[alarie]

I repair boats for a living, and this is the most common phone call we get. People with old, gelcoat finishes want to restore or redo their existing, faded finish to "like new". To regelcoat a surface, you must repair any crazing or cracking (which is a whole other subject), sand the whole surface to 80-120 grit without making the surface unfair, fill any last minute divots, holes, pinholes, lows, or whatever, and then reapply the gelcoat with spray equipment. You cannot roll or brush apply, it is a total waste of time. We typically spray on a thinned (lacquer thinner and Duratec) coat without wax, let that tack off and fill any visible pinholes, then spray on 3-4 more coats of the same mixture, putting wax in the last coat so that it is not tacky when it kicks. This will give you a textured surface when it is hard, that then must be sanded to at least 600 grit, and preferably 1000 and buffed a minimum of 2 times. Assuming a good spray job, you may be able to start with 220 or 320 grit, and you must sand smooth, change grits and repeat up to final grit. We use Dykum, a machinist dye to color the surface, so you can tell when all of the last grit scratches are removed, dying with each grit change. If you leave coarse grit scratches in the surface, it will yellow after a short time. After sanding you buff like crazy and then you are done.

This is a huge job for even a 20' hull, 60 hours if you really know your stuff and have good equipment. It is the best solution, however, so the work is worth it if you are willing!

Another solution is to get boatbuilding qualtity buffing compounds and really do a nice job buffing out your old finish. YOu can get very surprising results if the gel is in good shape overall, just faded. We use Aquabuff 1000 and 2000 to do this type of work.

Good luck,
Peter