VC 17M Extra Bottom Paint Failure

VC 17M Extra is ubiquitous on the Great Lakes and considered primarily a fresh water paint. However, I have had very good experience with it in 10 years of snow birding on two different boats, one sail and one power. I bought both boats in Detroit and nothing else can be applied over it so I’ve been stuck with it but found it very satisfactory, until now. We didn’t even need to paint the bottom until our second ICW trip and the paint had a good deal of time on it when we bought the boat.

I always painted myself, the last time in August of 2019. The boat then spent a month cruising Long Island Sound in September and on to Georgetown MD where it spent a month on mooring. It then went to Tybee Island, GA for another for another month in a slip over the holidays. We cruised to Saint Augustine, FL where it spent the month of February in a slip while we lived aboard before returning to Norfolk where the boat was hauled for a month while we returned home. There were only a few scattered barnacles and the discoloration was slime that could be easily scrapped off with a fingernail. We didn’t even have the boat pressure washed but just put it back in the water.

About a week after launch, we hit a log in the southern Chesapeake and had to have the boat hauled to repair shaft and prop damage. We decided to have the yard also paint the bottom so we could go right aboard on return due to Covid and the rather remote location.

We cruised from the yard back to Georgetown MD where we left the boat on a mooring for the month of July. The boat spent the month of August and September far up the Hudson River where barnacles are unknown and on a fresh water cruise of the Erie Canal. We then took it to Little Creek, VA where it spent a month in a slip before proceeding to Saint Augustine moving nearly every day on a fast delivery style trip. We hauled out in Saint Augustine last week to find the bottom covered with live barnacles.

Question: Did the yard screw something up here or is this just one of those things that can happen when conditions are right?


The picture with the prop was taken just after haul for the repair and the other picture is what we just found.

Possibly the yard did not use your tried and proven paint but only a branded facsimile.

You took a paint that (at best) has marginal anti fouling properties into one of the highest fouling regions in the country, that’s what happened.

fstbttms said:

You took a paint that (at best) has marginal anti fouling properties into one of the highest fouling regions in the country, that’s what happened.

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Yes, but I've been doing the same thing on the same general routes and schedule for 10 years. What changed?

Roger Long said:

Yes, but I've been doing the same thing on the same general routes and schedule for 10 years. What changed?

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Barnacle growth varies from year to year. Maybe you got unlucky and it's a bad year for them this year.

I would suggest to "find out what happened" means sending a sample of each paint to a lab.
I will guess the new paint is a failure even if the old paint would have been marginal.
I had that happen to me many years ago. Good Pettit paint, I thought, and 1 year later the bottom was a mess. Of course they gave me replacement paint but nothing for the hours to clean the bottom of the barnies.
Mine looked similar to yours.

A poor quality paint failure. It is possible they did not mix it properly leaving the bulk of the copper or whatever on the bottom of the can but that would be total incompetence.

Several of us sailboat racers in North Florida spent years trying to use that stuff because it was such a fast bottom but it's antifouling ability sucks in this area.
The manufacturer states " Low fouling cold salt water use ". That's not St Augustine !

I just heard back from the yard. Within half an hour of receiving my email they had double checked with the applicator and also sent me a detailed time sheet showing that he mixed and applied the paint exactly as I would have. Bottom line, you can't leave a boat for a month in Little Creek, VA in the summer with VC17M.




BTW the level of customer service, communication, and attention to detail of Yankee Point Marina in Lancaster, VA is beyond anything I have experienced. I can't recommend them highly enough but even the best yards slip up occasionally and I had to check.

For your next paint, I'd be tempted to try Pettit Black Widow. It's just about as smooth and hard as Black Widow, but has better antifouling properties. It still may not be enough down south though.

rslifkin said:

For your next paint (snip)...

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I don't think there will be a next paint. There are a lot of other things I would rather spend the money on than the cost of stripping back to bare gel coat, which VC 17 requires due to the Teflon in it. I've had 15 years of good experience with it as long as we keep moving and are careful where we leave the boat. I prefer to have it on the hard anyway when we are away from it. It usually doesn't cost much more, there is less to worry about, and corrosion and bottom growth are suspended.

I just took a look at the Interlux and Pettit compatibility charts. According to Interlux, nothing goes over VC-17 except more VC-17. However, Pettit does say a couple of their paints can go over VC-17. Any of the Hydrocoat paints as well as Neptune HRT say "sand and apply", while SR-21 says "clean and apply". Black Widow and most other paints are off the table though, as they'd require the VC-17 to be removed.



So if you're expecting to need to leave the boat in the water down south at some point in the future, you'd have the option of sanding and throwing some of the Hydrocoat ablative on there. And if you put it on thin enough, you could always power wash it off, sand a bit, and go back to VC-17 later.