Foam for sculpting fiberglass (rollpan)

[Larry Phillips]

Where would I get a block of foam similar to what Black Magic used to shape into a rollpan for a mold? What kind of foam would it be?

 

[Chops]

I have seen it at most of the fabric and upholstery stores here.

 

[Larry Phillips]

Do they sell them in big enough blocks to sculpt an entire rear valence?

 

[Chops]

I've seen HUGE blocks of that stuff, but it probably is according to demand. I don't think you'll have too much trouble finding it.

 

[Boodrodon Dykes]

Larry, a lot of time it is spray foam. You spray it on the desire place, then shave and shape. of course underneath u tape it off, and put a release agent for after shapeing. then fiberglass over it to make stronger.





boodro

 

[Richard L]

Look under "Surfboard Supplies" or "Fiberglass Supplies". They sell the correct type of foam for shaping and covering with fiberglass. Upolstery foam is too soft and rubbery. You need a rigid foam for bodywork.



PS: It is rather pricey, so don't say I didn't warn you.



...Rich

 

[Chops]

I'm talking about rigid white styrofoam, not spongy cell seating foam, styrofoam is sold around here in blocks.

 

[Richard L]

Chops,

Fiberglass resin will disolve styrofoam used in upolstry and for wall insualtion. I know because I have tried them. There are many closed cell foams that will work and there are many that will not work. The problem is that we tend to call them all Styrofoam, which they are not.



If you buy from a Surfboard or Fiberglass supplier you will get a choice of foams in different sizes with different properties, but they are all designed to work with fiberglass.



...Rich

 

[Chops]

I thought I saw a video of a person mocking up one, and they put a barrier-plastic over the foam to keep it intact. I haven't tried it though.

 

[Richard L]

Chops,

That may be true only if they don't want the fiberglass to stick to the foam so they can removed the foam later. I think it may depend on if you are making a custome piece or using the foam to make a fiberglass mold. You can then use the inside of the first molded fiberglass piece as a negative mold to make the finsihed fiberglass piece.



...Rich

 

[Matt Gerling]

The foam I used was a two part liquid you mixed and it expanded into the shape of the box I used. I got it from my local fiberglass supplier. Polyurethane Foam.



Wanna trade me making a follpan for your black head lights/corners?

 

[Larry Phillips]

I definately would, but I've still got the factory chrome headlights, and they're pretty nasty. They're yellowing and full of moisture.

 

[Matt Gerling]

Oh, I was thinking you had a set of the black heads/corners. Sorry. Yea, use the 2 part Polyurethane foam, then make a box bigger than you need to shave into shape. Use rasps and sanders to get your desired shape. Then you can use Fiberglass to make the shape and either make a plug to pull a mold as I did or just build that one part and break out all of the foam when you are finished and sand smooth the inside.