How to build a tough, buoyant canoe

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duncan
Posts: 17
Joined: Sat Oct 09, 2004 12:21 pm
Location: Halifax, Nova Scotia

How to build a tough, buoyant canoe

Post by duncan » Mon Sep 11, 2006 9:18 pm

Hello all,

I have been following this forum regularly for a couple years now, and am hoping that I will soon have the tools, the materials and most of all the space to start my own project.

I am looking at a 16' prospector, I have paddled prospectors before and have been consistently impressed by their responsiveness and capacity for gear but most of all for their ability to handle adverse conditions both in rivers and lakes. I have never paddled a wood/fibreglass canoe.

Now for the questions.
1) How buoyant is a wood/fibreglass canoe? Do they compare more closely to royalex or are they anything like wood/canvas canoes? Is there anything that can be done in the construction to improve buoyancy short of chambers built in? (Of course I am referring to buoyancy when swamped).

2) What is the best way to build in a) abrasion resistance, b) impact resistance.

I don't plan abuse any canoe, but I suspect I may find myself swimming unintentionally from time to time and would be heartbroken if I broke my canoe worse than I could fix it.

This forum is amazing, I look forward to asking many questions here...

Duncan in Halifax

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Erik, Belgium
Posts: 344
Joined: Fri May 14, 2004 5:31 am
Location: Gierle, Belgium
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Post by Erik, Belgium » Tue Sep 12, 2006 3:05 am

Jim Dodd has built in airchambers in lots of his canoes, I hope he can comment on this and will post some pics here.

Erik, Belgium.

Rick
Posts: 727
Joined: Thu May 27, 2004 9:23 am
Location: Bancroft, Ontario

Post by Rick » Tue Sep 12, 2006 8:09 am

Duncan,

:thinking

Hmmmm, according to some very rough calculations, the Huron that I built should displace at least 80 pounds of water when submerged... it weighs 53 pounds, so there's some extra margin in terms of flotation. I suppose a very heavily-built stripper could sink, however, most of them should float. Once you have your stripper totally waterfproofed with varnish, it shouldn't hurt to submerge it to see just what happens.

Abrasion resistance can be increased by appying a graphite-epoxy mix to the hull's bottom like described in Canoecraft, or graphite and silica in epoxy for a harder surface. Abrasion often occurs under the stems and extra layers of fiberglass can be added there to help prevent wear. The entire hull bottom can have an extra layer of glass applied to act as a wear barrier to help prevent rocks from penetrating into the wood. Several coats of good-quality paint also act like a thick layer of gelcoat, helping prevent rocks from wearing away the fiberglass underneath. A well-painted exterior on a stripper looks very good, IMO, and it's my preferred way of protecting against abrasion along with extra fiberglass.

Increased hull strength for greater impact resistance can be had by applying extra layers of fiberglass over the hull's bottom, inside and out. The inner layer is needed for impacts because this is the fiberglass that provides tensile strength when a blow from a rock or log under the canoe bends the hull inward.

Don't worry too much about repairing your canoe when damage occurs, since you've built it, you'll know how to fix it... there are repair methods described in Canoecraft, good luck!

Oshan OkaPini
Posts: 19
Joined: Wed Jun 01, 2005 6:57 am
Location: Jackson, Mississippi

Floatability

Post by Oshan OkaPini » Thu Sep 14, 2006 12:55 pm

Although it sits very low in the water, my Freedom 17 will float on its own when full swamped. The dry-weight is right at 60 pounds with no floatation chambers.

Norman in MS
Right now, there is no cure.

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Jim Dodd
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Joined: Wed Feb 08, 2006 11:08 pm
Location: Iowa

Post by Jim Dodd » Thu Sep 14, 2006 10:32 pm

Hi Duncan
Years ago we tipped a tandem stripper, without floatation.
It floated with the gunnels just above the water.
We then tried to get into it, and it went down and slowly returned to the surface when we got out.
This would not be a good thing on a river during high Spring water!
After that all my boats have been built with floatation chambers!
Do yourself, and your relatives a favor, build your canoes with floatation chambers, or the like!
I use the David Hazen method as described in his book," The Stripper's Guide to Canoe Building".
Good luck!
Jim
Keep your paddle wet and your seat dry!

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