Prop question: I am putting together a boat to fish for red fish and trout in the backwaters off the Gulf. Is a stainless steel prop a good idea or bad?

Oldfisherguy Loc: NE Kansas

I am putting together a boat to fish for red fish and trout in the backwaters off the Gulf. Is a stainless steel prop a good idea or bad?

Huntm22 Loc: Northern Utah. - West Haven

Welcome aboard old fisher guy. I’m inland so no help. Others will set you straight. Enjoy

Robert J Samples Loc: Round Rock, Texas

OFG: Nothing wrong with stainless that I know. Just be sure it is matched to your motor. Size and pitch. Just Sayin...RJS

Barnacles Loc: Northern California

The salt water shouldn't harm either aluminum or stainless. As far as corrosion is concerned, I believe that in salt water your anodes should be magnesium.

OKAY - PROPS: Aluminum is lighter than stainless or especially bronze, so it'll be easier on your gears as you shift in and out of neutral. While there are still bronze props for outboards, they've been largely replaced by stainless. It's tougher, so the blades can be a bit thinner. So I'll only address stainless vs. aluminum. If you run into sand, an aluminum prop will be abraided a bit, or even nicked, especially if there are pebbles in the sand. A stainless prop will fare better. If you manage to find a rock, you'll be looking at a prop repair no matter what it's made of. Stainless cost a lot more than aluminum, generally 2-3 times as much. Some shops will tell you not to bother repairing an aluminum one, as a repair costs around 80% or more of what a new prop costs.

SO - if you don't expect to ever hit anything, I'd choose stainless. If your prop has much of a chance of being damaged, weigh the cost of simply replacing an aluminum one against the repair of a stainless one, either choice for a more or less similar cost. One factor in the choice is whether you know of a shop that you can count on to PROPerly (pun intended) fix and balance your prop. Some folks just run aluminum and consider them as a consumable expense of operating a boat. If you'll be running in shallow water a lot or often running up onto the beach, stainless would be a strong contender for the choice.

When you buy any prop, try to cobble together some way to check the balance of it. The balance is more important than most people think, and a new prop on the shelf is not altogether certain to be well balanced. I rigged up two ball bearings in cone shaped bushings, and slid them onto a 12" long drill bit that I'd checked for straightness. I can slide the prop over the drill bit into one cone and then slide the second cone onto the shaft and into the prop. Holt the shaft horizontally, and viola! I'll post a photo of it later.

Foodfisher Loc: SO. Cal coast

Barnacles wrote:

The salt water shouldn't harm either aluminum or stainless. As far as corrosion is concerned, I believe that in salt water your anodes should be magnesium.

OKAY - PROPS: Aluminum is lighter than stainless or especially bronze, so it'll be easier on your gears as you shift in and out of neutral. While there are still bronze props for outboards, they've been largely replaced by stainless. It's tougher, so the blades can be a bit thinner. So I'll only address stainless vs. aluminum. If you run into sand, an aluminum prop will be abraided a bit, or even nicked, especially if there are pebbles in the sand. A stainless prop will fare better. If you manage to find a rock, you'll be looking at a prop repair no matter what it's made of. Stainless cost a lot more than aluminum, generally 2-3 times as much. Some shops will tell you not to bother repairing an aluminum one, as a repair costs around 80% or more of what a new prop costs.

SO - if you don't expect to ever hit anything, I'd choose stainless. If your prop has much of a chance of being damaged, weigh the cost of simply replacing an aluminum one against the repair of a stainless one, either choice for a more or less similar cost. One factor in the choice is whether you know of a shop that you can count on to PROPerly (pun intended) fix and balance your prop. Some folks just run aluminum and consider them as a consumable expense of operating a boat. If you'll be running in shallow water a lot or often running up onto the beach, stainless would be a strong contender for the choice.

When you buy any prop, try to cobble together some way to check the balance of it. The balance is more important than most people think, and a new prop on the shelf is not altogether certain to be well balanced. I rigged up two ball bearings in cone shaped bushings, and slid them onto a 12" long drill bit that I'd checked for straightness. I can slide the prop over the drill bit into one cone and then slide the second cone onto the shaft and into the prop. Holt the shaft horizontally, and viola! I'll post a photo of it later.

The salt water shouldn't harm either aluminum or s... (show quote)

In addition: a sudden stop ( rock/log etc.) With a s/s prop will put severe stress on the drive train spinning it. I agree, an aluminum prop is more sacrificial than those other parts(gears,shafts,transoms etc. For performance (speed) s/s is the way to go.

Barnacles Loc: Northern California

Here's that photo that I'd promised. This is my balance quick-check gizmo.

DozerDave Loc: Port Orchard Wa.

Foodfisher wrote:

In addition: a sudden stop ( rock/log etc.) With a s/s prop will put severe stress on the drive train spinning it. I agree, an aluminum prop is more sacrificial than those other parts(gears,shafts,transoms etc. For performance (speed) s/s is the way to go.

That’s what I’ve always heard,Food. I’m glad I had an aluminum prop last year when I hit a submerged log running about 40mph...🐟on

Barnacles Loc: Northern California

A busted blade is cheaper than a busted gearbox!

Oldfisherguy Loc: NE Kansas

Thanks guys. I can attest to the expensive stainless repair. I have a stainless prop on a 150 hp Yamaha. A bent prop shaft cost me several hundred dollars to replace. This boat I'm putting together only has a 25 hp motor and will be run in bays and back water flats only.

TomTrack44 Loc: Petaluma, CA

Oldfisherguy wrote:

I am putting together a boat to fish for red fish and trout in the backwaters off the Gulf. Is a stainless steel prop a good idea or bad?

On your 25hp motor go aluminum. The advantage of SS is as Fred says, speed, and less vibration and flexing under load on a larger heavier motor and boat, SS will give 5-8 mph over aluminum on say 150hp or more. Tom.

MuskyHunter Loc: Torrington, CT

TomTrack44 wrote:

On your 25hp motor go aluminum. The advantage of SS is as Fred says, speed, and less vibration and flexing under load on a larger heavier motor and boat, SS will give 5-8 mph over aluminum on say 150hp or more. Tom.

I have never seen a stainless steel prop give that much of a speed boost. Our fishing club compiled a lot of data about stainless props and these notes illustrate what generally happened when switching to stainless steel props:

1. If you went with the same pitch as your aluminum, there was a big loss in top rpm and a corresponding loss of speed.

2. Dropping down 2-4 inches of pitch usually restored most of the top rpm, but there was still a loss of speed, because of the pitch reduction. The boats handling quality usually improved dramatically, especially with cupped props. My boat could turn a top speed without even leaning.

3. Dropping the pitch and raising the motor generally improved top rpm and provided a slight gain in speed (1-3 mph). The great improvement in handling generally went away. The motor needs to be raised until a tiny bit of the prop is out of the water to achieve this result. Because stainless props flex less and grab the water better, there is far less ventilation that occurs.

4. As said before, if you hit something you can do a lot of damage. My motor's drive shaft can attest to that. A lot of people I know who fish Lake of the Woods on the Canadian border change out their stainless prop for aluminum due the enormous number of hazards in the lake. That's where I hit mine!

5. For myself, I tried all sorts of props, motor heights before I settled on the prop I chose which was a high cupped SS prop. I did not raise the motor as I loved the handling improvement, but I lost about 2 mph.

Huntm22 Loc: Northern Utah. - West Haven

That’s a lot to digest there.

MuskyHunter Loc: Torrington, CT

Barnacles wrote:

The salt water shouldn't harm either aluminum or stainless. As far as corrosion is concerned, I believe that in salt water your anodes should be magnesium.

OKAY - PROPS: Aluminum is lighter than stainless or especially bronze, so it'll be easier on your gears as you shift in and out of neutral. While there are still bronze props for outboards, they've been largely replaced by stainless. It's tougher, so the blades can be a bit thinner. So I'll only address stainless vs. aluminum. If you run into sand, an aluminum prop will be abraided a bit, or even nicked, especially if there are pebbles in the sand. A stainless prop will fare better. If you manage to find a rock, you'll be looking at a prop repair no matter what it's made of. Stainless cost a lot more than aluminum, generally 2-3 times as much. Some shops will tell you not to bother repairing an aluminum one, as a repair costs around 80% or more of what a new prop costs.

SO - if you don't expect to ever hit anything, I'd choose stainless. If your prop has much of a chance of being damaged, weigh the cost of simply replacing an aluminum one against the repair of a stainless one, either choice for a more or less similar cost. One factor in the choice is whether you know of a shop that you can count on to PROPerly (pun intended) fix and balance your prop. Some folks just run aluminum and consider them as a consumable expense of operating a boat. If you'll be running in shallow water a lot or often running up onto the beach, stainless would be a strong contender for the choice.

When you buy any prop, try to cobble together some way to check the balance of it. The balance is more important than most people think, and a new prop on the shelf is not altogether certain to be well balanced. I rigged up two ball bearings in cone shaped bushings, and slid them onto a 12" long drill bit that I'd checked for straightness. I can slide the prop over the drill bit into one cone and then slide the second cone onto the shaft and into the prop. Holt the shaft horizontally, and viola! I'll post a photo of it later.

The salt water shouldn't harm either aluminum or s... (show quote)

Clever device...my question is: if the prop is out of balance do you take it in to be fixed or have you been able to fix it yourself, and if so, how?

Bob Daniels Loc: Two Harbors MN

It is a VERY BAD IDEA. The standard aluminum prop is made to shatter or bend if you have a prop strike. The stainless is almost indestructible, so the damage is transferred to the gearbox. I lost a merc cruiser lower unit
Because of a stainless steel prop. You can buy 3 or 4 aluminum props for the price of1 stainless prop.

Oldfisherguy Loc: NE Kansas

Took the project boat to the lake today. Good news is that it runs great and everything on the boat operates as it should. BAD news is IT LEAKS. Brought it home and put the garden hose in the boat. Found five rivets that leak. Any tips on ways to seal the rivets from the outside. I really don't want to have to remove the floor to seal from inside. (until that is the only remedy).