Squigie wrote:Pmullen503 wrote:Over foam (which is the subject of this thread) the soft substrate can't provide the support the epoxy/glass needs to prevent damage to the epoxy/glass matrix from impacts. You really need a pretty heavy epoxy/glass layer to be able to support itself from impact damage.
And you expect newspaper and modge podge to be better?

I didn't say that paper would be better than fiberglass. I said that a flexible covering like canvas saturated with paint would be my prefered covering over foam. Could you use fiberglass/epoxy? Absolutely.
I do have many years experience in RC aircraft where paper and some adhesive (WBPU, glue or mod podge) has been used by many people including myself, for covering foam wings. Ounce for ounce, it works better than fiberglass/epoxy. But in that area, less weight for a given tensile strength is paramount. Puncture resistance is not really considered because weight wise, it's too expensive. It's something you live with.
I was referring to the OP's idea of using newsprint over foam. That is a viable option to provide the needed tensile strength. But the weight of the covering is less important on a camper, it's a much smaller percentage of the total. Puncture/damage resistance however, is very important in a camper. That why I suggested at least two layers of a much heavier paper. Specifically, Kraft paper which because it is unbleached, is stronger than bleached papers (like newsprint).
This also fits the Foamy "ethos" which is fast, inexpensive and accessible to people without extensive fabrication experience and tools.