Bottom Paint - Hydrocoat, Ablative

[Donzen]

Wondering if someone knows if one can put Hydrocoat paint over any "unknown"
bottom paint.  Would a fella have to completely remove all previous coatings or can you just go forward with the new paint after proper preparation of the old bottom paint.  Any wisdom here would be greatly appreciated...............Thanks

[Bob23]

Donz:
   Don't know about wisdom, but here goes:
   When I bought my 1985 23/2, it had hard, black bottom paint on, brand unknown. I used Hydrocoat in blue and had fantastic results! To prep, I hand-sanded with 80 grit, washed down with a hose, and I think I did an acetone wipe-down right before painting. Just can't remember right now. No problems with adhesion. The original black paint is coming off in small patches so a complete stripping and barrier coat job might be in my future. But no problems whatsoever with the Hydrocoat. In my opinion, this is the best bottom paint out there. Environmentally friendly, fast drying, super easy to apply and minimal odor.
   The Hydrocoat dries fast because it's water based, it's inexpensive and- best of all (hold on to your seats, ladies and gentlemen)- it's multi- seasonal. I put my first coat on in the spring of 2006, used the boat all summer and, upon fall haulout- found growth only on the botton of the keel where I manage to touch bottom now and again.
   During the winter of 2006-2007, I called the Pettit tech guys asking if I had to recoat. His exact words to me: "If there is paint still on the boat, just touch it up and it's good to go." I put her in spring of 2007 and sure enough, at fall 2007 haulout, same clean bottom. Did the same thing for the 2008 season. That's 3 summers with 1 coat, plus touch-ups where needed.
   This year, I recoated the entire boat because she's worth it! And I didn't know if I could squeak a 4th season of the first coat. I bet I could've, though.
Bob23, happy painting!

[Donzen]

Bob23...

About how much paint was required for one coat (Quarts/Gallons) ?

How did you apply it?  Roller or brush?  And, If you had a helper would you find any advantage to one guy applying via roller and the other guy brushing it out fairly quickly?  Thanks....

[Bob23]

Donz:
   I still have some of the original gallon left. It was plenty for the initial coat and all the touch-ups that I mentioned. After a few years, it started clumping up a bit so I bought a new gallon this year. Another nice thing about Hydrocoat- if you have to thin it after a while, water is the thinner!
   I cut in with a brush and rolled the large areas. I suppose a helper would be beneficial to brush out where you've rolled, but I did it myself.
   By the way, where do you sail? I'm in NJ, 40 degrees N lattitude. If you're in much warmer waters, your results might be different.
Bob23...have fun painting! 

[Donzen]

Bob23,
Sailing in NC, esp. Pamlico River & Sound & ICW.

Donzen

[Potcake boy]

I used Hydrocoat on my 19, after removing the previous unknown paint.  I suspect that it was an ablative but wanted a good clean start.  As was pointed out, if you don't start with a good substrate you could end up redoing the project anyway.  Part of the reason I went with Hydrocaot was that I applied it with an airless sprayer and could get a good cleanup with water.  The finish I got was much smoother than with a roller and better control of application - leading edges got an extra squirt.  I applied two heavy coats and used most of the gallon.  The adhesion is truly impressive with this paint and all I've lost so far has been from objects left submerged in the muck from Hurricane Charley.  Winter time the water level in the river stays persistently low and the salinity high.  One weird thing is that where the keel spent a good bit of it's time at the pier submerged in this muck, there were some really strange growths which finally came off with a focused power wash.  I'm thinking maybe the submersion in the muck inhibited the ablative design of the paint allowing the growth to remain.  Or maybe it was just some mutated from of amoebic life that lives in the toxic wasteland of silt at the bottom of the canal.  Anybody for a swim?

**Here is an improtant note for anyone who trails their boat a lot but may leave it in the water (fresh or salt) for extended periods.  A very good option is an epoxy copper coating. Tough abrasion resistant and water proof coating with good growth resistance prevents blistering and hard growth and won't come off from launching and retrieving.  Just need to scrub the algae now and then because it is free of biocides.  Here is a link to a company that sells this as a non marine product - meaning that it is priced within reason - same stuff you can buy for much more through commercial marine suppliers. 

http://www.epoxyproducts.com/  Give them a call, they are very helpful with application recommendations and technical support.