Cheap red antifouling

[Jenaline IV]

I am in the porcess of rebuilding a trailer sailor which has the cheap red antifouling on it of the type that you can get off ebay I am guessing. I have repaired the hull in places below the waterline and I wanted to reseal/repaint the bottom.

Can I be lazy and paint straight over or should I take it back to undercoat/bare plywood and start layering up with 2 pack primer?

I am not decided on antifouling it once as it will spend a week in the water at the most thus I cannot see the point.

Any advice greatly appreciated.

 

[oldharry]

First of all you say you want to repaint/reseal the bottom. Any repairs you have done MUST be watertight before you start painting - paint doesnt stop leaks. Well not for long anyway!

As to how you go from here: it depends on how much of a job you want to make of it. Two pack primer is not necessarily the best for use on old ply as it is expensive and rarely sticks any better than ordinary primer to old previously painted plywood, particularly if there are still traces of paint in the grain as there will be, or if the ply still has a high moisture content (not the same as 'wet' or 'damp', and really only measurable with a moisture meter).

If the original antifoul is in good condition - i.e. it is adhering firmly, not lifting anywhere - then your best bet is to coat the whole thing in an underwater wood primer, giving several extra coats over the new wood in the repairs. After that you can put what you like on it by way of overcoat.

If the old AF is crumbling and flaking, then it needs to come off, as it will continue to crumble and flake under anything you put on it.

 

[lustyd]

If you're day sailing and keeping it on the drive you won't need antifoul. If you're leaving it in the water give it a scrub with a deck brush and then paint over the top. If you plan to do no sailing but want a very pretty boat, strip it back, buy a bunny suit and wander around the boatyard telling people about your "project"

 

[Jenaline IV]

Thank you for the clear advice both of you ;-)