Casting A Small Resin Figurine

In this video I use a Platinum Silicone rubber to make a mold of a small, detailed figurine. Then I cast copies of it in urethane resin.
When molding a figurine in silicone rubber one of the most important aspects of the job is properly orienting the model in space. Doing so insures that you will make a clean casting with no bubbles and minimal parting lines. I positioned this model so that the sprue location would be very easy to clean up yet fill the mold rapidly and completely. Only two vents were necessary to let the air out of the cavity. Before pouring the mold I used a vacuum chamber to de-gas the silicone rubber.
The rubber mold is a one-piece cut mold. I used the absolute minimum amount of cutting to free the model from the rubber, making sure that the mold remain in one piece.
When casting with urethane resin is it it is important to measure and mix the resin properly according to the manufacturer's instructions. I use a pressure pot set to between 50 and 80 psi to compress the resin while it is curing. This helps to eliminate bubbles in the casting. But the most important way to make sure you get bubble free castings is to properly place air vents so that the air rises naturally out of the cavity as it fills with resin.
Thanks to Maria for sending in her fairy figurine. Check her work out at:
Thanks to Silpak.com for providing the Silicone rubber used in this video. It is a platinum rubber with a soft Shore rating of 20. Product number R-3700-20. Silpak has been my material supplier for almost 30 years. Check them out and be sure to tell them I sent you!
TIME STAMPS
00:00 Molding and casting a small figuring in urethane resin.
00:46 Correctly position the model in space.
03:12 Building a mold case.
05:50 Sprue and vent the model.
11:13 Assemble the model and mold case.
13:41 Pouring the silicone rubber.
14:12 Opening the case and cutting the mold to free the model.
19:13 Mixing and pouring the resin.
22:21 Removing the mold from the pressure pot and inspecting the casting.
24:21 Trimming the sprue and vents.
27:41 Strategies for correcting the flaws in the casting.
29:13 Evaluating the 2nd casting. Looks great!
Here is a list of suppliers for the rubber, resins and waxes I use in my videos:
www.dropbox.com/s/kz6mhmf7v5v...
Do you have a project to suggest for the channel?
Here’s a .pdf with everything you need to know:
www.dropbox.com/s/pjb0l6fr7zj...

[@damianpark236]

Rob , Brilliant the translucent silicon and the clear front have been revolutionary demonstrating moulding process.

[@RobertTolone]

Yes, the response has been great! I’ll continue doing that from now on.

[@humblehombre9904]

Robert, you never fail to raise my enthusiasm to a high level, almost always after your video, I will get up and at em. You are a teacher, and your love for your work is infectious. The fact that you also “rock and roll” is just an excellent and enjoyable extra, which adds a warmth to your delivery. Thanks brother. Regards.

[@levinebette15]

Love the translucent material, and the clear wall!

[@RobertTolone]

Yeah - I like it too. Just laid in a supply of clear sheet stock!

[@NicoleHam]

I was about to try a cast and was scared as hell but this video popped up in my sub page and It put a lot of my worries at ease ! Its always a pleasure to see you attack a sculpt and share your process. Also I actually have some clear silicone...but I've been using it for flat UV casting things. I'll definitley try them for bigger things / 1 parts

[@JohnJones-oy3md]

14:12 - "Here's Maria's little girl, entombed in this mold. Let's pull her apart and cut her open." The KZbin AI just spit out its coffee.

[@RobertTolone]

Hopefully the AI is intelligent enough to know that I’m not a degenerate pervert!

[@JohnClark-tt2bl]

@@RobertTolone Hah, the I part if that acronym isn't entirely accurate. Heck you can't say covid without getting flagged these days.

[@Nerdtronic]

HAHA!

[@templer4295]

LOL I just watched your video "Pressure Casting Resin On Wood" and you thank Freeman Manufacturing and Supply for the sticky wax in the comments.....asked and answered.

[@dcocz3908]

I find your work and videos fascinating

[@markhills3922]

Yet again, another helpful casting video Rob. I gave some thought to how I was going to approach casting my small objects after watching your video on casting the miniature car model. I looked around on my chosen suppliers website and noticed they had a translucent rubber with near enough characteristics to the rubber I have been using to teach myself this new craft of resin casting, so I purchased some of it. After seeing you using it in this demonstration, I know now that my thinking was sound in that it would make it easier to cut open the mold if I can see the piece! Great minds think alike my friend!

[@MrDanielphillis]

always a pleasure to watch ! Thank you Rob !!

[@paulhayton3423]

Interesting project, love the clear glass viewing window..

[@RobertTolone]

I’ll be doing clear mold fronts frequently from now on.

[@miguelmedina992]

I love your videos! If it helps, with that rubber you can leave it to cure inside a fridge and it will take more time to cure but it will look a lot more translucent :) your tips are the best!

[@RobertTolone]

I’ll give it a try !

[@shaunavconnelly9022]

I absolutely love the clear wall of the box and translucent mold. GENIUS!❤️

[@RobertTolone]

Yeah, it was very popular with everyone. Will be doing that regularly from now on!

[@magictorchproductions5308]

Really enjoyed this video thank you 🙏

[@peterplantec7911]

This was helpful, thank you.

[@dzzywibble7318]

Wonderful Video and very informative as always! Thank you Robert.

[@yugos.oficial]

Great work Rober!! 👌👌

[@flytrapjohn]

So much you taught us with this little form. Splendid rubber and clear sides. However I'm slightly concerned someone is not noticing their flooring slowly being removed. Love this channel, thank you and thank Maria!

[@RobertTolone]

Haha, pretty sure they won't miss the flooring remnants I scavenged from the dumpster!

[@wizardbrand1]

Your channel has helped so much with my mold making and casting! Thank you!

[@RobertTolone]

Glad to be of help Jose!

[@jerthemaker]

Woohoo! I have been chomping at the bit to see a new video! This is amazing!

[@RobertTolone]

Thanks for watching!

[@jerthemaker]

@@RobertTolone Sir, they getting better and better. Love the information that is gleaned from each video. Getting my first batch of Silpak products next week... going to be casting wands :)

[@rotten_comics]

Great work as always!!! Really wish you were my next door neighbor!!

[@RobertTolone]

Not certain my actual neighbors share your sentiment! 😄 But thanks for the nice comment!

[@vanthdreadstar8039]

Another awesome video! I cast small pieces and I always run the pressure tank to 80psi. I had to drill and tap new bolt threads in the paint pot "C" clamps in order to better seal the lid (as I stripped the thumb screws), but it works like a champ.

[@kryptoniangoth]

Your video was very informative...thank you.

[@RobertTolone]

Thanks so much for watching!

[@rumblehook9442]

Sir I wish I’ve watched your videos before wasting more than half of my silicone on fail molds 🥲. Hopefully the next ones I make turn half as good as yours!

[@melanie5442]

Love this.

[@RobertTolone]

Thanks for watching!

[@betogaona3d.]

Dear Mr Tolone, it would be great if you could show the different types of resins for sculptures, advantages and disanvantages from epoxis, poliesters, poliuretanes, etc, it would be awesome.

[@lokiwartooth1138]

I agree

[@kalbotero9232]

Hey Robert as always amazing job by doing this trick doll 🔥

[@RobertTolone]

Glad you enjoyed it!

[@thebeheader]

i will take a look on a sculpture i made of Bernie Sanders.. a complicated sculpture... on how much it could cost to ship and bring back the guy from QC to California it could be a great tutorial. i'll send you some detailed pics. i hope it could be a good learning subject. I have to mention this video is another great tutorial. I did some blanket mold past week end and i have to say those came out really good mostly cuz the little tips that only a really experimented guy can give. Thanls Robert!!!!

[@RobertTolone]

I am looking forward to seeing it Melo.

[@BC-fy1wn]

Nice to see yet another video from you. Doc BC

[@RobertTolone]

Thanks for watching Doc!

[@dannyfuller1]

I really enjoy watching your videos i've learnt so much from you. It is also most impressive that when you are explaining what you are doing you hardly ever say 'kind of', 'sort of' or errrm! Like most youtube commentators, which can get very tedious, very well done Sir!

[@RobertTolone]

Thank you very much Danny. I appreciate your nice comment.

[@SiliconRiot]

Ever looked at using Legos as reusable and versitile mold boxes or other assorted rectangular based shapes.

[@securityrobot]

Bubblephobic!😂 A new casting term has just been born.

[@RobertTolone]

I should trademark it for my merch!

[@levinebette15]

@@RobertTolone Perfection!

[@securityrobot]

You should indeed!

[@ryancreasey5833]

Top notch as always. Say, where might an aspiring mold maker find “sticky wax” or other sprue making material (namely the other thin strands of wax)?

[@RobertTolone]

Hi Ryan. Here’s a link to a pdf of my materials and suppliers: www.dropbox.com/s/kz6mhmf7v5vpy7l/Material%20and%20Suppliers.pdf?dl=0

[@evansn79]

I used what looks like the same rubber under a different name recently - I found that it was wildly inconsistent in hardness despite being fully cured, which meant it was very prone to tearing and gave quite rough casts after only a few pulls.

[@RobertTolone]

I have not had those problems with the EconoSil-25 rubber I buy from Silpak. It has worked consistently well for me. How many clean castings I can pull from a mold depends on many factors.

[@evansn79]

@@RobertTolone In that case I'll give it another look - My theory was that it's more temp sensitive and that my icy UK studio was causing it to slow during curing and giving me inconsistent hardness.

[@JohnClark-tt2bl]

I don't know if you have plans for next week, but casting some reason eggs would be a fun idea for easter. Could try roto-casting them.

[@RobertTolone]

An egg would be an ideal object to rotate. Only a sphere would be easier. What would be hard would be those 2-piece plastic eggs you fill with candy.

[@fuzzpuppets]

Another great video Robert, thank you. That translucent silicone sure makes cutting the mold easier. Are you considering using that more often? Did it have the same properties as your usual blue stuff?

[@RobertTolone]

This particular rubber is softer than the Econsil-25 I normally use. Specifically it is a 20 shore and I’m used to a 25 shore. but that is not a major difference. The main difference that would prevent me from using it is that it is a platinum rubber and therefore much more expensive than the tin rubber that I regularly use.

[@Littleboxofevil]

I love your casting and mould making videos! I do wonder though how you feel about 3D printing, which would minimize all the work. I for one have an Elegoo Mars 2 pro 300 euro 3D printer and it just prints full beds of highly detailed figures easily.

[@RobertTolone]

Love 3d printing and it is the way of the future. My channel has a large community from the 3d printing world and many of them are here to learn faster, easier methods to reproduce their sculptures than 3d printing. My feeling is that both methods are labor intensive but that 3d printing will win in the end.

[@greenplasticgun]

Thanks for the upload! Wonder if I'd be able to ask advice on a (for me) complicated mold/cast I need to do? Do you ever offer advice to the viewers?

[@RobertTolone]

Yes, reach me at roberttolone @yahoo.com.

[@davesilva9174]

Great vid Robert! This ‘clear’ platinum silicone looks very similar to Smooth on Dragon Skin 10-30. Have you used Dragon Skin before?

[@RobertTolone]

No, I’ve never used it.

[@merseymodels1073]

Love your work, just wondering how many models you might pull from a cut mold like that?

[@RobertTolone]

10 to 20 castings, more if I was willing to use mold release. I usually don’t use it, especially on castings I’m planning to paint because it takes time to thoroughly remove the release from the castings.

[@CajunCraftastrophe]

Another great video! I'll have to get some of that translucent platinum rubber from Silpak for cutting one piece molds open! Very cool. Are you sometimes wearing a Go Pro Camera on your head for some shots? Are are you just hand-holding the camera from time-to-time? Thanks.

[@RobertTolone]

I have been experimenting with a DJI action camera strapped to my head.

[@CajunCraftastrophe]

@@RobertTolone tres cool! I like it.

[@templer4295]

New to casting and using wax and not hot glue. When you say "sticky wax" , is there a formal name and a place to buy? Your channel is great and you can tell that you have a true passion for your art work.....Thanks!!

[@RobertTolone]

Sticky wax from www.freemanwax.com

[@chriselliott726]

Excellent video! Question please - if your tank will go to 80psi is there a reason you don't always go to a higher pressure?

[@RobertTolone]

I used to always run my tanks at 80 psi. One day by accident I ran it between 40 and 50 psi and it worked just as well. So I thought, why not run it at the lower pressure? The main advantage is that it takes less time to fill the pressure pot, therefore the compressor doesn’t have to run quite so long which saves wear and tear and electricity. The main disadvantage is that sometimes you can eliminate bubbles at a higher pressure that won’t disappear at 50.

[@GreydeDeuil]

Is it just me or does this guy sound so much like the guy from the Red Green show?

[@deanmpatton]

Great job trying out a new silicone. It's a shame the translucent platinums become nearly opaque after a dozen or so castings.

[@RobertTolone]

But it is also instructive. The reason that they become opaque is that the resin is wearing out the surface of the mold. You don’t notice it in opaque molds but it is obvious in clear molds.

[@chartle1]

I the clear window for our benefit or does it really help you?

[@RobertTolone]

I’ve been pouring blind for so long that I don’t really need it. But it is a lot of fun to see the mold fill up!

[@eddy5556]

Great job!!! One little question is it possible to reconditioned the silicone 1/1 in glass jars ?the original ones are unpractical in anticipation thanks

[@RobertTolone]

Do you mean, is it ok to transfer silicone rubber into smaller containers to make it easier to handle and dispense? If so, the answer is yes. I do that all the time.

[@eddy5556]

Thanks for your answer my problem is also what product use for cleaning this smaller containers for not polluted the silicone essence F and acetone? Sorry for my bad English 🌝 thanks again for your videos very inspiring for me I don't make 2 parts mold now!!!!

[@ArcticFlies56]

Bob, you really have to be careful with those exacto blades. I speak from too much knowledge in this area. They are really sharp buggers. A little tip. Get a few boxes of bandaids antibiotic ointment. Ouch!

[@RobertTolone]

Haha, my first aid kit is always stocked and at the ready! X-Acto blades and utility knives are the cause of nearly every shop injury I have ever had!

[@wing6093]

why do sprew cups always seem to cast so bubble free , its annoying

[@oncalldev]

What would be the downside to running at 80psi (assuming that you have a compressor that goes that high) for all molds? As always thanks for the video.

[@RobertTolone]

I used to always run my tanks at that pressure. I discovered that 50 works most of the time. The main advantage of the lower pressure is that the tank fills faster.

[@lokiwartooth1138]

Is the blue an alcohol ink?

[@Mokaygee]

Have you ever considered using pressure when you pour the silicone to eliminate bubbles in the mold? (Like in between the knees here)

[@RobertTolone]

When I began mold making I put the molds into the pressure pot to cure. The problem with that method is that many models have voids inside them. This is particularly true with clay models which are typically sculpted by adding clay over an armature. This is an excellent method for trapping air. So when you put such a model in the pressure pot it collapses. Early on in my career a sculptor brought me an exquisite little ship model made of wood. It never occurred to me that the hull and superstructure were hollow. I assumed they were carved from solid wood. When I put the ship model and mold into the pressure pot it collapsed into what was essentially a pile of sticks. I also believed that the silicone rubber did not stick to anything however the wood was unsealed and bonded beautifully and permanently with the silicone rubber. it was a humiliating disaster and an expensive one as well! That was the last time I ever put a model into the pressure pot! The other reason I don’t do it is that it is completely unnecessary. I did not say so in the video, but the reason that I caught that bubble under those knees was that I got into a hurry and wanted to keep the video on production schedule. So after I pre-filled in that space I did not wait long enough for the rubber fill to properly cure. I hoped that it had gelled enough to stay in place before I poured the mold but it didn’t. I should always listen to the alarm bells ringing in my head, but in this case I didn’t. And it cost me a bubble. Sorry for the long answer, but I want to add that I did consider filling in that space with wax or clay. Best practices are to do that because a sculptor should always design out molding problems in the sculpt phase of the project. But I don’t like to modify the work that is sent into me and I also think it is instructive to point out these mistakes. So I left it unfilled with the knowledge that there was a good chance it would catch a bubble.

[@Mokaygee]

@@RobertTolone Thanks Robert for always answering my questions, and that's a great answer! It's absolutely true that we learn best from our worst disasters, I can't imagine what I would do if I destroyed a master with pressure...

[@toolmaker3799]

Scrape with back of BLADE save your Razor Cutting EDGE !🧐 Try It .

[@bigosnation]

Does the pressure pot cause the silicone mold to distort? Or did you use a vacuum chamber?

[@RobertTolone]

If the silicone mold was made properly and does not have bubbles it will not distort in the pressure pot.

[@lafarms]

Robert you are a bad influence. I built a pressure/vac pot that would horrify you. My wife is wondering what I am doing this time! Playing with plaster so far, mistakes are cheap that way. Thank you! having fun. I really enjoy your channel.

[@RobertTolone]

Just be careful not to be near the pot when it explodes! Seriously though, they’re nothing to be trifled with.

[@lafarms]

@@RobertTolone I pressure tested it up to 120 well hidden from it then operated it as high as 80ish. Discovered that the silicone mould that I was given has internal bubbles, my plaster cast has pimples as a result of the silicon bubbles compressing!

[@gerbendenheeten6905]

Is a one part mold better for these small characters, or a double mold, I wonder?

[@RobertTolone]

My entire channel is an argument for one-piece cut molds. So I would say that, especially for characters, a one-piece mold is always superior to a two-piece clay up mold. It is much faster to make and delivers a much cleaner parting line on the castings.

[@gerbendenheeten6905]

@@RobertTolone Thanks for the clear answer, I'll keep that in mind when I will start moldin my own (little) characters. Keep up the great videos! :-)

[@annekabrimhall1059]

That platsil rubber looks softer. Is it?

[@RobertTolone]

Yes, it’s 20 on the A Shore scale. Softer than the rubber I usually use.

[@annekabrimhall1059]

@@RobertTolone well it looks great! I really love the new clear front boxes you make!

[@maverickstclare3756]

so would you *choose* to use the clear silicone if it wasn't on video ?

[@RobertTolone]

If I need to use a soft platinum rubber this material would work well. I usually use an economy grade of tin-based silicone because it is less expensive.

[@jameshakola3603]

That makes sense, and especially now since 3D printed resin parts really don't play well with the platinums

[@BioMusing]

Do you ever use food grade silicone to make things like chocolate statues?

[@RobertTolone]

Yes, in fact my daughter is a pastry chef and I have made platinum rubber molds for her restaurant. Fun fact, most chocolate molds are not made of rubber. If you look at cast chocolate it almost never has undercuts therefore it is molded in rigid molds.

[@BioMusing]

I never thought of that, I'll try that fo the little army men. Thanks for sharing your knowledge :)

[@Lgavenger]

Hello Robert, when people send in projects, do they pay for materials,,, Thanks

[@RobertTolone]

Rubber, resin and shipping. Most people’s projects are small so the cost is low.

[@ArcticFlies56]

Bob, I must have missed the increase in pressure from 55 psi to 80 when I first watched this video. I can’t speak for others, but my pressure pot caps at 60 psi. Let’s say for argument sake that you don’t have the custom pressure pot like you have. How would you resolve the bubbles without increasing pressure? I know you shake and bake which undoubtedly helps. The pressure is the question? Thanks.

[@RobertTolone]

it’s very rare when I have to cast something at higher than 50 psi. The simplest answer is to re-design the piece so that it does not catch bubbles. Otherwise you are pretty much stuck with the results you get at the maximum PSI of your tank.

[@davesilva9174]

Ps did you vacuum the rubber before pouring? I usually brush mold with Dragon Skin and don’t vacuum but still get bubbles when pressure pot curing the casts. Annoying!

[@RobertTolone]

I did vac the rubber. And I pre-filled that void under the knees. The mistake I made was not allowing the prefill to cure long enough. So it pulled away away from the model and I caught a bubble when pouring the mold. Moral of the story is never be in a hurry when you pour rubber!

[@chartle1]

Wouldn't connecting the vents to the funnel maybe cause an issue where if you are not careful pouring the resin? Not making an argument since I have no idea what I'm talking about. 🤪

[@RobertTolone]

No, I almost always connect the vents and sprue if it’s possible. It’s easier to mount the model in the mold case and follow the vents for the cut. True you must take care not to block the vent.

[@nayeemabdul8107]

How sir I need help from you I have rotomoulding machine and moulds i what to make mannequin hand I am facing some problem in material please can you give me e material name and list and ratio and temperature and time please reply

[@collprin]

way beyond my capiblities

[@eugeniobarreto]

This silicone is better to learn the CUT part.

[@ashes48]

when i was a kid i carved molds out of wood, then i got into sculpting, and now 3d printing, but i sculpt my own prints. it's still i hard thing to do in 3d. so no.. from the thumbnail pic.. none of it is ever easy.

[@RobertTolone]

It’s a funny thing about KZbin thumbnail questions. The answer is almost always no!

[@nayeemabdul8107]

Pvc material

[@RobertTolone]

I have no experience with PVC for roto casting. It's completely different than roto casting resin. I use urethane resin from www.Silpak.com. I use Quickcast or Silplastic for rotocasting. There are material data sheets on the website for both materials.

[@nayeemabdul8107]

@@RobertTolone thank you so much

[@wollibar5263]

First

[@annekabrimhall1059]

Are you sure it’s a girl? I would use that pattern for boys, girls, whatever

[@RobertTolone]

It’s a fairy. The way Maria decorates them they’re definitely girls.