Hey composite peeps; back in June I finally pulled a mold off a carefully made plug I really sweated at many many months/off hours on! All good except there were some distortion events in fit critical places:(. This was laid up from tooling fiberglass, epoxy and orange tooling gelcoat. The epoxy was applied within an hour of the gelcoat. This mold is for a string musical instrument it’s about the size of a classical guitar/1/4 cello. The problem came in the U shaped channel (neck) expanded about 1-1.5mm in all directions which is a problem for precise fit and feel of the fingerboard - A part that I’ve been successfully molding for the last couple of years and using on my wooden builds (my core business though I have been applying some composites since 2013). No doubt the dimensional distortion was a heat induced event. Other molds I’ve never had any problems scuffing it up a bit, wiping with acetone, and applying some layers of gel coat and sending it to correct polish shape if a repair was needed. This situation is a little more challenging though because I have to make sure that the fit/feel is perfect for the finished part that will be assembled to it.
My approach is to cast a part from the bad area (bondo and saran wrap)and carve its surplus dimensions it to the right proportions, feel and dimensions. Essentially what I’m thinking of doing is damming up both ends of the channel and floating this (polished/waxed/PVA Coated-temporary plug) in gelcoat to compensate for the deficit area. Lake a slightly smaller boat hull floating in the middle of another boat hull acting as a plug to correct the Bad area. Again we’re not talking about more than a millimeter two in all directions. Anybody out there pull off a move like this?:idea: