Perfect Castings From A Silicone Rubber Mold

[@TheCrafsMan]

Robert, this is my FAVORITE way to make a mold. Back when we made the "Free-Range Chicken" figure, it was just a cup mold that I cut (marked the underside so that when I flipped it over to open, I'd get the cut-line in the right spot). I have to say... I ALWAYS got cleaner castings from those one-part cut-molds. Any excess flash was so negligible it could be scraped with an x-acto blade. Two-part molds are a ton of extra work, and you still don't get as clean a result. Simple mold, properly vented, with a jagged jeweler's cut so it locks back... 100% the way to go. (P.S. I have to say, your venting technique is top-notch!)

[@RobertTolone]

Thanks Crafsman! I am so hooked on cut molds that it’s miserable having to clay up parting line. I preach one-piece cut molds constantly here on the channel and it’s funny to me that people regularly request clay-up mold videos. I appreciate you commenting on my video.

[@TheCrafsMan]

@@RobertTolone I hear you 100% on that one. :D And man, as far as I'm concerned, you are *THE* mold and resin guy. I am thinking about doing a "5 Channels You Need to Know About" video (or some number). Although I see you have a lot of success, I feel there may be some of my viewers who've not yet been introduced, and they are MISSING OUT. Would you be OK with that? Thank you so much!

[@RobertTolone]

@@TheCrafsMan Are you kidding? Of course! Whatever you need from me I’d be happy to provide -clips, whatever. It’s very generous of you to do that for me! I’d be also happy to repay in kind but my channel is dinky compared to yours. (nothing worse than channel envy!) Hardly a fair trade. If I can help you out in some way let me know.

[@TheCrafsMan]

​@@RobertTolone My friend, your channel is nowhere near what I would call "dinky"! You are TOP-SHELF! BIGTIME! :D And I appreciate how THOROUGH you are. Mannn, so many times I put out a video and there are 5 things I SHOULD have mentioned, but didn't. You really *cover your bases*.

[@RobertTolone]

@@TheCrafsMan Again, I appreciate your kindness. If you ever want to reach me in private: [e-mail]. I’m happy to help you any way I can.

[@cmarkme]

I am so Glad I found you Robert.. Your Masterclasses are second to none.. Thank you for your Patience and attention to detail xx :-)

[@RobertTolone]

Thanks Mark!

[@haesea3073]

I can not speak English well but I realy glad that I found you. I'm watching again and again to understand what you say! thank you.

[@RobertTolone]

Thank you for watching!

[@Gallus691]

Your great btw! I've learned so much just from watching your channel! Can't beat learning from the masters!

[@rickl9462]

I have learned so much from you Robert Tolone. Thanks for all the great videos! Keep them coming.

[@RobertTolone]

Glad my videos have helped you Rick! Thanks.

[@ka5ico324]

Most impressive, Sir! You are an excellent teacher--from your pleasant and calm demeanor to your quick edits to get right to the meat. I suppose it also helps that you REALLY seem to know what you're doing! Thank you--enjoyed it.

[@RobertTolone]

Thanks Bob!

[@gmoney6198]

You are a treasure!!

[@jakebodensteiner3318]

Love your excitement! Thanks for the great lessons!!

[@RobertTolone]

Glad you like them. Thanks for watching Jake!

[@Gallus691]

Boy you've got steady hands!

[@fernandovelazquez-alvarez4222]

Thanks Robert for posting these nice instructional videos! They are very well explained and entertaining. I have some figurines of my own that have been collecting dust, I think it is high time I make reproductions of them.

[@faroukchaabna8144]

Nice djob 👍

[@onurates9311]

Amazing !!!!!!!!!!!

[@CHUNKYNUGGET666]

Amazing i love how you go through the process, such a great teacher!

[@RobertTolone]

Thanks for watching!

[@sabengco]

Thanks for sharing. Very helpful.

[@RobertTolone]

Glad you found the video helpful Seymour. Thanks for watching!

[@KaamillieCat]

I love your videos so much, thank you!

[@RobertTolone]

Millie Ranaa Thanks for watching!

[@ronjlwhite8058]

home from work and we meet again buddy...on to the next one.

[@RobertTolone]

Appreciate that you watch my videos Ron.

[@ronjlwhite8058]

@@RobertTolone tons of useful info. I even know when the compressor is gonna kick on LOL!!!

[@Kaapstad420]

Good video, any recommendations for silicone rubber types for a newbie like me?

[@william_lynch]

Thanks. What If i dont have the pressure tank thing you used at the end?

[@RobertTolone]

Then you will most likely have bubbles in your castings.

[@Souvenirs444]

+1 в карму!!!

[@superbrawl986]

Love your vids! They help me out a lot!

[@RobertTolone]

Great! Happy that they’re helpful. Thanks for watching!

[@DragonempressCreations]

I have always struggled with molding the dragons I sculpt. How would you go about making a mold for a dragon with wings, tail, horns, 4 legs? I've been advised to do a multiple parts mold but its always a failure, could you do a block mold of one? Is that too many parts to get out of the mold easily? Any advice would be amazing. I have learned so much from your channel ! Thank you! ❤🎉

[@CuriousEarthMan]

Thank you for the well thought out, calm videos. Would vacuuming the poured mold with the resin in it reduce bubbles, similar to a plaster flask? Would adding a vibrating table help? Are those measures not necessary, or it depends on the model maybe? Thank you again!

[@larrytruex4428]

Mr. Tolone, I wish to ask where can I find someone to make a pressure pot of the type you use and how much pressure is required to pour rubber and cast resin?

[@RobertTolone]

Any good welding/metal fabrication shop could do it if they are competent to weld pressure vessel. Pressure tanks like the ones from semi truck brake systems are easy to find. The fittings are just standard air compressor hoses and valves.

[@hosk14]

Could you post a link to where you get the material for the mold and part? Thanks! Love your videos!

[@christopherdanko4145]

s/o from pandemic 3/11 2021! what an insane wealth of info I friggin love this man !

[@RobertTolone]

Hey thanks Christopher! I’m always trying to find the sweet spot between including lots of info and moving along at a good pace. It’s a constant challenge!

[@SeanBrown22]

Where did you get all those funnels? Home made on a lathe? Edit: forgot to say great video 😊

[@StainedFeathers]

Handy tip: To avoid having the cap on the bottle of resin get crusties as much or stick and require a wrench to get off, cut a piece of plastic film (like cling wrap, plastic trash bag, etc.) and put it over the top of the bottle and screw the lid on over that. Big enough so it covers the threads and sticks out under the cap when it's screwed on. This keeps less air in contact with the resin thats on the threads so it doesn't crust up as much and provides a barrier between the threads of the bottle and the lid so that the lid never welds itself to the bottle! I just cut a new piece each time I use the bottle since I always have some old bag or something I was going to throw away and can re-use for this.

[@RobertTolone]

I’ll give it a try, thanks!

[@jeanebotha5896]

Hi Robert. I've recently stumbled across your channel and I'm learning more than the course I've been on 😅 I'd love to get your input on a mold I've tried to make but horribly failed at. Please advise how I can communicate with you? Thank you for your informative content!

[@levinebette15]

Genius!

[@drvnlp6269]

Thank you. I've learned so much from you. I want to cast 100 copies of a small, oval part that has a hole 1/8" diameter x 1/2" deep and the angle of the hole to the part is important. To avoid drilling as a secondary operation I was thinking about inserting a 1/8" x 1" rod made of Teflon or nylon into the hole of the original part when casting the mold, then placing the rod back into the mold when casting the copies. Do you think that would work? This is going to be my first casting project. Thank you

[@3DPainting]

Hello sir, I like your videos. How much pressure should I use in a pressure chamber?

[@RobertTolone]

I run around 50 pounds but you should experiment to see what works. Pressure casting will not remove the big bubbles that get trapped if you don’t vent the molds properly. Obviously, never exceed the pressure limitations of your system.

[@johnathannyc]

What temperature is the hot box (fridge) set to? I assume it’s used if the room temp is lower that 72 F, but would you set it warmer to speed up curing?

[@RobertTolone]

I set it for around 80°F. Resin and rubber like to pour at between 70 and 80°F. And yes, I only use it in the winter when my studio is cold. If I make molds and want to cure them quicker I will set the hotbox for around 110°F. But only after I have poured of the mold.

[@rowanstephenson3192]

Love your tutorials Even looking at your archives now I’ve had a disaster with mixing rubber pls what is the usual ratio ? Came with no instructions and I’ve made a real mess … stupid of Manchester England 🙄x

[@RobertTolone]

Go online and pull up the ratio for your rubber. There is no standard ratio; it’s different with each rubber. What is the brand and name of your rubber?

[@rowanstephenson3192]

@@RobertTolone customcast

[@rowanstephenson3192]

Thank you so much for getting back to me sir ♥️

[@dianeharris2687]

Do you use the same rubber mold for all 200 tiki things? Does the mold wear out? Do you have to clean up (flashing, tube, etc) each casting? Love watching these. Thanks!

[@RobertTolone]

From this first mold I will make and clean up 14 castings. From those castings I’ll make 2 gang molds of 7 castings each which, after I cut the gang molds open, will give me 14 cavities to pour into. I should be able to cast them twice in one hour and complete the casting part of the job in one day. I need that many molds because they do wear out pretty quickly. The urethane resin degrades the rubber. And yes, each and every casting has to be cleaned, drilled, stained and strung by hand. You’ll see all these steps in future videos.

[@paulhayton3423]

@@RobertTolone How much shrinkage do you finish up with compared to the original..great instructional video..thank you!

[@RobertTolone]

paul hayton on small pieces like these the shrinkage is very small. Hardly noticeable.

[@paulhayton3423]

@@RobertTolone supposing the finished article was approximately 4" by 5" roughly 1" thick what would you expect shrinkage to be? thank you for the reply

[@RobertTolone]

paul hayton The resin I use is Fastcast A/B sold by www.silpak.com (I’m a customer, not sponsored by them). It has a shrink factor of .001 so you would expect a shrinkage of .005” in the longest dimension. You could measure it with calipers but it would be hard to detect by eye. Every resin is different. Get the material data sheet for the resin you’re using; the shrink rate should be on there.

[@LukeStephenson]

So much knowledge. Thank you for sharing it with us. I love the tips like putting knots in the elastic bands to make them smaller rather than double wrapping them...and putting the hardener in the cup first (before the rubber). What do you mean by the hotbox? Is it an oven that you cure the silicone in and if so, what temperature do you cure it at? Also. is there any merit to putting the filled mold inside of a pressure chamber to minimize any tiny air bubbles that might have gotten trapped (I mean for the silicone curing process - not the resin curing process)?

[@RobertTolone]

Thanks Luke! Here’s a video I did on my hotbox: kzbin.info/www/bejne/pqqkY4h9lJV9o6s. I used to put my molds in the pressure pot while they were curing but ultimately I learned it was unnecessary. Also, you have to be sure that the model will not be damaged by pressure.

[@LukeStephenson]

@@RobertTolone awesome, thanks. I'll give that a watch now :)

[@alexa.davronov1537]

Did you just used vacuum pump for degassing?

[@RobertTolone]

Yes, I don’t use it for resin casting.

[@youronlinepresencepro9348]

Great videos Robert - thank you! You are most definitely a pro at this! May I ask your advice on how you would go about making a mold for a relatively simplistic spiral? If yes how can I get a picture to you?

[@RobertTolone]

Reach me at [e-mail]

[@donnamurphy8299]

@@RobertTolone do you make figures on commission? I have an elephant chess piece (rook) and need 4 of them to use as newel posts on a dollhouse stair, with a hole in centre for light wires would be even better.

[@design321]

That came out amazing! I'm creating a mask with a sulfur-free Van Aken's Plastalina Modeling Clay, it is fairly soft, so I suspect that there might be plastalina residue left behind on the rubber once I demold from the rubber. Is there a special product needed to clean the mold out? Any product you'd warn me against trying? Thank you for these great videos. You're a wonderful teacher!

[@RobertTolone]

I don’t use Plastilina so I’m no expert. It is made of wax, oil and clay flour so I would test paint thinner or turpentine to see if that cleans the mold. Neither of those two solvents should hurt the silicone mold. Just be sure to thoroughly dry the mold before you pour in the resin.

[@design321]

@@RobertTolone Thank you, Robert!

[@Gallus691]

Why do you put vents in the molds?

[@RobertTolone]

To let the air out of the mold cavity as it fills with resin.

[@Gallus691]

@@RobertTolone Will this help when using a mix of gypsum, water and glue also. I want to water glid my pieces so I can't use anything that is not porous. Is there any other medium I can use for really small pieces that is porous? And thanks for taking time to answer. I'm completely new to mould making and your input and excellent videos are speeding up my learning 10 fold.

[@ferryalveritus2662]

Tq uncle for great video.. Hug!!

[@RobertTolone]

Thanks for watching and for your nice comment!

[@matostruck]

I have learned something today.Can you help me to make molds for front drive sprockets and rear idlers for a 1/35 Tiger 1 Tank. I want to make the sprockets in pewter metal. I just need step by step advice if? you are able. Thank you for your informative video.

[@RobertTolone]

Send pics to me at [e-mail]

[@donnamurphy8299]

Do you make any figures in commission?

[@lightzephyr3399]

What type of rubber are you using. I know silicone, but is there a number attached to that or a variety of silicone?

[@RobertTolone]

EconoSil 25 from www.silpak.com. It’s a soft and flexible tin-based silicone.

[@DanuLee_Wardoyo]

U r so amazing sir. And what those sticky wax made out of?

[@RobertTolone]

I don’t know, I don’t make it, I buy it. Here is a link to my material suppliers: www.dropbox.com/s/kz6mhmf7v5vpy7l/Material%20and%20Suppliers.pdf?dl=0

[@DanuLee_Wardoyo]

@@RobertTolone thx Sir.

[@jkrapenc1034]

At 15:50, can you not just put the mold back in the black tube and secure it with tape again? Why or why not?

[@albertcostell6034]

hi, could you please tell me, where to by stick wax? or which type of wax is it?, thanks, very interesting video!

[@RobertTolone]

It’s called sprue wax, or line sprue wax and it’s sold by many suppliers online. If you Google it, you will see that it comes in different colors and sizes and lengths. I prefer the 6 inch blue wax, which has proven to be the right hardness and melting temperature for my work. But you will see that it comes in other colors such as red and green which relates to different grades of hardness, brittleness and flexibility. You can buy a variety pack to test out the different grades to see which one works best for your work.

[@albertcostell6034]

@@RobertTolone hi Robert, thanks for your answer!, also the wax you use to fix the base of the master piece is the dame type of wax? , or its one specially for fixing?, thanks!

[@RobertTolone]

That is called Sticky Wax and it is sold by the same suppliers who sell the sprue waxes. Comes in many forms: rod, blocks etc but I just use the chunks. As I recall those are the best deal.

[@albertcostell6034]

@@RobertTolone Perfect Robert!, I will try it on my projects, thanks so much!

[@Zorkrum]

If I sent you some 3d printed resin parts would you be able to make some molds for me?

[@RobertTolone]

Here is a link to a downloadable PDF file with a list of the rubber, resins and waxes I use in my videos: www.dropbox.com/s/kz6mhmf7v5vpy7l/Material%20and%20Suppliers.pdf?dl=0

[@afarwiththedawning4495]

Thanks!

[@isidoreaerys8745]

What is Sticky wax? You seem to use it like solder, but honestly this is the first instance I’ve ever seen it used.

[@RobertTolone]

@@isidoreaerys8745 It is a hard wax that is used to glue things together. I believe it was formulated for the jewelry trade but it is commonly used by mold makers as well. It sticks well to most materials and especially to waxes.

[@isidoreaerys8745]

@@RobertTolone where is it conventionally sold?

[@RobertTolone]

@@isidoreaerys8745 These pieces were commissioned by the customer and were only resold by them. Most of my work is sculpting prototypes for customers that manufacture their products in Asia and sell them to retail stores.

[@strangecalibur]

Did you time travel?!

[@RobertTolone]

Yes.

[@patrickbutler1715]

ha ha Home Despot

[@mikesfound]

Can you send me that address again please it disappeared.

[@RobertTolone]

[e-mail]

[@hughjanus1135]

Becarful with resin you need to wear a mask and ventilated area look up videos about it

[@RobertTolone]

Safety is important, thanks for your comment. I have been pouring resin for 35 years. I have masks and my shop is extremely well ventilated. Stay safe!

[@ifeotto]

What I i use a vacuum instead of a pressure pot

[@RobertTolone]

they are used for two different things. Vacuum removes the air from the silicone rubber before the mold is poured. Pressure prevents bubbles from forming in the resin which is mostly caused by moisture absorbed from the air which causes resin to foam.

[@ifeotto]

@@RobertTolone thank you Robert for your time.