Efficacy of prop anti-fouling paint

[Don S/V ILLusion]

As it is "that time of year", I though I'd comment on my experience using Pettit Zinc Coat Barnacle Barrier Paint 1792 on my prop and shaft last season.

First, I should probably stipulate this isn't an opinion of the efficacy of whatever bottom paint we all use and love. There is ample discussion elsewhere here and on other forums discussing the wisdom of using typical copper- containing bottom paint on the running gear.
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With respect to this Pettit paint, prior to using it, upon pulling the boat at the end of the season, we would find varying amount of growth and barnacles ranging from moderate to heavy.

After our first season with the zinc coat paint, there was no growth... none! and one small barnacle on the shaft adjacent to a shaft zinc which I attribute to my sloppy tape job in which I tried to cover the shaft zincs prior to spraying the paint and overlapped the tape slightly onto the shaft.

I would be interested to hear others' opinions as to whether I was just lucky or is this stuff really as good as it appears to me.

Hope this isn't old news to folks that may have discovered it years ago.

 

[sailaway78]

Standard Reply

Don, I have a standard reply concerning prop anti fouling paints. If you need an anti fouling on your prop, you don't use the boat enough. A moving boat gathers no moss.

 

[Don12364]

Conundrum

We put metallic copper or copper loaded paints on the hull to inhibit marine growth.
A bronze prop is mostly copper but it still fouls up.
So why?
Could any marine biologists or chemists or metallurgists out there could help my confusion please.

 

[Steve Dion]

I thought that Don was talking about the paint on the shaft (no reference to the prop). My experience with the prop paint is that it does not last very long do to the particulate matter in the water. The shaft does not get this type of water movement over it.

 

[pvanv]

I'm going to be trying out the Aurora antifouling wax on my OB aux this season. Since it's not copper, it should work OK on my aluminum leg and prop. Unfortunately, I know of no one with experience to verify whether it will be effective or not.

 

[Maine Sail]

Good report Don

Did it stay on the prop for the whole season or did it wear away? Fortunately we don't really get much if any prop/shaft fouling up here but I suppose if I let my boat sit for longer periods this would be a good choice!

 

[CalebD]

I used the Petite Zinc Coat Barnacle Barrier paint last season on our prop in the lower Hudson River. Barnacle growth on the prop is a real concern in this area as we have experienced a badly fouled prop in seasons past.
Upon haul out last fall there was significantly less (but not zero) barnacle growth on our prop. We did have the bottom cleaned once over the summer by a diver though which may or may not account for the smaller amount of barnacles on our prop.
I would like to use it again this season.

 

[Don S/V ILLusion]

Don, I have a standard reply concerning prop anti fouling paints. If you need an anti fouling on your prop, you don't use the boat enough. A moving boat gathers no moss.

Very true!
Unfortunately, due to family matters ( a wedding and the birth of our first two grand kids), we didn't use the boat as much as we had wanted and it did sit unused for prolonged periods. To my mind, this in itself is a testament to the efficacy of the product as we found, upon haul, no growth on the prop and only the one barnacle on the shaft.

I did put three coats on both the prop and shaft.

Interestingly, for some reason I don't understand, there was very minimal paint remaining on the shaft but the prop seemed to hold the paint better with a thin coat still remaining.

thanks for the replies

 

[Rich Stidger]

My Pettit Zinc Spray experience is a bit different

I have used this spray for the last three years. The performance the first two years was OK with just some limited growth. However, last year was terrible- see the pictures below.

I suspect that most of the growth that I observe after hauling in the fall is due to the fact that my boat is often not used for the last 3 weeks prior to hauling.

I have dived on the prop during the season and not observed anything like that pictured below.

I am located in Bristol Harbor on Narragansett Bay, not too far from Don (Illusion). However I do believe that fouling can be completely different in different areas.

I do plan on using the Pettit Zinc spray again this year because it has worked for me in the past and because I've never found anything to work better.

 

[Warren Milberg]

Barnacle barrier? Boy, I wish someone had told me about that stuff....

 

[Ron20324]

Do you guys have permits to harvest marine life?

Rich, is that stuff like olive green? A friend loaned me his, and i don't remember the name.

 

[Rich Stidger]

Rich, is that stuff like olive green? A friend loaned me his, and i don't remember the name.

Olive green? Do you mean the color of the Pettit Zinc Coating? That coating is light gray in color.

And I think Warren is pulling our anchor chain with his barnacle barrier post.

 

[Ron McCoy]

I've used Pettit's Zinc Barnacle spray and it's worked as long as it stays on the prop and shaft. Unfortunately, the flip side to not using your boat, is using it so much that the prop spins the paint off during the summer. This year, I'm going to try Pettit's prop kit which includes a primer, a bonding agent, then my bottom paint. Three coats overall. Maybe the bottom paint will wear off during the summer, but I should have enough remaining to keep it reasonably clean until haul-out.

 

[John T1594]

I have used the same method for the past ten years and never have more that one or two barnacles on my prop or shaft. I clean the shaft and prop down to clean metal with a wire brush on an electric drill. Wipe with solvent and apply two coats of a marine primer. I have used Interprotect successfully but other primers work as well. I then apply two coats of any available copper based bottom paint and splash the boat. Don't prime or paint under the zincs. As I said, little to no fouling after six+ months. I use the boat almost every weekend and motor prehaps for 30-60 minutes total each time. By the end of the season, the paint has worn off the tips and parts of the prop blades but is intact elsewhere.
I have tried this method without the primer and always got bad fouling of the prop and shaft. The Interlux outdrive spray works well if used with the primer but is more expensive.
I sail in the salty waters of Barnegat Bay NJ and keep the boat in Forked River - a somewhat brackish river feeding the bay.

 

[RAD]

Are we talking about this product? because I too had some better results years before and last year my boat got used the most but had a ton on the sea strainer only

http://www.westmarine.com/webapp/wc...=true&storeNum=5000&subdeptNum=4&classNum=229

 

[Don S/V ILLusion]

Rad
No. WM often doesn't carry the Pettit paint named in my original post although they can special order it - you can buy it here on SBO too.
It is not the same as transducer paint.

 

[Jim 5757]

I keep hearing horror stories about using copper-based paint on the bronze prop, but maybe John's method of priming first would be OK. I have tried the Interlux method (Viny-Lux Primewash, Primocon, Trilux® Prop & Drive for 2 years now, and it just does not work here in the Barnegat Bay area.