Hey folks - need some advice on replacing the rubstrips on a royalex canoe I have. I have bashed off the current set and need something that is protective yet still hydrodynamic as the boat is mostly a flatwater model. The first outer skin on the royalex is gone so I need to encapsulate that with a fairly long piece as well. Any advice would be appreciated.
Thanks
Do you mean what we usually call
skid plates? The kind usually made from Kevlar felt and stuck on with resin? Or do you have some more unusual protective strips?
I have a Mad River Guide, Royalex, where the tan vinyl overcoat has worn off the aqua ABS structural layer underneath, on both ends. Some winter I will use bias-cut S-glass, maybe 4 concentric layers, to recover the ABS.
But here’s the thing. It really doesn’t matter. Just get a can of spray paint, maybe Krylon Fusion, that matches your vinyl, and spray over the ABS so it does not get degraded when you drive the boat around in the sun.
Kevlar and other skid plates really aren’t strong enough to protect a canoe that hits a rock head on. And skid plates are not light, nor are they hydrodynamically smooth. They serve mainly as an excuse for people to drag boats or land them carelessly. So perhaps you should just clean off the old protection and get a can of spray paint.
I should have mentioned that Kevlar
skid plate kits are available in thinner, lower profile form for flatwater boats, as well as in the thicker, more studly-looking form for whitewater boats.
Hmmm
Does spray paint offer any sort of protection from furthur abrasion. What about melting in some more outer skin. How do repair seriosly scratches that are not through the abs layer?
Easiest for me has been to trowel
on some PC-11 epoxy as if it were body filler. I put it on mt OT Penobscot when the ends finally wore through to the core about 5 years ago and the stuff has stayed put and has proven to be much more durable than I had expected. I did 3 thin applications with max. thickness @ 3/16-1/4 inch. You can fair it easily with med. sandpaper after partial cure, fine for final after 48 hrs. It’s white, but mfr. says you can color it with UTC’s and/or paint it. I never bothered.
The ABS is quite hard, and does not
abrade nearly as easily as the soft vinyl.
Scratches into the vinyl can be filled in with 3M two part Structural Adhesive, or maybe with JB Weld (which I have not tried myself). But those of us who paddle rocky rivers do not bother with most vinyl scratches, unless they expose the ABS to sunlight.
Spray paint is quickly re-applied.
On the issue of “melting on some more outer skin,” heat welding is not done on Royalex. But one can melt black ABS from the hardware store in acetone, and then paint layers of black ABS over what is there originally. The acetone will not soften the underlying ABS as long as you don’t prevent the acetone from evaporating quickly.
ABS slurry
I recently used the ABS slurry technique to reinforce the bottom of my old Encore in which the ABS on the hull bottom was starting to wear into the inner core.
Per a tip on cboats.net I used Lego blocks as the ABS source which allows some degree of color matching. The initial results seem good.
I tried both acetone and MEK as the solvent. MEK, although rather more toxic, seemed to give more consistent results in terms of application ease.
Small areas of wear exposing the ABS can also be covered using West System G-flex epoxy, with or without fiberglass. If one is using G-flex on ABS it is best to pretreat the plastic by briefly flaming it with a propane torch.
Flame?
Pblanc - I thought the flame treatment was for poly hulls. ABS too? I’ve used both Gflex and the regular West Systems epoxy on royalex boats without doing anything but a good cleaning and light rough-up. A year or more later, it seems to be holding just fine.
flame treatment for G-flex
West Systems considers flame pretreatment optional for ABS, but feels that it does increase bond strength some. Flame pretreatment for polyethylene results in a very dramatic increase in bond strength and is strongly recommended. For all plastics, wiping with isopropyl alcohol is also recommended and seems to work better than roughing the surface with 80 grit paper.
Cracks in any plastic material should be beveled and rounded. Deep gouges should be “guttered out” and the sides of the gouge beveled.
Here is a link from West Systems on bonding plastic with G-flex which also discusses beveling and rounding: http://www.epoxyworks.com/26/pdf/Gluing_plastic_Gflex.pdf
skid plate
fantastic info many thanks - my boat something like a Swift winisk; mostly a flatwater boat with some whitewater capability (just can’t be too technical). I will study all the solutions. The ABS slurry sounds interesting - and the epoxy build up for my uses. Many thanks