Fiberglassing Dilema

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Tom Friedel
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Joined: Sun Apr 09, 2006 8:45 pm

Fiberglassing Dilema

Post by Tom Friedel »

I am building a 15 ft Prospector and am up to the fiberglassing stage. I live in Sydney,Australia, and so far have only been able to find fiber cloth 1 meter (ie 39 inches) wide....as opposed to the 60 inch wide cloth specified in the Bear Mountain design. Obviously, I can therefore not cover the hull (or the inside ) of the canoe with one piece of cloth.
I therefore have two options :
1. I apply two strips of cloth longitudinally, one on either side of the hull (or inside) canoe, with an overlap of the colth down the keel line of the canoe, or
2. Apply the cloth in strips transversely around the canoe ( bit like applying a bandage!), and have a slight overlap for each of the strips
I have not built a canoe before, nor had any experience in fiber glassing, My concern about approach no 1 would be compromising the strength, while with approach no 2 it would be the visual effect of having at least 5 strips of cloth applied (with a small overlap) transversely.
I would appreciate any comments and advice as to the best solution to this problem ; maybe there is also another option I have not thought of
With thanks
Tom Friedel :confused
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Glen Smith
Posts: 3719
Joined: Sat May 08, 2004 9:08 am
Location: Baie-St-Paul, Quebec, Canada

Post by Glen Smith »

I would overlap the cloth along the keel line. On the exterior, leave a few inches overhanging each side of the sheerline and then whatever excess there is at the keelline would be overlapped. When you apply the epoxy, I would fold back the excess of one side and wet the first layer of cloth then carefully unfold the excess over it and wetout that. This will add strength to the hull bottom. Do the same for the interior but reduce the width of the overlap to just one or two inches. Again, wetout just one layer at a time to avoid bubbles, unfold second layer over top of first layer and wetout that layer.

Another possible method is to butt the two pieces along the keelline then add another piece a few inches wide over top the joint. This piece can come from what you cut off along the sheerline. Neither method will compromise the strength but you must be careful when you "feather" in the overlapped edges at time of sanding so you don't cut through the main layer of cloth.
John K
Posts: 18
Joined: Tue Jul 13, 2004 5:46 pm
Location: Tasmania

Post by John K »

Hi Tom,
Put the fibreglass on in the length and overlap along the keel line 10 mm each. Then you get a 20 mm rubbing strip in the area most likely to be worn down. After the epoxy hardens you can feather it in by sanding. It will hardly be visible and will strengthen your keel line.
JohnK
Tasmania
John K
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Jim Dodd
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Joined: Wed Feb 08, 2006 11:08 pm
Location: Iowa

Post by Jim Dodd »

The only problem I see with using the two pieces, is you won't get the Bias effect that you can get with 60in cloth.
This really helps the cloth conform to the hull shape, unless the cloth you have is Bias cut.
Good Luck!
Jim
Keep your paddle wet and your seat dry!
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GeirB
Posts: 60
Joined: Thu Oct 21, 2004 7:31 am
Location: Norway
Contact:

Post by GeirB »

I have the same problem in Norway, cloth is 100 or max 120cm wide. I solved the problem with four "stripes" of cloth near the shearline, actually the stripes I cut of on both sides of the stems. See pics on; http://www.kanokajakksiden.info/Bygging%20duk.htm
Text is only in norwegian but the pics speak for themselves.

GeirB
ludwig
Posts: 2
Joined: Tue Mar 14, 2006 10:40 am

Post by ludwig »

For all the Europeans:
You might want to check out www.vonderlinden.de.
They sell cloth (plain weave) 164 cm wide, 160g/m2.
You can download their product list from the website.

No, I don't work for them.


John K posted this hint some weeks ago (how to do a nice and clean cloth overlap)
Have a look at the instructions on this page. they might help:
http://www.oneoceankayaks.com/Wshophtm/Shop23a.htm


Ludwig
Patrick Miller
Posts: 7
Joined: Wed May 12, 2004 3:58 am
Location: New Zealand

Fibre glass cloth problems.

Post by Patrick Miller »

High Tom,
You may have already found the answer to your problem, I haven't checked the forum for a while. However, here is some information that is straight from the professional boat builders.
In New Zealand all the builders seem to use the narrower cloth. For you ,use your cloth either along the hull or crosswise. Overlap the edges. Go to a boat builder or a supplier of materiials and get yourself some " peelply". With this product in place over the eges of your cloth you appye the resin in the normal fashion. When the resin has cured you simple peel off the peelply and you have a perfect invisible join. You can just do a convential overlap but end up with fibreglass strands that need quite a bit of sanding off before more resin coats are applied. Another useful product is called " air tack " which invisibly holds the cloth onto your hull while you do the wetting out. Best of luck.
Patrick.
Patrick H Miller
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