Aluminum Canoe leaking, best repair?

I bought a used aluminum canoe (not Grumman,sp? - Chief maybe?) anyways, it leaks. It is a 15’ with closed ends and it is the ends that leak. Not much but what is the best way to repair them when you don’t know exactly where. Water comes in slowly from both ends but because they’re closed can’t tell the exact location of the leaks. JB Weld? epoxy glue? silicone caulking? are just a few of the suggestions from my buddies at work who don’t own canoes.

Aluminum boat
I once repaired an inlaws 12’ aluminum boat with a product I picked up from the local marine store. Sorry I can’t remember the products name but you simply painted it over the rivets and the overlapping seams and that was it. Did that at least 10 years ago and it still doesn’t leak. Give a marine supply store a call and see what they have to say or check out Defenders on the web.

Maybe you could try…
Aluminum duct tape, not the everyday duct tape, but actual aluminum tape for ducts.

Regular duct tape would probably work as well, as long as you heat it with a hair dryer and push it on really well with a spoon.

You might also take a tube of silicone-caulk (good silicone caulk like silicone II) and shoot some in where you think it’s leaking, wait for it to dry, then duct tape it, giving it the “double-whammy” if you will.

And if you want to find out where it’s leaking from, fill it up with water.

Just make sure it’s well-supported if you bring it off the ground any.

Try PC-7
it comes in a marine version in which both A and B parts are white (versus black and white A and B parts). Takes 4-5 days to completly cure and then it is as hard as plastic. Does not shrink when curing. Sand the aluminum lightly and then clean with 70% isopropanol (let dry), then just cover all the rivets and the seam with the PC-7. You can get a smooth finish by wetting your finger in water and then smoothing the epoxy with your wet finger (redipping finger in water as needed), otherwise the stuff is really sticky!

I love my aluminum canoe and have
made many repairs and modifications. The overall best, without a doubt is welding. It has to be done by an EXPERT aluminum welder. The weld is stronger than the original material.

The second best is fiberglass. You can do it yourself and it’s less expensive. Be sure the base material is as clean as possible, think microscopicly clean.

Great Answer…
Lean the canoe up on a sawhorse or even the front steps, and fill just one end at a time…use a # 2 pencil to mark the location of the leaks, then choose your poison on the repairs.

have you heard of
"Alumaloy?" I’ve seen some info commercials on the stuff…it looks pretty incredible, plus all you use is the welding rod and a regular propane torch from your local hardware store.

They showed guys repairing just about anything with this and it looked structurally sound.


Be very, very careful with this!!!
Looks very easy, but is also very, very easy to blow big holes in your canoe. To work the temperature of the area to be repaired must be held just below the melting point. Tricky, very tricky!!! Practice, practice, practice, and pratice some more on scrap before you even consider approaching your canoe with this!!!

I have experiance with high heat and metals. I have tried this very stuff. Doable, but not easy!!!


JB Weld
Repaired my al john boat with a product just like JB Weld, for aluminum. Put water into the boat to find the leak, mark, drain, dry, and patch with this epoxy-like substance. When dry it can be sanded down to remove any overage. Worked fine!

Any epoxy works OK, or
If you use sealant, get 3M 5200 from a boat store.

Thanks Mick
I did foundry work in the Navy and saw metal run like water. I appriciate the heads-up as I’m sure to try this product at some time or another.

Butyl Sealant
Aluminum colored butyl sealant works very well. It is flexible, long lasting and uv resistant. Buytl sealant is sold at Home Depot or Lowes and often called gutter and flashing or something like that. Clean the canoe surface with vinegar prior to appling the sealant.

To find the leak: hang the boat from straps, fill with water enough to cover the bottom of the boat. Stand back and watch for leaks.

Good luck.

have is so it’s fixed properly, take the bow and stern plates off. Drill out the alum rivets. carefully remove the foam floats. then scrub the keel areas along the rivets inside and out to clean the rivet area completely. go to a machinist supply and buy some red penetrating dye. spray the outside of the boat along the rivets and then look inside. the odds are that you have a few loose or cracked rivets. If so Grumman or any other alum boat builder has rivets. this come in slightly different lengths and sizes. buy long , cut them to desired length after putting them in the boat (first either tighten the old rivets with a hammer and bucking bar (takes 2 people to do) or drill out the offending rivets.and put in the new ones. when done check with the dye again and tighten any offenders.

otherwise goop it from the outside with liguid aluminum and go paddling

Best Wishes


A few more cautions on top of Mick’s
I have a very good TIG welder, and have done many repair welds, and Mick is correct - the melting point of aluminum rod and the substrate you are welding is very close together, and takes a good touch. On top of that, some of the aluminum canoes also have a rubbery seal buried in the keel, and heating that area will cause damage to the seal, and can contaminate the weld. Also, be careful of the closed ends - many aluminums have liquid foam insulation filling those chambers for flotation.