47 lightning

Threw a blade on a mercury racing 5 blade 17.5 x 36 pitch.. 21 degree rake..850 hp prop...running 800 hp thru it. Looking at the hub where blade broke off..looks like it was a manufacturer flaw..any help from previous experience would be helpful.

Wally

iTrader: (1)

I by no means am an expert in metals but have seen a few different failures throughout the years.....the black/dark rings looks like a fatigue failure are and the rest is a fast fracture...not sure if anyone could have caught that unless the parts were x-rayed and there may have been a pocket of air or something caught inside the metal allowing it to weaken and fatigue....

Unlimited jd

iTrader: (5)

What's the propshaft height and on which boat? Seen that several times when bravo props are run too close to the surface.
Looks like cleavers off the 47? How many hours on the props?

47 lightning

They are off the 47..bought these off of dan at outerlimits from a 40 ft white sv outerlimits with 725 ilmors.

47 lightning

I wasn't sure what the black was..i thought it was a flaw in the casting. I could just buy another one to match..but am afraid the other one will do the se thing.

Wally

iTrader: (1)

It could very well have been a defect in the material, but unless you have the other piece, or you have a big void in the hub that you have on hand showing where it could have caused the failure, i don't know if you could prove it a defect. but again i am no expert in metallurgy....may want to find a company that specializes in that to see if they could do a failure analysis on it....

Wally

iTrader: (1)

That black area is what they refer to as "beaching" i believe....you can see the rings from the metal fatiguing each ring is the progression of the fracture...the center point is where it started from....so if you have a void there then it could indicate there was a pocket of air or contamination trapped in the metal that could have caused the failure....

27daytona

[ATTACH=CONFIG]552481[/ATTACH]I lost a blade on a Mercury 850 h.p. 17 X 35 pitch. Similar break and my GoPro caught the blade in midair. Expensive picture but I did have a nick on the blade that I should have addressed.

Unlimited jd

iTrader: (5)

That's his dad's boat, boat has some hours on it as they use it quite a bit, but it wasn't abused. Interested in what maybe bblades would have to say.