Several years ago I made new front and back thwarts for my Old Town Guide 119 and added fishing rod holders
I just took them off to redo the varnish and when putting them back on I noticed the rear edge of the back thwart (about the last 1/4 inch or so) is touching the side of the canoe. From what can remember it didn’t before. Would the thwart touching the side of the canoe cause any problems?
It can cause problems. Plastics like polyethylene expand and contract with temperature changes to a degree greater than wood. If the hull shrinks enough in the cold the end of the thwart can push out and deform the hull.
It is always best to allow enough space between the end of the thwart and the hull so that water can drain. If the space is tight water is trapped and enters the end grain of the wood and rots it.
@pblanc I thought the same thing about temps after I posted the question. We had a bit of a warm spell for about a week (with highs in the upper 60s) but since then the temps have been back in the mid 30s to low 40s for the highs.
I took the thwarts out to revarnish them during the warm spell and had put them back on when temps were back in the mid 30s to low 40s. I had put the old thwarts in (without screwing them down) as place holders and stored the canoe as usual. Looking back, since it’s 3 layer poly it probably expanded a little when the temps were warm and then shrunk again when temps cooled down.
I took both thwarts back out today to remove a little bit from the ends just to play it safe (the old thwarts are there as place holders again). I’m hoping temps will warm up again so I can put them back in. I could probably put the canoe in the sun to let the 3 layer poly warm up when I go to put the thwarts back in too.