One of my FAVORITE silicone tricks! (We both know how expen$ive silicone is.) One time I misjudged and didn't mix enough to fully cover the object and leave a good thick wall, so I hurriedly cut a chunk from an old mold and stuck it into the cup to raise the level. :)
A while ago I tried mixing chunks of different rubber types and it actually caused cure inhibition. So make sure you're chunks are from the same type of rubber you are pouring. I wrongly assumed all silicone was the same!
Yes, that’s essential. I should have said so in the video but I mentioned that in the description. Lots of silicone rubbers don’t play nicely together; especially if you’re mixing platinum and tin cure rubbers. Thanks for pointing it out!
It's a high probability that I will never ever make a mold so why am I always watching a tutorial of something I'll never do you ask? I'm not sure really , maybe it's a combination of a couple of a few things , you are a great teacher and it's very easy to follow your directions, plus your voice is easy on my ears. Not to mention you're so darn cute too . Keep up the groovy vids. ✌-N-❤
Thank you for featuring my horse! Great video, was nervous about the whole mold process. Too bad you had trouble with that little piece. Fingers crossed for next week!
Brilliant! Being the same density of the pouring silicone, the chunks will not sink! I'm glad I found your channel Sir. You are truly an inspiration for enthusiast like me, keep up the good work!
Robert really appreciate your videos. I feel like most people are printing molds (We tried this), and doing mother molds, fancy four part molds. But a one piece mold with an expert level cut job is everything. Thank you for really going into your cutting strategy because I feel like this is extremely valuable in all of your videos. If you could one day make a video on how you plan your cuts with the graphics you make it would be so awesome. Thanks so much for all that you do.
Love what you do Robert. Not only are your videos informative, entertaining, and enjoyable, they make me a better artist by teaching me new ways to use silicone. These videos are such a wealth of knowledge unlike anything else on RUclips. Thank you!
I just discovered your youtube channel earlier today and I'm already learning sooooo much from watching your videos! Thanks so much for uploading such helpful info! I've been working in the mold shop of a fine arts bronze sculpture facility for 2+ years now, and I can't wait to share some of these helpful tips and techs with my coworkers!
I Love your videos and the pdf of the materials you purchase. Thank you for making such well-documented and taught how to's. + you remind me of my dad and that is a sweet feeling. Thanks!
Robert, your timing is perfect,i am just about to embark on making a mold and casting 8 different horses, this video has been priceless in how much it has helped me to understand how to go about it, i am ditching the two piece mold and going to try to do the cut mold as shown. Cheers 👍
Dear Mr Tolone, thank you for your nice videos. It is great that you are sharing your skills and tricks with the world. By watching the attempts of getting the pieces out of the moulds, it remembered me the difficulties that could come along with that practice. I was confronted with it many times as an dental technician. I haven't seen all your videos yet, so it is possible that you mentioned it already somewhere else. So excuse me if it is so. What helped me a lot, getting objects out of moulds was air pressure. In some cases the objects came out nearly by themselves. With the help of an cannula, I was able to bring air deeper in the mould even py sticking it through the mold. The air pushes the object on the one hand and creates an layer of air in between the object and the mould reducing the friction. It is certain that it won't work on every object but in some cases, it can prevent the cutting. Best regards from Germany
I have never tried it, except with rigid tooling to release fiberglass castings. It seems to me the air would simply find the shortest route out of the mold and escape there. I would like to see your method in action. Thanks for your comment!
I'm sure someone else has mentioned this over the past 2 years, but I bet you could change the infill on the print to get easier break points on the sculpt when you're splitting the mold open. The print itself would probably need some gentler handling, but adding in a weaker infill on 10-15 layers where the ankles are could have saved you quite a bit of energy & fussing. It's not easy to do in the slicing software, but certainly a possibility for more complex projects.
This is exactly what I needed! :'D Thanks to the pandemic I ended up finding a new hobby: butchering and customizing horse figurines to make them unique and paint them in nice (/more realistic) colours. Since I'd likely want to make some in multiple colours or even sell some in the future when I'm good enough, I was looking for a tutorial video to cast them that even a total beginner could work with. And I think I found that right here, thank you very much! Gonna try and get myself all supplies I need and then see if I can make something decent with the help of this video. ^^
It's common sense as this stuff is expensive. What I did was to take blocks and feed them into a strong food blender then put the whole lot into a moisture sealed food container. Doing that saved me a long time in chopping the stuff up by hand.
Dunkin' chunkies sounds like a donut shop for addicts. :D Thanks for this tip, that's an awesome trick! I wish I'd heard of it before, could have saved me some annoyance.
I really like the format of your videos or the way you make you videos, it's really fun to watch. It reminds me of some of those woodworking or painting shows I used to watch on cable. Great video, sir! Keep em coming!
G'day Bob , the difference between this and production , for this you leave the base and the horse together for an example of how it can be done and the complex manner . For production you would seperate the two . I feel a weak point in demoulding would be how thin the horses legs are and the chances of them breaking or the bulk of the horse curing before the thin sections do .
No easy ones for Bob. I guess we have to put 1 down for the tail “chunkies” ! Who will win? If you’ve been watching Bob’s videos, Bob usually comes out in top unless you’re a clear sphere or a frosted fixture. The smart money is on Bob! Thank you for the interesting project but we still have the resin pour before we can put one on the board for Bob. The pressure is on. Will Bob ride the horse or will the horse ride Bob? Don’t miss the next video to see!! Good luck Bob, I’ll be watching… Richard
Joiner and a chamfer bit-relieve that edge & make it float Now that I think about it, you could do the same thing with a sheet of plasticine and a needle tool
the cut pattern got me laughing soo hard.. I'm soo sorry. love your videos as always :) I usually grind my chunks and use the vacuum chamber to get the air out
maybe try a fries slicer used once in one direction and then perpendicularly again to get 5-7 milimeter cube granules. Or some other sort of kitcheeen dicing appliance. may save you a lot of time if it can be done that way.
Another great video! Quick question, can you "glue" two pieces of cured silicone together with liquid silicone? Like if you accidentally cut a piece off the mold, could you put it back using new silicone?
What would you think about doing a 2 part pour casting with having the horse laying on its side for half w/nubs & then flipping it over & pouring the 2nd half. I think that might have saved you a lot of frustration & time??? I’m not sure 🤷 could you do a video & try that way?
Hello Robert, your video as are amazing and you are so funny to watch. My question if you have a video showing how to cast a cereal bowl from rubber to resin. Thank you
Robert, thank you for sharing your depth of knowledge.. I really enjoy your videos tremendously! A question.. if the original was made of metal or was a one-of-a-kind, how would you approach cutting the mold?
I wouldn’t have taken the job unless the horse was separate from the base. It could have been done using a 2-piece clayed up mold. But I don’t like making those kinds of molds and I really dislike cleaning the castings that those molds produce because of the messy parting line that runs 100% around the sculpture. It is far better to design the sculpture for the process of silicone mold making. In this case all that was required was to make the horse separate from the base.
What do you recommend if you don’t have all these expensive wood tools? I use metal roof flashing usually for making sides of the molds, or wooden sides that I can clamp together and clamp and reuse. I also use plastic for the bottom, so I can reuse it.
I think you are doing exactly the right thing by using the materials and tools that you have on hand. You can make a mold case out of almost anything as long as the rubber won’t stick to it. A lot depends on the size of the object you are molding. Since most of the things I make are toy prototypes I use a lot of paper and plastic cups as mold cases. I scrounge most of my case materials so keep your eyes open for sheets of anything that people throw away. Things like box cardboard covered in 2 inch plastic packing tape worked great.
Hi Robert, an art club I am a part of uses plastisol (cured vinyl) to carve stamps. At the end of each meeting, we have a bunch of offcuts and little eraser-like scraps. I feel uncomfortable throwing these in the trash because they are so small. Are you familiar with any way to recycle these scraps? Or do you use these when making molds? Could we send them to you? I am trying to think of a way to create less waste and reuse the scraps. Best, Josephine
I like the video. I had exactly the problem, that my chunks didn't mold together with the new rubber. But I am not sure if it was dirty. I put it in an old Haribo candy box and as far as I know, those candys are covered with a thin layer of bees wax, right? Maybe I didn't clean out the box properly and some wax got on contact with some of the chunks. So advice about getting chunks is always welcome. =D
i have learnt a ton of stuff watching your channel and it is helping me so much with my lure company . i make a lot of silicone molds , nothing like your ones , just simple molds . i use Polyurethane Resin in my molds and they only last about 40 pours , is there anyway i can treat them so they last a little longer ? thinks for all the great content you do
You can experiment with silicone mold release. Very light sprays between each casting can greatly extend mold life. One downside is that you have to clean the castings carefully before applying any finish.
Wondering with that little left over chunk, is there a way to brush on a super thin bit of rubber and stick it back in place so it doesn't keep falling out?
Re-gluing the chunk causes several problems. The biggest one is that no matter how thin you try to make the glue line, the chunk will not be in the original position. Therefore the mold will not close properly and there will be flash all around it. True that it is a pain to reposition the chunk with each casting cycle but it results in very clean castings. So it is worth the effort. I was very disappointed when I cut that mold incorrectly. It is so much better to make a clean mold that it is to try to repair a mistake.
Robert, would it work if you put the chunkies in the blender to make them into finer bitts and then mix them directly into the rubber before you pour it?
@@danje748 you need fresh silicone poured against your pattern surface so as to give you the best chance of picking up the detail. If you mixed finely ground up silicone in to a fresh mix , 1 - it will add a large volume of air in to it , yes you can de air but it will take much longer in time . 2 if you do this mix it's possible it has contaminants in it , it could affect you're surface finish or cause curing problems . Bob plans where he is putting the chunkies that way they stay away from the patterns surface and limit the amount of new air in to the fresh RTV mix . Just a matter of keeping things as simple and easy as possible to get things done as quickly and cleanly as possible .
Just to prevent the rubber from leaking out between the wood box and the plexiglass face. The other joints in the mold box I sealed with wax. It’s very important that a mold box be watertight. It’s astounding how tiny a crack silicone rubber can flow through.
The part will never fit properly because the glue line will have some thickness and you’ll get a lot of flash around it. It’s a hassle either way but I’m still hoping to get clean casts out of the mold.
Because I get models from different clients and I don’t know how they are constructed. They often contain voids which can expand under vacuum or crush under pressure. So I never use either when curing my rubber. I also don’t do it because it is completely unnecessary.
searching 'dunkin chunkies' in an effort to find this video has returned some...interesting search results. i suspect my targeted ads to be a bit spicy for a few days now.
Question , when you put the Horse sideways and make an half mold. so you can cut inside the legs, without braking anything. Is this a possible way? Asking for an friend ;)
I could have used a more complex process and clayed up the parting line between the legs. But in a piece like this it would simply be better to cast the base separate from the animal.
It’s more about the space to fill rather than a weight ratio. You can cram in as much a you can fit. But if the model is delicate it’s easy to damage it without realizing it, so take care.
There are a couple problems with shredding rubber. The first one is that rubber is really hard to shred. And even if you solve that problem you will find that it is very hard to add shredded rubber to fresh rubber without trapping a ton of bubbles. When you try to vacuum out the bubbles that doesn’t work very well because so many are trapped by the shredded rubber. And the viscosity of the rubber is much thicker, it doesn’t pour well with all the chunky shreds in it. So you catch a lot of bubbles around the model. Then, when you put the resin casting under pressure, the tiny bubbles collapse and the mold distorts. All in all, it’s just a giant hassle and isn’t worth your time. To answer your question, the chunkies have no effect at all on whether or not a model gets stuck in the rubber.
Depends on what material you’re dealing with. Either toss it, find some way to salvage it or give it to a toxic waste collection site - if your city has them. The best thing is to use materials up so they don’t wind up going bad.
Resin shrinks due to heat it generates. You could use the same resin for two castings . If the first one is a small mould the shrinkage would be minimal or not all. If the second one has a large volume the heat generated would be much greater causing greater overall linear shrinkage . All resin data sheets have listed the shrinkage ratio and details .
Resin shrinks for two reasons, 1. It exotherms during cure and so expands as it gets hot this then shrinks as it cools. 2. The curing process itself causes some shrinkage the more ordered structure of a solid versus the mobile liquid. In reality depending on the size of your casting one or the other will be more significant. As to reducing shrinkage pick a resin that is resigned to shrink less, use a slower curing resin this will generate less heat as the cure is spread over a longer time. You can also reduce shrinkage of the resin by adding fillers as these do not shrink during the cure as they are alreasy solid they also reduce the reactive mass so reduce exotherm, but (and its a big one) they increase viscosity significantly so pouring is harder and filling small pieces is significantly harder. If you do add fillers to resin best practice would be to mix it into the polyol side (not the isocyanate) and then evaculate it to remove all the entrianed air before proceeding as normal (remembering to adjust your ratio of A:B to allow for the weight of filler), when adding fillers it is also importnat to pressure cast as most fillers contain some level of moisture which will cause foaming if not suppressed by the pressure tank.
Because a multi-part mold takes much longer to make. And it makes castings with heavy parting lines that require a lot of work to sand off each casting. And finally, because the original was a 3-D print. Which means it was not precious. I would rather damage a master to create a clean mold than preserve a master which creates an expensive, flawed and inferior mold.
@@RobertTolone Ahh, I’m used to making lots of multipart molds for precious models for glass castings or master molds for multipart plaster molds for slip casting, where you usually can’t damage the master to make a one or two part mold, and the seams really aren’t that difficult to deal with at all in slip casting, and while they can be a pain grinding and polishing in glass, we all have to do it. I make a lot of organic forms and am experimenting with nontraditional plasters for glass casting investment molds in an attempt to mimic what the Czechia glass masters do, which is make their models out of pottery wet clay directly into investment molds with plasters that are strong enough to make 1/2 inch molds instead of 3-6 inch mold walls, and make really big molds that are essentially open faced molds but with some curves, but one side is still open and you don’t have to do lost wax casting. It’s amazing to see the work they make that way, and the molds being so damn thin, and you don’t have to grind any seams…still have to polish the side not open that was fire polished, but a lot less work, saves you glass, and you can cast larger things because you don’t lose kiln room to a crucible. I just hope I the plasters I have to experiment with in the US are somewhat close to as strong as what they have…unfortunately don’t sell it here.
The only way to make that is to create a new model for the right side mirror. There is no mold-making a way to make a reverse or mirrored copy. The easiest thing to do would be to scan the existing mirror, turn it into a 3-D model and mirror it in the computer Then 3D print it. If you use the right printing resin you would be done at that point.
Sorry for the late video this week; I had endless problems uploading. Nowhere to go but up!
No worries, Bob. Your videos are always a welcome treat no matter when they get uploaded.
@@sonipitts lol He just knows some of us are out here biting our nails for that next video. ;D
We're blessed to have you posting such wonders as it is, don't go apologizing for life, you're doing a fine job.
Is the acrylic wall for our benefit or is it useful for when seeing where you put your chunkies?
@@sindrehsoereide I started doing that on this channel.
One of my FAVORITE silicone tricks! (We both know how expen$ive silicone is.) One time I misjudged and didn't mix enough to fully cover the object and leave a good thick wall, so I hurriedly cut a chunk from an old mold and stuck it into the cup to raise the level. :)
Works like a champ! Sent you an email btw. 👍
Hey there Crafsman! Nice to see you on another of my favourite sites. Keep on SC! No microwaves, please.
i just ordered a MEAT GRINDER to shred my old silicone into small shreds.. do you think that the smaller the chunky the better ?
8:15 - I appreciate the window view that helps so much to visualize what is going on inside a mold.
Yeah John, I’m trying to use transparent mold cases wherever I can. Much more fun and instructive than watching the rubber fill from the top of a box!
A while ago I tried mixing chunks of different rubber types and it actually caused cure inhibition. So make sure you're chunks are from the same type of rubber you are pouring. I wrongly assumed all silicone was the same!
Yes, that’s essential. I should have said so in the video but I mentioned that in the description. Lots of silicone rubbers don’t play nicely together; especially if you’re mixing platinum and tin cure rubbers. Thanks for pointing it out!
It's a high probability that I will never ever make a mold so why am I always watching a tutorial of something I'll never do you ask? I'm not sure really , maybe it's a combination of a couple of a few things , you are a great teacher and it's very easy to follow your directions, plus your voice is easy on my ears. Not to mention you're so darn cute too . Keep up the groovy vids. ✌-N-❤
Literally the same reason i am here!!
@@roastedbeans2051 Aww, thanks! You guys are way too nice!
Very well said on all counts! Highly agree!
@@kolitiokada9825 Aww TY Hun 😊
Thank you for featuring my horse! Great video, was nervous about the whole mold process. Too bad you had trouble with that little piece. Fingers crossed for next week!
Sorry about breaking your horse! I’m going to send you two castings back to make up for it.
@@RobertTolone Nice gesture, Bob. Good guy.
Man this guy is on the same level as Crafsman for me. Great content, lots of knowledge and relaxed.
That’s a high compliment, The Crafsman is the best!
'Dunkin chunkies' is such an onomatopoetic phrase. And that plexiglass removal was satisfying af
Brilliant! Being the same density of the pouring silicone, the chunks will not sink!
I'm glad I found your channel Sir. You are truly an inspiration for enthusiast like me, keep up the good work!
Bronco Busting Bob, Thank You For Sharing Another Great Lesson, Have A Most Awesome Evening!
Thanks Robert! It’s amazing how much chunkies can add to the amount of material.
Thanks Robert for another great video, learning a ton from you. Thanks again all the way from South Africa.
Robert really appreciate your videos. I feel like most people are printing molds (We tried this), and doing mother molds, fancy four part molds. But a one piece mold with an expert level cut job is everything. Thank you for really going into your cutting strategy because I feel like this is extremely valuable in all of your videos. If you could one day make a video on how you plan your cuts with the graphics you make it would be so awesome. Thanks so much for all that you do.
I did not know I like watching this type of content so much, and im learning a lot for my first project (soon) .. Keep up the good work Robert.!
Big man Bob back at it again. you should do a exhibition of all the pieces you've done, or show off your sketchbooks.
Love what you do Robert. Not only are your videos informative, entertaining, and enjoyable, they make me a better artist by teaching me new ways to use silicone. These videos are such a wealth of knowledge unlike anything else on RUclips. Thank you!
Incredibly well spoken and well done video. I appreciate the tips Robert
you are very skilled. i appreciate your teaching and insights.
The ol' chunk and dunk strategy
Thank you Robert for this good tutorial, it was nice you see you. sending you hugs!
I just discovered your youtube channel earlier today and I'm already learning sooooo much from watching your videos! Thanks so much for uploading such helpful info! I've been working in the mold shop of a fine arts bronze sculpture facility for 2+ years now, and I can't wait to share some of these helpful tips and techs with my coworkers!
Thanks for watching Linda; glad you find my videos useful.
You have great experience and expertise, love your work
I once put chunkies inside the box around the sculpture first before pouring the silicone…..disaster.
Air pockets galore. (Love your channel Robert)
I Love your videos and the pdf of the materials you purchase. Thank you for making such well-documented and taught how to's. + you remind me of my dad and that is a sweet feeling. Thanks!
Thanks Jessica. Sorry to hear you dad is a deranged lunatic but you turned out ok. ❤️
Robert, your timing is perfect,i am just about to embark on making a mold and casting 8 different horses, this video has been priceless in how much it has helped me to understand how to go about it, i am ditching the two piece mold and going to try to do the cut mold as shown. Cheers 👍
thank you Robert for all the great videos, you are an awesome human being!!! :)
Dear Mr Tolone, thank you for your nice videos. It is great that you are sharing your skills and tricks with the world. By watching the attempts of getting the pieces out of the moulds, it remembered me the difficulties that could come along with that practice. I was confronted with it many times as an dental technician.
I haven't seen all your videos yet, so it is possible that you mentioned it already somewhere else. So excuse me if it is so.
What helped me a lot, getting objects out of moulds was air pressure. In some cases the objects came out nearly by themselves. With the help of an cannula, I was able to bring air deeper in the mould even py sticking it through the mold.
The air pushes the object on the one hand and creates an layer of air in between the object and the mould reducing the friction. It is certain that it won't work on every object but in some cases, it can prevent the cutting.
Best regards from Germany
I have never tried it, except with rigid tooling to release fiberglass castings. It seems to me the air would simply find the shortest route out of the mold and escape there. I would like to see your method in action. Thanks for your comment!
I'm sure someone else has mentioned this over the past 2 years, but I bet you could change the infill on the print to get easier break points on the sculpt when you're splitting the mold open.
The print itself would probably need some gentler handling, but adding in a weaker infill on 10-15 layers where the ankles are could have saved you quite a bit of energy & fussing. It's not easy to do in the slicing software, but certainly a possibility for more complex projects.
I don't remember what video it was but the AC/DC chunkies had me laughing good 😂
This channel is so entertaining
The only person on the internet using a corded drill
You are really underrated! I just found your channel and really enjoying it. Thank you for making the video's :)
This is exactly what I needed! :'D
Thanks to the pandemic I ended up finding a new hobby: butchering and customizing horse figurines to make them unique and paint them in nice (/more realistic) colours.
Since I'd likely want to make some in multiple colours or even sell some in the future when I'm good enough, I was looking for a tutorial video to cast them that even a total beginner could work with. And I think I found that right here, thank you very much! Gonna try and get myself all supplies I need and then see if I can make something decent with the help of this video. ^^
It's common sense as this stuff is expensive. What I did was to take blocks and feed them into a strong food blender then put the whole lot into a moisture sealed food container. Doing that saved me a long time in chopping the stuff up by hand.
nice mold! i would have covered myself in hot glue, stick myself to the table. also use the chunk trick, great call
This was very informative, thank you! I got to refine my "chunky" technique : )
Wow can’t wait for next week such an inspiration mr Tolone TY x
I remember the first time I saw you do this and I went "oooh, those failed molds I threw away."
Thank you for your videos Robert.
Amazing work!
Love your work Robert. Thank you 👏👏👏 You are so lovely 🤗🤗🤗
Dunkin' chunkies sounds like a donut shop for addicts. :D
Thanks for this tip, that's an awesome trick! I wish I'd heard of it before, could have saved me some annoyance.
I really like the format of your videos or the way you make you videos, it's really fun to watch. It reminds me of some of those woodworking or painting shows I used to watch on cable.
Great video, sir! Keep em coming!
Thanks Kickapoo!
G'day Bob , the difference between this and production , for this you leave the base and the horse together for an example of how it can be done and the complex manner . For production you would seperate the two . I feel a weak point in demoulding would be how thin the horses legs are and the chances of them breaking or the bulk of the horse curing before the thin sections do .
No easy ones for Bob. I guess we have to put 1 down for the tail “chunkies” ! Who will win? If you’ve been watching Bob’s videos, Bob usually comes out in top unless you’re a clear sphere or a frosted fixture. The smart money is on Bob! Thank you for the interesting project but we still have the resin pour before we can put one on the board for Bob. The pressure is on. Will Bob ride the horse or will the horse ride Bob? Don’t miss the next video to see!! Good luck Bob, I’ll be watching… Richard
Ha! I’m irritated by the miscut.
But I have high hopes that the mold will produce good castings!
Wonderful job, Robert. I have a piece exactly like this & it was so informative to see to your one this model.
Oh style RUclipsr right here.
Glue the loose chunk in place with a little more uncured silicone
I have found surgical retractors to be helpful as extra hands during mold cutting.
I love your channel. I've been watching it since before Crafsman told me to..
Joiner and a chamfer bit-relieve that edge & make it float
Now that I think about it, you could do the same thing with a sheet of plasticine and a needle tool
the cut pattern got me laughing soo hard.. I'm soo sorry. love your videos as always :) I usually grind my chunks and use the vacuum chamber to get the air out
Thanks for sharing all your knowledge! Love your videos!
Thanks for watching Braden!
A tiny bit of fresh silicone will glue that little piece in if it can be held there, even if by hand.
maybe try a fries slicer used once in one direction and then perpendicularly again to get 5-7 milimeter cube granules.
Or some other sort of kitcheeen dicing appliance. may save you a lot of time if it can be done that way.
amazing tip thanks
Another great video! Quick question, can you "glue" two pieces of cured silicone together with liquid silicone? Like if you accidentally cut a piece off the mold, could you put it back using new silicone?
Quart yogurt containers are the spice melange of sculpture & ceramics
Robert's wearing a hoodie, that can only mean one thing: "Winter is coming"
Robert Tolone, of the Tolone Starks, Artificer to the King.
I loved you in Up!
That’s my Dad. I was still a kid back then.
Very interesting video 👍
What would you think about doing a 2 part pour casting with having the horse laying on its side for half w/nubs & then flipping it over & pouring the 2nd half. I think that might have saved you a lot of frustration & time??? I’m not sure 🤷 could you do a video & try that way?
I am surprised you didn't cut the horse from the base.
Someone should tell Chris that you can easily print a multi-part negative mold with a resin printer.
Hello Robert, your video as are amazing and you are so funny to watch. My question if you have a video showing how to cast a cereal bowl from rubber to resin. Thank you
you have a new subscriber.
Robert, thank you for sharing your depth of knowledge.. I really enjoy your videos tremendously! A question.. if the original was made of metal or was a one-of-a-kind, how would you approach cutting the mold?
I wouldn’t have taken the job unless the horse was separate from the base. It could have been done using a 2-piece clayed up mold. But I don’t like making those kinds of molds and I really dislike cleaning the castings that those molds produce because of the messy parting line that runs 100% around the sculpture. It is far better to design the sculpture for the process of silicone mold making. In this case all that was required was to make the horse separate from the base.
@@RobertTolone Gotcha, thanks for the explanation.
What do you recommend if you don’t have all these expensive wood tools? I use metal roof flashing usually for making sides of the molds, or wooden sides that I can clamp together and clamp and reuse. I also use plastic for the bottom, so I can reuse it.
I think you are doing exactly the right thing by using the materials and tools that you have on hand. You can make a mold case out of almost anything as long as the rubber won’t stick to it. A lot depends on the size of the object you are molding. Since most of the things I make are toy prototypes I use a lot of paper and plastic cups as mold cases. I scrounge most of my case materials so keep your eyes open for sheets of anything that people throw away. Things like box cardboard covered in 2 inch plastic packing tape worked great.
I know the chunkie who left these chunkies, Newman!
Did you put it in vacum?
Great video as usual. What brand is your hat? Thanks
can you wash the chunkies in a degreaser... like DAWN DISH WASHING LIQUID ?
What kind of heat gun are you using sir?
Hi Robert, an art club I am a part of uses plastisol (cured vinyl) to carve stamps. At the end of each meeting, we have a bunch of offcuts and little eraser-like scraps. I feel uncomfortable throwing these in the trash because they are so small. Are you familiar with any way to recycle these scraps? Or do you use these when making molds? Could we send them to you? I am trying to think of a way to create less waste and reuse the scraps. Best, Josephine
I like the video. I had exactly the problem, that my chunks didn't mold together with the new rubber. But I am not sure if it was dirty. I put it in an old Haribo candy box and as far as I know, those candys are covered with a thin layer of bees wax, right? Maybe I didn't clean out the box properly and some wax got on contact with some of the chunks. So advice about getting chunks is always welcome. =D
Yeah, you can definitely have problems with contaminates on your chunks. That’s why I like to cut mine just before I use them in a mold.
i have learnt a ton of stuff watching your channel and it is helping me so much with my lure company . i make a lot of silicone molds , nothing like your ones , just simple molds . i use Polyurethane Resin in my molds and they only last about 40 pours , is there anyway i can treat them so they last a little longer ? thinks for all the great content you do
You can experiment with silicone mold release. Very light sprays between each casting can greatly extend mold life. One downside is that you have to clean the castings carefully before applying any finish.
I was thinking something like that , maybe a good wash with dish soap would work ? Thanks for the help / reply 👍🏻
@@nic7289 I clean mold release off castings first with acetone or lacquer thinner, then soap and water.
Ahh ok , I'll try that , thanks
Can chunkies be used from molds that had release agents such as Mann's 200 on them? What to clean with before cutting up? Thanks.
Couldn't find this anywhere else: what do you call those little plastic tubes he uses to create the vents?
Google sprue rods, sprue wax, or wax wires. I get mine here: freemanwax.com/products/miscellaneous-specialty-waxes/jewelry-wax-wires
Do you use tin or platinum cure rubber? Thnx for a great video once again!
He usually uses tin cure because it's less expensive. 😉
Wondering with that little left over chunk, is there a way to brush on a super thin bit of rubber and stick it back in place so it doesn't keep falling out?
Re-gluing the chunk causes several problems. The biggest one is that no matter how thin you try to make the glue line, the chunk will not be in the original position. Therefore the mold will not close properly and there will be flash all around it. True that it is a pain to reposition the chunk with each casting cycle but it results in very clean castings. So it is worth the effort. I was very disappointed when I cut that mold incorrectly. It is so much better to make a clean mold that it is to try to repair a mistake.
I want to make A 'negative' mold from a driver-side mirror, can you please help me how to make it???
Robert, would it work if you put the chunkies in the blender to make them into finer bitts and then mix them directly into the rubber before you pour it?
I like it
You would add a lot more air to the mixture
@@glenfisher728 just deair it?
@@danje748 you need fresh silicone poured against your pattern surface so as to give you the best chance of picking up the detail. If you mixed finely ground up silicone in to a fresh mix , 1 - it will add a large volume of air in to it , yes you can de air but it will take much longer in time . 2 if you do this mix it's possible it has contaminants in it , it could affect you're surface finish or cause curing problems . Bob plans where he is putting the chunkies that way they stay away from the patterns surface and limit the amount of new air in to the fresh RTV mix . Just a matter of keeping things as simple and easy as possible to get things done as quickly and cleanly as possible .
how volatile is butanone and ABS?
New to this. Why do you need a gasket?
Just to prevent the rubber from leaking out between the wood box and the plexiglass face. The other joints in the mold box I sealed with wax. It’s very important that a mold box be watertight. It’s astounding how tiny a crack silicone rubber can flow through.
Could you mix up a bit of rubber, paint on some rubber on that chunk and essentially "glue" the piece back in? Or is that m9re trouble than its worth?
The part will never fit properly because the glue line will have some thickness and you’ll get a lot of flash around it. It’s a hassle either way but I’m still hoping to get clean casts out of the mold.
I'm curious why you don't vacuum the molds after you pour the rubber?
Because I get models from different clients and I don’t know how they are constructed. They often contain voids which can expand under vacuum or crush under pressure. So I never use either when curing my rubber. I also don’t do it because it is completely unnecessary.
@@RobertTolone I was unaware of that. I recently found your channel, and enjoy it.
Great video. If you’ve never been a teacher , I would be surprised.
I taught at Art Center College of Design for a couple of years. But I’m mostly a sculptor by trade.
searching 'dunkin chunkies' in an effort to find this video has returned some...interesting search results. i suspect my targeted ads to be a bit spicy for a few days now.
i just ordered a MEAT GRINDER to shred my old silicone into small shreds.. do you think that the smaller the chunky the better ?
Is there a rubber that’s better for moulds for a concrete casting?
Thanks for all the tips.. soon will be trying this all out..
There is , again size and shape matter. Your RTV supplier should be able to advise you what type of silicone is the best .
Urethane rubber is cheaper and can be more effective for concrete molds. As Glen said, contact your supplier to get their recommendation.
Question , when you put the Horse sideways and make an half mold. so you can cut inside the legs, without braking anything. Is this a possible way?
Asking for an friend ;)
I could have used a more complex process and clayed up the parting line between the legs. But in a piece like this it would simply be better to cast the base separate from the animal.
What's a good ratio for chunkage vs new rubber? Is it possible to replace up to half of the volume with chunkage? How about more?
It’s more about the space to fill rather than a weight ratio. You can cram in as much a you can fit. But if the model is delicate it’s easy to damage it without realizing it, so take care.
Would using your chunkies more "shredded" than chunkie, would that have prevented that piece from getting stuck there?
There are a couple problems with shredding rubber. The first one is that rubber is really hard to shred. And even if you solve that problem you will find that it is very hard to add shredded rubber to fresh rubber without trapping a ton of bubbles. When you try to vacuum out the bubbles that doesn’t work very well because so many are trapped by the shredded rubber. And the viscosity of the rubber is much thicker, it doesn’t pour well with all the chunky shreds in it. So you catch a lot of bubbles around the model. Then, when you put the resin casting under pressure, the tiny bubbles collapse and the mold distorts. All in all, it’s just a giant hassle and isn’t worth your time. To answer your question, the chunkies have no effect at all on whether or not a model gets stuck in the rubber.
@Robert Tolone awesome. Thanks for that answer.
Does it matter if the chunks you add to the new mold come in contact with the part you're molding?
Hello Robert, is there a danger that the chunks might touch the model and cause issues with a smooth cast?
Thank u sir
Regarding the vents, I understand the positioning of the start end, but are there any issues to be aware of for positioning where they end?
I almost always attach them to the funnel. But it’s most important that they exit the mold so that they at the top to let the air out.
@@RobertTolone Cool, thanks for the response
What do u do if the materials are not in a good condition throw out in the bin, renewed it or still keep it 4 recyclable in ur own depending
Depends on what material you’re dealing with. Either toss it, find some way to salvage it or give it to a toxic waste collection site - if your city has them. The best thing is to use materials up so they don’t wind up going bad.
Since you mentioned shrinkage (Seinfeld reference here) , are there any low shrink ratio resins?
Resin shrinks due to heat it generates. You could use the same resin for two castings . If the first one is a small mould the shrinkage would be minimal or not all. If the second one has a large volume the heat generated would be much greater causing greater overall linear shrinkage . All resin data sheets have listed the shrinkage ratio and details .
Resin shrinks for two reasons, 1. It exotherms during cure and so expands as it gets hot this then shrinks as it cools. 2. The curing process itself causes some shrinkage the more ordered structure of a solid versus the mobile liquid. In reality depending on the size of your casting one or the other will be more significant. As to reducing shrinkage pick a resin that is resigned to shrink less, use a slower curing resin this will generate less heat as the cure is spread over a longer time. You can also reduce shrinkage of the resin by adding fillers as these do not shrink during the cure as they are alreasy solid they also reduce the reactive mass so reduce exotherm, but (and its a big one) they increase viscosity significantly so pouring is harder and filling small pieces is significantly harder. If you do add fillers to resin best practice would be to mix it into the polyol side (not the isocyanate) and then evaculate it to remove all the entrianed air before proceeding as normal (remembering to adjust your ratio of A:B to allow for the weight of filler), when adding fillers it is also importnat to pressure cast as most fillers contain some level of moisture which will cause foaming if not suppressed by the pressure tank.
If you couldn’t cut it without breaking the base, why didn’t you make it a multipart mold?
Because a multi-part mold takes much longer to make. And it makes castings with heavy parting lines that require a lot of work to sand off each casting. And finally, because the original was a 3-D print. Which means it was not precious. I would rather damage a master to create a clean mold than preserve a master which creates an expensive, flawed and inferior mold.
@@RobertTolone Ahh, I’m used to making lots of multipart molds for precious models for glass castings or master molds for multipart plaster molds for slip casting, where you usually can’t damage the master to make a one or two part mold, and the seams really aren’t that difficult to deal with at all in slip casting, and while they can be a pain grinding and polishing in glass, we all have to do it. I make a lot of organic forms and am experimenting with nontraditional plasters for glass casting investment molds in an attempt to mimic what the Czechia glass masters do, which is make their models out of pottery wet clay directly into investment molds with plasters that are strong enough to make 1/2 inch molds instead of 3-6 inch mold walls, and make really big molds that are essentially open faced molds but with some curves, but one side is still open and you don’t have to do lost wax casting. It’s amazing to see the work they make that way, and the molds being so damn thin, and you don’t have to grind any seams…still have to polish the side not open that was fire polished, but a lot less work, saves you glass, and you can cast larger things because you don’t lose kiln room to a crucible. I just hope I the plasters I have to experiment with in the US are somewhat close to as strong as what they have…unfortunately don’t sell it here.
What is sticky wax? brand name?
Ferris sticky wax from Freemanwax.com
I want to make a "negative " mold for a driver side mirror to put it on the right side. Can You please help me????
The only way to make that is to create a new model for the right side mirror. There is no mold-making a way to make a reverse or mirrored copy. The easiest thing to do would be to scan the existing mirror, turn it into a 3-D model and mirror it in the computer Then 3D print it. If you use the right printing resin you would be done at that point.