Tuesday I took a break from being unemployed to help my friend Denis finish the gelcoat on a catamaran he’s building. Denis is French, so say ‘Dun-nee,’ and ‘finish’ here means ‘wet sand.’ By hand.
We started at 280 grit paper and ended at 2000, with 320, 360, 400, 500, 600, 1000, and 1500 in between. The 280 and 320 papers remove the bumps, bubbles, and ‘orange peal’ left over from spraying on the gelcoat, and the rest remove the scratches from the sanding. 360 polishes away 320′s scratches, 400 polishes 360′s scratches and so on until 2000 works it smooth into a dull glow, ready for buffing and wax.
Normally one wouldn’t re-apply gelcoat to a boat hull fresh out of its fiberglass molds. Before glass and resin are laid into the molds, a healthy coat of gelcoat is sprayed on. The gelcoat gives the part it’s finished texture and color and helps the part release from the mold after it’s set. Denis says the manufacturer didn’t spray enough gelcoat into the mold prior to lay-up and the finish on parts of the hull was too thin — the underlying glass and fiberglass matt were visible on the surface. To fix it, Denis sprayed additional gelcoat over the thin spots. To fix that, Denis asked me to help out with the sanding. The cockpits, rails, and cockpit hatches were in the worst shape, and those were the parts I spent the day on.
Cleaning up after sloppy fiberglass manufacturers requires skills I think I could learn in a few months (even a few weeks). Denis also built the catamaran’s ‘plugs’ — the boat parts from which the molds that later form production boat hulls are themselves formed around. I’d need a few years to learn the skills needed to carry out that kind of work. With a little thought, a little guidance, and the proper tools, most of us are capable of maintaining — or constructing — almost anything. Building the proper tools requires real knowledge.
Here’re several pictures of the plug and a prototype during construction a couple years ago, and here’s Denis beside his handiwork. The hull is not as big as it seems; Denis is short, even for a Frenchman.
