Devcon Plastic Weld

[milkman]

Last year I posted a video of a hull repair I did on a yellow Ocoee using Devcon Plastic Weld. This boat is a loaner and spare and I've now lent it to several people. The last time was for a class on a very rocky shallow river. The bow repair took a pretty hard hit and has a hairline crack in it. The Plastic Weld material is still bonded strongly to the hull, so the repair is going to be pretty easy--I'm just going to open up the crack big enough to put some more plastic weld into it. What is shows though about Plastic Weld is that it's a bit on the brittle side. The search for the perfect hull repair material continues ... though I'm still happy with how it added strength and rigidity to a very compromised bow.

[hazardharry]

i love adhesives feedback! PC-11 is drug of choice at the moment for skim coating a worn hull.

[pblanc]

Thanks for the feedback. I remember your post. I remember thinking I would have used G-Flex instead which has a longer pot life and would not have been any more expensive than the number of tubes of Devcon you used, and possibly added some cloth to the repair.

So far the repairs I have done with G-Flex on both ABS boats and polyethylene boats has held up well and has not seemed to become brittle. I do know folks who swear by Plexus for repairs to ABS however, which is another methacrylate adhesive like Devcon plastic welder.

[milkman]

I feel a little bad about the video right now--it's had over 1600 views and wonder if I should yank it. I think Plastic Weld does have its place though in canoe repair. It would be great in spot that doesn't get many direct impact hits, like the side of a hull, rather than a bow. I have posted a comment on my own video updating my experience with Plastic Weld.

I've used G/flex in smaller cracks and had great success with it. Recently I used it and fiberglass cloth to repair a Mitchell carbon blade paddle on which an small section of the side of the blade had broken off. It ain't pretty, but it's holding up great.

[avlclimber]

I have had some pretty disappointing results from the "miracle cure" Gflex repairs I have done. The small crack I prepped and filled held up well. The large "delam" patches have failed in precisely the way I expected them not to: brittle cracks straight through the G-flex material.

These occurred after rough but minimal use. (first outing or first major shock to the thighstrap d-ring) I accept that these may have been novice patches, but I felt good about them, and they adhered well, they just sheared.

[pblanc]

I have had some pretty disappointing results from the "miracle cure" Gflex repairs I have done. The small crack I prepped and filled held up well. The large "delam" patches have failed in precisely the way I expected them not to: brittle cracks straight through the G-flex material.

These occurred after rough but minimal use. (first outing or first major shock to the thighstrap d-ring) I accept that these may have been novice patches, but I felt good about them, and they adhered well, they just sheared.

Was it a polyethylene boat?

I have found that when using G Flex on polyethylene the manner in which you pretreat the poly by flaming it with a propane torch is critical. The tip of the inner blue cone of the flame must just touch the hull, and touch every little bit of the surface you want to get the G Flex to adhere to. I usually do this in a somewhat dimly lit room so that you can see the blue cone well. You should then apply the epoxy within a half hour or so.

As for Royalex, I have now used G Flex to patch and repair 4 whitewater canoes (using fiberglass cloth) and have used it to apply Dynel cloth abrasion plates to the stems of around 10 livery canoes (20 skid plates in all). Some of the repairs are 3 or more years old. None are showing any signs of delamination. Although West Systems says that pretreating with a propane torch is "optional" for Royalex, I have only done so on one boat and saw no difference in the results so I don't do that now.

To repair a serious crack with G Flex, I would definitely back the repair up with some type of cloth.

[hazardharry]

cracked an ash gunnel upta dead river. i ran over to local beer, bullets and bolts genral store hoping for some pc7 but they only had jb weld. i dried the boat and cut away a bit around the split and smeared it in and on. jb weld is way to runny to set up at odd angles. it looked ok in the morning but it started to let goafter it was lashed onto the shuttle trailer. at that point i ran for my bag of glues and fixitshit. i had a 1/4 tube of 6 minute set time loc-tite 2 part epoxy. i layered it on top of the jb weld about 1/8 thick on 3 sides. that stuff held all day and may just wind up as the go to wood fixer upper.