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Posted by on May 15, 2009 in Boat Maintenance, Sailboat Racing, UK, US | 1 comment

Bottom Paint Puzzler…The More You Paint, the More You Can Sand

Among the rites of spring is the ever-elusive pursuit of the perfect racing finish.

Five coats used most of these three gallons of top-of-the-line Trilux 33 bottom paint.

Five coats used most of these three gallons of top-of-the-line Trilux 33 bottom paint.

Early this morning, my partner, Peter, and I met underneath our International One-Design sailboat in New London and proceeded to sand off a fair amount of the 2+ gallons of Trilux 33 that our friend, John Evans, had spent all week applying. That was no accident; it’s just the name of the sailboat racing game as we pursue the ideal racing finish. Using soapy water and wet-or-dry sandpaper, we applied elbow grease with 220 grit, then 320, then 400, and pronounced ourselves reasonably satisfied with the smoothness of the bottom when we were done.

Of course, perfection is elusive on a wooden racing sailboat such as Norwegian Wood, built exactly 50 years ago (in Norway). And so, as usual, we discussed several ideas for improving on the bottom, next year. For example forward on the side I was sanding (to starboard), a few of the planks are in less than perfect sync. Maybe we should take the bow down to the wood and “spline” the seams, using epoxy?

Peter sands the soapy port side of our International One-Design.

Peter sands the soapy port side of our International One-Design.

On the other hand, the bottom of Norwegian Wood has remained much more stable over the last four years since we began leaving her in the water all winter. Our routine now is that she lives at the dock at Crocker’s Boatyard, and then gets pulled out in late April for just a few weeks. If we get our work done quickly, the wood never dries out and the seams don’t open up.

When you’re sanding on opposite sides of the boat, the conversation waxes and wanes. For some odd reason we found ourselves discussing sandpaper more than once. We compared our respective sanding styles, of course: in my case I don rubber gloves and use the sponge frequently; Peter prefers to be able to feel the finish with his fingertips. At one point, Peter explained that I was folding my sandpaper the wrong way and showed me how he rips the paper and folds it to avoid the grit working against itself.

“Where does the numbering system come from?” asked Peter, at another time. “Maybe something to do with the density of the grains of sand?” This afternoon, I floated the question past Jim Seidel, my technical guru at Interlux Paint. Here’s part of this answer:

“The number on the sandpaper refers to the size of the abrasive. I sat through a long but extremely interesting presentation from 3M about abrasives and as I recall there are a couple of different grading systems. The most common one is from ANSI (American National Standards Institute) and it ranges from 12-grit where they glue rocks to paper to 3000-grit which is like that green lined paper they gave you when you were learning to write in the 1st grade. The letter after the number refers to the backing A being lightweight and E is a heavy backing.”

Wikipedia has a whole section on sandpaper, and it shows three numbering systems; I was interested to note that they define the sandpaper we were using as very fine macrogrit to very fine microgrit. Especially since it was rough enough to have some side effects: Peter called me from his car to report that three of his fingertips were bleeding from his overzealous sanding. He admitted that gloves might’ve been a good idea. That may be true, but I think he got the port side smoother than I got the starboard, and I appreciate anyone who bleeds for his team.

With topsides and bottom freshly painted, Norwegian Wood looks good at age 50. A party might be in order this summer.

With topsides and bottom freshly painted, Norwegian Wood looks good at age 50. A party might be in order this summer.

Norwegian Wood should get wet over the weekend and hopefully her rig will be installed in time to tune her up over Memorial Day Weekend where the Wet Paintbrush trophy is up for grabs for any  IODs ready to sail in the first Fishers Island (N.Y.) Yacht Club race of the season. Hopefully our aches and abrasions will have healed by then, and we’ll be ready to go.

—John Burnham

1 Comment

  1. The boat looks great!