Propspeed on rudders

[Cliffhanger]

I am after some advice about whether using propspeed on rudders is a good thing or just a waste of money. I have a 36ft sailing catamaran with stainless steel rudders. I use the hard antifoul on the rudders as recommented for proximity to props and saildrives but doesn't seem to work well. (ablative antifoul on the rest of the boat.) I use propspeed on the props and I like it. Barnacles still attach themselves but simply wipe off. The rudders are about 400mm x 500mm and I can't seem to find any info on how much propspeed I would need.

[Fore and Aft]

I often survey fly bridge cruisers that have their metal rudders coated with Prop Speed. I don’t think the applicators treat them any different to a prop?
Cheers

[Simi 60]

Originally Posted by Cliffhanger

. I have a 36ft sailing catamaran with stainless steel rudders. .

So flat plat and no foil shape?

[Cliffhanger]

Originally Posted by Simi 60

So flat plat and no foil shape?

No, they are fabricated out of sheet stainless steel around a 2 inch rudder stock giving a foil shape. Quite a work of art - shame they are never seen!

[wingless]

This year I used Rustoleum Cold Galvanizing Compound aerosol spray on all my underwater metal.

So far I've been very satisfied.

[bill good]

Originally Posted by Cliffhanger

No, they are fabricated out of sheet stainless steel around a 2 inch rudder stock giving a foil shape. Quite a work of art - shame they are never seen!

G'Day Cliffhanger,


I would like to know if you put propspeed on the S/S rudders & how it went.
( Also see PM)


Regards Bill

[JBP]

I'm sure prop speed would be fine, or one might try the zinc based copper free ablatives like Total Boat Krypton that are supposed to be safe for metal.

[SailingHarmonie]

Propspeed is used all the time on stainless steel running gear. Props, shafts and rudders. Go to any yard that handles a lot of sportfish or superyachts. Nothing special about your application. It will do well for you.

There are two keys for a good application of Propspeed. Follow the application directions exactly, and don't over zinc. Too much zinc will actually cause the formation of tiny amounts of hydrogen bubbles on the cathode (the non-zinc metal) that can lift off the coating.

[Cliffhanger]

OK, so here is an update 4 years after the original post. I have gone back to ablative antifoul on the rudders instead of propspeed. The propspeed was good because it was easy to remove any growth. But you still had to dive regularly to do this. Antifoul reduces the amount of growth though it is a little harder to remove when it eventually happens. And antifoul is much cheaper.

[bill good]

Thanks
Bill