I have been using Pettit Trinidad on my 28 foot sloop for many years (1981
boat purchased new). When we haul, the boat is pressure-washed, and then in
the Spring the loose stuff is scraped off and the entire bottom wet-sanded
with 80 wet-dry. I use a foam roller and about 3 quarts per coat on this
full keel boat with a 22 foot waterline. At this rate every 3 years I've
had enough paint on hand to avoid buying a new gallon. This routine has
worked for many years, and even though the boat has never been taken down to
bare glass, the buildup is not an apparent problem. In recent years the
boat has been kept on the Jersey Shore in brackish water.

This year I have decided to honor the titans of Wall Street and what remains
of the financial system by "going cheap." I took a new gallon of Trinidad,
split it in half into a new empty gallon can, added what appeared to be
about one half quart of last year's paint, and then thinned each can to
bring the volume to about three quarts in each one gallon can. This means
the paint was thinned about 25 to 27 percent, which is well in excess of the
manufacturer recommendations. In fact just about any source I can find
would disagree with my approach and advise that I will end up with less than
adequate protection. The only advantage to me is, of course, cutting my
paint cost by half.

I suppose I will find out in the Fall if this plan is practical, but I
thought I'd throw it out there to see if anyone else does it this way or has
similar experience.

--
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http://home.comcast.net/~kerrydeare