pblanc wrote:
I tried applying an ABS slurry to it twice, once using acetone as the solvent and once using MEK. The initial results looked pretty good but both times after a single low water run, significant portions of the ABS scratched off or came off in chips where the slurry had been applied to the "valleys" of the rippled hull surface. The areas of the underlying hull to which the slurry had been applied looked unaffected, suggesting that the slurry had not physically or chemically melded with the hull, as some have suggested.
A word of caution: both acetone and MEK dissolve ABS. You can get away with applying these solvents briefly to the solid ABS elements of Royalex because they flash off so quickly (acetone quicker than MEK) but either will dissolve the foam core of Royalex pretty quickly.
Pete, that ABS slurry repair technique was greeted with great fanfare a few years ago, but the enthusiasm seemed to die off quickly as folks had various degrees of success. The lack of specifics, especially in DIYing the slurry mixture (which solvent, what scrap plastic to dissolve, solvent-to-plastic ratio and wait times, etc), was unnerving to me when I considered trying it.
More unnerving was the thought of spreading acetone slurry on an already damaged RX hull and possibly getting it into the foam core. With the extensive damage and outer skin cracks on the bottom of the OP’s Raven I’d keep any aggressive solvent as far from the hull as possible. A barely damp and quickly flashed-off swipe at most, or maybe just wash, dry and alcohol wipe the hull and keep the acetone in the next room.
The tales I’ve heard from owner’s admitting their boo-boos and from manufacturer’s telling stories of customers getting acetone into the foam core sound harrowing, like a creeping leprosy unstoppably eating into the foam core.
Speaking of manufacturer’s Royalex tales, with RX gone the way of the Dodo perhaps some “Now it can be told” RX stories are waiting in the wings; foam cores that didn’t expand properly, ovens that malfunctioned (or were re-assembled incorrectly after a factory move), bad Royalex sheets received from SparTech or PolyOne (with some manufacturers purportedly accepting RX sheets that others rejected), and the difference between pre and post 1991 Royalex when the sheet manufacturing process was changed.
I gotta wonder if any manufacturer rejected their last precious RX sheets they were able to order from PolyOne in its dying days. There could be another slug of queer RX hulls in the pipeline, similar to the oddities from 91/92.
(The best of those oddities may have been a friend’s OT Pack – that “Pack” must have weighed 50 lbs. The paddlers is a big guy and he removed the thwart, so the only cross-support in the canoe was the dowel hung seat. He still has the Pack and still paddles it thwart-less; it may truly be the world’s “best” OT Pack, at least until you pick it up).
In those “Tales that can now be told” department I still wonder why some (few) wood gunwaled RX hulls cold cracked and many others didn’t. I believe it was due most likely due to some combination of manufacturing miscues above, and not some peculiar freeze/thaw/expansion that could occur even in more temperate Maryland or Virginia and not crack every wood/RX hull in the northcountry.
It’s a mystery, and if RX sheet or factory mistakes are the reason I can see why the manufacturers were happy to have cold cracks remained unresolved and ill-explained.