Canvas weight for canoe and sponsons

[Shari Gnolek]

I am working on an 18' square stern Old Town canoe with sponsons (yes, I know they are heavy and I should leave them off, but back on they will go!).

When I removed the canvas the material on the canoe seemed thicker than the canvas on the sponsons. It seemed stiffer, and thicker, even considering that there was probably less filler on the sponsons than the canoe itself. I could tell that the canvas had been replaced, so it wasn't original.

Questions: Is there a way to tell from the build record, or from the time period the canoe was manufactured during (1961), or from any other method, what weight canvas would have been used on both the canoe and the sponsons? Would the same canvas thickness typically have usually been used on both the canoe and the sponsons, or would a lighter canvas been used on the sponsons?

I have some pieces of canvas left, but they have old filler and cracked paint on them (though the piece from the inside of the sponsons - the part against the canoe - is not filled or painted)

Thanks!

 

[Benson Gray]

The build records do not commonly contain this level of detail. The 1960s specifications in the catalogs as shown at http://www.wcha.org/catalogs/old-town/specifications.jpg did not specify the weight of the canvas. The 1920s catalogs shown at http://www.wcha.org/catalogs/old-town/specific.gif identified the standard canvas weight as number eight with number six on the guide models. Therefore, it is likely that your square stern model could have had eight, six, or both. It would not be unusual to find a lighter weight canvas on the sponsons since they typically experience less wear than the hull. Let me know if this doesn't answer your question. Thanks,

Benson

 

[Shari Gnolek]

I'm glad I asked. I incorrectly thought that the "standard" was ten. That's the weight I read about being used in both This Old Canoe and The Wood and Canvas Canoe. From the information you provided in the 1920 catalog it looks like the standard was eight. Was there a point as canoes started to be restored that people switched to using #10?

Do you know what the reason was behind the statement "Be cautious about buying a 16-foot or longer canoe which hasn't No. 8 canvas on it"?

 

[Benson Gray]

Heavier canvas is generally more durable and longer lasting. Weight has become more of a concern over the years so many builders have switched to lighter canvas. You can decide what is more important for you in this case.

Benson

 

[Shari Gnolek]

Do anyone have a sense for how much of weight difference there would be between using #8 and #10 canvas on a wide, 18-foot canoe?

I assume the heavier canvas would 1) hide imperfections better and 2) soak up more filler (adding even more weight).

You can decide what is more important for you in this case

I want it to last, but I also want be able to move it!

 

[Benson Gray]

My suggestion is to get a good trailer.

Benson

 

[paddler123]

The widespread use of #10 canvas today in large part reflects that most wood-canvas canoes today are used pretty gently. Before we had plastic and aluminum, people used wood-canvas canoes for all sorts of things that are now mostly the domain of synthetic canoes. People today who use wood-canvas canoes for heavier-duty applications still use the heavier weights of canvas.

 

[Benson Gray]

Do anyone have a sense for how much of weight difference there would be between using #8 and #10 canvas on a wide, 18-foot canoe?

The 1920 catalog page at http://www.wcha.org/catalogs/old-town/dimens-1.gif listed an 15 foot long HW model with number eight canvas at 60 pounds. The 15 foot long Fifty Pound model with number ten canvas and a keel was listed at 52 pounds. My guess is that the difference on an 18 foot long canoe would be at least 10 pounds. Your mileage may vary...

Benson

 

[MGC]

If the boat is going to be trailered, heavier is probably the way to go.
A canoe under motor power has a tendency to bash things with quite a bit more vigor than one under paddle power....rapids being the exception. The bow planking and canvas are almost always pretty dinged up in these square sterns.
The sponsons might be more easily done with a lighter canvas.

 

[pathologist]

Why not cover the sponsons with much lighter dacron, although it's not traditional.

 

[Benson Gray]

Canoes covered with Dacron typically have to be especially well faired to not look lumpy since the fabric is so thin that any imperfection will easily show through. Sponsons are usually more rough than most canoe hulls so one covered with Dacron might not look very good. Please post some pictures if you decide to do this so we can all see how it turns out.

Benson

 

[Gil Cramer]

An 18' square stern should have the sponsons replaced. They make the boat a lot safer. It is a trailer boat for all but the very robust young people. #8 canvas for the hull is appropriate, and #10 or even #12 for the sponsons is suitable. I have used #6 and #4 canvas, but NEVER AGAIN- I am way too old for that. You are correct in assuming that #8 canvas will take more filler, but not all that much. Mildew and rot are the main problems with canvas, and as long as the boat dries completely before being stored upside down, neither are a great concern.

 

[Dan Lindberg]

How do you think you will use this boat? And do you have ANY thoughts of actually carrying it? (unlikely)
And if you're planning to keep the sponsons, why ask questions about canvas weight, just put on 6 or 8 and don't worry about it.

 

[Shari Gnolek]

if you're planning to keep the sponsons, why ask questions about canvas weight,

The canvas on it when I bought it wasn't original, and it seemed to be different weights between the canoe and the sponsons. Some of the prior repairs made to this boat weren't typical so I wanted to know if it was possible to determine how the canoe and sponsons were originally canvassed. I'm glad I asked because I've learned a lot from the responses to this post.

 

[Dan Lindberg]

Questions are good, but it sounded like you were looking for ways to reduce the weight on a heavy boat,
without doing the biggest thing to reduce weight, ie; leave the sponsons off.

Again, what do you think you will use this for and do you plan to carry it or trailer it?
Is it paddle only or will you use a motor?

And pics, post some pics, we like looking at canoes.

Dan