Okay...all three of my Royalex canoes need some serious repairs. I've got two Old Town Penobscots. The older one has skid plates already installed (years ago) but has so much wear in toward the middle of the canoe, starting at the skid plates, that fairly large sections of the inner core are exposed. The newer one does not have skid plates but has similar wear, too widespread for a commercially available skid plate kit. My solo, a Wenonah Vagabond, has much less wear and could be fixed with skid plates, but I've always resisted putting them on until I had to because of the weight they add and the decrease in paddling performance. Mainly though, it has a patch about 4 inches in diameter and spreading where the vinyl outer layer just came de-laminated and continues to spread.
I've always just done minor repairs with JB Weld or similar epoxy, but the last time I tried this it took three tubes of JB and the repair area was wide and flat enough that it cracked because of the stiffer nature of the JB Weld. And now much of it is worn off.
I'm thinking of obtaining some kind of fiberglass or kevlar cloth and resin, enough of it to cover the wide area, and going in that direction. Any advice or alternatives?
An alternative is to paint on ABS that
has been dissolved in acetone. I have not done this, but a frequent poster named daggermat is very experienced, and so are some others.
You would not want to use Kevlar felt skid plate kits for other than the ends of the boat. If you added any cloth to the bottoms of your boats, it would be E-glass or S-glass.
You say one of your boats is worn down to the “core”. Do you mean right through into the foam? Or just that the vinyl overlayer is worn off so that the pale greenish ABS is exposed? If it is the latter, painting on dissolved ABS may be better than glassing.
If you get into glassing, you need to get West 105/205 epoxy, the 105 coming in a quart can and the 205 hardener coming in a small can. You also need the metering pumps. The stuff lasts a few years, so the approximately $60 cost is not a barrier. This epoxy (and similar) soaks very easily into cloth. Over-the-counter epoxy does not. West Marine may have West epoxy in their retail stores. You can also get it, and glass or Kevlar, at sweetcomposites.com.
It’s late so I’ll leave it to others to join in.
west
West epoxy and West Marine are two entirely different companies. West epoxy does not have retail stores.
Bill H.
I’ve Had Decent Results…
…with a fiberglass car repair kit with 'glass and epoxy that I got at the local hardware store (Turnboughs in Piedmont) a few years ago. I’ve still got glass and have bought more 2 part epoxy from Walmart. Had a “Rub-through” where I had it against something in the truck bed on a shuttle last fall that I patched this spring. Not sure if it’s as good as the stuff g2d is suggesting, but it’s available locally and reasonably and works on the same streams you’re paddling. I had a royalite Mohawk Solo 14 a few years back that I had glassed pretty much the entire bottom. Still was solid when I sold it. WW
I’ve used ABS on my WW boat
Had a large worn area in the middle of the boat and a couple of cracks through the ABS into the foam. I cut out the cracks and filled with Gorilla Glue before painting on lots of thin layers of ABS. I melted down red Lego blocks to match the boat.
Before
http://outdoors.webshots.com/photo/2303377910075003331OGAahz
After
http://outdoors.webshots.com/photo/2497148640075003331yWPhJZ
It works fine, but it does wear off eventually. You’ll have to reapply periodically. I also painted some on the stems. I really should put skid plates on, but the ABS is working for now.
Use the West System G-flex
with or without fiberglass.
I have tried Matt's method of dissolving ABS (I also used Lego blocks) in either MEK or acetone (tried both) and painting it on. Whitewater open boating legend Jim Michaud had also recommended the same technique. I may have screwed it up in some way. I found it worked after a fashion, but chipped off fairly easily when used on the bottom center of a Royalex whitewater boat.
If you use this method on an area of wear that extends into the foam core, you must do something to seal off the core (like apply Gorilla Glue) as the acetone or MEK will simply dissolve the core very quickly.
I have used G-Flex with glass to reattach the cockpit coaming on a polyethylene whitewater C-1 that was more than a third broken off, and used G-Flex without glass to repair the worn bottom of the same ABS whitewater OC-1. That Encore has now made several dozen trips down rocky creeks and the repair shows no sign of damage.
I've used G-Flex to repair a cold crack in another ABS boat and am currently repairing ABS boats from a local livery with G-Flex and glass. So far, the results have been uniformly good.
If you are worn into the foam core extensively you are probably going to need to use multiple layers of glass (using s-glass on the outer layer) to reconstruct an outer ABS layer.
I would definitely use G-Flex rather than the West System 105/205 2 part epoxy. I have seen Royalex boat repairs done with 105/205 that were durable, but sometimes adhesion to the ABS is problematical. West System developed the G-Flex formulation specifically to improve adhesion to plastics (as well as some dense woods and metal) and recommends it for ABS in preference to the 105/205 2 part epoxy that they sell. And G-Flex can be mixed 1:1 by volume by sight. You don't need to buy metering pumps.
But you can buy some West Epoxy
products at West Marine. I ordered my West G-flex from them.
Sorry if I generated confusion…
I only prefer 105/205 when I’m concerned
about easy cloth penetration and wetting out. Thinner works better. The one high-stress S-glass to ABS patch I’ve done is holding very well. The reason I recommend stripping off the vinyl before using 105 on bare ABS is that the ABS and the hardened 105 seem very similar in hardness and flexibility.
The real decision comes with Kevlar inside-the-boat patches. The 105/205 wets out several layers very well. But I suspect that the extra adhesion of G-flex will match Kevlar better after hardening. There is some evidence that resins don’t hold onto Kevlar as well as they do to other cloths. (I saw just one actual study putting the difference at up to 15% deficiency.)
Epoxy and FG
I’ve paddled the Chipewyan at least 30 days with repairs made with Fiberglass and West System Epoxy:
bow stem cut back 4 inches, refabricated with glass and epoxy over an oak plug.
stern stem crack a foot long filled with thickened epoxy and chopped up glass, then reinforced with layers of glass inside and out
hole in the hull bottom, about 2" wide and 8" long filled with thickened epoxy & chopped glass, then sandwiched between layers of glass in and out.
entire hull below the waterline covered with dynel fabric and epoxy.
These repairs added at least ten pounds to the boat, but show no signs of separation or weakness after 30 or so uses over two years. My experience demonstrates that West Epoxy will stick to your royalex hull just fine, and you can do all your repairs with FG and epoxy.
Last glass repair I did (different boat), I used G-flex. G-flex is much thicker than plain old West System, and I think for normal applications of a layer of glass, I prefer old West System.
I have boats that I put skid plates on, alternating with kevlar felt on one end and dynel or FG on the other. Both canoes I have done this with have wear spots through one end, and it’s not the kevlar end. I’ll use kevlar for skid plates in the future. All the plates are glued up with West System Epoxy, which seems to be working fine.
~~Chip
Let us know when you try S-glass.
G-Flex vs 105/205
E-glass is a little easier to wet out with 105/205 than it is with G-Flex but for patch repairs it doesn’t seem to be much of an issue for me.
G-Flex has a significantly higher modulus of elasticity than does 105/205 which might be an issue impacting durability of repairs made on ABS boats. The ABS, having considerable flex, may be more prone to crack at the stress riser created at the margin of a patch made using the stiffer 105/205.
As long as it is a single layer at the
margin, it won’t matter. And, the considerable tension strength of S-glass or Kevlar will dominate the issue, not the resin.
You’ve probably noticed that West says 105/205 and G-flex can be mixed separately, and then mixed together, to obtain a resin intermediate in characteristics between the two. I’m hoping for more data on that.
G is flexier
I agree that gflex is more flexible. I pulled some off the side of the mixing cup after it was hardened. Regular epoxy pulled off the side of the cup more or less flakes, while the gflex is markedly more pliable. I also like it for the way it fills voids, it being thicker, and does not seem to run so much as the old West System.
~~Chip
Yes
It is very good for filling voids and cracks, and can be further thickened with silica gel or other agents, of course.
Better on ice cream, too.