Saltram31
Well-Known Member
At what level of dezincification on a bronze prop will decrease performance? The prop has no pitting damage or loss of metal yet but is about 50% pink.
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Dezincification of prop
- Thread starter Saltram31
- Start date
Rappey
Well-Known Member
Saltram31
Well-Known Member
Thanks. Asking out of interest as the boat is being lifted our next week for annual maintenance and I know the prop will need replacing but am wondering if the blades can deform slightly when motoring as I am unable to achieve max revs under load lately. I have checked it with an inspection camera and it seems to be all there.
Rappey
Well-Known Member
Mine never deformed, just shrunk with 40hp turning it. 15" prop.
Mine was measured for a replacement so if it deformed it would have shown up.
Check fuel filters and exhaust for blockages ?
Mine was measured for a replacement so if it deformed it would have shown up.
Check fuel filters and exhaust for blockages ?
vyv_cox
Well-Known Member
Dezincification of brass (not bronze, which contains no significant zinc) occurs from the surface, penetrating inwards. You may well find that the pinkness is a very thin layer that will abrade off. Replacement of the prop is not needed until chunks of predominantly spongy copper are falling off.
Painting the prop is a very effective way of delaying dezincification.
Painting the prop is a very effective way of delaying dezincification.
Pye_End
Well-Known Member
Clean?
Saltram31
Well-Known Member
Mostly, A bit of slime and weed which I managed to brush off but no change.
Tranona
Well-Known Member
Unlikely that the prop has changed dimensions (pitch) or diameter sufficient to affect performance. As suggested the pink is probably only on the surface. If the blades ring when tapped with a hammer it is not dezincified