What natural resins could be used instead of fibreglass resin to build a boat?

Question

I want to try to build a non-toxic boat. I am hoping to use canvas and laminate it over a positive mold using a non-chemical resin. Problem is:
I don't know if there are any, and all the boating companies are looking at me funny when I ask. Does anyone have any ideas?
Thanks.

Answer 1

Four come to mind. One is pine pitch, which was used by the American Indians to seal seams on birch bark canoes (sewn with tree rootlets.) Another is chicle, the chewy stuff from South America that chewing gum is made of. A third is natural latex, also from South America. The fourth is natural latex of a different species (but it should work pretty much the same), found in dandelions and goldenrod.

My suggestion is to contact turpentine manufacturers. Turps are made from the destructive distillation of pine, and there should be some waste left over. They can tell you whether it is sticky or gummy enough to be used as a sealant.

Oh, and I almost forgot: linseed oil. It hardens in the sunlight (some people say it polymerizes.) I know it can be used to preserve wood, like tool handles, and seal the pores in thin, fine linen or coarse paper to make into kites. I don't know whether it would be waterproof. I suppose you could get some and test it. Linseed oil can be found in many hardware stores and art supply stores.

Answer 2

Complete Boat Building Guide - http://BoatPlans.NaturallyGo.com/?XqU

Answer 3

Pine tar

Answer 4

Maybe latex? I don't think shellac would hold up to the water over time.