Boat Building Forum

Find advice on all aspects of building your own kayak, canoe or any lightweight boats

Additions, corrections and clarifications
By:Paul Jacobson
Date: 7/4/1998, 10:25 pm
In Response To: Re: How do you paint #10 cotton duck? (Paul Jacobson)

> Wooden Boat magazine for this month (June/July? 1998) has an
> article on canoe builders which covers their method for filling the
> weave on cotton duck, and gives some formula for their base coat.

To be more accurate: this is issue number 143 of WoodenBoat. The cover of the magazine says August, but the pages say July/August 1998. The article is part 3 of a three part series, and titled Build a Cedar-and-Canvas Canoe, part 3 covering, finishing, and final detailing. Text and photographs by Jerry Stelmok. The article begins on page 66. If you want to get a photocopy, the portion pertaining to covering the canvas is completely covered on page 71. Check your local library.

According to the tag at the end of the article, Stelmok is the author of ``Building the Maine Guide Canoe'', and co-author (with Rollin Thurlow) of ``The Wood Guide Canoe''. Stelmok has a shop, Island Falls Canoe in Atkinson ME, and Thurlow is listed as a supplier of canoe building supplies at Northwoods Canoe Co, 356 Range Rd., Atkinson ME. 04426

Northwoods has an ad at the end of the magazine, offering a catalog for $1. Their order phone number is 888-564-2710 and their fax number is 207-564-3667 I think the 888 number is an extension of the 800 numbers, and should be a free call from inside the continental U.S.

A box in the story says a complete list of suppliers is available from The Wooden Canoe Heritage Association, P.O. Box 226, Blue Mountain Lake, NY 12812

Also listed as suppliers are: The Tender Craft Boat Shop, Inc. 284 Brock Ave. Toronto, ON, M6K 2M4 Canada


William Clements Boatbuilder P.O. Box 87 North Billerica, MA 01862-0087

By the way, this is the same magazine that has a nice picture of George Roberts doing a roll.

> Their approach seemed to be similar to that proposed by George Putz
> in his book on canvas covered craft. Both use an oil based paint that
> is significantly modified with filler materials and added driers.
> Putz uses ground chalk and the WBM article mentions silica (finely
> ground sand) for fillers.

If you haven't read Putz's book you are missing out on a light-hearted, but remarkably complete discussion of these topics, in a very readable format. It may take a while for the tongue-in-cheek humor to become evident. For example, there is a caption describing a scruffy-looking character holding a part. The person photographed is apparently the author, in work clothes and an old hat. Putz is building Greenland style kayaks, so he may be your best first reference.

The WBM article mentions using about 3 quarts on the first coat, which would be a very thick coat. Putz uses less, and suggests not worrying about putting a lot of paint on at first. His rationale is that you will be putting on a fresh coat or two each year anyhow, so let the finish improve over the years.

Stelmok adds white lead, and Putz adds a fungicide (from the garden department). These are supposed to soak into the fabric to prevent mildew damage and rot. I have no doubt that they work, but I'm not comfortable with either. A bit too toxic for my liking. I'd rather risk the rot, and replace the canvas every 10 years than get myself sick.

A couple of other thoughts on this mildew issue, though: A:) A letter in this same edition of WBM suggests using a thinned linseed oil as a primer, to soak into and waterproof plywood. I may try test that idea on a scrap of canvas and see if it saturates and seals the fibers. I also want to see if the stuff will dry and not stay oily. B:) Since I am going to spritz the canvas with water to shrink it tighter before I paint it, I might mix some mildew-cide or fungicide in that water. I would feel better knowing those chemicals has soaked into the fabric, and were completely covered by the paint, and not likely to leach out and get me sick. C:) I have read interesting things about using auto antifreeze (ethylene glycol) to kill rot and mildew. You would need to drink a lot (about 8 ounces) to get really sick from it. I'd feel comfortable spraying a light mist of that stuff inside the boat every few years if I saw any problems. Besides, it is not too expensive, and I usually have some around the house. D:) I don't completely buy Putz's reasoning for mixing the fungicide with the paint. Seems to me that stuff is water soluble, and he is adding it to oil based paint. Once it is covered with the paint, how is it going to protect the canvas? Is some of it supposed to disolve out of the paint film and soak into the canvas? That doesn't make sense to me. E:) Thompson's Water Seal, or the house-brand equivalents, seem to be good products for waterproofing canvas. I've thought of using this for an inside coat. They have worked well on my tent for years. F:)Most of these items I can apply to the very tip of my kayak using a common garden sprayer. The wand on those things is 2 feet long, or more, making it easy to direct the spray all the way to the bow, or stern. All in all, I don't think I'll mix the fungicide in with canvas filler. It will go on either before the paint, or after it.

> Of the two processes, I think the method described in WBM is
> stiffer. It might be great for canoes, which have a lot of wood behind
> the fabric, but I think it would crack on a kayak, which tends to
> have more flexible fabric.

This goes back to the amount of material put on.

Well, you get a bunch of additional facts, and some additional opinion. Hope it helps.

Paul Jacobson

Messages In This Thread

How do you paint #10 cotton duck?
Duane Strosaker -- 7/4/1998, 12:27 pm
Re: How do you paint #10 cotton duck?
jim champoux -- 7/8/1998, 9:20 am
Re: How do you paint #10 cotton duck?
Mark Kanzler -- 7/8/1998, 10:26 pm
Re: How do you paint #10 cotton duck?
Bram van der Sluys -- 7/4/1998, 2:26 pm
Re: How do you paint #10 cotton duck?
Paul Jacobson -- 7/4/1998, 1:17 am
Re: How do you paint #10 cotton duck?
Roger Tulk -- 7/5/1998, 11:01 am
Additions, corrections and clarifications
Paul Jacobson -- 7/4/1998, 10:25 pm