Preparation of GRP hull prior to antifouling

[Penbodlas]

I am going to convert my boat (MacGregor 26C) from a trailer-sailer to one on a saltwater mooring (summer only). Up to now it has had an unpainted, polished bottom and I may wish to go back to this one day. I only need single season antifouling, not too much work and am looking for advice on initial prepartion without power tools. I will go for an eroding/soft antifoul but the preparation - sanding, priming, etc. seems to be the bit I need to get right.

 

[SailJunkie]

Start by...

sanding the gelcoat to rough it up. Then you can either barrier coat the hull (with a barrier coat resin from Interlux etc.), OR acetone wash and apply your choice of anti-fouling paint. Personally, I'd do the extra work to barrier coat (which is usually 3 applications...a bit more work), and then add the AF. Most manufacturers (at least, when selling into the Great Lakes region) only barrier coat the keel...why...to save $$. I had issues with my '05 C-310 due to faulty prep work (the sordid detail should be in the archives), however my dealer went to the mat and stripped and barrier coated the boat at their expense (a $2500.00 job)...I still stand by a barrier coated hull.