Prop Antifouling

[Dale Jadus]

Next Monday I have to haul and clean the prop. Lady Susan will virtually not back, she likes to circle.

Any suggestions on how to keep barnicles off the prop?

[RB]

worked on props..where yard wrote price..when I hauled to clean the only part of the prop that was free of everythign was where the price was written in black magic marker..go figure!!!

[Dale Jadus]

I'll try it!

[Andiamo John]

I heard about that also and decorated the prop as a test leaving covered and bare areas on both sides of the blades. After a short period of time, the prop was fouled again. Some folks in Mexico told me to just put a garbage bag over the prop after you anchor and take it off when you're ready to leave. I feel reluctant to be in a position where I can't power up and leave in a moments notice.

[Logan S/V Scotty Ann]

The black bag idea works well. Covering the prop with lanolin works pretty well. You can get it near the nappies. Seems they use if for nursing mothers. I tried some. tastes horrid!

[stuartbell]

Resist the urge to paint the prop, strut and such with normal, copper, antifowling paint. The aluminium or bronze in the prop will be etched away by the copper - dissimilar metals - and you will be left with a hollow shell.

[DavenKaren]

754317 PETTIT ZINC COAT BARNACLE SPRAY. </= $15 This is the stuff for propellers. Works better than your average bottom paint on you boats bottom. Obviously safe for props.

Dave Wilkins
HR Rasmus
Nonsuch 30
Round Pond, MAine

[Dale Jadus]

When I hauled Ladys Susan her bronze prop was the most ridiculous mass of barnacles and green plant growth I have ever seen. Same for the stainless shaft. The yard's pressure washer took almost everything off.

I used the Zn paint, probably the item referenced in the last post.

In reverse the boat is better than I ever remember it. Namely, it has been a long while since I was able to back to starboard.

Anyone have a recommendation on a brand of underwater CCD camera - USB2 ?

[Roger Shields]

Ours may be a unique situation but for the past two years we have had no prop fouling, period. We eliminated the zinc donut from the prop shaft and voila, no barnacles and no signs of electrolysis. A friend (who always has a clean prop) has been doing this for decades with no electrolitic problems.
After a 4 year hiatus rebuilding our storm wrecked Bounty II 40 ft sloop w/4-108 Perkins powering Volvo hydraulic pump/motor (which breaks continuity of engine ground from the shaft) we had 3 years of end of season barnacle growth to deal with until I decided to take the risk and not replace the shaft zinc. Our through hulls are not bonded and all underwater metal is silicon bronze (shaft/prop/rudder stock/etc.). The 12 v ground system is contained within the batteries/engine/systems and thus are not a factor for concern with electrolysis.
I certainly don't recommend this approach for the vast majority of boats but in our case, it appears the slight electrical current produced by the zinc/bronze connection created a tempting attachment surface on the bronze prop for barnacles.
This would be a good subject for Ed Sherman w/Cruising World to address from a technician's standpoint.

[Dale Jadus]

What kind of shaft do you have: SS or Bronze?

It is possible that my barnacles got worse after switching to a SS - Aquamet 22 - shaft.

[Roger Shields]

Our shaft is 1 1/8 " diam silicon bronze.
Our prop is also silicon bronze. This shaft was new for our 2000 launch since the old one had severly eroded where the SS cotter pin passed through it. This is why we use all similar metal underwater and you can't beat silicon bronze for durability (though it weighs probably 20% more than SS).

We had a barnacle problem with this bronze shaft until I removed the Zinc Donut. Of possible interest, we use Petit Trinidad hard bottom paint which has provided an inhospitable environment for barnacles for years