Oh Dear!

[Jon]

Went down to the boat to fit my new prop today, thanks to Tony Davis:up:

Encountered few problems changing the prop in situ in the water with the exception of very cold hands, some very scary Mullet, and some kind of plastic wedged up in the bullet behind the prop!

Fitted the new prop on but did not get round to testing today. Will test tomorrow if fine.

Had a good look at the old propeller and found some nasty damage in the form of what appears to be some very aggressive localised corrosion to the stamped letters of the word "Mirage" on the prop. The prop appears to be ok everywhere else except the damage to the letters as seen in the following photos.

Any ideas as to what might have caused this anyone?

[Jon]

The thing is,

The damage has appeared since August and the boat has only been out three times during this time.

[Jon]

Could this be Cavitation Burns?

[Jon Fuller]

Originally posted by R-Don
Could this be Cavitation Burns?

No.

It's just corrosion/electrolysis.

Do you have 'Mercathode'?

What condition are the Anodes in?

[Jon]

Yes i do have mercathode installed.

But why would the corrosion be localised and why would the stainless give way to a softer metal like aluminium?

[Jon]

Is this prop now scrap?

[Captain Chaos]

Nah, you can use with only one blade.......................honest, i've seen it done!

[Jon Fuller]

The corrosion will be localised where there are impurities in the casting, as the 'Mirage' wording is bare casting, whereas the rest is dressed and polished, I presume impurities end up near the surface in the casting process, and get removed over the vast majority of the surface, but not in the recessed lettering.

As long as the structure of the hub is ok, there shouldn't be a problem using it.

[TidyBoy]

Originally posted by Captain Chaos
Nah, you can use with only one blade.......................honest, i've seen it done!

came accross a guy in his new boat this summer, pulls along the pontoon and tells me something wrong with his boat?

Not a single blade on the prop - manged to come back from being about half a mile out:eek: :dizzy:

[Dan]

If you want to get it back to the "as new" look. Whip it down to your local polishers who for around the 30 quid mark will get it looking the bees knees. :cheers: