Frequently Asked Questions
General / Troubleshooting
- What is the shelf life of my material?
- How can I safely dispose of these materials?
- How can I open a stuck container lid?
- What is polyurethane rubber?
- What is silicone rubber?
- What does 'Shore Hardness' mean?
- What is the difference between molding and casting?
- What effect does temperature have on the mold making and casting processes?
- Is there an easy way to test if a product is working properly?
- You recommend using disposable rubber gloves when using Smooth-On materials. What type of rubber glove should I wear? Is one type of glove better than another?
- What do the terms "heat curing" and "post-curing" mean?
- What are the best solvents for cleaning uncured materials from different surfaces?
- Definitions of Technical Terms
- How can I add color to liquid rubber or liquid plastics?
- I attempted to bond urethane rubber to stainless steel for an industrial application and it did not stick. What can I do?
- Are these materials safe to use?
- Winter Weather Advisory: What are the effects of cold weather on urethanes, silicones, epoxies, and latex-based materials?
- I bought a gallon unit of your mold rubber and almost broke my fingers trying to get the lids off. Is there a better way to get these containers open?
- How do I break down and dispose of empty material totes?
- I received my material, but one of my containers was only half full. Is this a mistake? Was I shorted material?
- How do I heat cure or post cure materials if I can't use a kitchen oven and don't have access to an industrial oven?
- How can I dispense material from a 5 gallon pail more easily?
- Why did we create an FAQ list?
- Is there a recommended surface preparation method for applying Smooth-On epoxy adhesives?
- How are these materials packaged?
- The color of my urethane rubber is different compared to the last batch. Is there something wrong with the material? Will it perform the same as the last batch I received?
- Are Smooth-On materials ‘vegan’? Do they contain ingredients taken from animals?
Moldmaking Questions
- I made a mold using silicone rubber and experienced sticking. I know that silicone rubber is not supposed to stick to anything. What happened?
- Do I have to vacuum de-gas the silicone rubber? Is vacuuming the rubber that important?
- Why are there bubbles on the surface of my rubber mold?
- How much mold rubber do I need?
- Why didn't my mold rubber cure?
- What are the major differences between tin-cure (condensation cure) and platinum-cure (addition cure) silicone mold making rubbers?
- Do you have a rubber that is food safe for casting chocolate and other food items?
- What type of clay should I use?
- How many castings can I expect to get out of my rubber mold before it becomes unusable?
- How long can I store my rubber mold in a "mold library"?
- Can a rubber mold that has torn in production be repaired?
- How do I release silicone from silicone?
- What is the best method for mixing mold rubber?
- I am making a mold for the first time. Do I need a sealer or release agent?
- Will wood surfaces cause silicone cure inhibition?
- My silicone rubber mold did not cure against my SLA 3D printed model - what went wrong?
- What variables will help determine which mold rubber is right for my candle making project?
- What is "cure inhibition"?
- How can I make my Mold Max tin silicone rubber cure faster?
- How should I store my rubber mold?
- Is there a way around investing in a vacuum pump and vacuum chamber?
- How do I decide which method (pour-on vs brush-on) is best for my project?
- I recently obtained a vacuum chamber and pump to get the air out of my silicone rubber. When I vacuum the material (after mixing Parts A + B), my silicone takes forever to de-air and I still end up with some bubbles in my silicone rubber. Is this normal?
- How do I build a mold box and what materials should I use to build it?
- I attempted to add new rubber to an already cured urethane rubber mold and the new layer delaminated. What happened and how can I get the rubber to stick?
- How do I release urethane from urethane?
- How many square feet (meters) will a unit of brush-on mold rubber cover?
- Why does my brush-on rubber run off of my model when I apply it?
- I have a vacuum pump and chamber, but mostly use urethane rubber that I do not vacuum. Is there any advantage to vacuuming my urethane rubber before pouring?
- Can I grind up old silicone and add it to new silicone?
Casting Questions
- How can I avoid bubbles in my casting?
- What paint should I use and how can I make paint stick to my resin castings?
- How do I enlarge or shrink a casting?
- Are any Smooth-On urethane or epoxy resins “UV Stable”?
- What is the best release agent for releasing concrete from a rubber mold?
- Which Smooth-On materials are aquarium safe?
- Frequently Asked Questions about Foam
- What is pressure casting? Will it completely eliminate bubbles from my plastic casting?
- How do I remove release agent from my cured urethane casting if I want to prime or paint the casting?
- How can I make my casting look like metal?
- What kind of fillers can I mix into Smooth-Cast resins?
- How can I make my casting look like marble?
- How do I polish Crystal Clear or other urethane plastics?
- What is the best way to sand/polish Epoxacast 690 Clear Epoxy to a high gloss finish when making a tabletop?
- How long will a casting, mask or sculpture made out of silicone rubber last?
- Is there a way to improve surface finish when casting a rigid or flexible foam?
- My Smooth-On plastic castings are partially cured and are exuding an oil. What is the cause?
- My urethane foam did not rise as expected (collapsed). What happened?
- Does it matter whether I mix Foam-iT! or FlexFoam-iT! liquid castable foams by hand or use drill mixing?
- How do I paint fully cured Foam-iT! rigid foam and FlexFoam-iT! flexible foam?
- I am looking for "iso foam"; is this something that Smooth-On makes?
- How flexible are FlexFoam-iT! foams?
- Are Foam-iT! rigid foams "closed cell" or "open cell"?
- Are Foam-iT! and FlexFoam-iT! "water-blown" foams or "solvent-blown" foams?
- What makes Foam-iT! and FlexFoam-iT! foams different from other foams?
- What does the number associated with each foam represent?
- What types of foam does Smooth-On offer?
- What material should I use for making prop weapons like a fake knife?
- Can my epoxy part be used outdoors for exterior applications?
- How long should I keep a material under pressure when pressure casting?
- What is rotational casting? Are some resins better for rotational casting than others?
Lifecasting Questions
- How do I choose between Body Double silicone and Alja-Safe alginate for lifecasting?
- Can I cast hot wax into an Alja-Safe alginate mold?
- How much Body Double silicone do I need?
- Is there latex in Body Double?
- How much Accu-Cast alginate do I need?
- Which Accu-Cast alginate should I use?
- How long does Accu-Cast alginate take to cure?
- What is the shelf life of Accu-Cast alginate?
- How do I clean up Accu-Cast alginate?
- How do you mix Accu-Cast alginate?
Skin FX Questions
- Are tin-cured silicones skin safe?
- What materials do I need to create a Silicone Gel-Filled Appliance?
- How can I keep from sweating Skin Tite off?
- How do I make Skin Tite appliances less tacky?
- Do I need to put release cream on body hair when using Skin Tite?
- How do I make paint stick to platinum silicone?
- How do I make a silicone baby doll?
Forton GFRC Questions
- How Can I Eliminate Surface Voids in Concrete?
- How much does GFRC weigh?
- What is plasticizer?
- What is GFRC?
- Is the type of sand used in GFRC important?
- I currently manufacture fiberglass (FRP). Can I use the same glass fiber for GFRC?
- What is the difference between Spray-Up and Premix?
- How thick is GFRC?
- What is the curing procedure of GFRC?
- Is Forton VF-774 a plasticizer?
- What type of cement is used in GFRC?
- Can I use any polymer in my GFRC?
- Are air entraining agents required in GFRC for freeze-thaw resistance?
- When comparing the cost of polymers, can I just look at cost/lb of material?
- Why do I need polymer in my GFRC?
- I read a lot about defoamer used in GFRC. Do I need defoamer with VF-774?
- If I want to produce GFRC, do I need to invest in expensive equipment?
- What are common applications for GFRC?
- What are the benefits of GFRC?
Forton FMG Questions
- What is FMG?
- Can I use any gypsum plaster for FMG?
- What are the set, demolding and curing times for FMG?
- What type of glass fiber is used in FMG?
- Is the Hardener added for additional strength?
- What colors and finishes are possible with FMG?
- Can I use Forton VF-774 in FMG?
- What are the benefits of FMG?
- Can FMG be patched?
- What are common applications for FMG?
- How is FMG Produced?
- How thick is FMG?
- What polymer is used in FMG?
- How much does FMG weigh?