This is one of those queries regarding techniques/processes for lightweight building.
I'm currently building a racing craft and a mate of mine is building a hollow timber surfboard. His plans don't call for any use of epoxy to seal internally and he intends to seal the inside surfaces by either painting or using a couple of coats of penetrating oil such as penetrol.
If an internal surface needs to be sealed against water ingress but structural strength is not an issue, would a penetrating oil be a lightweight (and cheaper) alternative to a coat of expoxy?
Thougts anybody??
cheers