please refresh my memory on this...

[boneymachine]

In the spring it will be time to re-do the bow deck. It is plywood and covered with canvas...starting to show cracks in the canvas. I guess the canvas was waterproofed somehow and painted. Now, what purpose does the canvas serve? It will need to be epoxied over the canvas, right? Does the canvas just provide a fiber to make the thing stronger (like the glass fabric in fiberglass)?
Seems like a few layers of good epoxy without the canvas would do quite well, finished with some 2 part epoxy type paint. I want to do this right the first time and I really don't know much about this subject. Can someone throw me a bone or two here?
Thanks

[TimH]

Usually the canvas is set in heavy paint or special canvas adhesive. Not epoxy. The canvas is meant to be a durable yet replacable covering. Epoxy would not leave it very replacable.

[Jack Heinlen]

Canvas, traditionally, was the waterproof barrier on a plank deck. It was(is) as Tim says set in paint or a special canvas glue. Well kept it gives years of service, but isn't as tough as some modern solutions in high wear areas, such as the bow where ground tackle is being handled. It also, if properly kept and not over-painted gives a pretty good non-slip surface. It's also, I think, rather attractive. If I remember correctly, Mystic's schooner 'Brilliant' still has her original canvas coverings to her cabin tops, some many decades on.

Don't epoxy the canvas. If you don't want to re-canvas use one of the modern fabrics set in epoxy that give a pretty good imitation of the original, like dynel.

You could, depending on how the deck is constructed, just epoxy it and paint, laying down some non-skid in the paint, but it wouldn't be as resistant to abrasion.

What's the boat, and what's the history of the deck?

[ 12-25-2003, 09:37 AM: Message edited by: Jack Heinlen ]

[Nicholas Carey]

What kind of boat is it? How big is it? and what is the subdeck under the canvas—is it tongue-and-groove planks? Is it plywood or a laid deck?

Canvas decks are put down two different ways: on tongue and groove planked decks, like, for instance, Beetle Cats, the canvas is laid dry on the subdeck—the subdeck moves as the boat flexes and you want the subdeck to be able move under the canvas, lest the canvas be torn or the paint on the canvas crack. Sometimes, local custom has the canvas laid on irish felt, a softish, pine-tar impregnated felt, rather like roofing tar.

On plywood or laid decks, the canvas is usually bedded in paint or a casein-based lagging compound.

The basic procedure is

(1) stretch the canvas on. It's a process much like stretching canvas on artist's stretchers in preparation for making a painting. The framework is just a bit larger. :D

(2) Fill the weave with highly thinned glossy, oil-based enamel. Start with it thinned about 80% (4 parts thinner, 1 part paint). Let it dry throughly between coats. After the first couple of coats, you want to start reducing the amount of thinner (gradually). The point of the exercise is to fill the fibers of the canvas with paint, but not fill the weave of the canvas. You want a tough flexible coating. If the paint film is too thick, it will fairly quickly craze and/or crack, creating leaks. The very last coat should be only slightly thinned. You might consider doping the paint, at least in the first several coats, with mildewcide.

Search the archives here for more detail on canvassing decks—we've been over the process several times.

A well-made canvas deck should last, with care, for 20 years or more. It's a fast, fairly economical way to put down a deck. And it looks proper for small boats of appropriate vintage. In addition, the texture of the canvas makes a fine non-skid surface for bare feet or Sperry-type deck shoes.

So unless you have a good reason for replacing it with a ply/epoxy/glass composite, you might consider leaving the deck canvas.

[Jack Heinlen]

He already said, it's a ply deck Nicholas.

[Paul Scheuer]

Has anyone ever used water dispersed vinyl adhesive, "carpet glue" for this sort of work ? This is the stuff that is used to glue the bottom flaps on corrugated cartons. It dilutes in water and dries to a soft plastic, water proof state. Everyone knows how good it sticks.

My experience with it, on a lamination project, was that whatever I got in my clothing survived many, many washings and remained flexible.

I also used it between the skin layers of the Folbot. I can't see it but it seems to still be able to move with the skin on frame layers.

[boneymachine]

I searched the archive and found some good info, thanks. This boat is a 1961 38' power boat. The bow is a plywood deck and the rest of deck is planked. So it might be best to use canvass on both surfaces for a consistent look. I take it that the cap rails have to be removed so the material can be streached over the surface properly. The rails need new bedding compound anyway...oh, I feel "mission creep" here. You all know that exponential effect that starting 1 job on an old boat has. Pretty soon there will be 9 simultaneous projects underway again... ;)
Thanks again, Brett

[Bob Cleek]

Paul, notwithstanding that people have probably used EVERYTHING on decks at one time or another, I haven't seen the product you are describing used as yet. However, there was once a very similar product which proved very servicable for "rough and dirty" deck surfacing, particularly among the working fish fleet. This stuff was called Arabol, manufactured by Borden's (yea, the milk guys.) It was quite similar to Borden's white glue, although it dried with much more flexibility. The fishermen would coat their decks (without stripping any old covering off) with "yellowjacket and Arabol." Yellowjacket was a yellow colored polypropaline (I guess) screening cloth material. It's intended use, I don't know. I suppose, though, it was used for some other sort of industrial purpose, since there wasn't enough call for it in the marine community to justify making it. I guess it could have been used by plasterers or something. Arabol was a lagging adhesive used to encapsulate asbestos pipe insulation and such. I have used it to very good effect coating the fibreglass insulation wrapped around engine exhaust pipes. It is water soluable before curing and soaks into cloth. It dries flexible and doesn't crack. It is generally very heat resistant. Swabbed down on top of "yellowjacket," it created a good non-skid deck surface that was waterproofed. Lots of little leaks got stopped with Arabol. It did look funky, though, and was impossible to "finish" to anything you might want to look at on a yacht. Alas, with the demise of asbestos insulation, Borden's stopped making it. If you find an can stashed someplace, grab it. You never know when it will come in handy!

[TimothyB]

What's kind of ironic about this is that the real old time solution.. white lead paste, canvas, lots of paint ... would be possible before using a decent lagging compound. You -can- still buy white lead paste from Kirby's and other sources, or make it yourself from any number of recipes (shown in the WB FAQ

But yes, Arabol seems to have vanished.

--T

[Bayboat]

Arabol was very good for laying Irish felt and canvas on decks. As far as I can tell it is no longer available. But a very similar product is "Chilseal." For information, call Foster Products Corporation, customer service 'phone 1-800-231-9541. The product designation is "CP-50AHV2/Chil-seal".

[ 01-01-2004, 06:39 PM: Message edited by: Bayboat ]