Patching a fiberglass canoe

-- Last Updated: Oct-26-05 2:07 PM EST --

i have a fiberglass canoe, looks homemade (bought it on craigslist for cheap). its a great little boat, i have two kayaks but i let my buddies use it just to get them out on the water and i want to use it this winter on the rivers in south georgia. so after a summer of trips taking it over some nice falls and boating during low water flows in late summer it needs some work but i know absolutly nothing about fiberglass, its scrathed to heck on the bottom with a few chips in the fiberglass. there is a crack in the side of the boat where my brother a neighbor got the boat turned perpendicular to the stream flow and pinned it on a rock, it look liked it was going to be a gonner. also i need to replace the seats, they were ribbeted in but have worked there way loose i rigged one seat with a screws but they are really uncomfortable and i would like to replace them.
so you all have come through in the past with some great ideas, so all suggestions would be greatly appreciated. thanks rick

Auto Zone…
Fiberglass repair kit for auto body work…get the kit and follow the directions…

Boat US has tape
or cloth which might be close to where you are at. I would go with some 5 or 6 oz cloth and keep it on the inside of the hull. you want to sand the hull first,then Use a foam roller to apply the resin and just put enough on to saturate the cloth. You can add more to fill in the weave latter.

duct tape it
I used duct tape to repair severe damage to my folks canoe last Thanks giving. This canoe had serveral holes and long cracks from a hurricane incident. We dried it carefully and apllied layers of duct tape on both sides to make it water tight. After letting it sit in the sun for another 20 minutes we paddled it fine all week. So far it has been in use for almost a year with no leaks. I’m thinking it might be easier to replace the tape once a year than it is to buy $60 worth of epoxy and glass to repair it that way.

Speaking of Duct Tape, Gorilla Glue

– Last Updated: Oct-26-05 9:14 PM EST –

Gorilla Glue now make this duct tape. Marketed as THE STRONGEST TAPE IN THE WORLD If it's anything like their glue I'd buy it...8 bucks
Anyone try it yet? It sounds like the best canoe tape in the world.

Need more detail about crack in side.
The other stuff is just cosmetic, but a crack in the side of a FG boat can increase in size quickly if not properly repaired. Plus, some cracks leak.

plain ol’ epoxy
Look, if you don’t care what it looks like, you can repair about anything short of a gaping hole in fiberglass with just a good, waterproof (not water resistant) two part epoxy, like JB Weld or Devcon 2 Ton that you buy at Wal-mart. I have an old Oscoda fiberglass canoe that I crunched a big divot in by running into it with the mowing deck of my tractor. Hug half-moon crack, gapped open an inch or more. I just pressed the crack back together, duct taped it shut on the inside, slathered epoxy all over the outside after sanding the finish, let it cure, then removed the duct tape from the inside and slathered a bunch more on the inside. Sanded it off once it was cured on the outside so that it was smooth enough it wouldn’t seriously affect the hydrodynamics, left it lumpy on the inside. That was several years ago and it’s holding up well. That old canoe is so worn on the bottom that there are large areas where the gelcoat is completely gone, but it doesn’t leak and it still floats.

Fifteen years ago, a tree limb fell on
my fiberglass mohawk canoe. Got the repair kit from an auto supply store, followed instructions, and, though it was messy and not the prettiest job, the cracks were repaired and hold to this day. Painted the canoe using an exterior latex paint and its still on the canoe with only one little place thats skinned. Of course, I don’t run rapids with a fiberglass canoe. Doesn’t seem like a good idea, knowing how easy it is to crack or splinter the glass on big rocks.

2nd AutoZone
Supertroll hit it on the head. Get a fiberglass repair kit from an auto parts store for about $20-25. Those kits come complete with two-part resin and more cloth than you’re likely to need. Read the instructions, do the job, go to the lake/river, paddle off into the sunset.

And by all means save that nasty-ass duct tape for emergency repairs in the bush!!! Although for those who desire the “I’m totally clueless and a step beyond helpless, please save me from myself” look nothing delivers the message in bolder print than several rolls of duct tape applied with abandon. Might even attract a knight in shiny (duct tape) armor! ;^) Randall

Saw a duct tape wallet yesterday at
a sporting goods store. Its nasty stuff and difficult to get the tape glue off without resorting to acetone or other noxious chemical. On the other hand, its great to have in an emergency.

If you’re going to repair the crack with
fiberglass which is an easy repair, don’t get the cloth that isn’t a cross-hatch pattern. The non-cross-hatch will pill when smoothing with a sponge and you’ll have a mess.

detail of the crack
the crack runs up and down (perpindicular of the ground) for approximately 4 or 5 inches. the epoxy has broken off and you can feel some minor flaking of the fiberglass. from inside of the boat you can barely see stressed area and it does not leak.

i also want to thank you all for all of responses. this way i can keep this on the water.


For the break you describe, and the use
pattern you describe, you might get away with a little epoxy swabbed into the crack and sanded down after it hardens.

The classical crack repair is to file or sand out the crack to remove loose layers, sand the surround for good adhesion, and then apply at least a 3 layer concentric cloth patch. The biggest layer goes on first, then the next smaller, then the smallest, which is just big enough to cover the crack with at least 3/4" margin. The patches should be bias cut so that the fibers cross the break diagonally. A thin epoxy like West is used, and if you use glass rather than Kevlar (usually best), you can see when each layer is wet out when it turns clear. Don’t use excess resin. When the third layer is wet out, you apply any clear food wrap (NOT Saran Wrap, which sticks to epoxy) and tension it with short lengths of vinyl electrical tape at the margins. This results in a smooth patch surface when the epoxy hardens, so you don’t have to do much sanding.

I never painted my patches. A good patch job is a scar to be proud of.