Safety note about bottom paint

[Jeff Gray]

Hi All,

I had an odd experience with anti-fouling bottom paint that might be worth knowing about. I’ve been having a problem with my Hunter 260 centerboard (long story), and fixing it has required swimming under the boat in about 4 feet of water to work on it (yes, one held breath at a time!). To keep myself from floating around with no leverage to do anything useful, I found I could plant my feet on the sand in a crouching position and wedge my left shoulder against the hull above to fix myself in place. Works great and I found I could quickly get into this position and fuss with my centerboard pivot for 15 seconds or so on each breath. I have to go back and do it some more next time I’m up at the lake, because I wasn’t able to solve my problem last weekend. Like I said - long story. But my “working underwater” technique worked out great!

At the end of the day of doing this probably 50 times or so, my shoulder was a little sore, but no biggie. I figured it for a bit of bruise from pressing up against the hull all day. By the next morning, though, I had what appears to be a nasty burn there on my shoulder, which is now, 4 days later, a blistered, peeling, oozy, mess. I also picked up a bit of sunburn all over my back and shoulders, so I suppose it could just be what happens when you combine a sunburn and a bruise, but it looks to me more like a chemical burn, which I’m thinking could be from a reaction to the bottom paint on the boat. Unfortunately, I don’t know what kind it is. Previous owner put it on. It a eems to be working, though, because the bottom is completely clean after being in the water since Memorial Day. So it seems reasonable to me that it could be corrosive to skin. I don’t know.

Anyway, thought I would share in case anybody else has bottom paint on their boat and a need to come into contact with it. I know I’ll be wearing a tee shirt next time!

Fair winds!
Jeff

 

[rgranger]

Thanks Jeff

I took my boat to the house this spring and pressure washed the boat. The grass under the boat died.

 

[Rick Macdonald]

I guess I guess it would be hard to wear this suit while under the boat in the water?

 

[nat55]

This shows up on just about every SDS sheet for bottom paint that I've ever read, water based paints aren't quite as caustic...

Hazard Statements:
Harmful if swallowed
Causes skin irritation
Suspected of causing cancer
Causes damage to organs through prolonged or repeated exposure
Flammable liquid and vapor

 

[thinwater]

I think it is far more likely a combination of abrasion and rubbing marine life and bacteria into your skin. I would never lean against the bottom without a shirt for that reason. In saltwater, barnacles are notorious for causing bad skin infections.

The primary antifoulants are zinc and copper. Zinc is not toxic to humans (but it is to plants) and copper is slightly toxic to humans, but far more so to plants. Curiously, though too much copper is toxic, there is actually a minimum RDA for good health (copper deficiency is rare).

 

[thinwater]

This shows up on just about every SDS sheet for bottom paint that I've ever read, water based paints aren't quite as caustic...

Hazard Statements:
Harmful if swallowed
Causes skin irritation
Suspected of causing cancer
Causes damage to organs through prolonged or repeated exposure
Flammable liquid and vapor

(You mean toxic, not caustic, which is about pH. Water based paints lack the solvents, which are some of the more toxic ingredients.)

The question in my mind is "which ingredients are suspected of causing cancer?"

Not copper. Search it.
Not zinc. Search it.

Solvents. Yes, some of them have been "suspected" for many decades. First, this suggests the case is rather weak. More to the point, they are ONLY a hazard when applying paint, and not when removing it. This is an important distinction, because it changes the PPE worn while working (VOC when painting, particle when removing).

Proposition 65 chemicals are NOT carcinogens by the common definition. These are materials that have failed certain classifying tests that suggest they may be a problem. With the exception of silica, these have not been established as carcinogenic by human or animal tests. With the exception of silica (ground sand) these are all volatile and are long gone.

(Petite Trinidad)

I am genuinely interested in understanding the hazards, but I'm not seeing anything dangerous here in old bottom paint that is wetted with water.

 

[Apex]

... but I'm not seeing anything dangerous here in dried bottom paint ...

...but the paint is wet, the boat is IN THE WATER.... :O) LOL I see you already modified, your post. I would agree more with thins 1st answer: ...likely a combination of abrasion and rubbing marine life and bacteria into your skin.

 

[thinwater]

...but the paint is wet, the boat is IN THE WATER.... :O) LOL I see you already modified, your post. I would agree more with thins 1st answer: ...likely a combination of abrasion and rubbing marine life and bacteria into your skin.

The reason I added "wet" is that sanding dust is hazardous if inhaled (most fine dust is), but that's not relevant here or even terribly specific to bottom paint.

I recently read a rigorous study of industrial sand blasting practice for ships. Wearing standard 95% eff OSHA masks (not the cheap white things) the workers were well within OSHA limits for 8 hour/day, everyday exposure. Assuming you use a vacuum sander (they won't let you work with out one--and for your yard mates sake this is reasonable) and you only do this one day a year, you would be hard pressed to reach over exposure.

• The vacuum with capture >90% (sand blasting is zero capture).
• The paint is largely spent before removal (about 2/3 of the copper and zinc were gone).
  
• You are only working one day.
• The solvents are not part of the equation.
• The sander is down wind, if you are at all bright.

I'm not saying don't wear a mask. Things can go wrong. I'm just sayin' that if you are doing a little prep sanding, as up[osed to stripping the bottom by sander, the math isn't very scary.

What have I missed?

 

[Apex]

good posts thinwater. I was only trying to make a joke about dry .vs. wet (by virtue of being in the water)...and if you have to explain a joke it was poorly delivered...

as far as bottom paint, stage of life, and toxicity go: excellent details.

I think your initial instinct for abrasion induced sealife or organisms is spot on for the OP.

 

[Jeff Gray]

Great points all, guys. I hadn’t thought about the possibility of it being from marine life, but that makes a lot of sense. It’s in fresh water, so there are no barnacles, but there’s a nice slimy feel there that does mean bacteria.

Either way, whether it’s the paint or the slime. I’m wearing a shirt next time!

 

[Rick Webb]

Knew a guy in Hawaii who wore a long sleeve shirt and a garbage bag to keep the critters off of him when he cleaned the bottom in the water.

 

[thinwater]

I wear a cycling balaclava when cleaning the bottom, even in summer, to keep the shrimp out of my hair and ears. Really.

 

[Crazy Dave Condon]

The use of a smooth sponge on the bottom of a boat to remove slime regardless of location is fine but be cautious of contact. Never use any scrubbing pads. Otherwise remove the boat from the water.
Use of protective gear is a must. In my yard sanding with electrical equipment I insisted vacuumming the dust Into a container; otherwise, the dust would get on other boats particularly the older boats which would cause many problems cleaning not to mention owners upset. In addition the dust was not good to health and does not present a clean yard to show boats. I generally stocked 2 acres of new boats of various sizes with a clean yard for presentation which my customers and competitors were amazed of cleanliness.

 

[JimInPB]

In the old days, some bottom paint had mercury in it. The stuff worked great, but mercury is a poison that can be absorbed through the skin.