I have been searching for this answer on here but haven’t found it. I’m sure it’s on here so I must not be using the right words.
What is the best foam for making molds? I have seen everything from 2 part polyurethane to the green stuff that florists use. Is there a breakdown on here that lists this?
Any help would be useful and may I add that my CF vocabulary is still pretty small.
Bit of a broad question I think. What is your application?
Well, I’m just getting started so maybe something like an air cleaner mount. Simple but essential. Eventually, a basic shaped valve cover. It’s for an older car so they aren’t like the new stuff.
Heavier pour foams work well for mold rigidity and backing, but you still need a mold surface that is non porous and smooth. You want your mold surface to be either gelcoat backed with fiberglass using polyester or epoxy, or you can even use a softer polyurethane material, which can then be backed with a heavy (such as 16lb) pour foam.
Why do you want to use foam rather than fibreglass?
Idk…Are you saying that I could just layup some fiberglass to make a mold out of? Just applying it to the inside of my part? I guess I just never thought of making my mold out of fiberglass. Sounds just as reasonable as anything else I guess. As a design engineer, I kinda over think things.
Lots of mold making tutorials and info here, but it really depends on the part you are making, how many you intend to produce, and the finish product requirements.
what does the part look like?
I would use the foam to make a splash of the part you want to make then make the mold off that. Foam is very delicate and can crush very easily. if you want to use the foam i would recommend coating it with resin to give your foam a little bit more rigidity.