Preventing Prop Barnacles

[jneely]

Does anyone have any new advice on preventing barnacles on propellers?

[mattlydon]

I've been smearing on a good coat of Johnson's paste wax. While it doesn't COMPLETELY avoid barnacles, the few I did have knocked right off.

[Oswego John]

Ditto Simoniz carnauba paste wax.

O J

[bottomscraper]

Use your engine more!

We have been using Pettit Zinc Coat 1792 for the past few years. It does seem to work better
than nothing and definetly makes the few that do grow easy to remove. I am about 99% sure
this stuff is the same as "Cold Galvanizing Compound" which is available at any hardware store
from Rustoleum or other paint brands. Since I ran out of Pettit this year I am trying the Rustoleum
cold galvanizing spray. I will give a report at the end of the season. Two coats is plenty and a can
will last several years.

http://www.pettitpaint.com/fileshare/pr ... 179320.pdf
http://www.rustoleum.com/CBGProduct.asp?pid=380

[Cathy Monaghan]

We started out using Pettit's Underwater Metals kit and then switched to Pettit Zinc Coat Barnacle Barrier. It has worked well for us. There may be a few small barnacles on the prop when she's hauled in the fall, but not the caked on mess of solid concrete that we get without it.

Cathy
CD32 Realization, #3
Rahway, NJ
Raritan Bay

[Neil Gordon]

Do you get more critters on the prop if you lock it or let it spin free?

[bottomscraper]

Do you get more critters on the prop if you lock it or let it spin free?

Haven't you ever heard the expression "a spinning prop gathers less barnacles"?

Actually I think it probably is true since we seem to get a few on the hub, none near the tips.

That's my story and I'm sticking to it!

[sharkbait]

Would it be possible to have one coated with Teflon? If so would it be to slick for the critters to stick to it?

[tartansailor]

Would it be possible to have one coated with Teflon? If so would it be to slick for the critters to stick to it?

That would be an ideal solution, however teflon needs to be
baked on at approximately 550° F to fuse the particles
and get (non-stick) teflon to stick to something as difficult
as bronze, and I do not know what effect that temperature
would have on the prop.

Dick

[sharkbait]

From what I have found out one would have to sandblast the prop. Then apply a special teflon primer and bake it. Then apply the teflon coat and bake it. I am still trying to find someone locally who does this kind of coating. Water is extremely abrasive so I wonder how long a coating like this would last.

[SurryMark]

Bottom paint?

[Maine Sail]

Bottom paint?

Copper based paint can ruin your prop & lead to serious dezincification..

[SurryMark]

Bottom paint?

Copper based paint can ruin your prop & lead to serious dezincification..

Oops.
Good to know. I wondered why you don't see painted props.

[John Vigor]

Copper based paint can ruin your prop & lead to serious dezincification..

Aren't props supposed to be made of bronze, an alloy of tin and copper? How can there be dezincification in the absence of zinc?

I have painted my bronze props with copper antifouling paint, two coats each time, for more than 40 years with no bad results. After all, the major part of a bronze propeller is copper.

There are some allegedly "bronze" alloys that contain a small portion of zinc, but a decent alloy shouldn't be affected by what amounts to just some more copper.

Cheers,

John V.

[Jim Davis]

The biggest problem I had with bottom paint, including Trinidad was that the water abraded it off. Electrolysis was not a problem.

I have tried a wide spectrum including waxes and even grease and STP with minimal luck. At least water pump grease made it easy to clean and reapply under water.

Like Cathy I have had reasonable success with Pettit 1792 (1793 is the same, just different label). I sand the prop clean, wash with acetone and give it two coats. Not perfect, but the best I've seen even with every other year haulouts.