How long will a prop last?

[Irv964]

Just in my reading about stainless and aluminum props, I see it mentioned that the stainless will last a lot longer than aluminum, I agree with that fact, it is common sense!
But what I don't know is, what is the life expectancy out of an aluminum prop? Of course that is not hitting anything and shortening it's life any but what if all I do is tube, ski and cruise with an average of say 25-50hrs a season?(guesstimate) How long can I expect my aluminum prop to last? What signs do I look for that would tell me it is wearing out? (Speed obviously?) ..........Irv964

 

[DJ]

Re: How long will a prop last?

If you don't hit anything, run in sand or heavily silted water it will last forever.

I have: 1958, 1967, 1975 outboards with the original AL props. that look brand new.

 

[walleyehed]

Re: How long will a prop last?

The Industry std for SS props of 15-5 composition is 10 yrs.
The Std for aluminum is 5 yrs.
There are particulates in water that wear on these surfaces even in open water.
The Std is based on the point at which the design no-longer performs as the original features built in to the prop were supposed to.

 

[mthieme]

Re: How long will a prop last?

The Industry std for SS props of 15-5 composition is 10 yrs.
The Std for aluminum is 5 yrs.
There are particulates in water that wear on these surfaces even in open water.
The Std is based on the point at which the design no-longer performs as the original features built in to the prop were supposed to.

Sounds like the industry wants to sell more props.
Assuming you have aluminum - do you change yours every five years just because?

 

[captlee]

Re: How long will a prop last?

I havent changed a prop unless i hit somehting and tore it up beyond repair or it wasnt pitched right for the boat.

 

[tashasdaddy]

Re: How long will a prop last?

i have a 1958 motor with original brass prop.

 

[walleyehed]

Re: How long will a prop last?

If you tested props for part of your living, you'd see what I and the manufacturers that I test for, see.
When you're looking for the final edge of performance, a 2yr old SS will not run as high or as fast as an out-of-the box new, same make and model. The cup wears faster than you think, as does the diameter.
Call Merc, Solas, Precision, Powertech, Mazco, etc....they all follow the same recommendations, and to back this up, if you would ask Dhadley, he will tell you pretty much the same thing.
Most people won't care, or notice, the 1-3mph drop, 5-7mph in some cases....maybe a slight lncrease in rpm over the years...Normally, you get slower but the rpm stays real close due to the boat gaining a bit of weight from water soak, hull wear, and even some engine wear.
It's fact, not a selling point. Now keep in mind, this figure is based on 75 hours of use a year, so if you run 25hrs, then yes, you may get 30 from an SS, and maybe even 18-20yrs from alum, but I can verify by Data, after 300-500hrs of use, that prop will NOT be the same as a new one of the same model and make.

 

[walleyehed]

Re: How long will a prop last?

Sounds like the industry wants to sell more props.
Assuming you have aluminum - do you change yours every five years just because?

Do I change every 5 yrs???? No,#1, I wouldn't wait that long with the hrs I put on, and I generally run anywhere from 2-10 props in a weekend testing. My go-to prop is a Turbo1 in 17-21P. I don't run aluminum much other than when I want a slower troll...I'll use something in a 15P with the smallest diameter I can find. If I'm on very large lakes, I'll use the T1 in a 17 and drop my over-center brackets on my smart-tabs so they are 90 degs to the hull bottom....good brakes.
If I'm running hard and using the electric for finesse-type fishing, I run either a Turbo TXP if I'm loaded or an 18-22P Raker if I'm light.
With the gas I burn, I need the best efficiency I can obtain-another reason I don't run aluminum-and to get anything substantial out of the proper SS, you still have to maximize the set-up...just as one should do with aluminum.
Think about the SS housing in a water-pump....if you've changed many, you'll see that housing is scored something terrible even when you don't run in the sand-bottom...it's particulates in the water and it does the same thing to your prop. If it scores an SS pump-liner, what do you think it does to an aluminum prop over time....????

 

[Irv964]

Re: How long will a prop last?

Thanks guy's, some great info there Walleyehed, I will be sure to keep an eye on things over the next few years. I know our lake is one of the cleanest around but where I get on and off my boat lift is relatively shallow and I tend to stir up a fair amount of silt which I am now sure will shorten my prop life? Thanks again.........Irv964

 

[109jb]

Re: How long will a prop last?

So if the industry standard for Al is 5 years and SS is 10, what are they assuming for "industry standard usage" (ie: number of hours per year)???? My dad's boat had a new AL prop put on in 2003 when I switched it from tiller to console steer. Has had maybe 20 hours use since then because his health has prevented hime from using it. I guess I should change the prop because it is worn out past industry standards. As far as the particles that wear on a prop, wouldn't it have to wear past the paint layer on an AL prop before it can wear the prop itself. Doesn't make any sense to me.

 

[walleyehed]

Re: How long will a prop last?

109, read 4 lines up on my post, #7 above.

 

[Prop MD]

Re: How long will a prop last?

I repair props, and to keep it simple here are a few things..

A prop can last for 10+ years, it depends on use..
And aluminum prop will slowly wear down in most cases. I have seem 10 year old props look almost new, but that have lost almost a 1" But they still work, and can de repaired back to original specs.

The life of a prop also depends on the hub. If you have a rubber hub,a nd your prop is more than a few years old watch it for cracking. If the rubber drys out, or you hub is spun you may need to replace the hub.

Stainless props last longer because they are harder, but they will loose their cup.

Both can be repaired, rehubbed, and recupped. If nothing else for a back up prop. All Props can be repaired multiple times!

And for those of you with older motors, or the odd balls keep your original prop and have it repaired. Many of those lines are discontinued, and finding them is gettign harder. Many times you pay double the price for the same prop because there are only a few left on dealer shelves..

 

[parrilladk]

Re: How long will a prop last?

109jb is right though. You can't wear the aluminum if the layer of paint is still on the propeller. You must wear the paint first before the particulates have a chance on the aluminum. And if the paint is wearing, repaint. The prop should last then....forever.

 

[ufm82]

Re: How long will a prop last?

It's not all sediment either. In perfectly clean, pure water, you can still experience wear on a prop via cavitation burn. Is that correct? Much like you see paint off the edges of a prop on the backside does it not also pull material off the prop blades? It's very noticeable on aluminum props as they are soft, not so much on SS. Just a thought.

UFM82

 

[Dhadley]

Re: How long will a prop last?

"How long will a prop last?" From here to there.

When we were racing our best prop was a Mazco (reworked Silver Streak) that we ran for a couple of years. I started running my V4 aginst the V6's and had one guy I couldn't keep up with. He had me by about 3 boat links every time. I finally mentioned it to John at Mazco in a joking manner. I was glad to be that close.

John took it to heart and built me another prop. Started with the same prop, a Silver Streak, and it looked identical. Blade tips were in the same place exactly and everything but the serial number was the same by looking. But it consistantly made up 2 of the 3 boat lengths.

Bottom line, like Kenny says, they can look perfect but they do lose grip.