Mold Making Tutorial: How To Make a Brush-On Rubber Mold of a Bust

This mold making tutorial video demonstrates how to make a brush on mold of a 3 dimensional model using Brush On 40 urethane rubber.
Step 1: Glue model to base.
Step 2: Apply SuperSeal sealing agent to all surfaces.
Step 3: Apply Universal Mold Release to all surfaces.
Step 4: Properly measure Parts A & B. Dispense equal amounts of Brush-On 40.
Step 5: Mix mold rubber.
** Mold Maker's Tip: Color pigment every other layer. This ensures thorough coverages and help avoid thin spots in the mold. **
Step 6: Apply mold rubber. First layer, or "detail coat" is applied thinly. Push or stipple rubber into detail. Mix and apply more material as needed.
Step 7: Allow rubber to gel until "tacky" (30-40 minutes at room temperature). "Tacky" means sticky to touch but does not come off model.
Step 8: Mix and apply second layer of rubber.
Step 9: Allow rubber to gel until tacky.
** Mold Maker's Tip: Thicken Rubber with Cab-O-Sil or URE-FIL 9. Use thickened rubber to make parting shims. **
Step 10: Add Cab-O-Sil to thicken rubber. Use thickened rubber in undercuts and indentations. Use thickened rubber to create registration keys.
Step 11: Mix and apply third layer of rubber. Mix and apply more rubber as needed.
Step 12: Allow rubber to gel until tacky.
Step 13: Build up parting shims and undercuts.
Step 14: Mix and apply fourth layer of rubber.
Step 15: Let all layers cure overnight at room temperature.
Step 16: Applying the support shell or "mother mold." Purpose: provides rigid support to flexible rubber mold during casting. Draw parting lines. Use modeling clay to make support parting shims. Apply clay supports to other side. Fill in any open spaces and smooth clay pieces together. Complete clay shim around model. Apply clay supports on other side.
** Mold Maker's Tip: Use sculptor's tool or paper clip to carve registration keys into clay. **
Apply Sonite Wax over rubber surface, clay shims and base. Apply Universal Mold Release. Measure and mix Plasti-Paste II. Mix ratio: 1A:2B by volume. Mix thoroughly. Apply Plasti-Paste II to mold rubber. Let cure about 90 minutes.
Next Step: Remove clay shim. Use clay to make second parting shim. This defines the second and third shell segments. Apply clay supports and smooth edges. Apply Sonite Wax. Apply Universal Mold Release. Measure and mix Plasti-Paste II. Let cure about 90 minutes. Remove clay shim. Apply Sonite Wax to Section 3. Apply Universal Mold Release. Measure and mix Plasti-Paste II. Let cure 90 minutes.
Step 17: Demold. Remove shell segments. Remove rubber mold from model. Use razor knife to cut seam. Perfect detail is captured from the original model.
Step 18: Ready to cast. Apply Universal Mold Release to all surfaces. "Seat" mold into shell making sure seam is aligned. Secure mold with straps or rubber bands. Mix and pour duoMatrix NEO into mold cavity. Mix ratio: 2A:1B by volume. Add more duoMatrix NEO as needed. Let all layers cure for about one hour.
Step 19: Ready to demold. A perfect lightweight reproduction.
Make It Now! with Smooth-On
www.smooth-on.com/
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/ smoothon
www.google.com/+smoothon
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Adult Supervision Required
Keep Out Of Reach Of Children
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[@wingitprod]

This video is invaluable. You're never too experienced to not need a refresher 🤠

[@mineralmax]

Thanks for your helpful and informative instructions, as always, on mold making and casting. Enjoyed watching. Keep up the great work!

[@maxabeles]

love the G Funk era music at the end lol

[@sammanthaluis3491]

Great tutor! Looks so easy and final mold is perfect

[@smoothon]

Thanks Sammantha!

[@martino8114]

I was looking for all the latest techniques on casting from clay sculptures, I’ve been away from it but now back and I came across this video….. outstanding!!! Thank you! Look forward to learning more about casting, mold making etc…. Funny though … sculpting is a thousand more times easy for me than casting hahaha I thought it should feel the other way around lol Thanks again

[@smoothon]

You are so welcome!

[@biswajitnarayan7040]

Thanks sir, for sharing this .

[@fallenslave6684]

so this is what actors and producers use in the movie! thank you for showing me

[@54321Judith]

Thank you!

[@smoothon]

To rotocast Smooth Cast urethane resin, you want to choose our Smooth Cast 65D.

[@smoothon]

This is correct. The same Brush-On rubber mold process was performed on the clay original to created the plaster master copy.

[@lenny108]

pays off when commercially having to make 50 or 100 of these statutes. For hobby craftsmen who make only one this is far beyond our budget

[@caradirisi4869]

Beautiful

[@wirewrappedforsale]

Awesum!! Rock On!

[@smoothon]

You can check our website for a list of distributors. Our materials are available around the world. In terms of price, ultimately it will depend on the size of your project and the materials you choose. Feel free to contact us to discuss in more depth. You can get an idea for the price of the materials on our website.

[@smoothon]

You could use a pourable rubber such as our Vytaflex and allow that to 'flow' over the surface before following up with brushed-on rubber.

[@Rachelof_arc]

Amazing

[@MikeKleinsteuber]

Nicely done

[@smoothon]

Thank you for watching!

[@lynniecbieber]

nice job guys :)

[@smoothon]

Generally you would use a bed or wall of clay to divide the piece so you could mold one half at a time.

[@smoothon]

Plast-Paste II is mixed 1A:2B by volume. Two cups of the paste (Part B) component were measured for one cup of the liquid (Part A) component. We did not explicitly show a second cup of Part B being dispensed in this video.

[@bernardopatino6263]

Art: Super cool. lol.TNX.

[@mahmoudzaefi2958]

thanks alot

[@smoothon]

Happy to help.

[@elhassaneelyamani7898]

Good work

[@smoothon]

Thank you for watching!

[@smoothon]

Yes, it is Chavant NSP non sulfur plasticine.

[@smoothon]

This depends on the casting material - but these are production quality molds.

[@smoothon]

Yes, as long as it is non-sulfur plasticine.

[@SeanOzz]

you guys should have Frank Ippolito do some molding videos. his are so clean and detailed and i think he uses your products already so win win for all of us little guys. lol

[@mainstay.]

I just went to his YT channel and he doesn't have any molding/casting videos at all, so I don't know why you reccomended him.

[@sticky170]

Thanks for the detailed instructions. One question, how many casts can you make from that mold. (how long will it last?)

[@smoothon]

You can cast urethane resin into the mold as long as you apply Universal Mold Release to the mold first.

[@luissanchez1159]

Smooth on, can you use this on a plastered crown molding that has tiny little flowers on?

[@rafexemt1]

Hey guys great vid, my question is can this be used on pink foam? I work using pink insulation foam to make Dios and would like to cast a few in hydrocal. I was wondering if this would destroy the foam?

[@casmaran545]

I have a moldel where you just can't pull the rubber mold off like a mask. I have a main large ball with 4 arching tubes/scrolls protruding from the top that meet at a small ball: {Like a viking helmut that has 4 horns that arch up and meet at a ball at the top center above the helmut for a visual example} How do I get the rubber mold off of that and still keep the form in the mother mold without the wax filling in behind the rubber in order to make a loss wax cast? I know I will have to cut it to make parting lines I am assuming, How do I keep it together after and aligned after I put it back into the mother mold? Do I have to glue it back together before recasting the wax?

[@GetToDaChoppa-k5r]

I am making small resin toys from super sculpey. Which is the best mould product for these?

[@Pimentel-Kreations]

Im in the process of reproducing a rubber boot for my 1952 Buick starter. I have experience in casting and working with epoxy eurethane resin just not rubber wich the part is. What do you recommend that will not tear easily, heat resistant and a flat black finish with the most minimal shrinkage?

[@rodlrfilmmakercreator1460]

Great video, question, Can I use the smooth cast 320 just around the walls, I mean not full solid casting? I want to save material and that way I use less resin

[@smoothon]

We actually have a resin designed specifically for that - kzbin.info/www/bejne/eHqQlp6Lhdqkm6M

[@khunthate]

I already asked this in another product vid, but can the model be made out of modelling clay? Thank you

[@jhovanacampos4498]

wow the final

[@HOTRODLED]

If you useing a porus material such as foam rubber. Would you have to seal it first before you spray the release agent on it?

[@smoothon]

A list of distributors is available on our website (smooth-on [dot] com).

[@smoothon]

The 2-part mother mold on the back helps keep the ears from becoming mechanically locked in the mother mold.

[@DavidKimFX]

Can a burlap or fiberglass matte layer be added when brushing on the Plasti-Paste II support shell? I'm concerned with the strength of the shell using Plasti-Paste II alone.

[@TheFinalformsora]

What if i have a prop that cant be glued down? Just one half at a time until it dries?

[@motherofpoms]

Could i cast with resin after doing this? and would the inside of it be smooth, Im planing on making a mask? thanks :) x

[@johnm.washbush591]

Great tutorial. What is the aproximate cost of all of the materials used in the video?

[@maxabeles]

nice g funk era @ the end lol

[@abryant5258]

I'm currently using the 25 and the viscosity even without the Thivex is rediculous its like peanut butter. "Brushing on" is implausible at best

[@smoothon]

AJ, can you contact the location you purchased the material from for assistance?

[@FreebieJeebiez]

What is the difference between silicone and urethane rubber, what are the advantages of each.

[@derekslang]

This hollow technique can be done with Smooth Cast 300?

[@MiamiNight01]

10:02.Is that a batman returns cowl fiberglass mold behind the guy?Let me know.thanks

[@PimpRandal]

What were the steps to create the bust - is it sculpted in clay then molded into a plaster or a resin ? is there a video you can suggest about creating the bust.

[@JJKnapich]

I just used rebound 25 to make a mold and after a day it's still tacky. My measurements were precise and i mixed really well. I'm not sure what went wrong.

[@smoothon]

+Justin Knapich Hey Justin, can you submit a ticket to us at www.smooth-on.com/techsupport.php - we can help you out.

[@DarkVisionArtDesign]

Hmmm, just one question...which one is better for concrete casting: Brush-On or Rebound?

[@smoothon]

Brush On Urethane has a higher abrasion resistance, which may be preferable for production concrete casting. However, many manufacturers are using Rebound in cases where the model shapes are very intricate.

[@thetonycanepa]

It would be great if you had a package on your site with all the materials from the video. I do appreciate the list of steps and materials in the description.

[@smoothon]

Tony C. That's a great idea, Tony. Thanks!

[@motherofpoms]

also how many layers of rubber does it need? thanks

[@FreeFlowArtist]

so how much would all of that cost? im looking into making slush molds for latex masks.

[@MySpace662]

A perfect replica! Thanks for sharing your knowledge on making a mold.

[@kksing6163]

Sir, I have a small silicone toy and it is of skin color. I want to change the color of that toy to green. Please tell me how to do it and what will be required.

[@TheIsraelgonz]

can the duoMatrix NEO be used for a mask

[@tomhillan2429]

hi, can you use this method and materials on a wet clay model? would a sealing agent need to be used such as petroleum jelly on the model to seal in the moisture before brushing on the rubber? thanks

[@smoothon]

Tom Hillan We would recommend sealing with a high quality spray shellac.

[@bobjohnson37]

will this material work over a plastilina clay bust?

[@morewaycharlie1294]

good

[@alaatemraz3328]

ممتاز ورائع ومحترف

[@Sage.....]

Could you do this method using silicone, to produce a silicone mask from the rubber cast ?

[@smoothon]

It would be possible, but generally flexible castings come from rigid molds. kzbin.info/www/bejne/hIfapGOorrhmY6c

[@inmylife2012]

Is it possible to use the brush on rubber on human models?

[@LeleOnVideo]

Thanks for the video! Why are your rubber shims in a different placement than your mother mold seams?

[@smoothon]

So the rubber shim can register within the shell. This is but one of the ways this type of mold could be made, however.

[@LeleOnVideo]

Thank you!

[@josephnguyen7335]

what quantity of smooth on does it take to create a mold the size of a human head including the 4 coats? And how much does it take to cast a copy? is a pint enough?

[@smoothon]

Hi Joseph, Thank you for your interest in our materials. I would take a look at our Body Double silicone for lifecasting. Generally speaking it should be 2 trial size units for a full head. However, everybody’s head is different. We also offer a coverage chart that you can examine here - www.smooth-on.com/index.php?cPath=1372

[@Joyousmicor]

How you did pigment Brush-On 40? Maybe you using So-Strong Color Tints or Silc Pig Color system?

[@smoothon]

+Joyousmicor So-Strong colorants are used for Urethane Rubber such as Brush On 40

[@trevorlaughlin3373]

I am trying to make 4 animatronic heads from molds. Can this DuoMatrix Neo be cut into/have holes drilled in it without shattering, cracking, or deforming? If not, is there another product that can be used with rotational casting that would be more fitting for this application?

[@MrCaptainDoctorMan]

Can this been done on a plasticine model?

[@FreebieJeebiez]

What kind of sealer did you use

[@sufifiberglass]

👍👍👍

[@genesisartesaniafrancisco2055]

Por favor Quiero comprar su producto en República Dominicana pero no no sé a dónde comprar lo conoce como comprarlo en otro país por favor informeme

[@smoothon]

About 4 layers is usually sufficient

[@wanderingintime]

hello! not sure if you still answer questions here, but I have the red rubber rebound 25 brush on and want to mold an antique glazed ceramic teapot.. I cant seem to find a way to ask google if that paint will potentially be damaged from the process...? what kinds of things are not safe in rubber and silicone molds??

[@smoothon]

Can you send us a tech ticket? Our team can help you - www.smooth-on.com/support/ticket/add/agree/

[@dillonwest9732]

About how thick is this mold? I'm doing a similar mold and I don't want to get it too thin. Thanks!

[@smoothon]

About 3/8" thick.

[@zheddo]

Is it possible to use one layer of rubber only to, let's say, paint the inside of a 3-D printed model to act as a buffer for another object that will go inside that one? How durable is this rubber?

[@smoothon]

+K1p57a this is a very durable urethane rubber, for your application we recommend some small scale testing.

[@smoothon]

It is best to secure the model somehow.

[@smoothon]

You can use sulfur free clay for your model.

[@smoothon]

Latex generally will not dry properly in a non-porous (rubber) mold.

[@kinkyink85]

hi there, thanks to your excellent toutrials i have the casting thing up to date in my mind, however i am a beginner to sculpture and casting reproduction. i know how to create an armature but im lost as to what kind of clay i should use for the sculpture itself, i want to sculpt a detailed 1:1 scale bust of a zombie. i am doing it at home and dont have access to kilns etc, i need something that airdrys but doesnt shrink or crack like kindergarten type clays, something that i can create skin details in and something that is compatible with the molding and casting components used in this video. can you help me or direct me where i may find help, im in europe (ireland) and would need a european distributer for the clay and your products, any help asap would be hugely appreciated as i am egar to begin.

[@smoothon]

We recommend either Chavant NSP modeling clay or Sculptex clay available from Reynolds Advanced Materials.

[@alicemaddocks8783]

what is the model made of? is it clay - and is it fired. I want to make a mold of a clay sculpture - but it's not fired as it has armature inside... can I make a mold of an un-fired clay piece and does it need to be dry or leather hard?

[@smoothon]

+alice maddocks This is a plaster original. Your original must be dry when using urethane rubber.

[@nixland]

How can I add silicone if my silicone mold already cured? I missed some spot. Thanks

[@smoothon]

Hi, if the surface of the cured silicone is clean, new silicone will bond to it.

[@nixland]

Smooth-On I see. Thank you

[@TalynStormcrow]

I can now steal bronze busts and replace them with fakes! Thanks!

[@MacKayla3Tears]

Im looking to create some Jason Vorhees head and shoulder busts. I need them to be very durable. Could I use oil based clay to sculpt the bust, spray with relief agent, apply the liquid rubber as shown, apply another layer of relief agent, use fiberglass resin and hardener to create the two half support shells, and when the rubber mask is put in the support shell add another layer of relief agent to the inside and fill with fiberglass resin and hardener to make a true fiberglass bust? Or would this be too tedious and complicated and time consuming?

[@smoothon]

Hello Manda, Thank you for watching! To better assist you, could you please contact our technical support team - www.smooth-on.com/support/

[@Lyrnix]

Is there a way to clean the brushes you use? Or are they totally destroyed after each layer?

[@smoothon]

You could try using mineral spirits, but in the end disposable brushes work best.

[@ozmoderntx4718]

(when applying Rebound 25) -- If you are using a sulfur-free clay for the partition wall... is it ok if the clay dries out?

[@smoothon]

Yes it is.

[@ozmoderntx4718]

@@smoothon Thank You!

[@ozmoderntx4718]

@@smoothon no its really not, as the clay dries out, cracks and falls apart. Hopefully I had enough silicone applied to retain the partition wall form. I would suggest no one use a water-based clay for anything to do with mold making.

[@345lamak]

hi how i can get the rubber material?

[@k2creates]

Is the Thi Vex a replacement for the Cab-O-Sil mentioned in this video. the thickening agent for mold max stroke?

[@k2creates]

+Kevin Smith II And also, I'm getting ready to use Mold Max Stroke for my first mold, is this the closest video to follow for the process

[@smoothon]

+Kevin Smith II Correct - for a silicone mold, THI VEX can be used. This video may also be helpful: kzbin.info/www/bejne/kHSsgJJof5aafJI

[@user-iv8zm6qv9t]

+Kevin Smith II أ

[@peterangel777]

At 04:25 you say "Use modeling clay to make support parting shims". Is this plasticine?

[@Darkbulb1]

how thick should the silicone glove mold be?

[@smoothon]

We would recommend 3/8" thickness for optimal strength.

[@eugeniabotezatu2557]

👏👏👏👏👏👏👏👏👏👏👏👏👏

[@54321Judith]

Did you seal the seam of the rubber mold before you put it in the plastic shell?

[@smoothon]

No, the rubber seals itself as long as registration between the rubber and the shell is good.

[@hippobrains]

can i cast in concrete if making a mold with this method?

[@smoothon]

Absolutely! Brush-On 40 is a great mod material for casting concrete. We recommend using Aquacon as a release agent.

[@repmighty2993]

Would this be a good method for making Halloween masks? Or just solid busts?

[@smoothon]

The Brush On rubber does not absorb moisture, so it would not be suitable for casting latex.

[@TK2236]

Hi there. This method could be used to make a mold for a Star Wars Stormtrooper helmet right?

[@smoothon]

+TK 2236 it could. Our Rebound 25 silicone may be a better choice of rubber to use as resin releases easier from it.

[@TK2236]

Thank you for the answer ^^ Have a nice day :)

[@emadsaleh8311]

please I want all amounts u use..how much does it coast. ..cause I never found it in my country

[@smoothon]

Emad Saleh if you visit our support page, you can submit a ticket. We can then write back with recommendations. Thanks for watching!

[@allgoodtube]

what song is this haa i like it

[@camilosatiro9126]

How much you complete kit to make that mold please put a link to it so I can buy it

[@smoothon]

We do not have a complete kit with these materials specifically, but pricing can be found here: shop.smooth-on.com/

[@ton.oprido]

smooth-on! you have a store branches in phillipines?

[@smoothon]

We have a full line distributor list here: www.smooth-on.com/distributors/

[@hondo2160]

@guysytaccount You should have longer than 5 minutes to work with the material. Urethane rubber is heat-sensitive, perhaps an elevated working temperature made the material cure more quickly.

[@maikeru01]

what about if the model is made of clay and stabbing it as violently as you are with a thick rubber on a brush would ruin the model? is there a gentler way to go about it?

[@KelliannKeeler]

How much Brush-On 35 would one need for a mold of this size?

[@smoothon]

This mold used approximately 2 gallon units of Brush-On 40 and 4 gallon units of Plasti Paste.