Soda Blasting and Bottom Paint

By Dave

Each year we and every other boat owner in the world put a copper-based paint on the part of our hulls which are under water to retard marine growth, like barnacles. After a while, the paint builds up to the point where it has to be removed. One of the methods of removal we use is soda blasting. An air-filled barrier is placed around the hull and a man wearing an environment suit and a full-face air mask goes inside and cleans off the old paint. It works like sand blasting but the soda won’t abrade the hull, just the old paint.

After they finish, the boat owner is left with a fine residue of sodium bicarbonate on the hull and in any fissures in the hull material which he usually removes by spraying it with vinegar and then washing it with water.

One of our neighbors in the yard had this done recently and so he got a garden sprayer and filled it with vinegar and began to work. The result was fragrant (and foamy).

A passerby smelled it and inquired, "Watcha spraying on your boat?"

"Vinegar."

"Why?"

"Makes it go faster."

The inquisitive man walked off mumbling to himself.

Shortly thereafter, another curious soul noticed the smell and stopped by.

"Whatcha doin’?"

"Spraying vinegar on the hull."

"Why?"

"My dad used to do this every year. Said it was cheaper than bottom paint." This is important. Bottom paint is EXPENSIVE. Some brands sell for more than $200 a gallon. Naturally the man was interested in this money-saving idea.

"No kiddin’? Does it work?"

Nope, but it’s cheaper than bottom paint."

Maine people have a weird sense of humor.