In my earlier post, I mentioned that the peeks get sanded down but not the valleys, they remain un-sanded; the inside of these microscopic broken glass bubbles (cups) are made of smooth glass or cured un-sanded epoxy. Knowing this, I would not consider "hard-shelling" as a practical alternative to the conventional lay-up.
Epoxy dose not stick to GLASS. Try gluing some epoxy to a mirror (reflective side - plz) and see how easily the epoxy peels off the mirror, after cured. Your creating much the same effect when you allow the Micro Slurry to cure (hard-shelling). By only knocking of the sharp points prior to your layup, you haven't even come close to preparing the Epoxy surface for the secondary bond (removing the impurities and the sheen). This is why we use peel-ply, if you can't sand it, you peel-ply it. Even then, hit it a few times with the sand paper and wipe clean before bonding! As for testing which is stronger, were not talking about grabbing a handful of glass cloth, epoxied to foam, and pulling to see which is stronger. Were talking about the bond between the cured fiberglass top layer and the hard-shell. The test I'm looking for would be to insert a balloon between the Epoxy/GLASS (hard-shell) and the cured Epoxy/Fabric layer and inflate. Isn't this what's going on during extreme temperature changes and differing atmospheric pressures? Maybe someone could show me where it say's, the best way to get a secondary bond on cured epoxy part is to do nothing, no sanding, no washing, no wiping/vacuuming - once cured just add more epoxy and your good to go. I'd luv to see that. Also, could someone be so kind as to show me where it says, Epoxy sticks to GLASS - It would really put this whole, should I or shouldn't I hard-shell to rest. Larry A Capps Naperville, IL "Good judgment comes from bad experience, and a lot of that comes from bad judgment." -----Original Message----- the problem was not in "hard-shelling" if it happened only in a localized area. I used slurry much the consistancy of honey. I applied it with a rubber squeege and removed as much as possible so as to seal the foam only. I brushed the foam with sandpaper once or twice after the slurry cured to remove little "prickleys" that would snag the glass when I would attempt to move it before wetting it out. I would then wet the glass in the normal manner. I laid up all the glass on my KR without assistance from anyone and never felt rushed and that includes scratch built wings. I'm still convinced that the bond between the cured slury and the glass/resin is stronger than the foam core and that the glass is bonded to the foam with the same strength as when the glass is laid up over wet slurry. Larry Flesner
