Yachts - Use Of Paint And Black Lead For Outer Surface
( Originally Published 1911 )
THE discovery of some mixture for the coating of a yacht's bottom that will fill all the needs of the racing yachtsman is still far from being made. The ideal surface coating for a racing yacht should embody the good qualities found in copper and white-lead paint, black lead, and any other racing compounds of note. The qualities necessary in a perfect covering are smoothness; giving the least possible friction to the water, durability, or being able to stand the action of salt or fresh water with-out softening or losing its luster, and the ability to keep off any growths of animal or vegetable nature. Another quality should be that exposure to the sun's heat shall not blister or soften the coating.
The matter of expense is, of course, an object to a great many people, but surfaces that are in common use to-day cost a hundred times more than any covering or coating in reason could possibly sell for, as now it is necessary to haul the racing boats out every week in order to have the best possible surface.
From my experience, both with salt and fresh water, pot lead or graphite polish, properly looked after and applied, seems to be the best racing surface for the small boat, the great objection being that it is not good for more than a week, as it softens after being submerged and becomes spongy.
I think the best preparation of pot lead today is the graphite powder called "Black Silk" mixed with spirits and varnish, so as to make a mixture slightly thicker than paint, applied to the hull with a brush. This, allowed to dry, becomes fairly hard and dull black in color. Then rub down with fine sandpaper, or old pieces that have been worn more or less smooth, so that the grains shall not cut the surface. This hardens, and it becomes a shiny, smooth surface. Then a rub-down with emery-paper, and lastly use newspaper for the final polish. The surface depends largely on the amount of elbow grease and labor, combined with care, that is put into it. The lead should not be put on the plain planks, but should have for a foundation a hard, smooth coat of white-lead paint to give it a body.
The first few coats of black lead will not be as satisfactory as the ones later in the season, and each coat put on is better than the pre-ceding one. You should never attempt to paint over black lead, as the paint will not stand, but very quickly peels off, much to the disgust of the owner. There is no benefit in using pot lead unless the owner is willing to haul out his boat very often and renew it, and it is not as satisfactory as a good surface of paint, unless you are willing to do this. Remember that it becomes foul very quick, and then is a great disadvantage.
There have been in the past few years many different sorts of composition, each one claiming to be far better than the last. This may be so, and every one for some reason or other has his pet composition ; one reason being that it is easier to secure, another, that it is better suited to the condition and temperature of the water where the racing is done. I do not think there is much difference between the best grades manufactured by the best people.
For the under-body the light green copper paint with a certain amount of varnish in it seems to be as satisfactory as any. It stands very well, and I have seen it, in some cases, come out after one or two months' submergence with a good gloss and shine. Barnacles, however, had adhered in certain places, and a few little bunches of weed showed, but on the whole it was very good.
The regular copper paint used on many of the large vessels is, of course, an excellent preservative against worms and vegetable growth, but it is very difficult to get a racing surface out of it. In the warm southern waters it is absolutely necessary to have some protection against boring worms and other animals, as they will soon perforate the planking and cause much trouble.
For the topsides a nicely smoothed surface of white paint or black varnish, standing hard, is about as good as anything, and has many believers among the racing fleet, with a good foundation for their belief.
Varnished mahogany topsides, when well done and cared for, compare favorably with anything ; but they are a great care, and it is necessary to keep working on them to preserve the surface free from seam trouble and scratches.
On this matter of racing surface a great deal can be said, according to the weather conditions in which it is to be used, and I know of no composition that can be said to be the best under all conditions.
Further, it cannot be impressed too strongly on the racing yachtsman that the skin friction should be reduced to, a minimum in order to obtain the greatest speed.