I shaped too far, how thin is too thin?

[Brian]

I am currently building a hiawatha. While shaping the hull I got pretty thin in a spot. There is a 4 inch by 10 inch section which is probably consistently under an eighth. I have not shaped through in any spots but that one section is pretty thin. I guess my biggest concern is from a structural standpoint. I dont know whether or not I should reinforce the inside some how maybe with a heavier clothe or if I should just be careful proceed as planned and hope for the best. Please help.

[Guest]

Hi Brian
On my last canoe because of some rather extreme tumblehome I started out with thin strips. My concern was the same as yours. After applying the 6oz cloth I applied a 27' wide piece of 4oz cloth the length of the boat inside and outside. I scraped the overlap flush with a scraper and proceeded with the rest of the epoxy coats. Can't even see where the cloth overlaps. So far so good. On the bottom I think I was under 1/8" but with the extra glass I think its plenty strong.
Dave

[Rick in PenderH]

I have a spot in a 4 year old wee lassie (my first) where when you hold it up to the light you can see through it.... Boat is just about 4 years old, has been used year-round and mostly stored outside..
also a veteran of two Bowron lake trips, 4 day and 6 day, and many miles on top of the car. still in one piece, still drives me crazy every time I lift onto the car... An eighth inch of wood and glass is probably still stronger than you think.

[Peter Hyde]

I think it was in the Gugeon brothers book that I read the wood is like a skeleton. It is only there to give the required shape to the epoxy and fibreglass and in fact adds little to the strength.

[Jeff in Pembroke]

Hi Brian
On my last canoe because of some rather extreme tumblehome I started out with thin strips. My concern was the same as yours. After applying the 6oz cloth I applied a 27' wide piece of 4oz cloth the length of the boat inside and outside. I scraped the overlap flush with a scraper and proceeded with the rest of the epoxy coats. Can't even see where the cloth overlaps. So far so good. On the bottom I think I was under 1/8" but with the extra glass I think its plenty strong.
Dave

I did something similar with my canoe. Excess fairing wasn't a problem, the hull was still thick enough, but I wanted to increase the strength of the hull. I put one layer of 4 oz cloth on the inside of the hull up to the 6" waterline. I then put a second layer of 4 oz cloth over the whole interior. I wet out both layers at the same time with WEST 105/207 and the results were great. The seam is invisible and I didn't find the wet out much more difficult than a single layer of 6 oz. cloth - just a bit more patience for the epoxy to saturate both layers of cloth. If you reinforced the thin area on both sides with a patch of 4 oz cloth uner the 6 oz I don't think you should have any worries about strenth.

Hope this helps,

Jeff

[don]

A friend went right through on his kayak. We cut a design of a shark morphing into a loon out of veneer, stuck it over the hole and glassed it. It looks great and no noticable diference in strength.
good luck
don