What do i need to use as a frame for fiber gling?

wood should work just fine.... I've done it hundreds of times.... The amount it expands is minimal.... Cardboard works great too.... if you need to sculpt something with foam, put wax paper over it... What you may need is a high density foam Don't know what it's called (the yellow foam mentioned previously).... Like the same foam that comes out of the cans of spray expandable foam for insulation.... sorry don't know the name of it....