how many layers of fiberglass

so im fiberglassing a 94 bumper to fit my car but how many layers do i need for it to be sturdey and stable

I'd say make it at least as think that the bumper is already, if not thicker.

It dependson the material type you are using and the weight of the material. 4oz woven cloth (the fiberglass cloth comonly found at parts stores) would take probalby 10 layers were as 20oz Woven Roven would take about 2 layers. Fiberglass mat (also commonly found at parts stores) would take probably 6 layers.