Trial and error aren't a waste of time, it's the only reliable process to learn such things, and master them given enough repetition and reflection. You show this very well, and it's an impressive video at that.
Kaolin, graphite, water. At one time I poured steel for a living and we white washed the inside of the mold halves before assembling them. It was done for each half so the molds had to be exact. When the white wash was dry the two halves were joined. A collar was added above the mold to control pouring into the mold. The ingredients listed make the white wash that seals the mold and helps to contain the heat to allow the mold to fill completely. It also holds the pouring channels open. Don't know if this is even necessary for aluminum that's at a lower temp. than steel but if you're having issues with the finish I'd suggest you white wash the inside of the mold halves before pouring.
I appreciate the video. I don't know if it could have been done better or worse, but don't let the negative comments stop you. The DYI sand instructions alone were worth the watch, Personally I find this method of mistake, correction, mistake, correction to be highly valuable. Thanks again.
You're welcome, and I appreciate that! I think I get a lot less grief than most creators. I've had to take a bit of a break from making these videos, but season 2 is coming soon!
I am a first year mechanical enginear student from Greece, i take a class about castiing and other metal procesing methods, and due to everything i just didnt had the chance to be in a lab-workshop and experiment with casting, videos like these help alot
Great! I never had a chance to work on much of anything but the required classes. Going through engineering and trying to have a social life took up all of my time. An actual Lab/Workshop class on this would've saved a lot of time! 😂
I used to work at an aluminum foundry and we hated making high silica alloy because it doesn't contract very much when it cools. Most alloys would fall out of the ingot molds at the end of the conveyor and roll down a roller to be stacked. The high silica stuff we had to hit each mold with a sledge hammer to knock out the ingot. Eventually someone engineered pneumatic hammers to do it. If they didn't come out it would cause problems when it got back around and get double poured, or they would fall 20 feet to the ground on its way back.
Не обязательно измельчать глину и сеять. Бентонитовую глину (наполнитель туалета для кошек) можно просто насыпать в посуду и залить водой. Перемешивая ее примерно каждые 5 - 10 минут и добавляя воды добиться консистенции сметаны. После чего ее можно по не многу добавлять в песок и перемешивать добиваясь нужной консистенции песка. Глины надо очень мало. Она очень сильно набухает в воде. На один литр воды примерно горсть глины. В процессе размокания глины и перемешивании с водой можно добавлять по необходимости как глину так и воду. Разница в том что при таком способе добавления глины в песок она обволакивает собой песчинки песка со всех сторон при перемешивании. Тем самым немного сглаживая неровности самих песчинок песка и лучше связывая их между собой. При твоем способе добавления глины в песок, частицы глины просто находятся между песчинками песка и связывают их собой. Я не утверждаю то данный способ лучше. В конечном итоге разница не будет видна невооруженным глазом. Я лишь говорю что есть и такой способ смешивания глины с песком.
Hello I cast all the time.your vid is good and you point out alot on the sand and molds but I've found that if your wanting a smoother look you need to pull slag off the top two or three times while your heating it up the best way to know your close is open smelter pull slag keep it in there heating up do it again each time it will get more shinyer when it looks like a mirror then pull out pour it fast then let sit this will give you the look your wanting.hope this helps out.
Skip the kitty litter and find actual sodium bentonite. Well drillers use it. If you can get a bag from them it won't cost much more than the kitty litter and you will have a lifetime supply. Try sourcing sand from a sand gravel concrete sort of place. Buy masonry sand. Some may call it pointing sand. It is like $40 US for a ton! May have to search for a place that will sell you less or buy the ton and leave most of behind. Extruded aluminum and aluminum cans are pure aluminum or close to it. They shrink. The best source for aluminum for casting is used cast aluminum. Lawn mower engines and aluminum car wheels are commonly used.
Personally this was so helpful. Especially the bit about why the metal was shrinking without silicon added. The diy sand is really neat as well, glad to see you gave it another try towards the end.
that is not why he added the silicon. the silicon made it flow better, and gave it a more consistent smoother surface, it did not change the expansion significantly.
@@MRGF78 what are you talking about? I've metal casted before, and yes the aluminum shrinks, but not by *30%!* usually it shrinks around 6% when solidifying, and often another 1% after cooling down completely, so 6-7% shrinkage in total depending on the alloy.
The Results looked good and you improved a lot from the first to last. But you can definitely improve even more! 1) Try to pour in one go. do not interupt the cast because the riser solidifies and cant fill up the shrinkage in the bottom. 2) the main reason for that is that the riser looks to small. The riser diameter should be dimensioned as such that you can pour in 1 go without stopping, if the metal doesnt flow fast enough and comes out on top, the riser diameter is to low. there are formulas for that, but for castings at home, no need to overthink it. just make it big enough, since you can remelt the raiser alloy anyway. 3) maybe try a smaller crucible with a beak for more accuracy when casting. also easier to manage :) So i hope you continue! you definitely have the skill.
Been home casting for about a year now and found with 3d printed patterns, printing the runners as apart of the pattern helps a lot. I also use 10mm and 20mm copper pipes for sprue and riser. With the ends of the runners I added 10mm and 20mm discs 5mm thicker leaving a step (my thinking that it'll reduce disturbing the sand as the metal hits the bottom of the sprue). I also printed out just the runners to use with non printed patterns. I use an old tin can to extend the sprue on top of the flask to make pouring easer. So far I've found this way helps quite a bit setting the mould up and cleaning up the part after pouring as the runners are crisper, leaving less work finishing. And to date I've not had any issues with sinking.
_if the metal doesnt flow fast enough and comes out on top, the riser diameter is to low_ I think he didn't heat it well enough, if he would heat it at about 800 degrees Celcius, it would flow better. There are nice temperature sensors on Amazon
Great video. We are just starting to get into pouring metals and are learning so much. We aren't quite ready to jump into sand casting, but this vid was great in my learning process! Thanks!
To get bentonite clay correct for greensand you've got to use a mortar and pesel. To get aluminum correct for pouring it MUST sit at constant temp for consistency before the dross is drawn off and poured.
@aspicyproduction_Luke-Seippel Nope ! When molten aluminum hits water , the water immediatly flashboils into steam and causes a splash explosion carrying the molten aluminum with the steam ... It's potentially deadly & has disfigured more than a few Foundry workers . Water is not an ingredient for green sand ... oil , we use oil !
We did this in 9th grade shop, 15-16 rarely had a bad cast. We used Texas red sand dampened with motor oil. Aluminum was scrap. Your aluminum is on the cold side and pour spru and vent needs to be cut in your top and then create a channel to your cast. When pouring it needs to be one single pour until it vents excess from the vent. ¾"-1" pour spru should have enough metal to prevent a lot of shrinkage.
I read about a trick to make for a smoother surface on a cast item. After making the sand mold, the interior surface is sprayed with a fine mister or atomizer with a solution of 10 parts water to 1 part molasses. Let dry then with a propane torch on low, gently warm the sugary mix to set it. This will give an exceptionally smooth surface (relative to sand casting). Hope this is useful.
Please, never cast on concrete. Concrete locks in moisture, and molten metal can cause this moisture to vaporize and explode. Molten metal bombs are no fun for anyone, so please be more safe in future videos
The concrete is not exposed to the elements, so does not absorb much moisture. Concrete can spall violently without much moisture too. This is due to the shrinking cement and expanding aggregate creating internal stress. I have tested this concrete and it will not spall when subjected to small spills of molten aluminum at 760C. However, I will certainly have to find a suitable pouring surface when melting higher melt metals. Thanks for the input and I'll be sure to include this point in a future video!
Ever think others are capable of figuring crap out with out a mother hen telling them what they can and can’t do? I know it’s difficult but people have brains.
I have done a fair bit of lost pla casting in ceramic shells in the past and one thing I did not get right for a long time was the necessity to include a reservoir for molten aluminium on top of the casting. It seems like a stupid mistake to make retrospectively, but I kept wondering why - especially the thinner features - always came out crooked and just weird-looking. I knew that shrinkage was a thing but I thought that it would not need much extra material to compensate for that. In one casting, I accidentally over-filled the mould like crazy and to my surprise, the cast came out almost perfect. Since then, I have always added a lot of material as a sort of 'thermal reservoir'. Since everything can be re-molten, it's not a big deal but the difference it made to the quality of my castings was night and day. It also made me re-consider part-orientation. Now I try to always have the thinnest features at the bottom of the mould to make sure they solidify first, pulling material from the bigger, still liquid parts of the cast downward and filling up any shrinkage.
I once cast a good detailed set of Abraham Lincoln using lime powder. It was an open top pour and not gas locked in a 2 part mold. It did not spew and made good casting. I would not try a closed mold though. I may do a small very small 2 part mold ( experimental) and see what happens. Bentonite added some may keep the steam away some. I did like the fine detail in lime powder with a small bit of water mix.
Yeaahh..After watching the beginning, I believe that I'll splurge the $44.95 for the 25 pound sand bag lol. Oh..and great video so far! I definitely Subd.👍😉🇨🇦
Help! I have a highly detailed Bas Releif plaque about 3.5" X 5" that I would like to use in an 'open casting' project using .999 silver. Is it possible? Any tips?
I have read every comment. I see the vast majority tried to help. I am very grateful for your video and learned some stuff. I was really getting started Al casting about 30 years ago when my ex filed divorce and wrecked my life. I did learn a few things. You need to degas your Al for one thing. And your sand looks awfully coarse. Some guys have recipes on the net for using synthetic two-stroke oil to make a cheap version of something like petro-bond sand. Looks like you're doing good. Ignore the haters.
Thanks for the comment! I read every one, and I don't have much time to reply these days. I agree, almost all are trying to help and I appreciate your help as well! I plan to incorporate some of the best ideas in future videos. PS I need to find a source for finer sand than 100 mesh, but I haven't had the time to call around to find out locally
A couple more tips to try… Try a higher temperature for the aluminum, 1200 -1300F. Yours didn’t look hot enough. Try aquarium sand in your diy mixture, it’s a little finer than play sand.
Very interresting.Casting is a kind of science .The thin parts of the piece get sooner hard,the thicker one later ,so there is were the metall will shrink.There is the place where you should place the feeder.The thiner areas must be at the bottom,the thicker at the top.Aluminium has low dencity, so its quite dificult to pour it.Thats why the feeder has to be quite high. Thanks for sharing. Lot of informations ,lot of work!
Finer grain sand to get smoother finish in the castings, pour faster and immediately from the furnace. Open furnace clean, grab crucible and pour fast. Just buy bentonite clay, it might need to be ordered but the time you will save crushing cat litter is well worth the extra couple bucks spent. I use broom stick pieces "dowel rod" for my sprues and risers are usually about half that size or less if there are multiple. Make sure to smooth your transitions in your gates, pack the cuts and smooth, anything rough has the possibility of breaking off, flowing into and ruining your pour when the molten aluminum flash bakes the casting sand as it flows in. I haven't cast in years but it needs to start happening again and soon!
Real 'Greensand' is a naturally occuring bed of Cretaceous age sands found in southeast England and contains some clay content that gives it its properties for casting. Its called Greensand because when dug fresh from the quarry it has a greenish hue due to the presence of the mineral Glauconite, that will weather to a brownish shade.
You're correct that "Greensand" refers to that specific type of sand. Maybe it was used for casting long ago. But these days, foundries don't use that sort of "Greensand", they use "green sand", and it's called "green" because it contains moisture (like green wood), not because of its color (which is typically brown).
Just a few pointers. Your mix ratio is going to give you a LOT of problems. 10:1 or 10% clay to sand is a little low on the clay side, this means you will need excess moisture to get to the break-test point, and will result in steam in the casting process, which will lead to voids, blowouts, slumps, early freezes on the gates and other defects. .. You want anywhere between 13% -15% depending on the average humidity level of your environment. watching the video at time stamp 1:47 you can see the sand does somewhat clump, but quite a bit is sticking to your hand due to the excess moisture. You'll also notice that the "commercial" casting sand, is finer grain, more clay, and less moisture. You also want to "degass" your melt, to remove as much dissolved gasses from within the molten aluminum A larger sprue and riser will help with shrinkage, but think bout your gating process as well
I worked in a foundery for ten years, your cast sand mix is missing some ingredients. A proper mix is... 7.5 parts fine silica sand, 1.5 parts non-food grade cornmeal, .75 parts fine charcoal .25 parts bentonite or talcum powder. Add water to molding consistency. I use to recipe all the time
I whack the sand into the flask with a whopping great big lump hammer, fine detail perfecto. Your flask seals are not tight enough and you're pouring too slow, pour it in fast.. whoosh. .
I use old soviet carburetor bodies for adding into clean aluminium, adding much zinc and some copper. this type of alloy does not shrink. it's named ЦАМ in RF
Please note that you should get a return through your vents. If no, you may not have enough superheat on your melt. The temperature of your melt should be be at least 200F over the melting point. Also heating the casting faces of the cope and drag will help you get better surface finish. hth
6:43 that's a good guess, I personally think that as it begins to crystalize, the metal shrinks, and so the remaining molten metal gets sucked into the empty space left behind. I also believe this because I've seen this happen with many metals, including pure aluminum and pure zinc.
I'm new to pouring. Every time I "pound" the clay into the mold, the clay "cracks" in certain places. It usually doesn't crack or split, where I was using the hammer. When I add more clay, it still happens. Is it possible I'm pounding too hard on the hammer? Thank you in advance.
I used to crush my sand in a ball mill, it also helped the sand stay together better when adding any modifications to the mould. Don't forget to degas ghe molten metal nothing worse than bubbles when everything else worked fine.
Just need dry building sand and some kind of oil, the shrinkage is due to rises not being big enough, the idea is that any shrinkage is done in the risers and finally you,ll find that ordinary table salt is more than adequate to lower the viscosity of the Aluminium , I was trained to do this by someone who had around 50 years of casting under is belt, give it a try.
Very bad to have your metal muffin molds sitting on concrete. Doing this can cause a steam explosion, turning pounds of concrete into flying projectiles. Always set your molds on a layer of sand or other appropriate
I don't know what homeade green sand you are using but with castings that small you need a much finer sand. The granuals are wayy too big and Will cause surface defects that need cleaning up. Get a coffee grinder and make the material much smaller and it will make tour castings look better.
I'm adding this to my 15 inch gauge farm railroad playlist I'll be 3d printing the master casting molds of a shay logging locomotive, pennsylvania a3 locomotive and a traction engine I want to run my farm on biomass fuels using equipment I built
@@TenTries just starting I've shown miniature horses for over a decade and last year dad and I planned an orchard bought longhorn, sheep and pigs I personally want to have a farm exactly like biggest little farm the documentary about apricot Lanes farm out by Los Angeles
Good video. Why it IS necessary to heat the aluminium silicon mixture for three hours to 1000 degree to combine them. IS there a way to shorten this heating Time?
What is the white powder you use i know you said talc but im looking for the exact bottle you have also do you just use a steel spoon to mix the metal and what are the tools you use to carve out the sand you need to remove
1:40 I added water. You can use baby oil to keep it together as heat will evaporate the water thus breaking up the sand. Maybe give it a try and see how fit works for you.
I am wondering, what would happen if you was to use about an inch of the good, commercial sand around the part, and fill in the rest with your cheaper home made sand? If it worked good, may help lower the cost, by not using the good sand for the entire mold. Only use it for around the part.
I think some casters do this. The nicer (facing) sand would mix into the coarser sand each time you did this, because you wouldn't be able to separate the two types very easily. I just don't do it, because I like the idea of reusing the same sand forever. Since I make mistakes frequently, the only cost of a mistake now is time, a bit of electricity, and a little dross loss. If you make money with casting each part, I think the method you bring up is a great idea. You could always buy more facing sand and write it off as just a per part expense
OK, your main error is not having a thick enough riser. The riser needs to be have a greater cross section than any part of the casting. This is to ensure that the casting solidifies while the riser is still liquid, so that the riser continues to supply molten metal into the core of the casting during solidification, to ensure minimal shrinking of the casting. Obviously, the running system also must be thick enough to not impede this. Also, it is a mistake to crush the silicone with a ferrous metal. Iron is a particular problem for Aluminium casting. You need to minimise iron contamination at every possible point in the process. Crushing the silicon with a steel tool, is likely to contaminate the silicon with fine iron particles from the tool. This is probably not nearly as bad as using an iron crucible though. There is a lot of metal recycling in foundries & I am sure that if you make casting a hobby, you will do the same. But recycling also multiplies contamination if there is a mistake such as this. Well done though, it isn't a trivial thing & you persisted to get a pretty good result.
For better finishes in Aluminium, use a facing sand called "Petrabond" or an equivalent. Its quite expensive, so you only cover the pattern with it and use your courser home made sand as a backing sand which is fine as it improves the "Permeability" of the sand. What is that ? read up and learn. Yes you lose the facing sand into your own sand backing mixes, but at least its being used and is slowly improving the quality of your backing sand which you should ALWAYS SIEVE. Traditionally we used graded sands above AFS120. What is that ? read up and learn. P.s. Don't bother with any of my recommendations if you just want to make a shaped lump of metal. If you want to make a casting do as I have suggested from a past MIBF.
You want to have more and bigger risers to the part. So the fluid metal gets into every part of the mold. I say its the lack of risers that made the failures happen. The small diameter also caused the metal to solidify on the way down. The risers feed the cavity with liquid metal. Sometimes the placement on the part make a difference too. Maybe you want to read more instead of cast more. Or maybe read as you are heating the kiln, so you get to know what is the deal. If you do everything the books say, you will get a lot better. RUclips only goes so far as information goes. Books are the way to go. Sometimes you can get them for free (online), sometimes you can get them at a thrift store online for little money. Greetings, Jeff
Absolutely, I was one class away from a minor in Physics. Wish I went further in it. Quantum physics is the best! I hope we get a grand unified theory in our lifetime
I would go to the scrap yards and get cracked Al car cylinder heads, usually about $5. I bought the High End makers as these are SiAl. Cast well, machines nicely
Adding strontium to your melt will help with your shrinkage as will adding gas , when you did the pour and you got speckled frosting on top of the metal it was gas you can get gasing tablets to put into your crucible or if you are feeling very VERY BRAVE you can introduce moisture into crucible the old fashioned way, you could start with a piece of dry timber 24 inches long and a half inch square and give it a stir it will burn and bubble the bubbling is the result of the gas going into the metal, if you think I'm joking or if you need a demonstration reply to this and I will be happy to show you a video that I will make on Monday at work, ps please wear a face shield and gloves , I won't bother I've been pouring aluminium for the past 28 years .
you need to find out what your casting weight for the relevant material is. this is a combined weight for the piece and the excess required to have the weight for the mold to be filled and gravity packed, reducing shrinkage by between .8 and 1.3% of the total volume. exceding your casting weight reduces this shrinkage to below .8% and the higher the weight the less the shrinkage, doubling your casting weight is best. also preheating your mould is recomended to avoid freezing the materialif you wish to gain greater definition. for gold I tend to use 4 times over CW, assuring full fill and negligeable shrinkage, for silver 3times over is most sufficient. every metal and alloy has a different casting weight, it is well worth researching this before commencing. it is also useful to add a little mineral oil to your casting medium as it will compact more tightly.
You can get bentinite clay at farm stores for less than 20 bucks. They are 50lb bags...With this you do not have to wet the sand as much once it is mixed..Just a few sprays of water and mix it in the play sand. I can cast 20 inch farm bells down to 3 inch bells..It works great....
@@TenTries Did you check with farm store about the bentnite powder Make sure its fine mesh...One is made to line ponds (fine mesh) other is added to their feed (course mesh)
green sand is olivine sand, use bentonite clay. if you use silica sand you need a chemical binder. you are not degassing your metal. aluminum is hydroscopic
I just use carbon molds sold on eBay and heat them on a gas grill to 400 then I shut off the grill and pour then I wait about 10 min and put the ingot in a 5 gallon bucket of water and clean with a brass brush and polish
Certainly, I've started planning the furnace build video. I'll warn you though: It can only run at 1000C for a few hours before the heating element needs to be replaced... apparently haha. However, it gets up to pouring temperature for aluminum very reliably. The shell is a former propane tank using 0.5" of castable refractory as the liner and rockwool as the insulation in the walls and lid. The insulation in the floor is a mixture of portland cement, vermiculite, and Sodium Silicate. Although, a mixture of vermiculite and castable refractory would have likely been a better choice. The heating element is a simple 6" stovetop coil heating element. It is computer controlled using Python and an Arduino. I've been debating how to approach the build video since Tries 1-8(ish?) were the inspiration for this channel, and naturally my memory is the only record of those. I may at some point explain the many different designs I tried, but a full on re-creation would be a challenge. The record of the latest version is a series of saved snapchats of the steps, so also not very helpful for making a video. Keep an eye out for the furnace build video!
Yeah, there was still some silicon at the bottom of the crucible, so it may have needed to be hotter or that hot for a little longer. Didn't have time to run a bunch of trials to be sure
@@TenTries Thanks for sharing your trials. I sell my aluminum cans at a metal recycling center and use the money to buy scrapped, previously cast aluminum, which has the right mixture for casting. Cheers!
I cast aluminum for a living. I can hardly start listing how many things you did wrong. Every alloy cast differently. Fire clay is better, but powdered bentonite is cheap if you insist on making your own. Petrobond is easy to make.
Personal question, just because i suffer too... Is your shaking from concentration? I forget the neurological term for it... But I'm rock solid until i concentrate on doing something at a small scale and then my hands shake.
Not exactly, stimulants, like caffeine or adrenaline, that help with concentration make my tremor worse, and depressants that hurt concentration, like alcohol in small amounts, make it a little better. If it's the same reason you shake, there's hope. It has slowly gotten better over the years. Not sure if it's because whatever underlying cause is better or if I've just become calmer as I've gotten older
Trial and error aren't a waste of time, it's the only reliable process to learn such things, and master them given enough repetition and reflection. You show this very well, and it's an impressive video at that.
Kaolin, graphite, water. At one time I poured steel for a living and we white washed the inside of the mold halves before assembling them. It was done for each half so the molds had to be exact. When the white wash was dry the two halves were joined. A collar was added above the mold to control pouring into the mold. The ingredients listed make the white wash that seals the mold and helps to contain the heat to allow the mold to fill completely. It also holds the pouring channels open. Don't know if this is even necessary for aluminum that's at a lower temp. than steel but if you're having issues with the finish I'd suggest you white wash the inside of the mold halves before pouring.
I appreciate the video. I don't know if it could have been done better or worse, but don't let the negative comments stop you. The DYI sand instructions alone were worth the watch, Personally I find this method of mistake, correction, mistake, correction to be highly valuable. Thanks again.
You're welcome, and I appreciate that! I think I get a lot less grief than most creators. I've had to take a bit of a break from making these videos, but season 2 is coming soon!
I am a first year mechanical enginear student from Greece, i take a class about castiing and other metal procesing methods, and due to everything i just didnt had the chance to be in a lab-workshop and experiment with casting, videos like these help alot
Great! I never had a chance to work on much of anything but the required classes. Going through engineering and trying to have a social life took up all of my time. An actual Lab/Workshop class on this would've saved a lot of time! 😂
@@TenTries yea tell me about it, i wish you good luck with your channel,you may have +1 subscriber from me
@@ΗλίαςΦασουλάς-π8γ Thank you!
@@TenTries Casting is more done just for things like arrowheads.
I used to work at an aluminum foundry and we hated making high silica alloy because it doesn't contract very much when it cools. Most alloys would fall out of the ingot molds at the end of the conveyor and roll down a roller to be stacked. The high silica stuff we had to hit each mold with a sledge hammer to knock out the ingot. Eventually someone engineered pneumatic hammers to do it. If they didn't come out it would cause problems when it got back around and get double poured, or they would fall 20 feet to the ground on its way back.
What a DRAG…. Not sure if I can COPE with all of this, But I will Try!…
🤙🏻
Не обязательно измельчать глину и сеять. Бентонитовую глину (наполнитель туалета для кошек) можно просто насыпать в посуду и залить водой. Перемешивая ее примерно каждые 5 - 10 минут и добавляя воды добиться консистенции сметаны. После чего ее можно по не многу добавлять в песок и перемешивать добиваясь нужной консистенции песка. Глины надо очень мало. Она очень сильно набухает в воде. На один литр воды примерно горсть глины. В процессе размокания глины и перемешивании с водой можно добавлять по необходимости как глину так и воду. Разница в том что при таком способе добавления глины в песок она обволакивает собой песчинки песка со всех сторон при перемешивании. Тем самым немного сглаживая неровности самих песчинок песка и лучше связывая их между собой. При твоем способе добавления глины в песок, частицы глины просто находятся между песчинками песка и связывают их собой. Я не утверждаю то данный способ лучше. В конечном итоге разница не будет видна невооруженным глазом. Я лишь говорю что есть и такой способ смешивания глины с песком.
Hello I cast all the time.your vid is good and you point out alot on the sand and molds but I've found that if your wanting a smoother look you need to pull slag off the top two or three times while your heating it up the best way to know your close is open smelter pull slag keep it in there heating up do it again each time it will get more shinyer when it looks like a mirror then pull out pour it fast then let sit this will give you the look your wanting.hope this helps out.
Thanks for the tip!
Skip the kitty litter and find actual sodium bentonite. Well drillers use it. If you can get a bag from them it won't cost much more than the kitty litter and you will have a lifetime supply.
Try sourcing sand from a sand gravel concrete sort of place. Buy masonry sand. Some may call it pointing sand. It is like $40 US for a ton!
May have to search for a place that will sell you less or buy the ton and leave most of behind.
Extruded aluminum and aluminum cans are pure aluminum or close to it. They shrink.
The best source for aluminum for casting is used cast aluminum. Lawn mower engines and aluminum car wheels are commonly used.
Personally this was so helpful. Especially the bit about why the metal was shrinking without silicon added. The diy sand is really neat as well, glad to see you gave it another try towards the end.
that is not why he added the silicon. the silicon made it flow better, and gave it a more consistent smoother surface, it did not change the expansion significantly.
Aluminum will shrink 30% no matter what you do...
@@MRGF78 what are you talking about? I've metal casted before, and yes the aluminum shrinks, but not by *30%!*
usually it shrinks around 6% when solidifying, and often another 1% after cooling down completely, so 6-7% shrinkage in total depending on the alloy.
To prevent shrinkage in a piece with more mass i just use an oversized sprue and riser and also stay out of the pool😂😂
The Results looked good and you improved a lot from the first to last.
But you can definitely improve even more!
1) Try to pour in one go. do not interupt the cast because the riser solidifies and cant fill up the shrinkage in the bottom.
2) the main reason for that is that the riser looks to small. The riser diameter should be dimensioned as such that you can pour in 1 go without stopping, if the metal doesnt flow fast enough and comes out on top, the riser diameter is to low. there are formulas for that, but for castings at home, no need to overthink it. just make it big enough, since you can remelt the raiser alloy anyway.
3) maybe try a smaller crucible with a beak for more accuracy when casting. also easier to manage :)
So i hope you continue! you definitely have the skill.
Been home casting for about a year now and found with 3d printed patterns, printing the runners as apart of the pattern helps a lot. I also use 10mm and 20mm copper pipes for sprue and riser. With the ends of the runners I added 10mm and 20mm discs 5mm thicker leaving a step (my thinking that it'll reduce disturbing the sand as the metal hits the bottom of the sprue). I also printed out just the runners to use with non printed patterns. I use an old tin can to extend the sprue on top of the flask to make pouring easer.
So far I've found this way helps quite a bit setting the mould up and cleaning up the part after pouring as the runners are crisper, leaving less work finishing. And to date I've not had any issues with sinking.
_if the metal doesnt flow fast enough and comes out on top, the riser diameter is to low_
I think he didn't heat it well enough, if he would heat it at about 800 degrees Celcius, it would flow better. There are nice temperature sensors on Amazon
@@absolute___zerotrue, that is also a factor. But depending on the form even 720-750° C can be enough.
Great video. We are just starting to get into pouring metals and are learning so much. We aren't quite ready to jump into sand casting, but this vid was great in my learning process! Thanks!
It’s simple. Just get petrobond and save the cost of experimenting
OMG its so fun!!!
To get bentonite clay correct for greensand you've got to use a mortar and pesel. To get aluminum correct for pouring it MUST sit at constant temp for consistency before the dross is drawn off and poured.
Just buy bentonite clay, it's a powder already!
@@tomhubbard353yup. Ceramic supplies will all have it lol
1:55 there is oil and no water in casting sand
@lenny108 you are correct in some regards, you are talking about petrobond, what he made is green sand. Green sand most definitely contains water
@aspicyproduction_Luke-Seippel Nope ! When molten aluminum hits water , the water immediatly flashboils into steam and causes a splash explosion carrying the molten aluminum with the steam ... It's potentially deadly & has disfigured more than a few Foundry workers . Water is not an ingredient for green sand ... oil , we use oil !
We did this in 9th grade shop, 15-16 rarely had a bad cast. We used Texas red sand dampened with motor oil. Aluminum was scrap. Your aluminum is on the cold side and pour spru and vent needs to be cut in your top and then create a channel to your cast. When pouring it needs to be one single pour until it vents excess from the vent. ¾"-1" pour spru should have enough metal to prevent a lot of shrinkage.
50% sand 50% clay, this is the correct approach, never use water to make it damp, use engine oil..
I read about a trick to make for a smoother surface on a cast item. After making the sand mold, the interior surface is sprayed with a fine mister or atomizer with a solution of 10 parts water to 1 part molasses. Let dry then with a propane torch on low, gently warm the sugary mix to set it. This will give an exceptionally smooth surface (relative to sand casting). Hope this is useful.
Interesting idea
You can also use a very fine sand covering the pattern
Please, never cast on concrete. Concrete locks in moisture, and molten metal can cause this moisture to vaporize and explode. Molten metal bombs are no fun for anyone, so please be more safe in future videos
The concrete is not exposed to the elements, so does not absorb much moisture. Concrete can spall violently without much moisture too. This is due to the shrinking cement and expanding aggregate creating internal stress. I have tested this concrete and it will not spall when subjected to small spills of molten aluminum at 760C. However, I will certainly have to find a suitable pouring surface when melting higher melt metals. Thanks for the input and I'll be sure to include this point in a future video!
@@TenTries Easy and cheap solution, just put a layer of sand down then place your flask on top of the sand.
Ever think others are capable of figuring crap out with out a mother hen telling them what they can and can’t do? I know it’s difficult but people have brains.
I saw a couple channels that just use a sheet of old plywood and it worked fine.
Even easier and quicker solution? Heat up the concrete area surrounding the cast. Problem solved
I have done a fair bit of lost pla casting in ceramic shells in the past and one thing I did not get right for a long time was the necessity to include a reservoir for molten aluminium on top of the casting. It seems like a stupid mistake to make retrospectively, but I kept wondering why - especially the thinner features - always came out crooked and just weird-looking. I knew that shrinkage was a thing but I thought that it would not need much extra material to compensate for that. In one casting, I accidentally over-filled the mould like crazy and to my surprise, the cast came out almost perfect. Since then, I have always added a lot of material as a sort of 'thermal reservoir'. Since everything can be re-molten, it's not a big deal but the difference it made to the quality of my castings was night and day. It also made me re-consider part-orientation. Now I try to always have the thinnest features at the bottom of the mould to make sure they solidify first, pulling material from the bigger, still liquid parts of the cast downward and filling up any shrinkage.
I think your home made sand needs tillering (you just beat it, like with a hammer), and probably some more grading, your mesh looked pretty big.
I once cast a good detailed set of Abraham Lincoln using lime powder. It was an open top pour and not gas locked in a 2 part mold. It did not spew and made good casting. I would not try a closed mold though. I may do a small very small 2 part mold ( experimental) and see what happens. Bentonite added some may keep the steam away some. I did like the fine detail in lime powder with a small bit of water mix.
Yeaahh..After watching the beginning, I believe that I'll splurge the $44.95 for the 25 pound sand bag lol. Oh..and great video so far! I definitely Subd.👍😉🇨🇦
Help! I have a highly detailed Bas Releif plaque about 3.5" X 5" that I would like to use in an 'open casting' project using .999 silver. Is it possible? Any tips?
I have read every comment. I see the vast majority tried to help. I am very grateful for your video and learned some stuff. I was really getting started Al casting about 30 years ago when my ex filed divorce and wrecked my life. I did learn a few things. You need to degas your Al for one thing. And your sand looks awfully coarse. Some guys have recipes on the net for using synthetic two-stroke oil to make a cheap version of something like petro-bond sand. Looks like you're doing good. Ignore the haters.
Thanks for the comment! I read every one, and I don't have much time to reply these days. I agree, almost all are trying to help and I appreciate your help as well! I plan to incorporate some of the best ideas in future videos.
PS I need to find a source for finer sand than 100 mesh, but I haven't had the time to call around to find out locally
@@TenTries hello, is sea sand good for molding, thank you.
A couple more tips to try…
Try a higher temperature for the aluminum, 1200 -1300F. Yours didn’t look hot enough.
Try aquarium sand in your diy mixture, it’s a little finer than play sand.
salt added makes my metal run like water
Very interresting.Casting is a kind of science .The thin parts of the piece get sooner hard,the thicker one later ,so there is were the metall will shrink.There is the place where you should place the feeder.The thiner areas must be at the bottom,the thicker at the top.Aluminium has low dencity, so its quite dificult to pour it.Thats why the feeder has to be quite high.
Thanks for sharing. Lot of informations ,lot of work!
Pretty cool video. I poured a lot of iron in my younger days and did a lot of molding as well. Always enjoy watching these kinds of videos.
Great video and very useful information 👌 I'm learning how to make aluminium moulds for plastic recycling, and this will definitely help 👍🏼
Good to hear! Hopefully I'll make recycled plastic injection molding series before too long. But it'll probably be a while if I'm being honest 😂
How did you make your furnace
Finer grain sand to get smoother finish in the castings, pour faster and immediately from the furnace. Open furnace clean, grab crucible and pour fast. Just buy bentonite clay, it might need to be ordered but the time you will save crushing cat litter is well worth the extra couple bucks spent. I use broom stick pieces "dowel rod" for my sprues and risers are usually about half that size or less if there are multiple. Make sure to smooth your transitions in your gates, pack the cuts and smooth, anything rough has the possibility of breaking off, flowing into and ruining your pour when the molten aluminum flash bakes the casting sand as it flows in. I haven't cast in years but it needs to start happening again and soon!
Real 'Greensand' is a naturally occuring bed of Cretaceous age sands found in southeast England and contains some clay content that gives it its properties for casting. Its called Greensand because when dug fresh from the quarry it has a greenish hue due to the presence of the mineral Glauconite, that will weather to a brownish shade.
You're correct that "Greensand" refers to that specific type of sand. Maybe it was used for casting long ago. But these days, foundries don't use that sort of "Greensand", they use "green sand", and it's called "green" because it contains moisture (like green wood), not because of its color (which is typically brown).
@@billthacker6527 it was used for casting long before somebody came up with an alternative.
First off u messed up making ur own sand leave it to the pros but I love the video knowledge is always good bro thx
Just a few pointers.
Your mix ratio is going to give you a LOT of problems. 10:1 or 10% clay to sand is a little low on the clay side, this means you will need excess moisture to get to the break-test point, and will result in steam in the casting process, which will lead to voids, blowouts, slumps, early freezes on the gates and other defects. .. You want anywhere between 13% -15% depending on the average humidity level of your environment. watching the video at time stamp 1:47 you can see the sand does somewhat clump, but quite a bit is sticking to your hand due to the excess moisture. You'll also notice that the "commercial" casting sand, is finer grain, more clay, and less moisture.
You also want to "degass" your melt, to remove as much dissolved gasses from within the molten aluminum
A larger sprue and riser will help with shrinkage, but think bout your gating process as well
Good points
hello can i use chamotte and an oil mix for casting sand?
I just want to say...you're awesome!
Thank you!
I worked in a foundery for ten years, your cast sand mix is missing some ingredients. A proper mix is...
7.5 parts fine silica sand,
1.5 parts non-food grade cornmeal,
.75 parts fine charcoal
.25 parts bentonite or talcum powder.
Add water to molding consistency.
I use to recipe all the time
Cool! Does the cornmeal degrade over time or use?
@@TenTries it does breakdown after each use, the heat turns it to carbon.
I whack the sand into the flask with a whopping great big lump hammer, fine detail perfecto. Your flask seals are not tight enough and you're pouring too slow, pour it in fast.. whoosh. .
I would never have thought to alloy with silicon, that is a very clever idea indeed.
رائع ومفيد جداً
اعتقد ان رجفة اليدين عندك بسبب الكحول لذالك يجب عليك التقليل منه
شكراً لك على هذا الابداع عزيزي 😘♥️
I add table salt to the melt and it runs like water
I use old soviet carburetor bodies for adding into clean aluminium, adding much zinc and some copper. this type of alloy does not shrink. it's named ЦАМ in RF
Interesting, I had never heard of that
Nice home operation. Like I do. But I do about 500 units a week at home. Great job. No
Ever stop the craft
nice cc what you casting
I use a 60/40 mix of barite/clay (kitty litter) mixed with old motor oil...... gives a nice firm mold, with very very fine surface texture......
Please note that you should get a return through your vents. If no, you may not have enough superheat on your melt. The temperature of your melt should be be at least 200F over the melting point. Also heating the casting faces of the cope and drag will help you get better surface finish. hth
And pure aluminum shrinks because it's pure.... That's an easy way to tell if your Al is pure or not.
6:43 that's a good guess, I personally think that as it begins to crystalize, the metal shrinks, and so the remaining molten metal gets sucked into the empty space left behind.
I also believe this because I've seen this happen with many metals, including pure aluminum and pure zinc.
Huh, haven't seen this happen with aluminum, but I'll have to keep a closer eye on it
I'm new to pouring. Every time I "pound" the clay into the mold, the clay "cracks" in certain places. It usually doesn't crack or split, where I was using the hammer. When I add more clay, it still happens. Is it possible I'm pounding too hard on the hammer? Thank you in advance.
Those bubbles forming at the surface is hydrogen escaping from within the metal. There is a process called degassing that removes them.
I used to crush my sand in a ball mill, it also helped the sand stay together better when adding any modifications to the mould. Don't forget to degas ghe molten metal nothing worse than bubbles when everything else worked fine.
I bet crushed sand works 10x better than these smooth grains
Just need dry building sand and some kind of oil, the shrinkage is due to rises not being big enough, the idea is that any shrinkage is done in the risers and finally you,ll find that ordinary table salt is more than adequate to lower the viscosity of the Aluminium , I was trained to do this by someone who had around 50 years of casting under is belt, give it a try.
Very bad to have your metal muffin molds sitting on concrete. Doing this can cause a steam explosion, turning pounds of concrete into flying projectiles. Always set your molds on a layer of sand or other appropriate
I don't know what homeade green sand you are using but with castings that small you need a much finer sand. The granuals are wayy too big and Will cause surface defects that need cleaning up. Get a coffee grinder and make the material much smaller and it will make tour castings look better.
I'm adding this to my 15 inch gauge farm railroad playlist I'll be 3d printing the master casting molds of a shay logging locomotive, pennsylvania a3 locomotive and a traction engine I want to run my farm on biomass fuels using equipment I built
Cool! A combine that runs on chaff would be a cool concept (no idea if it's feasible). What do you grow?
@@TenTries just starting I've shown miniature horses for over a decade and last year dad and I planned an orchard bought longhorn, sheep and pigs I personally want to have a farm exactly like biggest little farm the documentary about apricot Lanes farm out by Los Angeles
Good video. Why it IS necessary to heat the aluminium silicon mixture for three hours to 1000 degree to combine them. IS there a way to shorten this heating Time?
Scanning the photo of the package of the Christmas tree was funny.
Thanks! 😀
Thanks for this video! I learned something! Would you think adding silica to copper or other elements would give them that shine as well?
What is the white powder you use i know you said talc but im looking for the exact bottle you have also do you just use a steel spoon to mix the metal and what are the tools you use to carve out the sand you need to remove
great channel concept. subscribed.
Thank you for sharing!
1:40 I added water.
You can use baby oil to keep it together as heat will evaporate the water thus breaking up the sand. Maybe give it a try and see how fit works for you.
I am wondering, what would happen if you was to use about an inch of the good, commercial sand around the part, and fill in the rest with your cheaper home made sand? If it worked good, may help lower the cost, by not using the good sand for the entire mold. Only use it for around the part.
I think some casters do this. The nicer (facing) sand would mix into the coarser sand each time you did this, because you wouldn't be able to separate the two types very easily. I just don't do it, because I like the idea of reusing the same sand forever. Since I make mistakes frequently, the only cost of a mistake now is time, a bit of electricity, and a little dross loss. If you make money with casting each part, I think the method you bring up is a great idea. You could always buy more facing sand and write it off as just a per part expense
@@TenTries Nice.
Why did you heated aluminium for 3 hours? In my coal furnace it take less than 20 minutes for aluminium to dissolve.
Thank you for your video is great!!! and very helpful the best!!
Have a good one
OK, your main error is not having a thick enough riser. The riser needs to be have a greater cross section than any part of the casting. This is to ensure that the casting solidifies while the riser is still liquid, so that the riser continues to supply molten metal into the core of the casting during solidification, to ensure minimal shrinking of the casting. Obviously, the running system also must be thick enough to not impede this.
Also, it is a mistake to crush the silicone with a ferrous metal. Iron is a particular problem for Aluminium casting. You need to minimise iron contamination at every possible point in the process. Crushing the silicon with a steel tool, is likely to contaminate the silicon with fine iron particles from the tool. This is probably not nearly as bad as using an iron crucible though. There is a lot of metal recycling in foundries & I am sure that if you make casting a hobby, you will do the same. But recycling also multiplies contamination if there is a mistake such as this.
Well done though, it isn't a trivial thing & you persisted to get a pretty good result.
For better finishes in Aluminium, use a facing sand called "Petrabond" or an equivalent. Its quite expensive, so you only cover the pattern with it and use your courser home made sand as a backing sand which is fine as it improves the "Permeability" of the sand. What is that ? read up and learn. Yes you lose the facing sand into your own sand backing mixes, but at least its being used and is slowly improving the quality of your backing sand which you should ALWAYS SIEVE. Traditionally we used graded sands above AFS120. What is that ? read up and learn. P.s. Don't bother with any of my recommendations if you just want to make a shaped lump of metal. If you want to make a casting do as I have suggested from a past MIBF.
hello, is sea sand good for molding, thank you.
Very good information. You deserve a lot more subscribers. Keep up the good work!
Thanks, I appreciate the support!
You want to have more and bigger risers to the part. So the fluid metal gets into every part of the mold. I say its the lack of risers that made the failures happen. The small diameter also caused the metal to solidify on the way down. The risers feed the cavity with liquid metal. Sometimes the placement on the part make a difference too.
Maybe you want to read more instead of cast more. Or maybe read as you are heating the kiln, so you get to know what is the deal.
If you do everything the books say, you will get a lot better. RUclips only goes so far as information goes.
Books are the way to go. Sometimes you can get them for free (online), sometimes you can get them at a thrift store online for little money.
Greetings,
Jeff
_Maybe you want to read more instead of cast more_
definitely! I would recommend to start with reading quantum physics, the mother of all sciences
Absolutely, I was one class away from a minor in Physics. Wish I went further in it. Quantum physics is the best! I hope we get a grand unified theory in our lifetime
Way back in high school when we did aluminum sand casting it was always alloy and we used oil in the sand, not water
I would go to the scrap yards and get cracked Al car cylinder heads, usually about $5. I bought the High End makers as these are SiAl. Cast well, machines nicely
As opposed to sand, can one make a re-usable mold using casting marble?
try sodium silicate for castings and use 325 mesh sand and you can cote the inside of your mold
Try what i got Burnco calls it golden sand it is used for mortor work and feels like velvet in the hand its more like facing sand.
I'm based in the US. Is Burnco only in Canada?
I did try green sand then try molasses sand ,and i found molasses sand much better and easier to work with
Adding strontium to your melt will help with your shrinkage as will adding gas , when you did the pour and you got speckled frosting on top of the metal it was gas you can get gasing tablets to put into your crucible or if you are feeling very VERY BRAVE you can introduce moisture into crucible the old fashioned way, you could start with a piece of dry timber 24 inches long and a half inch square and give it a stir it will burn and bubble the bubbling is the result of the gas going into the metal, if you think I'm joking or if you need a demonstration reply to this and I will be happy to show you a video that I will make on Monday at work, ps please wear a face shield and gloves , I won't bother I've been pouring aluminium for the past 28 years .
Mix Portland cement with machine oil , it’s much more fine and reusable
Nice tips.. with the mixed aluminium & sillica.....
have you tried using used motor oil instead of water? I believe its called greensand.
After 3 hours I was surprised there was anything left.
Few lumps of charcoal made it a reducing environment :)
What respirator do you use while casting aluminum?
This is the one I have. amzn.to/3GNFuNH
Thanks for the video, helpful. Detailed without being to long and no non sense...
Sincerely,
' MK X '
//-MarK CarsTens-//
Glad you enjoyed it!😀
you need to find out what your casting weight for the relevant material is.
this is a combined weight for the piece and the excess required to have the weight for the mold to be filled and gravity packed, reducing shrinkage by between .8 and 1.3% of the total volume.
exceding your casting weight reduces this shrinkage to below .8% and the higher the weight the less the shrinkage, doubling your casting weight is best.
also preheating your mould is recomended to avoid freezing the materialif you wish to gain greater definition.
for gold I tend to use 4 times over CW, assuring full fill and negligeable shrinkage, for silver 3times over is most sufficient.
every metal and alloy has a different casting weight, it is well worth researching this before commencing.
it is also useful to add a little mineral oil to your casting medium as it will compact more tightly.
You can get bentinite clay at farm stores for less than 20 bucks. They are 50lb bags...With this you do not have to wet the sand as much once it is mixed..Just a few sprays of water and mix it in the play sand. I can cast 20 inch farm bells down to 3 inch bells..It works great....
I haven't seen it yet. Do you have a brand name or a picture of what the bag looks like?
@@TenTries Go to farm store and ask for bentinite they use to line cow ponds.
add a little table salt to your mix and it will run more runny and not bead
@@TenTries Did you check with farm store about the bentnite powder Make sure its fine mesh...One is made to line ponds (fine mesh) other is added to their feed (course mesh)
So just buy sand got it
Did you try lost wax or lost foam?
Ive added a bit of old cement powder as its so fine
green sand is olivine sand, use bentonite clay. if you use silica sand you need a chemical binder. you are not degassing your metal. aluminum is hydroscopic
what heating element /composition /alloy are you using on your furnace?
The heating element is just a 6" stove element. They seem to last a lot longer than the bare wire elements I tried
I just use carbon molds sold on eBay and heat them on a gas grill to 400 then I shut off the grill and pour then I wait about 10 min and put the ingot in a 5 gallon bucket of water and clean with a brass brush and polish
I'd suggest watching OlFoundryMan's channel. He gets gorgeous results from sand molds.
I’m interested in your furnace. I want know how you made it.
Certainly, I've started planning the furnace build video. I'll warn you though: It can only run at 1000C for a few hours before the heating element needs to be replaced... apparently haha. However, it gets up to pouring temperature for aluminum very reliably.
The shell is a former propane tank using 0.5" of castable refractory as the liner and rockwool as the insulation in the walls and lid. The insulation in the floor is a mixture of portland cement, vermiculite, and Sodium Silicate. Although, a mixture of vermiculite and castable refractory would have likely been a better choice. The heating element is a simple 6" stovetop coil heating element. It is computer controlled using Python and an Arduino.
I've been debating how to approach the build video since Tries 1-8(ish?) were the inspiration for this channel, and naturally my memory is the only record of those. I may at some point explain the many different designs I tried, but a full on re-creation would be a challenge. The record of the latest version is a series of saved snapchats of the steps, so also not very helpful for making a video.
Keep an eye out for the furnace build video!
@@TenTries
Python with arduino? What dark sorcery is this!
Hello new subscriber here I just started pouring 3 weeks ago this was a very helpful video thank you very much
Glad you found it useful! It's a complicated hobby that can be dangerous, so if you have any questions, don't hesitate to ask!
You plan on posting pouring videos?❤🤙
Great video you're closing the whole off before the aluminum gets to drop down in the hole poor the aluminum straight in the hole first better results
Don't you get porosity issues and sand inclusion when you do that?
@@TenTries it all depends on how fast you poor and yes but it's a 50/50 but I still love the video
Adequate runners and risers are very basic foundry practice.
So is pre-heating the sand moulds.
Helpful video
Thanks man
Our cope and drags were 150 pounds empty and 300 pounds 240 molds a hour
NIce! Adding silicon was cool. Did it need 3 hours to mix?
Yeah, there was still some silicon at the bottom of the crucible, so it may have needed to be hotter or that hot for a little longer. Didn't have time to run a bunch of trials to be sure
@@TenTries Thanks for sharing your trials. I sell my aluminum cans at a metal recycling center and use the money to buy scrapped, previously cast aluminum, which has the right mixture for casting. Cheers!
Does this work with Kinetic sand and Bismuth?
I cast aluminum for a living. I can hardly start listing how many things you did wrong. Every alloy cast differently. Fire clay is better, but powdered bentonite is cheap if you insist on making your own. Petrobond is easy to make.
Well done!
Thank you!
Personal question, just because i suffer too... Is your shaking from concentration? I forget the neurological term for it... But I'm rock solid until i concentrate on doing something at a small scale and then my hands shake.
Not exactly, stimulants, like caffeine or adrenaline, that help with concentration make my tremor worse, and depressants that hurt concentration, like alcohol in small amounts, make it a little better. If it's the same reason you shake, there's hope. It has slowly gotten better over the years. Not sure if it's because whatever underlying cause is better or if I've just become calmer as I've gotten older
The mould has to be 10% bigger to allow for shrinkage otherwise the part will not be the same size, just thought I'd say.