Bottom paint and barrier coat project

[paulswagelock]

So my marina is a family owned place, and very flexible. I had them block and sand my boat so I could do the bottom paint.

I chose Sea Hawk Tuff Stuff epoxy for the barrier coat. Picked up a 2 gallon kit on Ebay for $130 shipped to my door. 1:1 mix ratio, and very thick. Only needed two coats to get recommended thickness.

I selected Blue Water Marine Aqua Shield. It is a hard ablative, water based paint with ~45% copper. Very similar to Pettit Hydrocoat. I contacted them during the winter and offered $160 for two gallons shipped to my house. To my surprise, they agreed.

So, sanded early this week. Two coats of epoxy early today, and the first coat of bottom paint late afternoon. Storm coming in the morning so I did not do the second and third coat of paint. I will go back and do those.

Here are the pics. Gray is epoxy, black is bottom paint.

 

[jmagdaz]

What "nap" roller cover did u use? I'm gonna b starting the same project next week.
Thanks

 

[paulswagelock]

I went to Sherwin Williams and purchased their Mohair roller covers for the 6" mini rollers (~1" diameter roller). They are only available in one nap length, which appeared to be about 1/8" nap. The epoxy or any other solvent based coating will cause the regular rollers to leave lint and eventually have the roller tube fail. These applied the epoxy very smooth, and using the Tuff Stuff it only took 2 coats.

For the water based paint I used the multipurpose covers from Lowes. They were 3/8" nap. The water based paint leveled out nicely with this nap. I wanted a thicker coat hence the longer nap for the bottom paint. If I was using a solvent based bottom paint, I would use the mohair covers for it as well.

It was very easy work - since I did not sand....

 

[paulswagelock]

Here is the end of season update.
We had some very warm weather and the summer water temps went well into the 80's. The boats around me had heavy slime and growth, very thick and heavy. Mine stayed clean, just black paint.
I pulled it this weekend. There was a little light slime right at the water line since the boat sat the last two weeks, but very light. Spraying with a garden hose cleaned it right off. Not a single area needed scrubbed. This paint worked perfect.

 

[firecadet613]

Good to hear. I may paint my boat next year as we are leaning towards slipping and not trailering.

 

[ppwhite]

What is the trick to removing bottom paint ? Sanding ,soda blasting,paint stripper. I sanded on my old boat and it was not fun. If you are sanding what kind of sander are you using.

 

[Henry Boyd]

I went through a similar process last spring as well. I started with having the bottom soda blasted, followed by the Pettit epoxy barrier and Hydrocoat bottom paint. Same results at the end of the season.

To answer the question about preparation, I went with soda blasting because my existing bottom paint was failing and flaking off in big patches down to the gelcoat. To sand it would have taken at least a day (at $ 85.00 per hour) and still would not have guaranteed that more old paint would not flake off in the future. The soda blasting cost about the same ($ 750.00) and removed everything, and left a nice rough surface to work with. The downside, if there is one, is that soda blasting may reveal pin holes in the gelcoat that require filling with thickened epoxy, before painting with the barrier. But then again this is why you would be barrier coating.

In my case it took 4 coats of epoxy and 2 of bottom paint to get the right thickness. And while I got a good deal on the paint, my paint bill was substantially higher than Paul's. I personally think that given the level of work and cost of materials, if there is pre-existing paint soda blasting is the way to go.

Henry