ANY EXPERIENCE W/ APPLYING ABLATIVE OVER HARD BOTTOM PAINT?

[John Stone]

Cape Dorians,
It's time for me to repaint the bottom of the Far Reach. I initially applied Interlux CSC because the boat would remain out of the water for a couple years after painting during the rebuild. It was also supposed to be a good paint for the brackish water of the Neuse River, where we sailed before our voyage to the West Indies. The paint did not perform well in the tropic--which we expected.

The Far Reach in on the hard back in NC. I recently talked with a very experienced local boat yard manager. He recommended we remove the initial coat of ablative bottom paint (not that difficult to do) and then apply two coats of a high copper hard paint. He recommend to apply hard paint for two seasons. Then, the third season, apply an ablative over the hard from then on out. He stated they had been doing this for decades with very good results. He made a very convincing argument for this approach. However, I have been unable to find any info about this technique. I have a phone call in to Interlux to discuss it. My experience with interlux tech reps has not been the best. But, I thought I would do due diligence by talking with them.

Does anyone have experience with this technique?
Thanks.

[Jim Walsh]

I've never heard nor read about this technique. It's a personal choice whether one chooses to use hard paint or ablative. Each has its good and not so good points, but I fail to see the advantage of resorting to the technique recommended by the yard manager.
My personal choice was to strip and barrier coat my bottom, add a coat of red ablative, then put on two coats of blue ablative. When I see red it'll be time for a coat (or a touch-up) of blue. Every environment is unique so what works in one harbor may be so-so in the next harbor. Some adjacent harbors have a good tidal stream, some do not, etc. I previously used Interlux CSC and Micron Extra but neither seemed ideal. I tried Sea Hawk Cukote and that is all I use now. It performed very well in Bermuda and performs very well in New England. I used to give the bottom a scrub mid-summer while at anchor but it hasn't been necessary since I changed paints. Everyone uses their boat differently and each harbor is unique but I've been lucky enough to find what works for me.

[Jim_B]

John - I'm using a similar process and it seems to work.

2008:
Soda Blasted bottom to gelcoat, Interlux Barrier Coat applied followed by Trinidad SR applied (this is a Hard Modified Epoxy).

2012:
Lightly Sanded bottom and applied 3 coats BlueWater Copper Shield (this was an ablative that at the time got high ratings from Practical Sailor).

I dive on Jersey Girl myself and recently notice the ablative is getting thin (I switched colors between Trinidad and BlueWater). I'm starting to see places where Trinidad is starting to show thru - and these areas show some growth between cleanings. I plan on re-painting with another ablative (need to research which one as the formulas have changed in 2016). I went this route because I didn't want to remove the build up of epoxy layers in the future. So far so good.

It is my understanding that ablatives can be put on top of ablatives or hard/modified epoxy bottoms. But Hard/Modified Epoxy cannot be put on top of ablatives. So you'd need to thoroughly remove your existing ablative.