Barnacles - More Good Than Harm?

[GeneM]

It sounds like you have a fully ablative paint. That will come off with barnacle scraping. I've switched to a hard paint, which is still a little ablative. I use Pettit Trinidad.

The deciding factor for fully ablative seems to be good if you do much cruising, like twice a week. I let the boat sit for months and then do long trips, going to the Bahamas.

Before a trip, I scrape the propellers and rudders (express cruiser). I let the barnacles grow when I'm gone and find that they saturate the props and rudders, especially in FL summer. I don't scrape monthly because that seems to remove too much paint.

The rudders and props pretty much lose their paint, but the hull doesn't attract many barnacles. I clean them when convenient, like in the clear Bahamas water.

I have a SCUBA tank, but prefer to freedive for scraping. My daughter was a competitive freediver and taught me how to do it safely.

[Tillerjockey]

take a quick trip up the hudson to around pougheepsie and spend a couple of days. Barnacles don't like fresh water and will fall off. Back in the day, way back in the day when bottom paint wasn't very effective, I'd take a weekend trip up river in the middle of each season. Now the abalative paints are fantastic at keeping your hull clean, sometimes for multiple seasons.

[Seighlor]

Scrape your waterline barnacles now. Removing the mature barnacles will be something of a chore. Once clean, go over the side every few weeks and scrape away the baby barnacles. This will be much easier than the job you're facing at the moment.

As to bottom paint, here in Florida I use Trinidad 75. Just repainted a few weeks ago but the old paint lasted three years and, except for the waterline, the bottom was still pretty good.

[Dougtiff]

Crush them with a hammer, this way you don't remove the bottom paint, only thing left is the glue, owning wood boat's, i crush them between haul outs, scraping will expose the wood planking, and Toredo warm can damage the planking.

[Boatguy30]

You could possibly careen it on a beach a bit an repaint the waterline areas. Seahawk Monterey dries very fast and is water based. Don't do it on a weekend!

[KBDick]

I live in Miami where everything underwater grows super fast so I use Blue Water ablative 64% copper using three coats annually. I use a 12 inch scrapper like plasterers use from HD and gently scrap off the scrum and some barnacles to avoid removing the paint. A brush will remove too much paint.
A. Hooka rig is great to allow you more time to properly clean the bottom every month or so. I wetsuit helps keep the critters off and cold water! The best way to keep the bottom clean is to go sailing !!!

[Scaramanga F25]

Using a wide drywall spackling trowel is past and easy at or just below. the waterline.
Remove them while you can. A T-shirt over wetsuit, goggles, and fins are best to help.
A 1/2 in.line from pushpit to pulpit above the waterline is good for a rest.

[geoff3nebel]

I switched to sonic anti fouling - and it works - no more barnacles except sa couple of small patches about the size of a badminton or squash racquet...

[Sandydog]

You need to have the bottom cleaned regularly, If you do so, the barnacles will not attach because there is no algae on the hull to feed them.

[Cheechako]

I would choose : "a barnacle free hull with missing spots of bottom paint"
Paint doesn't stop barnacles, it just kills them eventually while stuck to your hull. I suppose it retards growth some though.

But your paint should not come off like that.... ever. Use hard paint. So you are going to need to redo that properly at some point. I've had boats I took probably 2-3 gallons of barnacles off of with no paint loss. ... or I should say no undercoat showing. You always lose a little.

[JPA Cate]

If you have a bunch of barnies at the waterline, your prop is most likely fouled. Make keeping your prop clean the first priority, so that you can move the boat at all. I agree with Cheekako that ditching all the barnies is your best course. You will probably need to keep cleaning the hull every 3 or 4 weeks throughout the summer till haulout time. It is as if water doesn't like surprises, even slime can slow your hull down.

The downside to hard bottom paint is that it, too builds up, and it's hard to remove. Eventually the hull becomes paint sick (paint adhesion fails, and chunks drop off) and requires to be scraped back to gelcoat, then recommence coatings. That is why we use ablative paint. Buildup is much easier and quicker to remove. You will want to check with your local environmental restrictions, they may not want you taking your ablative paint up into the fresh water sections of the river. That said, we, too have experienced saltwater growth falling off after a trip up a river. Some of the corals stay stuck regardless, and I never really noticed about the baby barnacles, so can't comment on that.

Good luck with it.

Ann

[Jim Cate]

Fresh water may kill barnies, but they will most definitely not fall off when dead. That is simply not true. The carapace will stay until removed, either mechanically or chemically, and the latter ain't practical on a hull in the water!

Can you have a look at the rest of the hull via snorkeling? That would clear up a lot of questions, like do the barnies go deeper than the waterline? Likely they do, and as Ann said, cleaning the prop is important.

Bloody things... why the good lord made them so tough and avocado pits so large is a big mystery!

Jim

[letsgetsailing3]

Scrape the waterline/bottom.

The whole point of the paint is to slow the attachment of algae and barnacles...

[ScubaPete]

Originally Posted by Jim Cate

Fresh water may kill barnies, but they will most definitely not fall off when dead. That is simply not true. The carapace will stay until removed, either mechanically or chemically, and the latter ain't practical on a hull in the water!

Can you have a look at the rest of the hull via snorkeling? That would clear up a lot of questions, like do the barnies go deeper than the waterline? Likely they do, and as Ann said, cleaning the prop is important.

Bloody things... why the good lord made them so tough and avocado pits so large is a big mystery!

Jim

I didn't believe the advice about fresh water causing barnacles to fall off of your hull or running gear.

[belizesailor]

Originally Posted by Jim Cate

Fresh water may kill barnies, but they will most definitely not fall off when dead. That is simply not true. The carapace will stay until removed, either mechanically or chemically, and the latter ain't practical on a hull in the water!

Can you have a look at the rest of the hull via snorkeling? That would clear up a lot of questions, like do the barnies go deeper than the waterline? Likely they do, and as Ann said, cleaning the prop is important.

Bloody things... why the good lord made them so tough and avocado pits so large is a big mystery!

Jim

+1 they do die, but they do not fall off. Their shells are adhered with an epoxy like adhesive.

https://phys.org/news/2014-07-nature...t-unstuck.html