Wrinkles in canvas

[Zenith]

ewitzel
I forgot to mention that as I pulled the canvas tight at the stems, I used a carpenters stapler to attach the canvas to the stem while I pulled it tight. This made it easy to get the canvas tight instead of trying to tack it while pulling on the pliers. It also allowed me to check the results before tacking. When I was done I tacked the canvas to the stem and removed the staples. It was a lot easier than I thought it would be.
John

 

[ewitzel]

Thanks to all for sharing here. I replied the canvas and attached with stainless steel staples- so far all is wrinkle free.

 

[ewitzel]

Thanks to all for this great information; I have re stretched the canvas and so far no wrinkles!

 

[Tim Belcher]

I had wrinkles appear after the 3rd week of curing the filler and I let it sit for another 2 weeks and they disappeared. They then reappeared with a vengeance after the 5th coat of paint and I stopped. It's too late to re-stretch from end to end, and doing it laterally didn't help. The stretching was nice and tight until it wasn't. My quandary is whether to go ahead and start varnishing or whether there is anything else I can do at this late date. I haven't tried McLeod's wet blue jean solution. Maybe just forge ahead and get this poor boat into some water?

 

[Michael Grace]

Hi Tim - I see that you didn't get any replies to your last post. Have you done anything more with your canvas? I remember another thread in which you were worried about sags in the canvas between fasteners. As others replied there, that's a sure sign that the canvas wasn't stretched tight enough lengthwise. This is probably the reason for the wrinkles, and these wrinkles will come and go with changes in humidity or with chemicals added to the surface (filler, paint, etc.). I don't know anything you can do about this after the canvas has been filled and painted... nothing except remove the canvas and start over. Of course you can use the canoe as is, though. A wrinkly surface may be unsightly but that alone shouldn't compromise the integrity of the hull. You should stay dry if all else is good.

 

[Tim Belcher]

Thanks Mike. The canvas tightened up after a few days and has stayed tight after another final coat of paint. It looks pretty good right now, including the areas around the tacks. If I do this again I'll try to stretch the canvas another notch or so on the come along, but I have to say it really seemed taut when I did it. I'm on to other tribulations, but may have it in the water by next weekend. I appreciate your help.

 

[Floyd Reid]

Question for the experienced people. Do you pre stretch the canvas? I understand many folks will stretch the canvas with no canoe in the envelope then release the tension, insert the canoe, and proceed normally. Could this method possibly help eliminate wrinkles ?

 

[Michael Grace]

I stretch canvas as tight as I can using a winch/come-along with no canoe in the fold, then let it sit for an hour or more, then stretch again. After marking the position of the cable at the final pull point I release the tension, drop the canoe into the fold, and then tighten back up as close as I feel safe getting to the cable mark. I've had wrinkles form only once over many canvassing jobs. This was with a square stern, and in this case I know I just didn't have nearly enough tension applied. After removing the filled and painted canvas (ugh!), went back to a super tight pull on a new canvas and it turned out great.

 

[Stmcglynn]

Hello all,

I used the advice in this forum to fix the wrinkles caused by canvassing in humidity. It did indeed work, and here are some photos showing the system I used to pull the canvas and staple alone.

I disconnected the canvas from one stem, and removed the staples along the side all the way back to the last wrinkle. I then used vice grips and a towel (to soften and broaden the bite) to grasp where the canvas was cut. I then secured one side to a static anchor, and the other to an anchor on the wall using a loop of paracord. I twisted the paracord with a piece of wood (almost like a tourniquet) which slowly tightened the canvas. Once the wrinkles began to flatten (I never got them perfectly flat at this point), I began to re-stretch and staple along the rails. This was successful in completely flattening and stretching the canvas.

The most difficult part was re-fastening along the stem since there wasn't much material to grab. I ended up getting it pretty much as tight as I could by hand (plyers were too sharp and ripped the fabric), then scratching from the deck area.

Thank you all for your help, a lot of great info in this thread.

 

[chris pearson]

Food for thought, 40 pounds of downward force(weight) is not even close to enough when doing an upright canvasing job. Gotta really put the coals to her!!! I’ve actually seen people but almost all their weight into a canoe when doing this! Aka Jack McGreivey!

 

[Gil Cramer]

How about all of my 160lbs.
Gil

 

[Gil Cramer]

Your assessment, as Dave Osborn's ,of canvassing with too much humidity, is likely correct. Canvas shrinks with moisture and expands after the moisture leaves. In the summer, I only canvas the day after the cold front/high pressure arrives. The shop in winter has such little moisture that it doesn't matter. It took more than one saggy canvas for me to decide this.

 

[Stmcglynn]

OH another note, may be common knowledge. I laid on some BLO to the interior in attempts to swell the wood (since water seemed to work for other folks, my not try something that would help the wood as well?).

It didn't work at swelling the wood at all.

 

[Mark Giovannetti]