kennorth

I just lost 4" of the tip on a 6 blade RH 20X32 SS Rolla propeller. I didn't hit anything. The boat is in the salt water all the time. The propeller is 3 years old and has about 500 hrs use or about 17,000 miles. I have been told that this can happen to SS props. Do props wear out like tires? Will this happen to my other 2 props? Is there anything that I can do to help prevent this from happening? I'm waiting for a quote for price and delivery time for a new prop now but it may take 10 weeks to get one.
Ken

Wobble

Metal fatigue can be an issue particularly with labbed props

CigDaze

The simple answer, Yes props wear out. They are thin and undergo severe cyclical loading and like any other metal they will fail through fatigue. Lab-finished props are especially susceptible because they are further thinned down from stock.

Dents, dings and scratches will hasten the process by providing areas of stress risers.

And since most props are cast there's always the possibility of embedded imperfections like inclusions and/or voids and those areas will fail first.

Ron P

I believe racers in Supercat only get a few races out of a set of props.

I also believe it takes big HP to wear em out. I don't think a 50hp OB will ever wear a prop out, even if it's aluminum.

throttleup

Cig Daze very nice! However, I would add that you may want to take a look at your set-up and have your props inspected to get a professional opinion, as to the failure and possibly look for ways to improve the set-up and/or your propellers. You will have to match the new propeller, to your intact propeller. As you will now have a new propeller made at a different time by a different technician. This way at least you know you have done everything that you can to aviod future failures that are set-up related, possilbly. Food for thought.

Julie

kennorth

Thanks for all the advice. The drives are Arneson ASD8 on a Fountain 48 this is their standard setup. I would like to prevent this prop failure in the future. I'm disapointed that I have to wait 10 weeks to get another prop. I can only imagine what it will cost. Ken

CigDaze

Thanks Julie.

czy40p

I just met I guy with cryogenic freezer he use it to treat just about anything they can get in them (connecting rods, ball joints, cutting tools), would that process benefit a prop?

kennorth

Very interesting. I looked it up on the web and called one these services. They told me they could use this process on a new prop to relieve stress but on the used props they have to be good condition. He suggested that I have the other 2 props magnaflexed to see if there are any cracks and if none he could do the service. From what I read the -300 Deg deep freeze realigns the molecules to relieve stress. The company I called was in IL named "300 Deg. Below" 217-423-3070.It would cost about $75 per prop. Has anyone used this process before? Are there any of these services in S Florida? It's been 2 days now and still no quote for delivery and price for my new prop. Ken

masher44

I did it with my baseball and softball aluminum bats. The freeze eliminates weak spots....