more just add some gerstley borate to the mix which will flux them. The amount of gerstley borate will vary so it is important to test before applying it to a special piece. I will use as much as one tsp oxide to one tsp gerstley borate. If it dilutes the color or the decorations run just reduce the amount of gerstley borate. You can also add a bit (1 to 2 oxide) of a clear glaze to the oxide to help them melt.
Yes, just be aware of the glaze that you are applying them to, for example a barium matte, and avoid too thick an application where they don't melt into the glaze thoroughly. Good luck and have fun
Hello, I do not know why but somehow I was convinced I can apply iron and other oxyde s (mangane, cobalt) straight on fired clay. No glaze undeneath or above. Reading here it seems I was wrong. What should I do now (apart from doing my homework BEFORE using materials I do not know…)? Fire the sculpture? And at what temperature? Try and brush off some of the oxydes?. When I touch the sculpture now oxydes come on my fingers as powder and it does not promise a good end result. Any other way to “salvage” my work? Thank you for your answer!
Yes there are many ways to utilize oxides with your ceramics. They can be on the raw bisque, under the glaze, in the glaze and on top of the glaze giving different results. Oxides will brush off if they are not fired to a high enough temperature or have something to flux them. Even Iron will brush off at earthenware temperatures. The higher the temperature the less flux you need until you need none. This varies from oxide to oxide. Iron is interesting because it can actually act as a flux at high temperatures. If you fire to a low temperature you can still use oxides as long as you either mix a little flux, like a clear glaze, frit or gerstley borate, with the oxide or apply a very thin wash of a clear glaze over the oxide before firing. You can work with the oxides like charcoal or graphite on paper and apply a fixative which can be a commercial artists fixative, clear acrylic spray, or even hair spray. These all burn off cleanly during the firing leaving the oxide on the piece without smearing. Good luck and make beautiful work, Richard
If it is a sculpture that no one can use for food you can treat it like a charcoal drawing and seal it with a fixative or a matte acrylic spray. This is not as permanent as firing but will last. I have some drawings that I did about 40 years ago using oxides and acrylic medium and they are like the day I made them.
How would you make a wash to make a matcha type color? Also my iron oxide wash is mainly brown in color. I would like a wash to have a bit more red color. There are different types of iron oxide aren't there? What to use to make the wash a little more red? Really enjoyed the video and your listing of components of the various washes in one of your replies.
Matcha, as I understand, is a vivid green color like green tea. To get that color use a little chrome (how much is determined by experimentation) with some iron to tone the intense green color of the chrome. The color of iron is affected by many factors in ceramics. Temperature, atmosphere, cooling and glaze composition all will help determine the final fired color of the glaze. The natural color of red iron oxide is due to oxygen, while in a reduction firing iron turns black. You will get warmer tones in an oxidation firing while the natural red color is a challenge. I found that phosphorus in the form of bone ash or tricalcium phosphate will encourage the iron color to go to a more orange or red orange color also known as iron red.
@@richardmccoll9297 I think of the matcha as a subtle sort of light green color. I will try experimenting. I've seen different iron oxides available and I didn't know what what some of them would look like - yellow, red, black, spanish, etc. I am firing cone 5/6 oxidation. You are so helpful, thank you.
@@debfrederick1920 Hi Deb, All of the irons fire the same and will give the same results, with some weaker and some stronger. Your best bet for 5-6 might be a Mason stain mixed with some gerstley borate. The one that Tom Coleman uses that gives a nice light green color is called celadon, Mason 6201. Do not go by the picture of the stain on web sites because the intensity and quality of color will vary depending on your situation. The gerstley will help keep it in suspension for brushing and help melt the stain into the glaze. Start with 50/50 and adjust to your taste. Good luck, Richard
The techniques work great on low fire work. Commercial stains will be more consistent and brighter than when fired hot. If you use the metallic oxides, a couple (Rutile and chrome) will need additional flux, like a bit of low fire glaze, frit or gerstley borate. The colors will be different in oxidation and you need to consider how your glaze of choice reacts. The classic glaze is a stiff, opaque white used for majolica. Copper is one of my favorites in low fire because of the beautiful greens. The best green is copper on a lead based glaze. This is frowned upon now because it is even more soluble (toxic) than the straight lead glaze when any food containing mild acids like tomatoes, lemon or vinegar is placed in it dissolving some of the lead out of the glaze. If you want to recognize your brush work after firing do a little testing to see how fluid, aka runny your glazes are. Take a look at the amazing Tang Dynasty work. Good luck and have fun! Richard
Hi Patrick, Yes, the oxide washes work well on cone 6 glazes. Test them first and if the refractory ones, chrome and rutile, are a bit dry try increasing the flux or clear glaze added to the wash mix. Good luck, Richard
Thank you for watching. I keep my oxides simple and mix most by volume except for the black wash which I got from Tom Coleman. Most have clear glaze mixed in to help suspend the mix and slightly flux it. Rutile and chrome are refractory and need some help melting so I add a bit of Gerstley borate (calcium borate) which is a natural material that lowers the melting temperature. These can be adjusted to your taste and how you apply and fire them so this can be a starting point for you. If you use commercial stains like those produced by Mason add some Gerstley borate to suspend them because they like to settle. Here is how I do it: Oxide Wash Recipes
Use the proportions BY VOLUME: • 2 Tablespoons of oxide • 1 Tablespoon of liquid clear glaze • Add Water to thin to ink consistency Iron - Brown Red Iron Oxide Water (no glaze) Cobalt - Blue Cobalt Carbonate (you can use cobalt oxide which is stronger but coarser and can cause speckling) Water (no glaze) Rutile - Tan (tends to bleach and mottle dark glazes) Rutile 2 tbl Gerstley Borate 2 tbl Chrome - Green Chrome Oxide 2 tbl Gerstley Borate 2 tbl
Iron and Rutile - Rust Gold Red Iron Oxide 2 tbl Rutile 1 tbl Clear Glaze of your choice (wet) 1 ½ tbl Cobalt and Rutile - Mottled Blue Cobalt Carbonate 2 tbl Rutile 1 tbl Clear Glaze 1 ½ tbl Black - by weight Red Iron Oxide 25 Cobalt Carbonate 15 Manganese Dioxide 10 Chrome Oxide 5 Gerstley Borate 10 If you want to use stains it will depend on the temperature that you fire your ware to. For mid range and high fire pottery, cones 5-11, water is all you need. Some of the stains will settle and require frequent stirring which can be reduced by adding some clear glaze (of your choice) or a brushing medium. Some oxides (like chrome oxide and Rutile) and some stains are refractory and will need help melting so you might have to add gerstley borate or a frit. The best way to tell is to test it. Most stains will not melt or bond without the help of a flux at low temperatures, cone 06-04.
@@richardmccoll9297 I have low fire clay 04 and low fire glaze to cone 05 I purchase some underglaze and one opaque. I have also bought mason stains for adding to clay body I am not sure if those will work, and as well...I want to use for glazing instead...it takes alot to color the clay...I used almost an ounce of stain for 2 pounds of clay. I loved your art work on the ceramic peices you made. I love to paint so two of my favorites in one! Thank you for the recipes!
@@richardmccoll9297 what would you recommend for brushing medium? I heard someone say using gum Arabic, would that be a good one or do you have suggestions? Thank you
Yes the glaze is applied before the oxides. Oxides can be applied under a glaze which can cause blurring and possible crawling of the glaze. If you apply oxides on top of a glaze you can have a second chance if you make a mistake or do not like what you have done. The glaze can be washed off and you can start again. When oxides are applied directly to bisque ware they soak in like paper and are difficult to erase.
How do your fire your pieces with oxide washes? I tried a simple iron oxide wash decoration over a satin white glaze and fired it to cone 6. The iron oxide was barely visible...eaten up, so to speak. Was this the firing process or the base white glaze? Can this be done fired in oxidation? Or do you reccomend a satin white glaze? Thank you!
Iron is an interesting oxide, it can fool you. Iron looks strong when applied and can be weak after firing. If you put too much on it can saturate and go black, behave like a flux, and run. You are absolutely correct in suspecting your glaze because some glaze compositions are much more receptive to iron than others. Glazes that have high calcium like a celadon base will bleach/lighten the iron which is the basis of the classic celadons. 1-2% will give a celadon and 8-10% will be a temmoku. What you can do is test a piece with your glazes of choice with different strengths of iron brushed on, say one stroke, two strokes and three. Make sure the oxide wash is stirred well just before dipping your brush because it tends to settle which makes it a stronger suspension on the bottom of the jar and weaker at the top of the suspension. When brushing you will notice after firing that the beginning of your brush stroke will have a stronger color and will fade at the end of the stroke which can be very beautiful. A simple potter's test for an iron wash is to mix it up and brush some on a vertical stainless steel sink or bowl. If the iron wash stays it is too strong, if it just starts to run and you can't see the metal through the brush stroke, it is good to use, and if it runs and you can see the metal beneath it it is too weak. I hope this helps. The challenge is part of my joy in ceramics. I had many pieces disappoint before I found the sweet spot. Good luck and embrace the magic, Richard
When I started I used commercial glazes too. An advantage of the oxides is you can have a few commercial glazes and create a variety of colors and designs without too much work mixing or developing glazes. The commercial glazes are consistent too.@@lynnwilson359
@@richardmccoll9297 I'd love to have a little instruction on that! I inherited a lot of oxides, engobes and dry Amaco glazes from the artist who sold me my kiln, so I've always been drawn to them. I love the look and Michael Cardew!
That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods.
Hi, I answered this from an earlier comment: "That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods." We are dealing with complex chemistry in our craft with many variables so I can only answer you generally without having control of the making of the object from beginning to end. Take care and be safe, Best wishes, Richard
Hi Janice, This work is fired in gas, reduction. I also use electric kilns for the clean, oxidizing, atmosphere which produces different colors with some oxides like copper and iron. Thank you for watching. Richard
Hi, Read through my replies and I have answered this question several times before with different amounts of information depending on the question. Here is an answer from a couple of years ago: "That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods." Thanks for the question, it is always important to consider the safety of your ware. Take care, Richard
Hi Julie, Yes I have used glycerin when I did majolica which helped the oxide flow and allowed a stronger concentration of stain. I have not used it with the basic oxides because I like to keep things as simple as possible. Try it, it will do no harm and may help with the brushability.
Hi Bri, Thank you for watching. I keep my oxides simple and mix most by volume except for the black wash which I got from Tom Coleman. Most have clear glaze mixed in to help suspend the mix and slightly flux it. Rutile and chrome are refractory and need some help melting so I add a bit of Gerstley borate (calcium borate) which is a natural material that lowers the melting temperature. These can be adjusted to your taste and how you apply and fire them so this can be a starting point for you. If you use commercial stains like those produced by Mason add some Gerstley borate to suspend them because they like to settle. Here is how I do it: Oxide Wash Recipes
Use the proportions BY VOLUME: • 2 Tablespoons of oxide • 1 Tablespoon of liquid clear glaze • Add Water to thin to ink consistency
Iron - Brown Red Iron Oxide Water (no glaze) Cobalt - Blue Cobalt Carbonate (you can use cobalt oxide which is stronger but coarser and can cause speckling) Water (no glaze) Rutile - Tan (tends to bleach and mottle dark glazes) Rutile 2 tbl Gerstley Borate 2 tbl Chrome - Green Chrome Oxide 2 tbl Gerstley Borate 2 tbl Cobalt Carbonate ½ tbl Iron and Rutile - Rust Gold Red Iron Oxide 2 tbl Rutile 1 tbl Clear Glaze of your choice (wet) 1 ½ tbl Cobalt and Rutile - Mottled Blue Cobalt Carbonate 2 tbl Rutile 1 tbl Clear Glaze 1 ½ tbl Black - by weight Red Iron Oxide 25 Cobalt Carbonate 15 Manganese Dioxide 10 Chrome Oxide 5 Gerstley Borate 10
I feel so calm watching this guy. Such a soothing way of teaching. Trying this technique soon.
Liked and subscribed! Great video. Thanks for no music, good info and the finished product at the end. Well done sir.
Thank you! You've answered a lot of questions as I am getting into oxides. Thank you!
Your instructional style and content is excellent! Great videos and I so appreciate them!
Thank you so much!
Such wonderful happenstance that I viewed your video on oxides. I've wished for such insight for years. Thank you!
Thank you for watching, it is great being able to share my experience with you.
Great work! Returning to pottery after 20+ years and want to get back into the swing of things. Thank you for the classes. #Keepupthegreatwork I will certainly stay tuned.
Thank you and keep up the good work!
thank you so much for the video . Its such a boon to beginners like me ! So glad to have found your channel.
This is exactly the video I have wanted to see about oxides and applications. I learned so much. Thanks !!!! I subscribed
Thank you Sally. Oxide washes are so simple and rewarding to use. Enjoy!
Thank you, I am glad I am able to share my experience with you.
Thank you do much for your very calm, clear and helpful instructions. Also enjoyed and related to your freedom of play with the brushstrokes. Lookd forward to more.
Thank you for your kind comments. I will be releasing more on a weekly basis.
The freedom and play comes from a lot of practice producing many, many pots.
Great clear instructions and demonstration.
Thank you so much for this video. All those small tips make a big difference to the confidence with which one can approach the technique.
Thank you. The more you do the more confident you will be. I developed these techniques over the six years I had a shop.
I love that you show the finished pieces afterwards! So many don't do that. This was very informative. Thank you!
Thank you!
I check the end of the video and only watch if a finished photo is provided.
Thank you ☺️ This was such a great tutorial!
This video is such a great help...I have been trying hard to get all this information and wanted to see the fired results.Thank you so much....
You are very welcome.
Thank you for this great video Richard. I’ve been looking for information on how to mix up and apply oxides. This is super helpful for the home potter. 🤗
Thank you, I am glad it helped you. Keep checking for more content weekly.
I'm so glad I found you! I'm setting up my 2nd studio (new 2nd home in pacific northwest) I don't have much of my chemical supply, but I did bring some bits of oxides, so with your help I'm going to have enough to test. I've tried to find a recipe for satin matte clear or satin white cone 6 electric for years, with no success. I've got a waxy white, I think it has tin in the recipe, also have some clear. Thanks again, wonderful information!
Good luck in your glaze hunt, enjoy the process and make it your own.
Thank you so much for this good and informative tutorial. It's so nice to listen and watch you working. I will absolutely come back and subscribe for sure.
Thank you for watching and learning.
Wow, you are like the Bob Ross of pottery! Thoroughly enjoying your videos: thank you!
Thank you for the compliment...I think.
Extremely useful information, many thanks for putting it together! Subscribed 👍🙂
Thank you Stu!
very impressive work there in the back, you have really mastered glazing.
Thank you for your kind comment. I am always learning and experimenting. One of the best ways to get better is to teach it which forces you to understand it better.
The best knowledge about oxits👍🌹Thanks for sharing your life time experianses. Love from Tufkey, Bodrum
Thank you Inci!
I’m so happy to be here new subscriber and great information
Hi Tracey, Thank you so much!
This is wonderful knowledge! Thank you very much!
Thank you, glad to share!
Very informative! Thank you!
Very welcome!
Wonderful instructional, thank you!
Thank you so much!
Thank you so much I have learnt so much from your video.
You are so welcome!
Excelente me encantan los oxides en la ceramica, yo usaba chromium, cobalt, oxido de hierro, agabe o engabe rojo ladrillo y blanco , el blanco era porcelain fina blanca
Pleasure to watch your videos. Very informative and useful, thank you 🙏🏼🤌🏼
Thank you for learning.
Thank you for this video! It is very helpful.
Thank you, I am glad to share with you.
So informative. Thank you!
Thank you!
This video is the bomb! First of all, thank you for sharing your knowledge in such an exciting way. I am not clear on the proportion between oxide and water. In the tests I performed, they came out too concentrated. thank you for your work. Greetings from Berlin
Hi Lorenzo,
Thank you for watching and your great comment.
I will thin the oxides to an ink consistency, on the watery side. The proportions will vary with the strength of the oxides you are using, for example cobalt is very strong and needs to be thin and Iron tends to look strong but is in reality quite weak in its coloring ability. It is better to apply the oxides too thin than too thick. The solution needs to be stirred frequently to keep the oxides in suspension. I had a friend who did beautiful cobalt blue painting on her work who would let the oxide settle and when she used it the deeper she dipped the brush the stronger the color. Be aware that cobalt carbonate is pinkish when in the raw state and is sometimes difficult to see when applied. I fix this by adding a small amount of either Iron Oxide or Manganese Dioxide to darken the oxide mix and it also softens the intense blue color after firing to a more pleasing shade. Both Chrome Oxide and Rutile are refractory (they don't like to melt) so it is important particularly with these to apply thinner and even flux the solution with a little glaze or gerstley borate or frit to help it melt. Rutile, when it is applied too thickly will be crusty and rough. Iron when it is applied too thickly actually will melt at a lower temperature and run. Also when too thick, Iron turns black and rough.
Good luck, I hope this helps you.
@@richardmccoll9297 Thank you for your prompt and detailed reply.
Have a nice day and good work!
@@lorenzorumonato8174 Thank you!
That was very nice!
Thank you
What a helpful video! You gave me enough information to make washes that I can really use as well as a demonstration of how you use them. I really appreciate that. I would be interested to know if you fire gas or electric, and, if gas, how some of the colors would come out in a cone 6 electric firing. Again, thank you. I have subscribed to your channel and look forward to more really helpful videos from you.
Thank you for your kind comment.
I fire to cone 10 in a reduction atmosphere in a gas kiln. The colors do come out differently from an oxidation (electric) firing particularly copper which depending on the base glaze that it is applied to. In a reduction firing reds and pinks are possible while in an oxidation firing you can expect turquoise to green to black depending on the glaze and application thickness.
Good luck and be sure that you test your ideas before committing them to an important piece of work.
Thank you for this lovely lesson in magic ✨
Thank you and you too can make magic!
Take care,
Richard
Fantastic video! Thank you! I'm going to subscribe.
Thank you for subscribing. I hope I can help you with your enjoyment and success with clay.
Thank you!
Thank you very much!
That was fabulous.. thank you!!
Thank you!
Thanks you so much for making this video 👍
You are very welcome, thank you for your kind comment.
Thanks for knowledge of main glazes
You are very welcome.
Muito obrigada mestre, 🙏🙏🙏
Muito obrigado!
Richard - What can I say that so many others have already stated? Your 2 videos around Oxide Washes are simply excellent. Your delivery, demonstration and pace are all spot on for truly grasping a difficult topic. Most pottery videos are about process or recipes,, but yours included actually demo’ing the the subject title. This is what makes your videos stand out from others.
My ask to you is: can you produce more videos of just your decoration and artistry approach on a blank plate using washes? I found that watching you just perform the deco process; your color choice, brush saturation & stroke, it’s placement, etc made all the difference in learning “how” to use the oxide wash, not just making it & hoping. You said it yourself: it’s hard to visualize your deco with washes. Don’t I know it. So why not continue with follow-up videos with a format even more terse: An Overhead camera view, very little dialogue, maybe state the oxide wash you choose, brush out a decoration, then show the final fired piece so a direct correlation can be made for the viewer. The focus of it is you performing your artistry using a tool we all have come to love and are showing great perseverance to master. I hope you can consider my request. Thank you for your contribution to the pottery world. Hats off to you!
Thank you for your kind words. I made my living as a potter with a shop in Playa del Rey California for 6 years and found that I could create the variety of colors and surface decorations using oxides. I taught it for about 40 years to all of my students and the video was produced for my last classes at Glendale Community College before retiring. I have published the videos that I produced for my classes on RUclips and have had wonderful feedback from potters like you. My studio is currently changing into my personal creative space and once I am ready I will probably create some more videos for you. Thank you for your good ideas and thank you for watching.
Be safe and creative,
Richard
@@richardmccoll9297 Your career has served you well. I am in a similar transition into pottery here in Oakland, CA although a bit late in the game. Nonetheless. I look forward to your future knowledge sharing as you have much to give. We are fortunate to have teachers like you in the world. Cheers
@@damonmanni It is never too late to squeeze clay. Learning something new that has so much depth, such as ceramics, is a joy and will keep you going like Harrison Macintosh, Beatrice Wood, Warren Mackenzie, Otto Heino, and many others.
Cheers to you too
@@richardmccoll9297 thank you for your encouragement. I am constantly amazed at how complex pottery/glazes can be. Now I know you mentioned that oxide washes can also go UNDER a final glaze layer. Should I assume that the final glaze would be a clear glaze (so it does not obscure/block the deco beauty from the wash)?
@@damonmanni Be careful putting oxide under a glaze because it is like putting dust on your piece which will resist the glaze leaving bare spots. Think of the oxide washes as a way to add the oxide of your choice to an existing glaze. The Chinese blue and white ware like Ming, is painted under a clear glaze. If you use another glaze the oxide will mix with the glaze in the firing and change the color of the glaze you put over it. I will often "stain" a textured piece with oxides and wipe the high points off to enhance the texture. Beware of refractory oxides like chrome oxide and Rutile because it will change the surface texture of the glaze and firing temperature of the glaze you put over them. They don't melt well at even cone 10 without the addition of a flux.
Very nice
Richard. Do you have a clip on how to mix oxides. Thank you. Paul
You’re like a mad scientist but I love it!
Thank you. My dad was a rocket scientist and my daughter is a brain scientist so it only makes sense that I have to combine science and art in my clay work.
I have a sweet lair.
Random chemicals
Bad hair (at times)
MU-AH HA HA HA!
I like this guy :)
Thank you!!
You are welcome!
great! thanks
Thank you for the video! So soothing to listen to you patiently show us your technique :) I am wondering about copper oxide black which I brush over some work. Sometimes it comes out coppery turquoise, other times jet black. What ratio of Gerstley Borate would you use with the oxide, and would you add Frit 3124 to it as well? If I didn't want it to go jet black, would mixing 50/50 Copper Oxide Black and Copper Carb do the trick?
Thank you for your kind words.
Copper behaves like a flux so more flux like a frit is not necessary. Copper is very sensitive to thickness and will go black when it is applied too thickly. Copper carbonate oxidizes early in the firing creating copper oxide so mixing oxide and carbonate will do little. An advantage to copper oxide is it is easier to see than copper carbonate when you apply it. Copper carbonate disperses better in a glaze than copper oxide which can produce specs.
A little goes a long way. I will often band an area and the copper will volatilize in the firing and in reduction will create a pink to red halo much like it was airbrushed. I like it when the kiln helps me decorate.
Excellent!
Thank you!
Great video, I am changing In the new year from terracotta slipware to terracotta tin glazed earthenware with oxide Decoration.
What fun, I love both. Check out my reply to Janet Mclees comment on applying these techniques to low fire work.
Best of luck,
Richard
@@richardmccoll9297 will do and thank you 😊🌲
Would love to know specifically what brushes you are using.
Thanks for sharing.
You are very welcome.
Useful and...you have a very nice hand.
Thank you. I have admired your work for years and think that I have your book.
Take care
I'm honored, Richard.
Some add ball clay to oxide mixture. Do you know the ratios of clay to the oxide powder?
Can I mix the red iron oxide powder with wax resist and splatter decorate a pot?
Thank you very much for the video! If I apply these oxides on the glaze, will the piece be food-safe? If yes, it has to be a stoneware or can be also a low fire clay? Thank you in advance!
You are very welcome, thanks for watching.
That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods.
As someone whose English isnt very good, this is after glaze is applied on biscuit or after glaze is fired to be fired again? Thank you so much for any help! Great video by the way!
Thanks. My horizions have been expanded.
Thank you for your kind compliment!
Really like the effects you create. Can cobalt and copper oxide be used alongside each other.
Yes they can be used together and the result will vary depending on the glaze, firing temperature and atmosphere of the kiln. I often will put a fine accent line of copper next to another oxide and with luck it will blush pink in cone 10 reduction. The picture at the front of the video has just dots of copper on my glaze which after firing were green in the center and blushed pink around the copper dots.
Great video Richard. Thank you! Which white glaze do you recommend? I have used Laguna white and clear experienced that cobalt isn’t stable - runs a bit. Is this the potential nature of cobalt or this a matter of doing the drip test you demonstrated?
I recommend a stiff white glaze which should be high in calcium for durability. I have taken a four part celadon and added up to 12% zircopax to opacify it.
The old Choinard Celadon, Cone 10, base is excellent.
Custer Feldspar 27%
Whiting 19%
EPK 19%
Silica 35%
Add: 10-12% Zircopax (any zirconium opacifier will do)
I am not familiar with pre-mixed glazes so cannot recommend any at this time.
The cobalt will not make the design run it is your base glaze that is causing the running.
Thank you so much!
Was most of your talk in the context of a reduction or an oxidation environment in the kiln? You refer to a wash on a celadon glaze, which I assume is a reduction kiln. But at other times I think you may be talking of an oxidation kiln.
I produced the video for my students at Glendale College where most of the firing is done in gas kilns in reduction. All of the oxides and techniques will work in oxidation except the colors will be generally warmer and copper will not go pink to red. My mantra is always test, test and test again in your situation, with your glazes and kilns. I hope this helps and inspires you to try something that I discussed in the video.
Best of luck and have fun at it,
Richard
Excellent videos and tutorials! So I can use these oxides on dinner ware, if the transparent glaze is food safe over the top of it?
Hi,
The oxides are best on top of the glaze. The colors are not as strong and if you put them on under a glaze it sometimes is like putting dust on the piece and the glaze will crawl. The famous Ming ware from China did paint cobalt under the glaze with great success.
In a reply to another comment asking about safety I said:
"That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods."
We are dealing with complex chemistry in our craft with many variables so I can only answer you generally without having control of the making of the object from beginning to end."
Take care and be safe,
Best wishes,
Richard
Beautiful! Can these all be used in low firings? Sadly I don't have access to a reliable enough high firing kiln where I live
Some oxides will work in low fire: cobalt, iron, copper. Rutile and chrome are refractory, they melt at a high temperature, so you need to add a flux so they will not be dry. A natural one is Gerstley Borate or you could add a frit like Ferro 3134, and test to get the correct proportions for your glaze. Gerstley will help suspend the wash while the frit will settle unless either a little macaloid or bentonite is added before adding water.
Oh, good question. It helped also me! Thanks.
If the oxides are applied over a glazed bisqueware such as the plate you painted in this video, will it be food safe?
What kind of bamboo brushes are you using on this video?
Richard, very clear and detailed. But as a novice in pottery, what is the next step? Firing for sure but any finish on the oxide wash? Cover glaze, cone etc. Thanks
Hi Bob,
Thank you for watching!
This is one of the simplest and oldest ways to decorate pottery. Just brush the oxides on the unfired glaze and fire. The oxides melt into and become one with the glaze. The challenges are to find a glaze where the oxides don't run too much (unless that is what you want) and to get the application right. I hope you get some great results.
Richard
Hi Richard
Thank you for the great video. Was this piece Matt glazed before?
The piece is glazed and then painted on the raw glaze before firing.
Thanks for watching!
Richard
Sorry to say I ouldnt catch what you added to your oxides to help them mix? I've just subscribed as I love your style.
Water is fine. I have found a little (teaspoon) of clear glaze works well to help keep the oxide suspended. Some oxides like cobalt carbonate are very fine and can settle so in the dry form you can add a little bit of bentonite, just do not add when wet or it will clump and not go into suspension.
Love it! Can you get a purple with Iron and Cobalt? and a lighter purple with a bit of Rutile?
The color that you get with cobalt will vary depending on the glaze that you apply it to. If you use a high magnesium glaze, which is waxy or a buttery matt, a little cobalt will go purple. What is unusual is that if you add rutile it can go green. The best way to get a lighter purple is simply to use less cobalt. Some cone 10 glazes that will work are MG2, waxy, eggshell and Stoney matte. Check out Glazy.org for glaze recipes and look for ones that contain dolomite and or talc which provide magnesium as a flux.
Iron will soften the cobalt but will not make it go to a purple. Think of adding brown to blue...
@@richardmccoll9297 thanks a lot mate
What type of cobalt is this wash? IT IS SO PRETTY!!!!
I use cobalt carbonate which is finer than cobalt oxide and does not spot like the oxide can. I also add a little Iron oxide and Manganese dioxide to darken the cobalt which makes it easier to see when brushing. We get almost pure cobalt which is, in my opinion a bit too intense a blue when fired so the iron/manganese softens the color a little bit. In historical ceramics the cobalt was naturally mixed and not as pure as ours.
Hermoso
Muchas gracias!
One to one chrome to gertsley borate by weight or volume?
I use volume. Be aware that rutile and chrome oxide melt at high temperatures and need the addition of Gerstley Borate or a flux to keep the surface smooth not dry and textured. Gerstley Borate has the added benefits of helping to suspend the wash and helps with the brushability. Good luck and be sure to test your mixes on your glazes before using them on a special piece. Good luck and have fun.
This is such a fantastic and helpful video! Could you share the recipe you use for the black wash?
Hi, I use Tom Coleman's black wash recipe.
This is by weight:
Red Iron Oxide 25
Cobalt Carbonate 15
Manganese Dioxide 10
Chrome Oxide 5
Gerstley Borate 10
Add water to the consistency of your choice.
Enjoy!
@@richardmccoll9297 so helpful, thank you!
You are very welcome.@@jeffkthompson
Hello Richard, I love your videos. They are so helpful. I am wondering how food safe oxides are when applied over glazes.
That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods.
@@richardmccoll9297 Thank you so much for your reply! I am firing cone 5/6.
@@beverlywilson5788
The oxides will melt and bond at cone 6 which is only about 150 degrees F less than cone 10. The best thing to do is to test them in your kiln on your glazes. The ones which can cause problems are the refractory oxides, chrome and rutile. To melt them a bit more just add some gerstley borate to the mix which will flux them. You can also add a bit (1 to 2 oxide) of a clear glaze to the oxide to help them melt. I learned this from an amazing Potter, John Glick.
@@richardmccoll9297 Thank you so much!! I love your videos.
I've been looking for a video on this subject...THANK YOU :^)....Question....Can you use these washes on pieces fired to cone 6? or will some of them not melt well enough?
The oxides will melt and bond at cone 6 which is only about 150 degrees F less than cone 10. The best thing to do is to test them in your kiln on your glazes. The ones which can cause problems are the refractory oxides, chrome and rutile. To melt them a bit more just add some gerstley borate to the mix which will flux them. You can also add a bit (1 to 2 oxide) of a clear glaze to the oxide to help them melt. I learned this from an amazing Potter, John Glick.
@@richardmccoll9297 Thanks SO much for the reply....I can't wait to try this.... I'm so glad I found your channel.... ~!! Thanks Again ~!!
is burnt umber toxic if used as a wash? (i think it contains manganese oxide)
Hi Mike,
You are correct that burnt umber contains about 11.5% Manganese Oxide so when using it in dry form you should always wear a mask (n95) and also be careful to make sure it is fired in a well ventilated kiln. When Manganese is fired it will give off dangerous fumes which is why we are cautious with it. The main people who were harmed were steel workers which is why we know to be careful when using it. Umber is calcined at a low temperature (burnt) which drives out organics and leaves just calcium, alumina, silica, a lot of iron and some manganese. The proportions vary depending on the source and you can even buy it to color concrete. My black wash contains some manganese dioxide and I will put some with cobalt carbonate to soften the intensity of the blue.
I apologize if I missed it during the video, but which wash creates the Yellow/orange/green shown in the first picture at the end of the video?
Hi Elizabeth,
I believe it is Rutile wash on a high alumina cone 10 reduction glaze. The glaze you paint on will determine the colors that the oxides produce. The application thickness will also change the colors which I really enjoy. For example a brush stroke will be stronger at the beginning and lighter at the end of the stroke. The glaze is porous in the raw state when the oxides are applied so the color will bleed to the edges of the brush stroke and be thinner there creating (if you are lucky) another color.
@@richardmccoll9297 thank you so much for the reply!
Nice demo. What is the ratio of oxides to make the black.
Thank you.
Black - by weight
Red Iron Oxide 25
Cobalt Carbonate 15
Manganese Dioxide 10
Chrome Oxide 5
Gerstly Borate 10
Thanks for your instruction! Are these oxides food safe?
The oxides are food safe when applied to the right glaze and fired to the right temperature. Applying too thickly can saturate the glaze creating a dry spot with some oxides which could cause problems. If in doubt have it tested or just do not apply any oxides where they can come in contact with food. I have answered this question several times in the comments below in more detail for your viewing pleasure. Have fun!
How do you apply oxides on top of glazes? Is this all after bisque firing?
I bisque, apply a glaze and then brush on the oxide washes. Check out Italian Majolica where this has been done for centuries beautifully.
tY for sharing this knowledge! are you using cobalt carb or oxide in your wash - specifically the cobalt & rutile one? also, is it only to the chrome wash you add gerstley borate?
Hi Alex,
Thank you for watching and the good questions.
I use cobalt carbonate because it is finer, does not spot like the oxide and is less expensive. I do add a bit of either Iron oxide or manganese dioxide to color the wash and tone down the intensity of the blue. These oxide additions are also to allow me to see my brush work better when I apply it because the carbonate is a very light pinkish color in the raw state.
I add the gerstley borate to the two refractory oxides, chrome and rutile, to lower their melting temperature and prevent a rough dry surface if too much is applied.
@@richardmccoll9297 Thank you! What ratio of gerstley borate to oxide do you generally use?
@@alexchouinard3384 To melt them a bit more just add some gerstley borate to the mix which will flux them. The amount of gerstley borate will vary so it is important to test before applying it to a special piece. I will use as much as one tsp oxide to one tsp gerstley borate. If it dilutes the color or the decorations run just reduce the amount of gerstley borate. You can also add a bit (1 to 2 oxide) of a clear glaze to the oxide to help them melt.
New to glazes and oxides just checking if these oxides are food safe and good at cone 5 or 6
Yes, just be aware of the glaze that you are applying them to, for example a barium matte, and avoid too thick an application where they don't melt into the glaze thoroughly.
Good luck and have fun
Is red iron oxide the same as the 'iron oxide' you used?
Yes, Red Iron Oxide is the preferred form.
Hello, I do not know why but somehow I was convinced I can apply iron and other oxyde s (mangane, cobalt) straight on fired clay. No glaze undeneath or above. Reading here it seems I was wrong. What should I do now (apart from doing my homework BEFORE using materials I do not know…)? Fire the sculpture? And at what temperature? Try and brush off some of the oxydes?. When I touch the sculpture now oxydes come on my fingers as powder and it does not promise a good end result. Any other way to “salvage” my work? Thank you for your answer!
Yes there are many ways to utilize oxides with your ceramics. They can be on the raw bisque, under the glaze, in the glaze and on top of the glaze giving different results. Oxides will brush off if they are not fired to a high enough temperature or have something to flux them. Even Iron will brush off at earthenware temperatures. The higher the temperature the less flux you need until you need none. This varies from oxide to oxide. Iron is interesting because it can actually act as a flux at high temperatures.
If you fire to a low temperature you can still use oxides as long as you either mix a little flux, like a clear glaze, frit or gerstley borate, with the oxide or apply a very thin wash of a clear glaze over the oxide before firing.
You can work with the oxides like charcoal or graphite on paper and apply a fixative which can be a commercial artists fixative, clear acrylic spray, or even hair spray. These all burn off cleanly during the firing leaving the oxide on the piece without smearing.
Good luck and make beautiful work,
Richard
@@richardmccoll9297 Thank you so much! I really appreciate it!
If it is a sculpture that no one can use for food you can treat it like a charcoal drawing and seal it with a fixative or a matte acrylic spray. This is not as permanent as firing but will last. I have some drawings that I did about 40 years ago using oxides and acrylic medium and they are like the day I made them.
Just to be clear - you are painting the oxides on an unfired glaze base? Not as an overglaze on a glaze fired piece?
Yes, I am brushing oxides on the unfired glaze.
How would you make a wash to make a matcha type color? Also my iron oxide wash is mainly brown in color. I would like a wash to have a bit more red color. There are different types of iron oxide aren't there? What to use to make the wash a little more red? Really enjoyed the video and your listing of components of the various washes in one of your replies.
Matcha, as I understand, is a vivid green color like green tea. To get that color use a little chrome (how much is determined by experimentation) with some iron to tone the intense green color of the chrome.
The color of iron is affected by many factors in ceramics. Temperature, atmosphere, cooling and glaze composition all will help determine the final fired color of the glaze. The natural color of red iron oxide is due to oxygen, while in a reduction firing iron turns black. You will get warmer tones in an oxidation firing while the natural red color is a challenge. I found that phosphorus in the form of bone ash or tricalcium phosphate will encourage the iron color to go to a more orange or red orange color also known as iron red.
@@richardmccoll9297 I think of the matcha as a subtle sort of light green color. I will try experimenting. I've seen different iron oxides available and I didn't know what what some of them would look like - yellow, red, black, spanish, etc. I am firing cone 5/6 oxidation. You are so helpful, thank you.
@@debfrederick1920 Hi Deb,
All of the irons fire the same and will give the same results, with some weaker and some stronger. Your best bet for 5-6 might be a Mason stain mixed with some gerstley borate. The one that Tom Coleman uses that gives a nice light green color is called celadon, Mason 6201. Do not go by the picture of the stain on web sites because the intensity and quality of color will vary depending on your situation. The gerstley will help keep it in suspension for brushing and help melt the stain into the glaze. Start with 50/50 and adjust to your taste.
Good luck,
Richard
@@richardmccoll9297 Great, thanks again.
I would benefit from a few words from a low fire perspective too. Thx for a great video.
The techniques work great on low fire work. Commercial stains will be more consistent and brighter than when fired hot. If you use the metallic oxides, a couple (Rutile and chrome) will need additional flux, like a bit of low fire glaze, frit or gerstley borate. The colors will be different in oxidation and you need to consider how your glaze of choice reacts. The classic glaze is a stiff, opaque white used for majolica. Copper is one of my favorites in low fire because of the beautiful greens. The best green is copper on a lead based glaze. This is frowned upon now because it is even more soluble (toxic) than the straight lead glaze when any food containing mild acids like tomatoes, lemon or vinegar is placed in it dissolving some of the lead out of the glaze.
If you want to recognize your brush work after firing do a little testing to see how fluid, aka runny your glazes are. Take a look at the amazing Tang Dynasty work.
Good luck and have fun!
Richard
This is great - very informative. Do you ever use oxide washes on cone 6 glazes?
Hi Patrick,
Yes, the oxide washes work well on cone 6 glazes. Test them first and if the refractory ones, chrome and rutile, are a bit dry try increasing the flux or clear glaze added to the wash mix.
Good luck,
Richard
@@richardmccoll9297 - Thanks Richard... very helpful.
@@patrickkennedy8420 You are welcome Patrick! Good luck and keep squeezing clay.
How do you mix those, are they mason stains? I can't hear well so I may have missed what you said. The painting on the plates were pretty.
Thank you for watching.
I keep my oxides simple and mix most by volume except for the black wash which I got from Tom Coleman. Most have clear glaze mixed in to help suspend the mix and slightly flux it. Rutile and chrome are refractory and need some help melting so I add a bit of Gerstley borate (calcium borate) which is a natural material that lowers the melting temperature. These can be adjusted to your taste and how you apply and fire them so this can be a starting point for you. If you use commercial stains like those produced by Mason add some Gerstley borate to suspend them because they like to settle.
Here is how I do it:
Oxide Wash Recipes
Use the proportions BY VOLUME:
• 2 Tablespoons of oxide
• 1 Tablespoon of liquid clear glaze
• Add Water to thin to ink consistency
Iron - Brown
Red Iron Oxide
Water (no glaze)
Cobalt - Blue
Cobalt Carbonate (you can use cobalt oxide which is stronger but coarser and can cause speckling)
Water (no glaze)
Rutile - Tan (tends to bleach and mottle dark glazes)
Rutile 2 tbl
Gerstley Borate 2 tbl
Chrome - Green
Chrome Oxide 2 tbl
Gerstley Borate 2 tbl
Iron and Rutile - Rust Gold
Red Iron Oxide 2 tbl
Rutile 1 tbl
Clear Glaze of your choice (wet) 1 ½ tbl
Cobalt and Rutile - Mottled Blue
Cobalt Carbonate 2 tbl
Rutile 1 tbl
Clear Glaze 1 ½ tbl
Black - by weight
Red Iron Oxide 25
Cobalt Carbonate 15
Manganese Dioxide 10
Chrome Oxide 5
Gerstley Borate 10
If you want to use stains it will depend on the temperature that you fire your ware to. For mid range and high fire pottery, cones 5-11, water is all you need. Some of the stains will settle and require frequent stirring which can be reduced by adding some clear glaze (of your choice) or a brushing medium. Some oxides (like chrome oxide and Rutile) and some stains are refractory and will need help melting so you might have to add gerstley borate or a frit. The best way to tell is to test it. Most stains will not melt or bond without the help of a flux at low temperatures, cone 06-04.
@@richardmccoll9297 I have low fire clay 04 and low fire glaze to cone 05 I purchase some underglaze and one opaque. I have also bought mason stains for adding to clay body I am not sure if those will work, and as well...I want to use for glazing instead...it takes alot to color the clay...I used almost an ounce of stain for 2 pounds of clay. I loved your art work on the ceramic peices you made. I love to paint so two of my favorites in one! Thank you for the recipes!
@@richardmccoll9297 what would you recommend for brushing medium? I heard someone say using gum Arabic, would that be a good one or do you have suggestions? Thank you
@@richardmccoll9297 oh the black recipe in weight portions are those grams or ounces?
@@samanthanicholson9015 I use grams but either will work. The important thing is to weigh them not measure by volume as with a spoon.
Is this on the plate which has already been dipped in glaze ???
Yes the glaze is applied before the oxides. Oxides can be applied under a glaze which can cause blurring and possible crawling of the glaze. If you apply oxides on top of a glaze you can have a second chance if you make a mistake or do not like what you have done. The glaze can be washed off and you can start again. When oxides are applied directly to bisque ware they soak in like paper and are difficult to erase.
@@richardmccoll9297 thank you so much
How do your fire your pieces with oxide washes? I tried a simple iron oxide wash decoration over a satin white glaze and fired it to cone 6. The iron oxide was barely visible...eaten up, so to speak. Was this the firing process or the base white glaze? Can this be done fired in oxidation? Or do you reccomend a satin white glaze? Thank you!
Iron is an interesting oxide, it can fool you. Iron looks strong when applied and can be weak after firing. If you put too much on it can saturate and go black, behave like a flux, and run.
You are absolutely correct in suspecting your glaze because some glaze compositions are much more receptive to iron than others. Glazes that have high calcium like a celadon base will bleach/lighten the iron which is the basis of the classic celadons. 1-2% will give a celadon and 8-10% will be a temmoku.
What you can do is test a piece with your glazes of choice with different strengths of iron brushed on, say one stroke, two strokes and three. Make sure the oxide wash is stirred well just before dipping your brush because it tends to settle which makes it a stronger suspension on the bottom of the jar and weaker at the top of the suspension.
When brushing you will notice after firing that the beginning of your brush stroke will have a stronger color and will fade at the end of the stroke which can be very beautiful.
A simple potter's test for an iron wash is to mix it up and brush some on a vertical stainless steel sink or bowl. If the iron wash stays it is too strong, if it just starts to run and you can't see the metal through the brush stroke, it is good to use, and if it runs and you can see the metal beneath it it is too weak.
I hope this helps.
The challenge is part of my joy in ceramics. I had many pieces disappoint before I found the sweet spot.
Good luck and embrace the magic,
Richard
@@richardmccoll9297 Thank you!
@@richardmccoll9297 Yes. It helps! I guess I have a lot of testing to do! I hope I get lucky fast. I use commercial glazes and do not make my own.
When I started I used commercial glazes too. An advantage of the oxides is you can have a few commercial glazes and create a variety of colors and designs without too much work mixing or developing glazes. The commercial glazes are consistent too.@@lynnwilson359
@@richardmccoll9297 I'd love to have a little instruction on that! I inherited a lot of oxides, engobes and dry Amaco glazes from the artist who sold me my kiln, so I've always been drawn to them. I love the look and Michael Cardew!
What about food safety issues?
That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods.
Are the dishes food safe with the oxides on them?
Yes, as log as you fire your gla,e to maturity.
Can I ask if oxides are safe to use for dinnerware?
Hi,
I answered this from an earlier comment:
"That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods."
We are dealing with complex chemistry in our craft with many variables so I can only answer you generally without having control of the making of the object from beginning to end.
Take care and be safe,
Best wishes,
Richard
What kind of kiln are you using. Gas or electric?
Hi Janice,
This work is fired in gas, reduction. I also use electric kilns for the clean, oxidizing, atmosphere which produces different colors with some oxides like copper and iron.
Thank you for watching.
Richard
@@richardmccoll9297 Thanks Richard, I thought it must be reduction firing with the rutile colour you were getting.
8:05 what is the name of that matte glaze??
It is one that I created that is a high alumina cone 10 matt.
Hi Richard would this be foodsafe?
Hi,
Read through my replies and I have answered this question several times before with different amounts of information depending on the question.
Here is an answer from a couple of years ago:
"That varies depending on the glaze and temperature the pieces are fired to. With cone 10 ware it will be safe unless you are using a high barium glaze which might leach with mild acids. With low fire ware, cone 06 to 04, if the base glaze has lead in it copper wash will increase the solubility of the lead again with acidic foods."
Thanks for the question, it is always important to consider the safety of your ware.
Take care,
Richard
Hi Richard. I have scrolled through the comments, but apparently not far enough. Thanks for answering!@@richardmccoll9297
Have you tried to use glycerin
Hi Julie, Yes I have used glycerin when I did majolica which helped the oxide flow and allowed a stronger concentration of stain. I have not used it with the basic oxides because I like to keep things as simple as possible. Try it, it will do no harm and may help with the brushability.
I will try it on both underglaze and glaze
what is the % of your oxide solutions?
Hi Bri,
Thank you for watching.
I keep my oxides simple and mix most by volume except for the black wash which I got from Tom Coleman. Most have clear glaze mixed in to help suspend the mix and slightly flux it. Rutile and chrome are refractory and need some help melting so I add a bit of Gerstley borate (calcium borate) which is a natural material that lowers the melting temperature. These can be adjusted to your taste and how you apply and fire them so this can be a starting point for you. If you use commercial stains like those produced by Mason add some Gerstley borate to suspend them because they like to settle.
Here is how I do it:
Oxide Wash Recipes
Use the proportions BY VOLUME:
• 2 Tablespoons of oxide
• 1 Tablespoon of liquid clear glaze
• Add Water to thin to ink consistency
Iron - Brown
Red Iron Oxide
Water (no glaze)
Cobalt - Blue
Cobalt Carbonate (you can use cobalt oxide which is stronger but coarser and can cause speckling)
Water (no glaze)
Rutile - Tan (tends to bleach and mottle dark glazes)
Rutile 2 tbl
Gerstley Borate 2 tbl
Chrome - Green
Chrome Oxide 2 tbl
Gerstley Borate 2 tbl
Cobalt Carbonate ½ tbl
Iron and Rutile - Rust Gold
Red Iron Oxide 2 tbl
Rutile 1 tbl
Clear Glaze of your choice (wet) 1 ½ tbl
Cobalt and Rutile - Mottled Blue
Cobalt Carbonate 2 tbl
Rutile 1 tbl
Clear Glaze 1 ½ tbl
Black - by weight
Red Iron Oxide 25
Cobalt Carbonate 15
Manganese Dioxide 10
Chrome Oxide 5
Gerstley Borate 10