You can make pitch by burning certain woods like pine and collecting the stuff that drips from the fire. Also, maybe I’ve been particularly lucky, but I’ve foun

You can make pitch by burning certain woods like pine and collecting the stuff that drips from the fire. Also, maybe I’ve been particularly lucky, but I’ve found bituminous deposits in the wild before that would probably be usable. Barring that, tree sap or beeswax would also be very useful for sealing.