I just got a very used aluminum canoe some holes that i fixed. I need help fixing the thwartship supports. I have 3 that are cracked on or near the keel. any suggestions to fix this would be welcome. thanks Ken
Not clear what you mean by
“thwartship supports” and “near the keel.” The thwarts go crossways between the gunwales and aren’t near the keel at all.
Do you mean the ribs that cross the inside of the hull, ending at the keel?
Someone may need to suggest sources on fixing aluminum canoes. I never got to try fixing one.
Oh, regarding what I wrote below, I had some other post in mind when thinking about "Grumman". You didn't tell us the brand name. If it's Grumman or Alumicraft you have a good chance of being able to get replacement parts. Not so with a number of other brands of Aluminum canoes that have come and gone over the years.
If the thwarts are cracked, you can most likely order new ones from Grumman (now called the Marathon Boat company). Just bolt the new ones on instead of using rivets. If the boat has cracked ribs, that's quite a different problem. I've heard recommendations before to take the boat to someone who can weld aluminum, but I bet you can get replacement ribs from the factory, even if it means a special order by talking to someone on the phone. In that case I'd fix it myself. I'd drill out the existing rivets, and fasten the new ribs in with bolts. You'd want the ribs to be un-drilled so that you could insure the new holes (the ones you would drill yourself) would line up with holes in the hull. I'd shop around to find round-topped "stove bolts" made of stainless steel, and I'd goop plenty of sealant on all contact surfaces surrounding each hole. To make the holes line up, you'd need to drill most of them AFTER the rib is tightly installed with a few bolts, so each rib would need to be installed twice, once for alignment of the holes, and once again with sealant. Once it were all done, I'd trim the bolts on the inside to remove any extra length, and file them flush with the top of the nut so there'd be no burrs to snag bare feet or gear bags (the round bolt heads would go on the outside of the hull, and the nuts would go on the inside, on the top surface of the rib). Assuming you can get new ribs, it should be quite simple, even if very time-consuming.