Molding Question

**Ryven** · 01-16-2011, 05:25 AM

I'm looking to do a custom in-dash car PC and want to make sure not to screw up and end up designing the exterior around the components I put behind it. What I want to do is find a way to fit as large an object as possible in the dash area (something that can easily be reduced in size) so I can create a fiberglass shell that I can use for a space reference without constant fit testing.

I was thinking of using a styrofoam block that I can easily cut away or simply crush down (like hobby styrofoam) into the shape I need. My concern with that was the mess. Is there by chance an expanding foam I could use for this task? Otherwise, does anyone else have any suggestions?

**soundman98** · 01-16-2011, 12:07 PM

you can use foam like this: http://greatstuff.dow.com/

but once it hardens, it will be just as messy to cut as the normal pink foam..

**PhilG** · 01-16-2011, 12:15 PM

I would suggest using the green foam used in floral arranging; trim it to the max size of the interior space you have to work with then do a FG mold off the outside.
Cover the foam in foil tape or similar and wax it up. You then might even be able to pull the mold without having to dig the foam out of the inside.

**djvillar** · 01-17-2011, 11:45 AM

Go with Greene block. Greatstuff will expand and spill all over. Also, it's like sludge so you'll have to spray a bit, wait for it to harden. Spray again, wait... Spray again...

I guess maybe a mix of both method might be best. Tape it all off inside and surrounding areas. Rough block it out with the green stuff. Then work the tube from Greatstuff in the back, spray a bit to fill in the voids/gaps, then a bit in the front to match the surrounding dash opening. Pop that sucker out and glass it to get your container... Done.