My 10 year old MR Synergy has been wearing through the vinyl, right under where I sit on the triple saddle. For about a year I have been protecting the exposed ABS with 303 or spray paint, but it became clear that the vinyl under the whole area beneath my butt was worn quite thin. I wanted to get a thin patch on the area to take the wear and protect the ABS from UV.It is possible to apply various patches over the vinyl, but on my boat the vinyl was so gouged and cut that I thought I would rather just remove it. I also have a superstition that epoxy and other "hard" adhesives may stick better to hard ABS than to soft vinyl. Can't prove it, just seems like it might be so.
When putting glass cloth skid plates on an OT Tripper I owned, I removed the vinyl by using a cabinet scraper. But on the Synergy, working on that flat undersurface, I thought I would try a 1/2" wood chisel.
That chisel worked great!
It was properly sharpened, and I held it at the lowest possible angle of attack, with the wood handle down against the boat. Pushing steadily, the vinyl peeled away from the ABS cleanly, and the chisel did not cut into the ABS.In fact, I found that once I had a decent vinyl peeling started, I could often take it in my fingers and pull it away from the ABS by hand. I formed a stronger respect for whoever origninally chose vinyl as an over-skin for ABS. The vinyl is very tough, and the bond is every bit as good as it can be for very dissimilar plastics.
With the vinyl removed from the ABS in the area under the center seat, I took some 100 grit paper and first roughed up the ABS. Then I sanded down the edges of the vinyl so that the patches would lie properly across the transition zone. And I sanded out a ways on the vinyl, feeling that I wanted to see how a glass patch would stick to the viny as well as directly to the ABS.
I cleaned the area carefully with alcohol and dusted it as well. Then I cut two concentric oval 6oz satin weave S-glass patches. I couldn't find the cheap scissors I prefer, and cutting that satin weave on the bias was as hard as cutting Kevlar.
It was 90 degrees in the carport, and it was darn lucky I had the slower West 206 hardener. The larger oval patch went on first, extending well past the skinned ABS area. Satin weave does not wet out easily, and by the time I had the entire patch wet out and laying down, I could feel the epoxy getting hot in the plastic cup in my hand.
I mixed more epoxy, and laid the second patch on top of the first. The second patch extended only a little beyond the skinned ABS area. It started to wet out on its own, pulling excess resin from the first patch, and I brushed on more to get the second patch wet out. Then I worked over the area to take care of resin-starved areas and bubbles.
Tomorrow I will have some serious sanding to do to smooth the exposed edges of the S-glass. Then I will brush on some UV protecting urethane varnish to protect the epoxy.
I could have mixed graphite powder into the epoxy to get the patch to slide off rocks more easily, but I decided not to do that so that I could see into the patch and see how it holds up in the future.
There was perhaps no need for two layers of S-glass, given that the skinned ABS appeared undamaged. And I will have to sand those layers a good bit to get them smooth. But the area immediately under the pedestal seat is a high stress area.
What we really need is something as hard or harder than the vinyl, that sticks extremely well to the vinyl, and that goes on thick so that it replaces wear on the vinyl. Ordinary paints stick pretty well, but cannot be built up in thickness without getting gummy. Then we could just sand vinyl to prepare it, and then apply this magic substance. Epoxy, in my opinion, is too brittle. Ideas anyone?
