Like Tree0Likes

Hairline crack in prop blade - what the ?

Reply
Old 09-16-2002, 08:26 PM
  #1
Uncle Toys
Guest
 
Posts: n/a
Default Hairline crack in prop blade - what the ?

Took the boat in this Saturday to have the oil changed and found a hairline crack half-way through one of the blades on the port-side prop. Mechanic strongly recommended not using that prop and I agreed. So B.O.A.T. for another set of props (old ones were too big anyways).

Anyone else run into something like this? There were absolutely no burrs on the edges of the blades and I canít remember hitting anything. Iím really puzzled
 
Reply With Quote
Old 09-16-2002, 08:37 PM
  #2
DOCTOR DAVE
Guest
 
Posts: n/a
Default

let me guess...................bravo ones?
 
Reply With Quote
Old 09-16-2002, 08:45 PM
  #3
DJD
Registered
 
Join Date: Oct 2000
Location: Greenwich CT. U S of A
My Boats: 38' Cigarette, 42'Post, Driver:F2-07 Wild Child
Posts: 1,839
Default

I bet they are Hydromotive??
I have cracked a few blades & have heard of many others.
No dings, no hits, just a plain old stress crack
DJD is offline  
Reply With Quote
Old 09-16-2002, 09:11 PM
  #4
Registered
 
Turbojack's Avatar
 
Join Date: Sep 2001
Location: Houston, TX, USA
My Boats: 2003 Eliminator 30' Daytona
Posts: 2,285
Default

UT- Thought we had problems. Have you read elimi's story about his year of boating.

Looking at buddies 28 daytona lab finshed props one day & found blade with small crack. He & I checked around & we were told that with 130 hrs on lab finished prop he was lucky it made it that long. Talked to local prop guy & charged him close to $300 (new stock bravo was 500) repair. (70 of that was to polish it) Prop lasted for 2 weekends before it slung the blade. I guess lucky no one got hurt.

I was having second thoughts about getting my prop labed after that & now I learn this week or last, that when you lab a prop you loose midrange cruise rpm. I guess I am going to save my $ & stick with my stock 30. Maybe will be missing a mile or 2 but I do more crusing @ 3k & below that I do at WOT.

I guess this will postpone/cancel the motor rework since new props are in order.
Turbojack is offline  
Reply With Quote
Old 09-16-2002, 09:32 PM
  #5
Byron
Guest
 
Posts: n/a
Default

Tell us what brand of props they are?
 
Reply With Quote
Old 09-16-2002, 09:43 PM
  #6
Official OSO boat whore
Charter Member
Trade Score: (2)
 
Join Date: Oct 2000
Location: Mequon, WI
My Boats: 8' row boat
Posts: 6,157
Default

This happens more frequently than what most of would think. I remember being at a professional high performance prop shop one time and seeing dozens of cracked blades. It's my theory that this happens most frequently on props that are surfacing. When the blade is in the water it is loaded and leans back. When the blade come out of the water it is suddenly unloaded and springs forward only to get slammed back into the water. I believe that it was this flexing that work hardened my Hydromotive prop and resulted in it's failure with in hours.
Cord is offline  
Reply With Quote
Old 09-16-2002, 09:44 PM
  #7
Registered
 
fountain1fan's Avatar
 
Join Date: Dec 2000
Location: eden nc
My Boats: 162 scout flats 90 merc
Posts: 2,728
Unhappy

ut jana has a cracked hydo if you have them labbed that is what they do they thin the blads and they can not take it but it sounds like they got it too thin
fountain1fan is offline  
Reply With Quote
Old 09-16-2002, 10:10 PM
  #8
Platinum Member
Platinum Member
 
Interceptor's Avatar
 
Join Date: Feb 2002
Location: Traverse City, Michigan
My Boats: one slow Fountain, one fast ice boat.
Posts: 3,840
Default

I threw a blade on a Mach prop this summer. Looking at the break which happened at the hub there was evidence a very fine crack had been there.
Interceptor is online now  
Reply With Quote
Old 09-16-2002, 10:17 PM
  #9
Registered
 
RedWarlock's Avatar
 
Join Date: Mar 2002
Location: I knew I shouldn't have made that left turn in Albuquerque...
My Boats: 2001 Warlock 25 World Class
Posts: 632
Angry UT...

Had to have Merc. warranty one about a month ago. Blade developed a stress fracture on the back of one blade, no impact marks whatsoever! Just had finished a great run and was wiping it down when my son said "Dad, your prop's broke!" Absolutely ruined my day!

Last edited by RedWarlock; 09-16-2002 at 10:21 PM.
RedWarlock is offline  
Reply With Quote
Old 09-16-2002, 11:16 PM
  #10
Registered
 
H2Xmark's Avatar
 
Join Date: Apr 2001
Location: beaumont tx
My Boats: 1997 Fountain 35 Lightning
Posts: 1,703
Default

Feel for you, it seems like when it rains it pours, I had the same thing happen on a mirageplus23, found the crack and replaced it before it let loose, at least you caught it before it broke!
H2Xmark is offline  
Reply With Quote
Reply

Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
mattd7
Donzi
1
04-22-2008 07:00 AM
Inspector
Prop Talk
1
07-09-2007 08:50 AM
Boomer 880
Prop Talk
2
04-21-2006 10:37 AM
CA_Southpaw
American Offshore
13
11-06-2005 08:18 PM
NetGain
General Q & A
19
06-29-2004 09:32 PM



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 10:31 AM.


Copyright 2011 OffShoreOnly. All rights reserved.