You all know about this: When your boat is out of the water you see what happened to your hull. And most likely you mention to yourself that it would be time to redo the antifouling. Probably you wonder whether some mending work will be enough or whether you should remove everything that has been put onto the hull over the years, scratch off everything until you can see the original gel coat again and make it all new.

You may then decide to mend it once again and do the major refit of the bottom next year, because we all know what kind of job this is.

Anyway, the time will come when no excuse will allow another "next year".

For Dido's bottom the end of the last season was the point where to make a fundamental decision: everything on the bottom had to be removed and something new had to be applied. Thus, this raised two questions. First: How to remove the old stuff both entirely and conveniently (if one might hope that there could be any kind of "convenience" in that sort of work). Second: What antifouling to put on Dido's hull then?

Removing The Old Stuff

Sanding and scratching for many hours, if not days. This is the usual approach. And this is probably the major reason why most of us hate thinking about a new antifouling so much. Instead of starting sanding and scratching immediately I spent some hours with Google in the internet. This was my result:

I ordered some bottles of "Dilunette", a paint remover to remove any single-component coating (would not work with 2-components coatings), such as most AFs, and I ordered a sandblasting device that would work with my pressure washer. So it is not actual "sandblasting" but it is rather "wet blasting with some sand". Details below.

Dilunette

This paint remover is not too expensive and it is highly effective, I found out. If you want to use a paint remover you must make sure that it will not affect the GRP, especially the polyester resin of the gel coat. "Normal" paint removers contain chemicals that will aggressively soften the gel coat. Dilunett does not. Second reason why I used Dilunette of all paint removers: Most paint removers for boat hulls need to be covered with some sort of plastic foil for some hours in order not to dry out but do their job. Not so Dilunette.

What the hell is this Dilunette? It is a very simple substance that you even might make yourself: caustic soda resolved in water plus a thickener (otherwise it would run down the hull like water) plus an indicator color that indicated when the paint remover has done its job.

The paint remover has a consistency like jelly or jam. You apply it richly with a brush or so (the brush might vanish during the job if it is not resistant against caustic soda. Soft nylon brushes are appropriate).