Props - Aluminum, Stainless or ???

[Chris Z]

I always wander back and forth between the desire for a stainless prop and the reality of my boating environment. With the last boat I stayed with aluminum and was very pleased after some surprising bottom strikes (sand bars everywhere).

Once again with the new boat, and a larger motor (115 to 150), I'm thinking about whether or not the performance at the top end is worth the added expense and risk of expensive repairs that could come along with a blade strike.

Also factoring in is the Yamaha outboard's distaste for spinning a heavy prop. This shows up as an annoying ticking at and just above idle as the splines just below the power head load and unload. It does go away once you load up the outboard a bit with some throttle but if you're out for a sunset cruise and have the slightest hint of OCD you'll hate it as soon as you hear it.

And, my dealer also has mentioned something called Black Steel as a prop material. He claims it carries the blade stiffness of stainless with the lightness of aluminum. That takes care of one issue... but.

So, once again the solution is clear as mud to me. He's going to prep the boat with an aluminum prop for delivery but I figured I'd do a little research here to gather some opinions. I notice in the pictures many of you are opting for stainless props.

Thoughts?

    CZ

 

[kaydano]

I have an aluminum Black Max and a stainless Enertia that both fit my 150.  Top end speed is pretty much identical between the two (stainless is 1 mph faster).  The stainless stays in the water a lot better, but that is likely more to do with blade design than the type of metal.  The Black Max (aluminum) blows out and ventilates with even the slightest amount of trim on the motor.  The Enertia will trim up quite a bit before it sucks air.  Again, this is likely to have everything to do with the design of the prop, and nothing to do with the metal.  Point being, stainless vs aluminum is only part of the equation, and in my experience, with up to a 150 HP motor, I would say aluminum vs stainless has very little performance difference.  The prop design is far more important.  Again, that's up to 150 HP.  Bigger motors are more likely to benefit from the stainless.  The Enertia rattles pretty good at idle too, which is an annoyance that can be fixed with a better hub.  My aluminum prop is quiet at idle.

If you are worried about prop strikes, then that should be the sole factor in which your decision lies as the performance difference between the two metals will be pretty negligible up to 150 HP in my opinion.  Forget about the top end speed difference.  Without a GPS, you'd likely never notice the difference.

I'd take your dealer up on a demo of the "black steel" props...

 

[cwag911]

Our boat came with a solas aluminum prop and it was just ok. After trying many (6) different props and different pitches, I liked the 15 x 15 Enertia. It never loses grip. If you just have sandbars to worry about then go for it.

 

[keithkz]

After trying several props last year (which I documented on here) one thing I took away was that what (prop) might work great on one boat/motor might not work the best on all boat/motor combinations.  I do wonder if my having an I/O makes a difference because what kaydano mentioned above with certain props coming out of the water with the slightest trim, I found that happened with my boat regardless of what prop I tried on my boat.
 

 

[Bill N]

I feel that shifting into neutral requires more effort with an alum prop than it does w/stainless prop.

The bigger the engine, the more this is noticed.

I recommend stainless on 150 & up.

 

[Bamaman]

I used to go through a prop a year on my old inboard outboard boat.  We live on a rock bottom, but deep, lake.  Fortunately the prop shop owner is a cousin, and he fixed them cheap.

When I bought a new boat, I switched over to a stainless prop.  I barely scratched it in the 10+ years' usage.  It was very, very durable.

My new Bennie has a 15 pitch Reliance stainless prop, and it's great.  I keep it trimmed to 3/4 up on my gauge, and seldom even change the height. 

But if I was running 115 hp or lower, it'd have one of the new generation aluminum props on it.

 

[Bull]

I am in this same situation. ..

I am on Squam lake in NH and is known for unmarked hazards and eating props..water is high

, so I have not pulled the 15 stainless prop off, but will soon.....so, any thoughts on an aluminum that will be a suitable substitute?

 

[lakeliving]

No prop chatter with the SDS hub on a reliance prop.