do not use the home depot resin. that stuff will fall apart and desentigrate. use epoxy and vinylester resin not polyester. also you do not want to use foam underneath fiberglass for a final product. you can make a plug with it. also just fyi to make a good mold for stuff like that it takes alot of work and time and can cost in the upwards of 500 to a grand for a good mold. side skirts would be very easy but bumpers. making them from scratch would be a [censored].
