I can't answer specifically for your area of the Chesapeake, but I've been using an ablative for about a decade, applied over a hard epoxy paint, originally applied by the dealer. I've been using Interlux Fiberglass Bottomkote ACT, using just about a gallon per year (I haul out every winter). I do have a few areas that flake off over the winter each year, and could probably benefit from a soda blasting to remove it all, since there are about 13-14 years worth on there. Maybe next year. The past few years, I've had lots of soft growth, and more than a few barnacles. But... I get a quick haul and wash in Sept. and asked the marina owner how I compared to everyone else, and he said I was actually better than most he sees. Seems the extra hot, wet summers of the past few years affect the growth.

I'm on Worton Creek which is fresh/brackish water, so may not apply to your area.

A recent discussion over here in Australia about the application of antifoul.
Some yards do not allow enough time between coats for the paint to dry properly. This is all done in the name of reducing the yard rental costs. Plus if if wears off quickly because it was not applied correctly, then you have to haul it out again and reapply - generating them some extra $$$.

Conclusion - check the drying times and follow the manufacturers recommendations.

If you can develop a product that would keep the prop and shaft clean you'll make a fortune... people try all different things but none work really well.

I've been using the Hydrocoat water based paint with the slim resistor for the past two years. Its a multi season paint and last fall it came out of the water in such good shape I'm only going to touch up a few spots, particularly along the water line. Before this coat, I had sanded it pretty much down to the gelcoat. I found one gal was pretty much all I needed.

I use hard paint on the prop and shaft. If you use ablative, it just washes off. I still get some junk on it and have to clean it a couple of times during the summer. Someone is going to say I shouldn't do that because the brass prop and the properties of the paint don't coexist, but I've been doing it this way for over 20 years and have not had a problem. The only issue is I get a slight hum sound at lower RPM when I first launch from the paint on the tip of the blades. This stops once some of the paint on the tips wears off.

By the way, we had a paint company guy give a talk about bottom paint and he was asked the question you asked about the prop. He suggested a primer paint and then hard paint. I followed his directions to the letter and had no better results then what I do now... simple hard bottom paint.

We use Prop Speed on the prop (funnny about that). I was told that for it to work, you need to spin the prop every few weeks - to throw the growth off the prop. Even if you are not going out sailing, just rev the engine and turn the prop. Not sure if its ideal for the engine to run for a short period of time, but I am sure somebody will let us know.

I used Pettits barnacle barrier coat on the prop and shaft .I haul out every 3 years and it seems to work. Alot of boat yards in the pacific northwest are using it

We've used Lanocote or some automotive bearing grease on the prop and shaft. The grease seemed to work better than the Lanocote.

We're in different waters than you (East End of Long Island) so our paint experience may not be relevant, but we've used WestMarine PCA Gold (ablative) for a while with good results -- seems to last several seasons with just a light touch-up at winter haulout. 1 gallon will do.

I usually get almost 2 coats with one gal. That being said, if your going with 2 gal's, keep painting until your out of paint. Then you'll be sure to get at least 2 years out of it. Some people use abaltive with a different color from the base bottom coat so you can see when your abaltive is wearing thru.

I sand with a medium grit before painting and wipe it down with acetone... I guess any thinner would work as well. I don't know about where you are, but in our yard we have to use a vacuum sander. I use a shop vac and put a large contractor garbage bag inside the vacuum. That way most of the dust is right in the bag for disposal. The sander itself gets messy but all you can do it wipe it down afterwards.

Pressure washing will remove the barnacles and growth

Robert, the jack stand question depends on the yard. Some are VERY insistent that no one touch the jack stands except yard employees. They are afraid that someone who messes up will topple the boat and maybe damage others, too.

What is done, however, is to place an additional jack stand next to the one you want to remove. Get it set properly against the hull, chain it to the opposite stand, and then remove the old one to prep and paint the spot it covered.

Your keel will be resting on a block of wood. The only way you will get access to that for any work/painting is when the boat is hanging from the travel lift. My yard builds in a little time for you to scrape/paint the bottom of the keel if you want.

Good luck with the work. It can be grueling at times, but worth it knowing you did a good job.

[QUOTE=rtrinkle;21622]...the boat yard says ablative can be put on hard paint, but not vice versa.[/QUOTE]

This is an untrue generalization that says plenty about the boatyard.