Barnacle problem

My boat collects a LOT of barnacles on the underwater metals during a 7 month summer season. The marina paints the bottom for me and I forget exactly what they use for the metals but it's an anti-fouling paint made for metal, like you would use on an outdrive for instance. My main concern and my main question is dealing with the bronze hull strainers at the water intake thru-hulls. They not only get covered in barnacles, but the barnacles also get inside the strainers and are hard to clean out. I'm worried about an over-heating problem some day. Any suggestions on what might work well on bronze specifically? Is zinc paint ok to try such at Pettit Barnacle Barrier? Any other suggestions?

South Bay strainers. They allow you to remove the grate and clean and paint inside. On Long Island they are a must have item. We have lots of eel grass

Arc said:

South Bay strainers. They allow you to remove the grate and clean and paint inside. On Long Island they are a must have item. We have lots of eel grass

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What Arc said. I installed one on my last boat. Easy to paint. Pull a pin and it opens for cleaning.

We use the same bottom paint on the strainers as the bottom itself. No real issues with a 6 month season in SW FL or on a 14 month trip up and back along the East Coast.

With 4 years in warm Florida waters we initially had the same problem. During a haul out we cleaned the strainer grates only to find the inside was full also. The man that owns the boat yard suggested that we try cold galvanizing spray from 3-M. We used it on all of the bronze intakes and outlets. At our next haul out two years later we found that everything was still clean. I don't know if the stuff is recommend for that use, but it worked well for us.

fgarriso said:

With 4 years in warm Florida waters we initially had the same problem. During a haul out we cleaned the strainer grates only to find the inside was full also. The man that owns the boat yard suggested that we try cold galvanizing spray from 3-M. We used it on all of the bronze intakes and outlets. At our next haul out two years later we found that everything was still clean. I don't know if the stuff is recommend for that use, but it worked well for us.

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Thanks I think I will try the same. I appreciate the suggestions for removable strainers but that is not a simple change because mine are part of the thru-hull and seacock and I don't want to tackle that a couple weeks before launch. I will try to clean as best I can from inside and outside the boat and spray with zinc the best I can.

Feed a piece of heavy gauge copper wire into the cavity of the strainer in a loop and it will kill off any invertebrates that venture inside the strainer.

Copper bottom paint goes dead on metal unless it has a barrier between it and the metal. You could use a non-metallic primer (several coats) or I have had luck coating all my metal, except propeller with thickened epoxy. Then apply your bottom paint and it will work. Layer upon layer of "dead" bottom paint can also act as a barrier but that's doing it the hard way.

Brooksie said:

Copper bottom paint goes dead on metal unless it has a barrier between it and the metal. You could use a non-metallic primer (several coats) or I have had luck coating all my metal, except propeller with thickened epoxy. Then apply your bottom paint and it will work. Layer upon layer of "dead" bottom paint can also act as a barrier but that's doing it the hard way.

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It's interesting stuff

I thought we had electrical issues and had a corrosion expert on ours recently trying to find out why we are blowing antifoul and epoxy primer off of the bronze prop and bronze rudder but not the adjacent steel nozzle (epoxy primer coated and free of growth) or full length steel shoe (no epoxy coating and covered in growth) The shoe did have vinyguard used prior to antifoul.

Electrically we checked out ok but apparently it is to do with noble metals and where copper, bronze and steel are on the scale.

He said we need to go multiple coatings of the epoxy primer on the bronze and steel to make it invisible to the high copper content antifouling.

Brooksie said:

Copper bottom paint goes dead on metal unless it has a barrier between it and the metal. You could use a non-metallic primer (several coats) or I have had luck coating all my metal, except propeller with thickened epoxy. Then apply your bottom paint and it will work. Layer upon layer of "dead" bottom paint can also act as a barrier but that's doing it the hard way.

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Huh?

I posted on this subject about the "Sonihull" electronic hull cleaner. I can't say if it works, but it sounds good!!