Early last fall I canvased my 1928 Oldtown, and it came out very well with no wrinkles. After waiting for some good weather I applied the sealer, and there was about a week of warm weather for it to start its cure, again with no wrinkles. The boat has been and is in my shop for the whole winter. Since I don't do much in the winter due to the cold, I did not notice any wrinkles. A couple of weeks ago I opened the barn and wrinkles were very pronounced, and I assumed that I had done something wrong. After a week of good weather I again looked at the canoe and the wrinkles were gone. They had taken about three days to smooth out. Now with some damp weather, the wrinkles are back, and even more pronounced than before. The sealer is cured. I figure that the wrinkles may disappear again, but I guess they may keep coming back, and I suspect that painting the boat when they are gone will not help much. If humidity or moisture causes the rippling, that is not a good thing since the canoe will look its worst when it is in the water. I can pull the tacks and try to stretch the canvas some, but the sealer is hard and it may not pull well over the stems. This is the first canoe that I have canvased, but I have a lot of boat repair and building experience. I know a lot of folks are against fiber-glassing a canvas canoe, but I have never had a wrinkling problem using glass. If there is no way to fix this I will probably pull off the canvas and go with the glass, because these wrinkles are not acceptable. I have read the threads on this subject from April 2012 and July 2017, and there is a mention of the cause but no fix. I have some pictures of the non wrinkled job on my site at http://johnmaciver.tripod.com/id13.html , but I can't seem to get a picture of the wrinkles on there.