Hull blasted, now what?

[Bigjim]

I just had my hull soda blasted, which took off a ton of old paint. The hull looks good. No bad damage. Just a couple of blemishes that will need some filling and sanding.

Here's the starboard view of the boat:



Here's the stern view:



It was suggested that I use a couple of coats of Petitt Protect and then a bottom paint.

Some say to use an ablative, others say to use a hard paint.

What paint do you use?

Also, does the barrier coat go right on now? Or do I have to do any other prep work to the hull, other than fill and sand any fissures?

[senormechanico]

barrier coat should be followed up with first coat of paint while it's still tacky to get a good bond.
If the boat is sailed a lot, ablative has advantages. Self polishing, smoother surface.
It will show you when you need to repaint.
Hard paint is better if the boat sits a lot without being sailed, because it doesn't depend on new surface being constantly exposed.

[keepondancin]

I would suggest you look into Interprotect by Interlux, and follow their directions. Now is the time to do it. One thing about ablative paint over hard paint, the ablative washes away so you keep reducing the amount of paint on the bottom. Hard paint keeps building up, and at some point, all has to be removed again. You mentioned tons of paint. You also should probably find what is most successful in your area of use.

[Bigjim]

People are using both types here.

The ablative paint is good because you can see when and where it has worn away (if you use a different color). According to the paint rep, you can simply paint over the old paint because the new paint automatically resolves into the old paint (if you are using the same type).

Hard paint has to be sanded and prepared, according to him, but can last several years. According to him, the price differential is even if you follow recommendations and replace paint as suggested.

Obvious, actual experience differs. This is my first time painting any bottom. A friend, who has lots of experience, said that he recommends spraying the paint for the best results, or we will have to sand imperfection that occur when using a roller.

[Bigjim]

Originally Posted by senormechanico

barrier coat should be followed up with first coat of paint while it's still tacky to get a good bond.
If the boat is sailed a lot, ablative has advantages. Self polishing, smoother surface.
It will show you when you need to repaint.
Hard paint is better if the boat sits a lot without being sailed, because it doesn't depend on new surface being constantly exposed.

We sailed almost every week, but only for an hour or two each time. A few times we sailed 6 hours down to Chicago and then back on the next day or day after. So, frequently, but not demanding.

We were setting the boat up for racing, but never did any.

The new boat is larger and NOT designed as a racer. I'm planning on doing more extended cruising this year.

[CSY Man]

I had my bottom soda blasted a few weeks ago.
Use 2 coats epoxy primer and or barrier coat before bottom paint.
Have always used hard paint and have gotten as much as 4 years from 2 coats of Trinidad Pro in Florida and the Bahamas.

[steamgoat]

My two cents, barrier coat followed quickly by one coat of hard anti fouling ,a different color from what the final coat will be. Then ,if you go ablative,you will know when it’s getting thin as the other color will start to show.

[JOHNMARDALL]

Before you apply a two part epoxy barrier coat in accordance with the manufacturer's recommendations, and using a different color for each layer so that you can see where you've been, check the hull for divots, mini-craters and other surface damage. Fill all of them with a soft finish epoxy putty, such as West System resin and 410 filler, fortified with a little fumed silica to reduce sagging (can't remember the West number). This is very easy to sand, either by hand, palm sander or orbital sander. As all of it will stay cool below the waterline, there is no reason to use a rock hard, heat-tolerant filler. It's a couple of day's work that will significantly increase the longevity and effectiveness of the barrier coat.

Good luck
John Mardall
Vetus Maxwell Group.

[fatherchronica]

We are not using Mana much right now, but due to being in Humboldt Bay an ablative paint would be fine. The tides rush in and out, not like some places I have been in Bristol Bay, but pretty fast.

[aluijten]

Originally Posted by CSY Man

I had my bottom soda blasted a few weeks ago.

this “paints” a quite colorful image in my head

Cheers!

[fkittson]

Just a suggestion, and we do this all the time in the high end boat shop I run. Do your first coat of barrier paint and once you have reached you recoat time mix your next batch up. Once you induction time had passed pour of a small amount of the paint and mix in cabosil to a peanut butter consistency. Go around with a plastic spreader and fill any pin holes, gouges, and nicks. Make them as smooth as possible. Then apply your next coat. Another tip is when you tape your water line do as many layers of tape including bottom paint. Your first layer of tape will be at the exact hight you want you paint to be. The next tape layer will be 1/16 to 1/8” lower and so on. That way you will not have a big ledge of paint at the water line.

[icemate]

Originally Posted by senormechanico

barrier coat should be followed up with first coat of paint while it's still tacky to get a good bond.
If the boat is sailed a lot, ablative has advantages. Self polishing, smoother surface.
It will show you when you need to repaint.
Hard paint is better if the boat sits a lot without being sailed, because it doesn't depend on new surface being constantly exposed.

How right you are. When I first purchased my sailboat I did the same thing. West Systems Barrier Coat, two coats and used an offshore epoxy paint. 13 years later and a trip to Australia from NY and not one blister. Good advice.

[flyingfin]

Here is another vote for Interlux Interprotect. Apply first cost, then the next day do a second coat, use a tint on the second coat so you dont miss anyplace. If you have enough left, do a third coat. No more than 24 hours between coats and you dont need to sand. Then bottom paint

[CSY Man]

Originally Posted by aluijten

this “paints” a quite colorful image in my head

Cheers!

Haha, I should had specified.

[Bigjim]

Originally Posted by fkittson

Just a suggestion, and we do this all the time in the high end boat shop I run. Do your first coat of barrier paint and once you have reached you recoat time mix your next batch up. Once you induction time had passed pour of a small amount of the paint and mix in cabosil to a peanut butter consistency. Go around with a plastic spreader and fill any pin holes, gouges, and nicks. Make them as smooth as possible. Then apply your next coat. Another tip is when you tape your water line do as many layers of tape including bottom paint. Your first layer of tape will be at the exact hight you want you paint to be. The next tape layer will be 1/16 to 1/8” lower and so on. That way you will not have a big ledge of paint at the water line.

Thanks. I saw the same suggestion on a video. Good idea. That's why this forum is so good. Things you'd never know or learn only after hard experience.