Rigid Foam Casting Tips

In this tutorial we explain the basics of casting polyurethane foam into a silicone mold and tips for getting good skins and minimal cleanup.
This video explains how to calculate how much foam to use to produce consistent parts and how to generate back pressure to get good skin on your cast foam parts.
Get Rigid Casting Foam here: bjbmaterials.c...

[@lordronin593]

Thanks for the information, I have cast a lot in PU but not yet in foam, so this is very useful. One general tip that might be of interest: weigh an empty cup and then a cup with the leftover after mixing and pouring, to get an impression of how much is left over. This is a way to get better in mixing the right amount, as sometimes you lose more than you'd expect, but overcompensation is just a waste of material. :)

[@brickintheyard]

Great tip!

[@spotoncam3640]

Thanks for sharing. The compression method ensures minimal waste too ❤

[@brickintheyard]

Yes indeed!

[@kapitanleutnant1]

This will be helpful when I fill the beach ball with the mixture of that kind of foam to create the head of a home made DIY life size nutcracker for a Christmas decoration

[@lupusk9productions]

excellent tutorial thank you!

[@brickintheyard]

You are welcome!

[@jimji2774]

Really nice video thank you.

[@brickintheyard]

Thanks for watching!

[@rajkumargiri5789]

How did you made hard pink sides of mold? I think did you used white cement coats? And stain is wooden ?? Plz reply

[@dhanusha223]

Very nice

[@brickintheyard]

Thanks!

[@STUNTMANIAAFRICA]

wow great job

[@brickintheyard]

Thanks!

[@michelllerobison843]

Can you cast in a latex mold? What would you use for a release? If you cast in a plastic mold, would you need release?

[@brickintheyard]

I have not tried to cast foam into a latex mold. We have some customers that do, but painting is tricky because the release required is difficult to clean off the cast parts. Our E236 could be used as a release, but the part will be VERY difficult to paint unless the part is thoroughly washed.

[@misc328]

How much lifespan does a rigid polyfoam structure have you think? I purchased a display piece that is 30 years old and I’m worried about its longevity, even though it seems fine now

[@brickintheyard]

Rigid foam that is painted will last many decades. UV damage is the ultimate destroyer of all things synthetic so watch out for that!

[@Gatorraider]

I'm getting hard brown plasticy areas in my cast. Any help?

[@beefan1596]

How effective would this be at lost foam casting?

[@brickintheyard]

@@beefan1596 I have not tried it, but I remember hearing some of my customers doing it with 3lb rigid foam.

[@beefan1596]

​@@brickintheyard Thank you for your time, and the wonderful video. I will have to watch your previous videos on mold making, as this one turned out perfectly, at least to my eyes. Is there any solvent that would dissolve this material? Polyurethane chars, or so I've heard, so it may leave residue when burnt out - I can imagine something along the lines of acetone would leave little to no residue.

[@LongTrout]

fill you mold with water, measure and write with permanent marker the volume of mold.

[@brickintheyard]

Just be sure to dry out the mold really well before casting!

[@JeremyMcKinney1979]

How rigid is the foam and what kind of buoyancy does it have

[@brickintheyard]

This foam is very rigid, like wood. I have not used it for flotation so that is uncharted territory for me!

[@sindrome303]

Could these PU foam heads be turned into metal with green sand casting?

[@brickintheyard]

I have not tried that. That is uncharted territory.

[@sindrome303]

This requires further investigation would make a great Video and you would be a first of its kind. One green sand, and One ceramic coating in regular sand. The heads in this Video would be amazing if the where cast alloy.@@brickintheyard

[@SaintAngerFTW]

What is the lifespan of the silicone mold for rigid casting foam?

[@brickintheyard]

This mold has been in use for several years and used to cast resins and foams. If a mold is made properly it will produce lots of parts and last many years. The quality of the silicone and the casting material will determine the lifespan.

[@Greyboa45]

What product was this mother mold made of? Thanks

[@brickintheyard]

That is our ArtKast Brushable resin.

[@TheRomell24]

will this work on 4 foot statue?

[@TheRomell24]

​ @bitymoldsupply

[@brickintheyard]

Yes, we have customers casting large pieces with this foam. That said, mold construction, configuration, and skill are a big part of that process!

[@othername1000]

Are any of your forms closed cell for watercraft?

[@brickintheyard]

Self-skinning foams, like 6# Rigid Foam, are closed cell. We supply this formula for a wide variety of applications. I have not personally used this for watercraft but I suppose it could be used that way.

[@shawnmurray7232]

One GLARING error.... 6lb foam is always going to be 6lb foam, it doesn't reduce weight & become 4lb or 5lb foam. I think what you meant to say is through restriction in the mold, it may fill the same volume (not density) as 5lb or 4lb foam.

[@brickintheyard]

6lb foam can increase in density if restricted by the shape of the mold.

[@balua9]

That makes sense - but if you increase the density it would increase from 6 lbs/ft^3 to 7-8 lbs/ft^3 (because you have the same weight of material in a smaller volume).

[@surindergujjar1482]

Could these components be painted? Or may we use any kind of pigment to add in casting process

[@brickintheyard]

Our rigid foam can be painted once cured. Any release agent will need to be washed off. I use Rustoleum primer or Prime-it primer before painting.

[@Rob-fn1kp]

Couldn't you just pour water in the mould before hand? and measure? to get your foam requirement?

[@brickintheyard]

Water is a contaminant for polyurethane and difficult to completely dry out if complicated molds.