Bottom paint

[pschauss]

Do you guys paint the bottom of your boat every year? Two years ago, my yard media blasted my hull, filled in the blisters, and applied a barrier coat. They applied antifouling paint that year and last spring. Assuming that the paint has good adhesion (I still need to do an inch-by-inch inspection to verify this), can I skip having the bottom painted this spring and have it painted every other year? When I bought her seven years ago, it appeared that the previous owner had had her painted every year and she had a serious amount of paint built up on her bottom.

My boat is usually in the water from early April to early November. My slip is on the Connetquot River, Great South Bay, Long Island where salinity runs 20-25 parts per thousand.

[Tony Meola]

Peter

Was the first coat they put on a different color than the next several coats of Bottom Paint? If they did, then it should be ablative and then you only need to touch up any areas that may peel or repaint when the first coat starts showing through. It also depends on the power washing when you come out of the water.

If they hit the bottom hard, they may wash off enough paint that you have to repaint. The Marina that pulls me for the winter, does such a good job, I think half the paint is taken off. They have a really strong pressure washer.

If you have to recoat in two years, then when you do, I would put on at least two coats, three is better only because it may last longer.

If they used hard bottom paint, then they say paint every year. But if you want to gamble you might be able to skip a year. I have a friend who only uses hard bottom paint. He touches up any peeling and wipes the rest of the bottom down with paint thinner. Never has a problem but his boat moves at least 4 times a week.

No matter which way you go, you will probably have to repaint the running gear each year.

[Yannis]

Peter,

I only use hard anti fouling.
Every year I keep the boat in the water for 4 months (June-Sept).
When I take her out in late September, they power rinse it within a few days.

Before launching the following June, they pass it a mild sandpaper.
Then, they apply two coats of anti fouling.
Half way through the season I may grab a rough sponge and try to clean some nuances of a thin green film, no barnacles of any kind though. When I'm lazy I don't do anything.

Anti fouling doesn't build up.

On my other little boat I tried to skip a year. There was a more significant green film accumulated during the season. I had to clean a couple of times during the season mainly for aesthetic reasons. But this is an easy task, the boat is very small. On the Bertram I wouldn't want to go through this so I apply anti fouling every year.

[Carl]

The hard bottom paint builds up as each layer is applied. The copper and chemicals leach out from the paint surface when in the water preventing growth. I believe some of these surface leaching paint stop working after long layup periods…check that last bit it may be old tech, or I may just be wrong

I prefer Ablative bottom paint…soft, it wears away as the boat runs through the water leaving a fresh surface of growth inhibitors. The paint is usually multi season as layups do not affect it from working…just run boat to wear away the old for a fresh layer or protection.

The down side of ablative…it is often more costly. It also needs boat to be run often for a fresh layer of inhibitors to be exposed, and by run a quick putt-putt ride may not cut it. Boats gotta go… the other issue is the paint wears away…run it long n hard often you”ll wear away a layer of paint. It’s a reason they recommend a layer of one color paint with finish coat of preferred color. If you see the under color being exposed you know you went through the top layer. Those areas are in spots that see aggressive running…bow to keel and aft running surfaces. It’s spots to be doubled up with paint for next season.

Other down side is a scrub at the beach will see lots of paint removed, an aggressive power wash on haul out means your painting again next season.


I’ve recently become a fan of water based ablative. It works very well keeping growth at bay, it goes on very easy, thins with water, no stench, and it washes off me with soap n water. The other stuff…scrubbtill red, wash in acetone n still had paint all over…I’m not a neat painter. I also found water based is not as expensive…but can come close.

Running gear…I don’t bother painting it with bottom paint, I just try to use boat to keep it clean . Or I’d use prop speed..,but easier and cheaper to just use boat more.

[Tony Meola]

Carl

I moved to water based bottom paint 12 years ago. Have not looked back. Big downside, it really comes off when power washed. More than the ablative I was using before I went to the ablative water-based paint.

I will say that at the old yard, I did get two to three years out of a couple of coats of bottom paint. Just that the current yard does such a good job, well I am painting every year.

[Carl]

Tony-

I use use about 3/4 gallon of water base to paint bottom. I usually give a quick 2nd on running surfaces.

If boat was not power washed so aggressive at the end of the season I’d be good for another year without painting.

[Yannis]

We avoid ablative anti fouling because we use our boats for swimming.

The water around the stationary boat is contaminated and as you climb up you may touch the hull that transfers the paint on you. Which is a poison...

[Carl]

The water around the stationary boat is contaminated and as you climb up you may touch the hull that transfers the paint on you. Which is a poison...

...poison never killed anybody.

[Tony Meola]

Yannis

I always found that the hard bottom paint would come off on me if I rubbed up against it when climbing in the boat. So I don't think you can win either way.

Plus, a little paint never hurt anyone. You can just ask the yard dog. Every spring she use to wind up with paint in her fur as she wandered the yard checking out who was working on their boats.

If I worried about a little paint on my hands, arm, face I would have been dead years ago.

[Yannis]

The hard paint does not rub against you, the ablative does.
This usually rubs on your back, without your noticing, as you touch the boat while swimming. You then sit somewhere and you pass it on the backrest of the chair...
If it rubs on your fingers and you then touch your face and eyes...you will remember it for quite some time.
Also, the tests carried out on dogs came up with inconclusive results, as the dogs didn't live long enough to prove any theory...

Stay away from anti fouling, whether striping it off with a grinder, or applying it with a brush. Touching, smelling, inhaling this thing is highly toxic.
Have other people do this job for you.

[Carl]

Yannis- your concern will have me rethink the mask I use when scuffing bottom to re-apply before spring launching. I have not noticed any sensation after swimming around boat, or my usual routine of checking bottom n gear at beach involving a brush n scrape in water. That said, I may give a good rinse after doing so and avoid diving into a sandwich or whatnot right after that swim.

Tony- I think many us us have ingested way too much bottom paint dust, toxic chemicals and such over the years, including yard dogs and yard people. Yes, many make it to ripe old ages seemingly fine, but do we know what life would have been like if that ingestion did not take place. Aside from the biocides in many paints, copper, and cupreous oxide are known toxins. I'm not altering my life, but will modify to avoid within reason. Want to go down a rabbit hole...start researching the "toxic" effects of alcohol on the body.

[Yannis]

Carl,

You will not notice anything just by swimming around the boat.

However, if your anti fouling is ablative, then by definition it disperses constantly into the water and if you swim around it you're bound to ingest it as you sometimes rinse your mouth with water while swimming.

Furthermore, what is terribly toxic is the dust of anti fouling while grinding old surfaces to prepare for the season, or just by sand papering.
I would never do any such work without a proper mask, better yet, I would always assign this job to the yard people.

The fresh paint itself is equally toxic, and rightfully so, how else would it prohibit marine life to stick to the hull?

PS: In Greece we have many shipyards. Ships come into the floating docks where their hulls are sand blasted or water blasted to remove old anti fouling. The cancer rates in the vicinity are twice that of the standard population as the wind blows this toxic dust to the houses nearby, onto the clothes left out to dry, onto the outside verandas where people inhale the dust while sweeping them,..., in general I would consider anti fouling as toxic as asbestos.
Why do you think you are supposed to cover the ground under the boat before you start grinding to remove old anti fouling? It's because this thing is so toxic that it will pollute everything in its path.

[Carl]

Yannis- Ablative disperses sorta kinda. I believe ablative means it gets carried away, that is it gets removed by the friction of water when moving. Boats sitting in a stagnant slip with ablative will get growth as the old layer is not being removed to present the new layer of anti foul. But I am far from a chemist and never researched enough to make any stand or proclamation.

Now ships, commercial big vessels used to be able to use antifoul paint that was banned for recreational use. Things may or may not have changed, but the stuff they used was far superior to what we can buy, way more toxic.

Whatever the case, better mask this coming season and our place has mandated bottom sanding must have vacuum attached with correct filter. And of course tarp under...

[Tony Meola]

Yannis- your concern will have me rethink the mask I use when scuffing bottom to re-apply before spring launching. I have not noticed any sensation after swimming around boat, or my usual routine of checking bottom n gear at beach involving a brush n scrape in water. That said, I may give a good rinse after doing so and avoid diving into a sandwich or whatnot right after that swim.

Tony- I think many us us have ingested way too much bottom paint dust, toxic chemicals and such over the years, including yard dogs and yard people. Yes, many make it to ripe old ages seemingly fine, but do we know what life would have been like if that ingestion did not take place. Aside from the biocides in many paints, copper, and cupreous oxide are known toxins. I'm not altering my life, but will modify to avoid within reason. Want to go down a rabbit hole...start researching the "toxic" effects of alcohol on the body.

Carl

I can't imagine how much asbestos I have inhaled in my youth. My father had a gas station. When doing a brake job we use to use the air gun to blow out the brake dust. Filled the garage with a cloud of asbestos. But back then, who new.

[Yannis]

Carl,

Alcohol can only have positive effects on the body !!!
For enhanced positive effects, simply augment the ration, what is it you don't understand!! Hahaha!!

[Amberjack]

It’s interesting we all have such different experiences with bottom paint. Amberjack usually get 6-7 years between coats. The boat was painted spring of 2023 and last spring on the annual lift didn’t even need a pressure wash. We lift the boat every year late one morning for a quick bottom inspection and zinc change (every year) and the yard crew drops it back in when they return from lunch. 1 1/2 hours in and out.

We are in salt water 6 months and fresh water 6 months but I don’t think that’s the whole story. We usually log 500 miles every summer at 22-24 knots which probably helps inhibit bottom growth.

Yard practices are strict around here as we are on the “ left” coast. No boat washing except on the lift pad which drains into a settling tank which is pumped and hauled away. All yard work is done over a tarp and sanding is prohibited unless tented. I’m OK with that since I like to catch salmon, but then I look out my window at the 520 floating bridge which drains directly into the lake including copper brake pad dust and tire dust both of which are toxic to Sockeye salmon. Lab experiments showed it killed 50% of young fish which came into contact with it.

Back to bottom paint, early in my career I did our own bottom painting on our 52’ sailboat. One year I got into it up to my elbows working overhead. I wound up sick as a dog for 3 days and my wife, bless her heart, finished the job for me. Now I don’t touch the stuff and even the smell makes me queasy.

[Tony Meola]

Doug

The secret to a clean bottom is keep the boat moving. As you know from your own experience.

Our regs on bottom paint are almost like yours. Boat can only be power washed over the pad. We started out with containment and filtering of the water but some reason they stopped mandating it.

If you sand or scrape, you need to have the ground covered. We do not have to tent when sanding only when sandblasting.