expanding foam with fibreglass

[wolfie]

I'm making a new dashboard for my gold convertible and the plan was to use expanding foam and cardboard to sculpt it and then use fibreglass over it to form the actual structure. Is anyone on here a bit of a fibreglass guru as I'm wondering whether the expanding foam and resin will react with each other in any way?

[Hans Efde]

Interesting, I am thinking the same way since it seems the LHD Rover 200 moulds have gone forever. I've seen a similar procedure on "Overhaulin" where Chip Foose attacks a Lotus Europa (2 hours special), maybe worth finding on Youtube. I have it on my DVR recorder so can check if you want but recall no problems with these materials when they did the dash and doorcards.

[streetsy]

I have used expanded foam insulation in the past to make things, waxed it to form a barrier then fibreglassed over it. The foam can then be dissolved with acetone. That was on smaller items though, air boxes, etc. Alistair, proprietor of Midas cars, may be a good person to speak to, he may be able to supply a dash or advice.

[justamin]

I expect you have already done this project by now, but there is another technique which may be of interest. You can use ordinary expanded polystyrene as a former. As there is so much of the stuff used for packing, you may be able to find some pretty interesting shapes to build on. Once you have made your blank, cover it with several coats of a water-based emulsion to act as a barrier from the resin. Then lay-up as normal. I think this is used on surf boards!