Prop Cavitation repair ?

Orthop

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The bronze duoprops are now 10 years, have a pair of D4 300 engines. Now I have some cavitation after this period of time, which I think this is ok (or not?).
Is it worth to give the a repair, are there companies who can do this well? Or is it time to invest in new ones?
In case of rapairing I think Nebral is the stuff broze props should be welded with.
Are there any experiences?
Kurt
 

oldgit

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There are many propeller repair specialists around who will refurb your props and extend their life.
The down side is the time taken to undertake any repair , the upside cost.
With new props you can just remove old units and refit new ones on the same day and go straight back in.
Good idea to get the old props refurbished anyway and keep them handy as spares.
Best if you have local company , you can drop them off and collect rather than have to wait for couriers.
Usually delays at start of season for propeller repairs .

Not sure about Bronze or Nibral. Thought Duoprops were either Alumium or Stainless ?
If performance is OK would avoid any temptations to fiddle with prop sizes or pitch.
 
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[2068]

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Not sure about Bronze or Nibral. Thought Duoprops were either Alumium or Stainless ?
If performance is OK would avoid any temptations to fiddle with prop sizes or pitch.

G-Series props for DPH are Nibral.
Latest whizzy H-Series props for DPH drives are stainless.
 

Bandit

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For high performance propellers on a fast boat is that you fill the cavitation holes on a propeller and make it look good but structurally you cant repair the propeller.

This is based on 950mm hydrofoil propellers running 9 hours a day at 1000 rpm 35 knots with low water pressure/ immersion.

looking at blade failures and revenue, better to buy new props than risk a blade failure and a service day lost.
 

Orthop

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Thanks for the replies.
Can I change the Duoprops from nibral/bronze to stainless steel on my D4 300?
Is the cavitation also present on stainless steel props?
 

[2068]

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Thanks for the replies.
Can I change the Duoprops from nibral/bronze to stainless steel on my D4 300?
Is the cavitation also present on stainless steel props?

Yes, you can put H-Series stainless steel props on any DPH drive.
Sizing should be the same.
Cavitation damage should be less.
But stainless props will cause anodes to fizz away faster.

If I change props, I will probably go with the stainless steel ones - getting hold of Nibral Props will become increasingly difficult as the Nibral Prop part numbers are now showing as being "replaced" by the equivalent stainless ones on the EPC.

Note that you need new cone kits as well if you go stainless.
 
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QBhoy

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Are you certain it’s a cavitation issue ? If it is, it’s a world of problems more than usual. Not often an original set up boat, suffers from cavitation. Serious issue if so.
 

Orthop

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Are you certain it’s a cavitation issue ? If it is, it’s a world of problems more than usual. Not often an original set up boat, suffers from cavitation. Serious issue if so.

Original set up... And I think its cavitation, Props are 10 years old...D4/300. Test this year was 36 kn, 3500 rpm, full fuel 660 l, 2 persons. Cruising speed 22-24 kn with 2600 rpm, which of course I do mostly during the season...
 

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