Hi, I recently intalled a Fins Unlimited box into a board-and for some reason, in certain spots the outside edge of the box did’nt bond with my fiberglass/resin filler surrounding the box. I’ve filled the the hairline voids with lam resin and plan on adding a sheet of glass to try and assure stability. Is this a good idea? Has this ever happened to anyone before? Should I just router out the whole box and try again? Any suggestions are appreciated.
I think the problem you descibe is due to the box expanding a bit when the resin heats/kicks then contracts back when it cools back down. This has happened to me in the past. All I did was fill the hairline crack with some pigmented resin and I had no problems. Some would disagree but I would not bother with glass over the seam (then you will have problems blending it into the rest of the board). And you don’t need to route out the box, again, unless you just want to practice. The best way to install the box is to route your slot after shaping, put a cap on the box and laminate/hotcoat over it (this area will be elevated a bit). Then when you sand the board you sand through the elevated area knocking off the cloth and sanding through the cap on the fin box. If you don’t go crazy with your sander very little touch up (with hotcoat) is needed. You can do the same tech, with lease plugs. Good luck.
Graham!..next time you install the box, make sure that you PRE-WASH the box - itself - in warm, soapy water (a LITTLE Dawn or Palmolive dish detergent added to the h2o)…RINSE WELL, and DRY WELL! Sometimes there is residue from the mold release, and this can affect bonding. It never hurts to add a cloth patch reinforcement about the box (especially in your case). Good luck,…T.
P.S…what mike d. said - above - is most likely the case. You can also rough up the sides of the box a bit (sand lightly) before installation to provide more “tooth”.
Graham!..next time you install the box, make sure that you PRE-WASH the > box - itself - in warm, soapy water (a LITTLE Dawn or Palmolive dish > detergent added to the h2o)…RINSE WELL, and DRY WELL! I thought the best way to clean up something before gluing with resin was acetone(sp?) wrong? -Håvard
Havard…You are correct, sir! the only caveat is that some boxes vary in composition. Acetone can melt. (handling issue). But, yeah, you are right (I try to play on the “safe” side/“green” side).