Is it proper to apply primer + anti fouling on the boat shaft and propeller or not ?

Question

I have a sailing boat and I tried several painting cycles, it seems to be good for the shaft but not for the propeller because the antifouling was removed after few months the boat had been in the water.

Answer 1

Many boaters have done this over the years. one of the problems is the buildup of paint over time and if you use a copper based paint it can increase electrolysis to the running gear and engine. I have had great luck using the clear anti-fouling spray paint used on outboards. However that is not available any longer in my state and I am looking for something else. There are non copper based ablative anti-fouling paints that I am checking into.

Answer 2

providing that you have a stainless shaft and a brass prop im guesssing you might be apply a antifoul primer to these parts which will get the results as you are now.

Using a wire wheel and a grinder clean all the surfaces up to a clean well keyed surface

mask up the area on your shaft where the anode bolts on.

clean well with acetone

apply metal etching primer such as international PA-10 which is availible in a pressure pack designed for this type of job in two thin coats

apply antifoul as recommended

unmask shaft and refit new anode to clean bare surface(important as the prop is the next softest metal and will be affected by electrolisis which may be your problem)

otherwise visit propspeed.com for a silicone based system(good but expensive and harder to apply)

If you have an aluminium saildrive strip of all paint an apply an aluminium antifoul or it'll be stuffed real quick. copper+ aluminium=fizz

Answer 3

pay attention to those others that have mentioned the problems of electrolysis.....and yes paint the shaft, put on your sacrificial zincs. especially if its a stainless shaft and a bronze prop; clean the prop well and paint it with anti fouling and be resigned to the fact that the paint will come off the prop no matter what you do...the reason is the tremendous forces of water over the prop when it turning....say a12" diameter prop is turning at 900 RPM....the tip of the prop is therefore turning thru a circle of 37.69 inches each revolution, or some 2800 feet and change feet EVERY MINUTE or about 30 miles and hour....that's a LOT of force washing the paint off......I've hardly ever seen any anti fouling paint stay on prop in the last 30 years........just make sure you dive on it and clean it regularly.....growth, weeds or God help us barnacles destroy the hydrodynamics and cut your thrust dramatically, sometimes to the point the boat is uncontrollable under power

Answer 4

There is a special antifouling paint especially for shaft and prop. Any paint with metal base will cause problems with the metal shaft and prop. There also is a new nylon prop available to stop the problem.

Answer 5

Hey buddy. What if a lonely dolphin was reading this very question? It would be awkward for all of us! Oh, plus, what's a diabetic mermaid doing that close to the surface!? Their blood sugar will get low, and they may pass out, and it just won't be a good time! Plus, baby whales are still quite large. It would probably just get cut a little. So, I mean I guess if the dolphin had no friends, there's a good chance he's suicidal. So I guess it wouldn't be a complete tragedy. At least he got what he wanted.

Answer 6

Contact "Interlux paint co.", you may apply "anti-fouling paint" to metal, it just has to be "Rated" for "Metal" (Aluminum) hull's, NOT Fiberglass, it's a differerent paint than for "Fiberglass", you can get the same color too.

Answer 7

you can but I've never don it just just pout a zinc on the shaft and clean it every few months

Answer 8

HAVE THE PROP SANDBLASTED AND THEN PRIME AND PAINT