Yes, it works. I mixed the acid with water in a bucket, brushed on with a deck
bush, let it sit a bit and then scrubbing. Sometimes it takes three or four
scrubbings to get the slime loose, but time seems to work wonders. Don't let
the stuff dry and you just have to rescrub. Do a few feet at a time, soak
down, scrub, resoak, rescrub, etc.

btw, in case anyone is not familiar with oxalic acid it is sold in hardware
stores as "wood bleach" (read the label as other things are also sold as wood
bleach).

OK guys, here is one to sink your teeth into.

I was advised that the best option for cleaning growth off the bottom of a
fibreglass hull is Oxalic Acid. Apparently it does not damage the glass or
gel coat, but it literally strips any foreign matter on the hull clean off.

Has anyone had any experience with this?
--
Garry Beattie
Ocean Spirit Trailer Sailer &
Small Yacht Cruising Emagazine
www.ocean-spirit.com