Prop corrosion?

[first230sl]

I was looking through my bottom pictures, educating myself in preparation for the rudder port I have to do, when I noticed that I have some pitting in my propellers.

I don't have enough experience to tell whether this is normal, minor, or extensive in terms of corrosion, so I was hoping someone might be able to tell me whether these props look OK?

The rudder port has my attention now, but a bit of quick advice here will be helpful.

Note that some of the pics were taken when the props were still wet right after haul-out.


Thanks so much!

 

[first230sl]

Re: Prop corrosion? (last two pics)

Here are the last two pics.

 

[Fanfare]

It's pretty hard to tell from a photo, but those look pretty normal to me. Props tarnish in the water, and, because there is no bottom paint (or at least it won't stick once you start running) oysters and barnicles tend to attach to the blades. The area beneath these critters then tends to darken. Unless there are actual pits you shouldn't have to worry. Also, the edges of your props look fine. They would look ragged if they were being eaten away. Do you have zincs on each shaft? I have them on the shaft ahead of the muff coupling and a zinc collar right in front of the prop. Mine look about half dissolved after a year in salt water.

 

[first230sl]

Thanks Fanfare.

Yes - I have shaft zincs. They disappear after about 6 months - so I have a problem. One more thing to get to.

I appreciate your comments on the props. Thanks so much.


Murray

 

[67hat34c]

agree, props look normal. How is the rest of the underwater metal? does the paint tend to blow off? if not then you look good to go

 

[first230sl]

Thanks again. No - the paint seems to adhere very well to thru-hulls, etc. All of them have been painted in the past and have a thick coating of paint on them. I spent some time at last haul-out inspecting the thru-hulls from the outside. I chipped off a bit of paint and looked at the metal of each. They all looked excellent. I've been sleepoing better (especially while on the boat) since doing that

Best regards and take care - Murray

agree, props look normal. How is the rest of the underwater metal? does the paint tend to blow off? if not then you look good to go

 

[jim rosenthal]

If your other underwater metal parts are not exhibiting this level of corrosion, I wonder if cavitation is the problem. I think excessive blade loading can cause voids in the water that can pluck off small bits of metal from the prop faces as they implode. I don't know whether this can occur on both faces of the blade or only the aft face. Have the wheels been looked at by a propeller shop since you acquired the boat?

 

[Genesis]

Yeah, it looks like cavitation to me. I'd have a prop shop look at them - they can usually figure out what's up with a close examination.

 

[first230sl]

Thanks - no the blades have not been looked at since I bought the boat. The surveyor (who I believe was good) did not indicate any blade issues - and as I say - they have not been looked at since.

Given that I'll be taking the boat out shortly to do the rudder port, that will provide me with a good opportunity to have someone take a peek at the blades.

Thanks Guys.

Murray