Autopsy of an Old Town sponson canoe canvas job

[nmerrill]

I began removing the old canvas from my 1942 Old Town square stern sponson "paddling" canoe. This boat was re-canvased at some point in the distant past, so this is not an autopsy of the original factory canvas job.

From what I found, it seems that the boat was canvased in a simialar way as a standard canoe. The sponsons were already on the canoe when the canvas was put on over the hull, and sponsons at the same time. It seems that a "tuck", or fold, of canvas was cut off along the outer, top, edge of the sponson where the sponson's outwale covered the remaining seam. This seam extended almost to both ends of the sponson and then ended. At this point, the canvas of the hull began to fold over the top of the sponson in a continous piece. I'm guessing that the canvas was folded over the top of the sponson and attached, pulled tight along the outer edge of the sponson and attached, and the only way to get this to lay tight, required a fold of extra canvas be cut off along the length of the sponson.
There was a line of brass tacks along the bottom edge of the sponson that was later covered with a wooden strip - like a lower outwale. There was also a double line of brass tacks along the outer edge of the sponson where the seam from cutting the tuck off was -and covered by the sponson's outwale.

Looking at the sponson itself, I'm not sure how it would ever be canvased separately, and then attached to an already canvased hull. Primarily because the ends of the sponson appear to be independent wooden parts that are screwed to the hull from the outside. Looking at the picture of the sponson canoe in the Old Town catalog, it really does not look like there is a seam in the canvas at the front egde of the sponson - as there would be if the sponson was attached after the hull was canvased. Also, the attached picture of the same style boat (from ebay) shows that this boat was also canvased in one piece.

So, as I begin to think about recanvasing, I really wonder if this method was that used by the factory in the first place?
Does anyone have a picture, or personal experience, of a sponson canoe that indicated otherwise?
In the end, this makes the sponson a much more integral part of the canoe, with no seams to allow water entrance behind the sponson.

[nmerrill]

one other shot of the end of the seam in the canvas along the outer edge of the sponson.

[nmerrill]

Ok, so I just found a description of how to re-canvase a sponson canoe from the Old Town web site. It indicates why there would be no seam between the sponson and the hull - it is to be filled with filler...

[Michael Grace]

Hi Nathaniel,

Once you take off the sponsons, it may be clearer how they were canvassed. But first, I'm not sure if the questions in your earlier thread were answered. I agree with others that the keel may be a later addition, and I also think that the wooden strips below the sponsons are non-factory because (1) I've never seen them on any of many Old Town sponson canoes, and (2) you mentioned that they are through-bolted; this is not the way Old Town would have attached them if they were original.

Now, for this thread... I'm not sure of your meaning, but it sounds like you're suggesting that one piece of canvas was used to cover the canoe AND sponsons. This should not be the case, unless someone did a VERY creative job of re-canvassing. The canoe should be canvassed, and then the sponsons canvassed seperately. When you remove the sponsons, you'll likely find two layers of canvas behind them- one for the hull, and one for the sponson.

How to re-canvas? I think that in an earlier thread you mentioned ordering The Wood and Canvas Canoe- this is outlined very thoroughly there, but just in case... First, get the whole boat (minus sponsons) in canvas, then tack additional pieces of canvas to the hull on each side at the level of the sponsons. These pieces whould be longer (maybe 8" at each end) than the sponson, and wide enough that they can wrap completely around the sponson. After these pieces are in place, re-attach the sponsons, stretch the canvas from the bottom of the sponson to the outer margin of the sponson (where the rub rail will be placed), and tack there. Make a clean cut to remove excess canvas, and then stretch the canvas over from the top and tack along the sponson's outer margin. Closing up the ends requires some careful manipulation of the canvas- you want it to be as flat as possible. Once this is all done, fill the entire canvas, being sure to repeatedly work extra filler in at the ends of the sponsons, at the junctions between the sponson and the hull, and at the outer margin where the cut canvas edges lie.

I've got photos of the process, but they were made with film, so I'd have to scan. Maybe someone else can post some pics of sponson canvassing. If no one else beats me to it, I'll try to scan some when I return from the antique boat show Sunday night or Monday.

Just for fun, see pics below- I am about ready to re-canvas a hull just like yours- sponsons and all. Note- this is NOT my backyard! The last photo is cropped from a recent sponson canoe restoration.

M

[nmerrill]

Thanks for the reply Michael,
Yup, that is what I suggested - the boat was re-canvased with one piece of canvas over the canoe and sponsons - The sponsons were attached before any canvasing was done, at least as far as I can tell. I have not removed the sponsons yet, but it appears that there may be the remains of the original canvas still behind the sponsons - like they were never removed when the re-canvas job was done.
Thanks for the sponson canvasing methods, and I would love to see some pictures if you get a chance.
unfortunately, I have a little repair work to do before I get to canvasing! see the other thread for details...