John - and others - RE: additives to epoxy for repairs, and especially for repairing cracks. If abrasion resistence is the only criterion, an aluminum additive is available. For practical purposes, epoxy thickened with Cabosil silica hardens to an almost stone-like consistency and has very high heat-of-deformation properties. But - it's very difficult to sand. I mixture of Cabosil and silica microballoons (the while ones) can be made up to be acceptably abrasion resistent for most practical purposes. Certainly it can be much tougher than gelcoat or unthickened epoxy. I've used a mix of 3 parts microballoons to 1 part Cabosil with good results, and it doesn't heat-soften even at temps of ~200 F for 45 minutes or so. It sands pretty well. System Three sells this pre-mixed, but you can just as well make it up yourself. A mix of 2 parts microballoons and one part Cabosil is tougher, but more difficult to sand. Wear a good HEPA filter mask at all times until this is completely mixed into the epoxy. You DO NOT want this stuff in your lungs! Also - for color - pigments are available. I got mine from "System 3" but I think they're available from West , from West Marine, and probably lots of other places. Mixed with the Cabosil-microballoons, the pigments aren't pure and colors will never come close to matching your gelcoat, but they make an acceptable undercoat. You can then paint with your favorite toxin, for color match. Bill Hansen Ithaca NY *************************************************************************** PaddleWise Paddling Mailing List - All postings copyright the author and not to be reproduced outside PaddleWise without author's permission Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Thu Jun 15 2000 - 07:36:05 PDT
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