PART 2: GEL COAT REPAIRS
Last week was the easy stuff: washing, polishing, drinking beer. Now we get to the real grit, to separate the boys from the men. GEL COAT REPAIRS - not for the feint of heart. I am of course, joking. It is so easy, even your wife could do it, in fact she'd probably do it better than you!
The most difficult part of a gel coat repair, is matching the color accurately. So fear not, oh novice handyman!
To start, wash the area with soap and water, removing all the wax you applied last week. Then tape off the area with automotive tape. Tape off an area about double the size of the repair, to allow enough working space.
Next, gouge out small, narrow cracks until they are wide enough to fill with gel coat paste. A miniature grinding tool like a Dremel is ideal, but the sharp point of a can opener will work, too. (If you don't open the crack, you won't be able to force the gel coat into the repair area or expose enough surface area for the repair to adhere.)
Then sand lightly with 220-grit sandpaper. After sanding, thoroughly clean the area with acetone to remove the sanding residue and any waxes or other contaminants that might interfere with the bond between the damaged surface and gel coat. Don't get high on the acetone, open a window!
The next step is to match the color of your existing gel coat. Start with a white or neutral gel coat paste (not resin) and begin adding tiny amounts of coloring agent. Mix several test batches of gel coat and pigment, add hardener and allow them to cure (gel coat changes color during the curing process). Once you've found an acceptable match (an exact one is nearly impossible), mix a final batch using the same ratio.
Next, using a putty knife, fill the areas to be repaired with the paste you've mixed. Force out any air holes and be sure to overfill, as gel coat has a tendency to shrink as it cures. When you're finished filling, seal the repair off from the air with a PVA curing agent or a piece of plastic wrap or wax paper. Gel coat does not cure properly when exposed to air.
Once the gel coat has fully cured, sand the repair smooth (wet sanding works particularly well with gel coat). You can start with 220-grit sandpaper and, for a really slick surface, finish with at least 400- or 600-grit. Finally, apply a coat of high-quality marine polish and your repair is complete. Time for a beer!
If your gel coat has major cracks exposing the fiberglass, you are better off not trying it yourself if it's your first time working with it. Take it to a pro for advise and to make sure there is no structural damage.
Till' next time, mateys!