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PostPosted: October 20th, 2009, 12:41 pm 
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Without getting too proprietary a typical H20 all-fibreglass canoe:

- Consistently weighs just under 60 lbs
- Has an outer layer of gelcoat paint, roughly 12lb to 14lb or so.
- Has an outer full glass layer 9oz wt right behind the paint
- Has a heavy base layer or pan of 16oz glass just in the bottom of the boat
- Has roughly ten structural band layers (like a fine felt material) running gunwale to gunwale
- Has an almost equal number of foam stiffeners which sit on the bands, but just about 10" to 16" in width, kind of like speed bumps that are centred in the bottom of the boat
- And has an entire inner layer of 9oz glass.
- followed by a skim coat of gelcoat for interior appearance and durability (about 4 lbs I would guess)

Please note the above information is pretty darn close but may not be spot on, as I am relying on memory, and also is stuff that someone familiar with composite construction can actually determine from a careful inspection of the canoe anyway.

So you get two layers of glass on the sides with structural material between for strength, and three layers of glass on the bottom of the boat with material and foam stiffeners sandwiched between.

In my rather limited knowledge of canoe building, I would guess they could be considered bombproof and heavy, and the only thing keeping them under 60lbs is the fact they are vacuum infused, which compresses the crap out of all the materials before catalysed resin is run through.

Interestingly (luck may have played a part) of the 20 or so fibreglass boats we happened to actually weigh (I have no idea how many of these we produced, 60 or 70 perhaps?) they all came in between 57.5 and 59.5 lbs in the three 16' canoe models we produced. (We did a 15' I think weighed a bit under 55lb)

In the grand scheme though, a sub 60lb 16'6" all fibreglass canoe is pretty damn light compared to all other fibreglass boats on the market.

Here is a blog post with a pic of my own 16' Fibreglass Prospector, and if you click on the pic of the canoe sitting by the takeout, It shows a great deal of detail.

http://theaccidentalcanoeist.blogspot.c ... art-2.html

and (for Erhard) that kid in the picture is my adventurous youngster (Rudi, age 7), who happens to have a dad almost as adventurous (though not as fearless) as he is!


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PostPosted: October 20th, 2009, 10:19 pm 
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Can't say that I know of a 50 pound or less 17' tandem tripping canoe that is gel coated.

Gel coat does intercept UV and it serves as an ablation layer for abrasion, but gelcoat does almost nothing for boat strength, and unless gelcoat is atypically thin, an outer layer of S-glass will weigh less, will abrade less, will make the hull stiffer, and will help the hull resist damaging blows.


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PostPosted: October 20th, 2009, 10:46 pm 
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Location: Missouri, U.S.A
I'm wondering if something like automotive paint could be used instead of gelcoat. I'm not sure how it would compare in weight, but it would be better as far as having less (or no) crack propogation. Cars get dinged up all the time without the paint cracking; can't say the same for gelcoat.


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PostPosted: October 20th, 2009, 11:01 pm 
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For BeenDigging:

From what I know, price. Of all the quality paint available for finishing a product like a canoe, gelcoat is far and away the cheapest. I have heard that years ago in the early days of composite canoe building, other paint was used, but the sheer expense was what caused all major manufacturers to go to gelcoat...

find the wholesale price for 5kg of gelcoat from an industrial supplier ($80?) versus the price of 5kg of high quality paint ($150 to $300?) and you get the idea.

For EZWATER:

That's because you're not from up here, where we like our beer strong, our women curvy, and our canoes painted! If you count a 16-6 as close enough to a 17, the vast majority of Canadian made canoes are painted with gelcoat, and weigh between very high 30's and the low 50's range in lbs (excepting fibreglass only boats). Personally, if two layers of cloth on the sides, and three layers on the bottom is strong enough, I would much rather have a pretty red on white two tone any day!

http://theaccidentalcanoeist.blogspot.c ... h-new.html

shows my gelcoat kevlar standard (full glass outer, kevlar inner, plus foam core and second kevlar layer on full bottom, 16'6, and only 44.5 lbs)


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PostPosted: October 21st, 2009, 1:00 am 
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Been Digging wrote:
I'm wondering if something like automotive paint could be used instead of gelcoat. I'm not sure how it would compare in weight, but it would be better as far as having less (or no) crack propogation. Cars get dinged up all the time without the paint cracking; can't say the same for gelcoat.


Yep, said that earlier in the this thread:

Battenkiller wrote:
Some of the best wood strip builders are sending their boats out to be sprayed with catalyzed poly. They do this for durability, but I see no reason why a skin-coat boat can't get the same treatment and save several pounds while providing a much tougher and more easily repaired surface.


You'd be hard pressed to add 5 kg of catalyzed poly to a canoe hull. From what I'm told, the guys are getting them sprayed for about $100 and it weighs next to nothing when done. That lack of weight buildup - plus the more durable and repairable surface - are the big payoffs.

Convenience is a big reason gel coat is used, that and the lack of a need for talented sprayers. All of the orange peel gets covered up from the inside by the outer layer of cloth. The sheen of a gel coat boat comes directly from the mirror-like polish on the inside of the mold transferring its surface quality onto the finished hull. Plus, there is no extra step once the hull is removed. Trim it out and you're done.

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PostPosted: October 24th, 2009, 12:12 pm 
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davidchiles, I have a Bluewater Chippewa, 16' 10", with more layers in the bottom and sides, and just a thin layer of green epoxy on the outside, no gelcoat. It is 16' deep in the center and weighs 48 pounds.

I accept your weight claim for your H2O, but first, I wonder if you DID use gelcoat, and if you did, maybe that's the reason you didn't get more than two layers in the sides.

I would welcome more examples of 17', or even 16'6" tripping tandems that genuinely use gelcoat and are under 50 pounds. Your report of 44.5 pounds is pretty good, but it's not close enough to 17 feet.

Did someone say gelcoat makes for easier repairs? How? Cosmetically? Not timewise.


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PostPosted: October 24th, 2009, 12:58 pm 
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ezwater wrote:
Did someone say gelcoat makes for easier repairs? How? Cosmetically? Not timewise.


Not me. I said paint is easier to repair. Twice.

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PostPosted: October 24th, 2009, 3:05 pm 
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reply to ezwater:

you're exactly right... with a 10lb+ or so layer of gelcoat, the standard construction seems to be 2 layers up the side sandwiching lightweight structural material, and 3 bottom layers sandwiching a core.

This ends up with kevlar/glass hybrids in the 49 to 56 range, full kevlars in the 43 to 49 range, and carbon boats in the 39 to 44 range (based on 16 adn 16-6 length boats), and this seems to be what scott, swift, H20 and other canadian boats are doing, when they use gelcoat, which is the predominant paint used for canadian boats now.

As far as I can see, 2 side layer / 3 bottom layers of cloth seem to make a canoe strong enough, the question is, depending on type of paint and cost of paint, is it worthwhile to go to a lighter 'paint' rather than the heavier gelcoat....


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PostPosted: October 24th, 2009, 4:03 pm 
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davidchiles wrote:
As far as I can see, 2 side layer / 3 bottom layers of cloth seem to make a canoe strong enough, the question is, depending on type of paint and cost of paint, is it worthwhile to go to a lighter 'paint' rather than the heavier gelcoat....


Do Canadians really all call gel coat "paint", because most folks down here definitely distinguish between the two when discussing them. That may be part of the confusion.

Be that as it may, the cost of paint (or "top coat" if you will) may be higher, but the coverage is vastly greater. Some of the best two-part polyurethanes like Interlux "Perfection" get about 5-600 sq.ft./gal. Yes, a gallon of Perfection will cost you $200 (maybe less by the pallet), but you will get up to 8 sprayed coats out of it - enough to do about four boats with the recommended two coat coverage. That's $50/boat, give or take, for either method.

Something to consider is the extra prep and application time involved with painting, which can far outstrip any differences in the actual cost of materials. Add a couple of extra hours to the time to build each boat and the bean counters at the biggest companies will tell you it just can't be done. In a small custom shop, where they may be only capable of a boat a week, the difference in time means that you are now working a 62 hour week instead of only a 60 hour week. The choice is easier to justify for the small builder, and he can therefore offer a vastly superior boat, both in weight and in durability.

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PostPosted: October 28th, 2009, 8:46 am 
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Location: Lower Saranac Lake, NY
Lamination Schedules

I think it's overly simplistic to focus on two layer sidewalls and three layer bottoms; better to look at total fabric weight and beam thickness.

H2O's two layer sidewalls are 15 oz, their bottom 31 oz. Bell's hand laid Black/Gold has three layer sidewalls, 1 carbon, two kev, that total 16 oz. The bottom totals 36 oz under the paddler not counting spine and belly band.

What material goes where, and why and at what orientation, is another, proprietary, story, but basically we want compression resistant stuff on the outside and high tensile strength stuff on the inside.

Wet bagging doesn't change beam thickness much from hand lamination, but infusion does because the dry plies are compressed before resin is applied, so more fabric layers/ weight are is required.

Placid boatworks StarFires had 50 oz of carbon and Kev in the bottoms and 60 oz under the seats. 15 ft tandem weighs 39 lbs with three seat, infused rails and will be down to 35 lbs when the infused seats come on line with Colden Canoe. Swift, infusing with bottom core and integral rails has their Matawa/ Kipiwa /Algonquian down to 31-32 lbs.


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