I have been thinking about the aging fleet of composite gliders around the world and the problem of gelcoat crazing and cracking. Every owner must be wondering at times about the remaining life they have on their gelcoat and about the eventually inevitable refinishing. The approaches to this issue so far have been three-fold in my opinion.
First and most often practiced is to dump the problem on someone else and to sell the glider to the next unsuspecting owner. That of course solves nothing as far as the problem of degradation and crack progression is concerned. With refinishing prices >$25,000 often exceeding the value of the glider, the owner may be stuck with a severe depreciation of the aircraft and eventual cracking and chipping of gelcoat down to the composite load bearing structure. The glider might not pass the next annual inspection.
Second and practiced by many including me, is to postpone the aging by frequent waxing and buffing and by re-sanding the crazed surfaces. John Murray when asked about my LS-4 some 20 years ago said: ‘ Just sand the be-Jesus’ out of it, that will make the cracks less visible and you can fill them easier with wax thus delaying moisture progression down to the glass’. Did that on this one and other gliders with good success but again, not a permanent solution.
Thirdly, the repainting or re-gelcoating of the entire glider or affected components. This begins with the removal of the old gel-coat by means of grinding and sanding. The major concern with this method is the very significant price for the procedure (if you can find someone willing to do it at all) and the question of how close the resulting profile is to the one the glider had coming out of molds. Re-painting with urethane based paints may give you a 20+ year peace of mind but these paints don’t really have a track record yet.
Looking at new products in the automotive and powered aircraft field there may be a fourth option. Paint replacement and paint protection films are offered for example by Avery and 3M and they seem to be just the ticket to get many more years out of virtually all composite gliders. The protection films seem to be the cheapest way to go (used for Auto-Bra’s and such), they are clear films of about 0.2 mm thickness and the installation is fairly easy. They should protect the gel-coat from UV-light and oxidation but crazing may still be visible through the film.
Total paint replacement would use a slightly thicker film with white probably the only color of interest to us. They are also called car-wrapping films and can be printed on in any color, the base film is white. You see them on delivery vans with colorful graphics advertising their services and recently on race cars. Application is probably best left to an expert. They come in glossy or matt colors and would completely hide the gelcoat imperfections. If I went for these, I would probably still go through the sanding and buffing steps mentioned above to prep the surface. Manufacturers of these films give a “lifetime guarantee” whatever that means but all stress that the film can be removed any time after installation without damage to the underlying surface.
Questions arise regarding small dings and the chafing glider surfaces experience for example in trailering as well as hangar rashes. From what I found online, repairs can be done but I have yet to talk to an installer. A full car wrap is said to cost $2,500 to $3,000 and I wonder how much an entire glider would go for. My gut feeling is that wrapping a glider in total or only the wings and elevator would be a cost effective way to get some 10+ more years out of your middle-aged glider. Gelcoat protection for newer gliders might also be of interest. Information from experts in this field and from applications on aircraft including gliders would be helpful.