ABLATIVE BOTTOM PAINT

[nornaj]

We have just hauled NornaJ (SO39i). The boat is located in the PNW.

The bottom paint is black Pettit Horizons ablative. One coat was applied on commissioning in 2010, and a second coat in 2011. In 2012, we opted to leave be, and just touched up the water line, the stem, the leading edges on the keel and rudder, and (of course) the hull/keel joint.
There was more slime on the hull this year but, after power washing, the coating still looks pretty good.

On our last boat we used an Interlux ablative product and applied a black coat over a blue coat so we would (or might) know when to repaint.

Theoretically, it is my understanding that an ablative keeps on working until it has been entirely sloughed off. In practice, I am not so sure.

So, do we recoat now? Or do we leave be again, and just touch up the more vulnerable bits?

Appreciate advice, especially from multi-year users of ablatives.

Thanks
NornaJ

[sitara]

My experience with ablative bottom paint is that the copper leaches out leaving a powdery film that can sloughed off at rates determined by conditions of use. On slipping I have found that this layer sands off relatively easily, any antifould that still contains copper seems to be harder to remove and has a faint pinkish tint to it (the copper?).

My current boat was painted with International Ultra (dark grey) at commissioning and I am planning to use an ablative antifoul of contrasting colour over this when I slip in a few weeks time. I did get some fouling (shell fish) in places where the original coating was a bit thin so this was touched up at last slip.

[MartyB]

I usually get at least 2 yrs out of ablative pains in straight saltwater/Edmonds. I got 3 when in a brackish river/salt area, ie Everett. Not sure where you are in the PNW, you might be way north, or in my back yard.

I used Micron the first two coats since buying my boat. The original owner used micron the previous 20 or so. He claimed in the south sound, typically 2-3 yrs. I;ve used West Marines PCC the last two times. I prefer it over the micron as it seems a bit softer, so sluffs slime etc quicker at lower speeds. Cost was a lot less too. I went this way 2 yrs ago, hoping to sand off ALL of the bottom paint I have, epoxy and go to hard paint, as in washinton, you can get fined upwards of $10K for cleaning the bottom in the water. Where as with hard, you can lightly scrub off the slime etc with a towel or other soft item. When one races a bit, weekly in the summer, this is a nice option to have.

Marty

[nornaj]

Thanks, Guys
Marty, the boat is kept in Gibsons, BC. Brackish water. Less stringent regulations.
I scrubbed the hull yesterday, gently overall, with more vigour at the water line - to remove the blue stuff (copper sulphate...) and the associated roughness.
It looks pretty good. So (except for the waterline) I think we'll leave a full paint job until year 3.

[jdl01]

I have used petit horizons ablative paint for years in the Salish Sea and found that after two years the biocide qualities have been severely reduced. I tried going three years with just annual power washing but in year three the slime buildup was continual although no barnacles or mussels appeared.