Bronze or nibral propeller?

eztbone

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Holland 38
Just had my bronze 26"x26.5" Michigan prop cleaned and balanced. The shop found stress cracks and suggests replacing. I'm looking at $2119 for a bronze and $3100 for a nibral. The shop recommends nibral for engines pushing over 300 hp. I'm in a holland 38 dd 6v92 450 hp. The only history I have on this prop is it was a 26x28. Any thoughts or recommendations would be great.
 

CEShawn

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Loving to see how this turns out. I'd go with NIBRAL based on how many hours I run a year . Somewhere about our 350HP engine we noticed that there used to be lots of corrections when we had the prop inspected. So we went to Nibral and seemed to stick up to the forces on the blades. So in my mind it was clear, NIBRAL stood up to the forces, didn't distort basically. Mind you we were running 400-600 hours at this time. I'd consider how often you use the boat, etc.
 

tunaorlater

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40' Northern bay
Any chance you can fit a 28 inch wheel? I have a 28x26.5 3 blade Nibral I can give you a good deal on.

I would go Nibral if you can.
 

captainlarry84

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KristenFormer Charter Captain
Just had my bronze 26"x26.5" Michigan prop cleaned and balanced. The shop found stress cracks and suggests replacing. I'm looking at $2119 for a bronze and $3100 for a nibral. The shop recommends nibral for engines pushing over 300 hp. I'm in a holland 38 dd 6v92 450 hp. The only history I have on this prop is it was a 26x28. Any thoughts or recommendations would be great.
Those are good prices on both wheels. I would go Nibral.that is me. Bronze will perform just as well. It all depends on spending the money. You old wheel had stress cracks which could have started after the re-pitching of the wheel. Older bronze wheels and even nibrals do like being re-pitched. The process of re-pitching must be done extremely carefully so as not to damage the metal strength.
I dont think HP is the only criteria for nibral. In your case you have 26.5s of pitch. That is a lot of load on the blade. Nibral is much stronger and with that much pitch it will flex less.
Back to your bronze wheel. How many season did you get out of the wheel after the re-pitch? How old was the wheel & did it only have one re-pitch?
Is electrolysis a problem at your dock? If so Bronze is less prone to having a problem.

Lastly If you are going straight replacement I would order a new 26 X 26 and add the .5 of pitch. It is an easier bend than buying a 26 X 27 and removing .5s. Last note is that if you go with the Nibral, I would do 26 X 26 and if you need more wheel add some cup instead of the pitch
 

eztbone

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Holland 38
Thank you for the input. I bought the boat in June and do not know when it was repitched or how old it is. I keep it on a mooring in Salem and I know the yard that commissioned the boat didn't install or replace the zincs that they were suppose to. I brought it to the prop guys to check for damage due to electrolysis. I did not feel any vibration or cavitation and it achieved rpms.
 

captainlarry84

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KristenFormer Charter Captain
Thank you for the input. I bought the boat in June and do not know when it was repitched or how old it is. I keep it on a mooring in Salem and I know the yard that commissioned the boat didn't install or replace the zincs that they were suppose to. I brought it to the prop guys to check for damage due to electrolysis. I did not feel any vibration or cavitation and it achieved rpms.

Mooring, no zincs and maybe electrolysis? Make sure you are bonded and bonded correctly. If you had electrolysis a new nibral will not last a season. So you may want to consider staying with a bronze wheel.
 

Tuna Pursuit

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Thunnus
Thank you for the input. I bought the boat in June and do not know when it was repitched or how old it is. I keep it on a mooring in Salem and I know the yard that commissioned the boat didn't install or replace the zincs that they were suppose to. I brought it to the prop guys to check for damage due to electrolysis. I did not feel any vibration or cavitation and it achieved rpms.

I don't know where you went to get the prop worked on but i would highly recommend these guys:

AccuTech Marine Propeller, Inc. - Prop Scan and Hale MRI Technology: Home
 

tomy

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EZT: I sent you a pm ! please read

Tuna Persuit. Your opinion and mine are 180 out.
 
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