posted 03-10-2009 07:32 PM ET (US)            

Tony

posted 03-11-2009 07:58 PM ET (US)            

or a drysuit.
or a buddy boat to do the change from.

Chuck, who does have really, REALLY long arms
AND a drysuit.

posted 03-12-2009 09:48 AM ET (US)            

What will happen with an aluminum prop is the blades will be easily mangled if you hit a piece of driftwood or touch bottom. With stainless steel the prop will be much more likely to not be damaged at all being five times stronger than aluminum.

In reality, you may be safer with an SS propeller because it may hold together where an aluminum prop can be destroyed leaving you stranded.

The hub kits that Joe refers to are Mercury's Flo-Torq hub kits that use a plastic insert that is field replaceable. But all modern outboard propellers have had protection built into them (with just a few exceptions) in the form of a pressed in rubber insert if they do not have the Flo-Torq hub or its licensed siblings: Michigan XHS, BRP TBX, Precision Guardian SQ-Lok, etc. These hubs ae designed to let get before the propeller blades are completely destroyed or your outboard is damaged.

Any prop strike severe enough to damage a the drive train of an outboard propeller will also do so if you use an aluminum prop.

I think the myth is perpetuated by fathers teaching their sons this advice over the years the same way we still embrace the old myth of never leave a battery sitting on a concrete floor. Maybe, generation ago, there was *some* basis for these bits if advice but there is none today. I try to squash these myths every time they pop up.

Yes, stainless steel propellers are much heavier than aluminum propellers and that can contribute to "shift clunk" and "prop rattle". But again, the hub systems available can help remedy these problems.

The Flo-Torq III and Flo-Torq IV hub kits are designed to be spring-loaded acting as a damper between the propeller and the prop shaft to help absorb that shift clunk.

PowerTech Propellers has the Cushion-Lok hub system that allows you to adjust the degree of softness by using different rubber rods in the hub coupling to fine tune strength of the hub to eliminate shift clunk.

posted 03-12-2009 10:47 AM ET (US)            

Not pretty, and it shattered my previously held notion that aluminum props "save" the outboard drive shaft. To the point made above, they probably contribute to potential safety problems by leaving you with a mangled prop resulting from minor interaction with flotsam or other small debris in the water.

I switched to SS late last summer and am extremely pleased with the change, after buying and repairing 6 or 7 aluminum props over 2 years. I swear that even getting CLOSE to an obstruction bent the blades!

Worse, I have twin engines, so even a minor 'tweak' on one prop made it difficult to sync motors due to changed operating characteristics.

posted 03-12-2009 09:22 PM ET (US)         

The replacement prop is also stainless.

posted 03-13-2009 09:36 AM ET (US)            

quote:

---

I don't want to deal with the whole lower unit gear shaft being messed up when I could just replace the aluminum prop for a 120 bucks

---

And right there is the essence of The Myth. As if the choice between stainless steel and aluminum were the choice between replacing a $120 aluminum prop and an entire gear case. Poppycock.

If you are going to drive your boat on he rocks, you WILL have gear case damage. Tim wonders what would have happened last summer if they had had an aluminum prop instead of a stainless steel prop. I know what would have happened: the exact same thing.

Look, no propeller or hub system yet invented is going to save the day in every situation. If you hit solid rock, you will have damage. There is no magic spell surrounding an aluminum propeller to protect your motor.

posted 03-13-2009 09:55 AM ET (US)            

I guess it really depends on how frugal you are and where you boat. Like I said, I chewed through lots of aluminum props in two years - one of them actually "threw" the repair on the first shot out of the hole upon reinstalling it.

And again...I've personally inspected a beefy prop/drive shaft out of a 225 HP that was sheared clean after hitting an obstruction using an aluminum propeller.

All of my propeller damage was done at slow speed, where striking the same objects with a SS prop would have resulted in an engine stall, rather than a mangled prop, excessive vibration, etc.

posted 03-13-2009 10:24 AM ET (US)         

From the damage, I do think it's likely that if we'd had an aluminum prop on there we'd have lost all three blades and have been making a call to SeaTow. With the stainless, we were at least able to make it home - which was about 40 miles, so I am glad of it.

For reference, the mechanic who replaced our lower unit agreed with Tom - said we'd have been no better off with aluminum.

posted 03-13-2009 12:56 PM ET (US)            

On my 15 I ran across a gravel bar in the river once and trashed the aluminum prop to hell...since i was running at speed, the engine did not stall and I was able to coast off the gravel bar before the boat really came off plane.

With the 150 Merc on my 18, I hit a stump and stalled the motor (at idle) - SS prop didn't even show the mark.

If you will note in my post above - slow speed was a component of my assertion.

Running flat out at cruise and striking a submerged rock is quite different than doing it when idling along in a difficult patch of water.

You do the type of boating that I like to do (limited chart availablility/remote water, etc. and you will find bottom.

In fact, a true test of seamanship would be to navigate the Georgian Bay Small Craft Route without touching bottom or going more than 1/4 mile off course. That would be a fun "competition" for a Whaler owner event...

posted 03-13-2009 06:45 PM ET (US)            

Thanks,

Tony

posted 03-13-2009 07:42 PM ET (US)            

I've also hit floating wood up to the size of a 4x4, and as far as I can tell the stainless prop either bounced off it or cut through it. Either way, no damage. Not that it would never happen, mind you, but at least in that incident I got away lucky.

The stainless prop also goes through sand very nicely, and comes out shiny and polished.

posted 03-14-2009 04:50 PM ET (US)            

Had a 13-1/4 17 aluminum, prop, and I whacked a piece of concrete in shallow water.....was low tide, very stupid on my part.

That said, one blade of that prop was missing - broke off at the hub. I putt-ted slowly back to the resort where I was staying - ran very rough since it was obviously out of balance with a blade missing.

I believe that had I been running my stainless prop that major lower unit damage would have occurred, probably catastrophic. In this case, my skeg was bent slightly like a banana...that and the prop only damage. Mav

posted 03-14-2009 11:24 PM ET (US)            

quote:

---

I believe that had I been running my stainless prop that major lower unit damage would have occurred, probably catastrophic. In this case, my skeg was bent slightly like a banana...that and the prop only damage. Mav

---

There is no evidence to support that claim, hence the myth.

posted 03-15-2009 11:14 AM ET (US)            

You struck a piece of concrete with an aluminum propeller. A blade of the propeller broke off. This is consistent with what everybody in this thread has already pointed out; aluminum propellers are weak.

I should also be pointed out what you did not experience: striking a piece of concrete with a stainless steel propeller and suffering a catastrophic failure of your lower unit.

posted 03-15-2009 11:24 AM ET (US)            

I've boated all my life. I have operated outboard powered boats since I was a young teenager over 30 years ago. I have owned numerous power boats including seven Whalers over that period of time. I think I have owned about two dozen different outboard motors and sterndrives.

I have bent, torn, mangled and otherwise damaged countless aluminum propellers (in my teenage years) and have spent a fair number of dollars on aluminum propeller repairs.

I have bent a stainless steel propeller blade exactly once, two years ago during a full throttle high speed test run in my Revenge going 47 MPH when I struck an unknown floating object in the water and bent the tip of one blade on one propeller almost 90 degrees.

The propeller, a Mercury Offshore four blade, was repaired to like-new condition for about the same price as an aluminum three bladed bought at discount. That same propeller is still giving good service on a friend's Bertram 25 today.

posted 03-15-2009 11:47 AM ET (US)            

"It is illogical to conclude that you would have suffered a catastrophic failure of your lower unit if you had a stainless steel propeller. Your personal experience does not support that conclusion."

Didn't "conclude", but do believe.

I'd rather break off a "weaker prop" than a lower unit. I was lucky.

The best scenario, of course is to avoid hitting a submerged object. Mav

posted 03-15-2009 12:06 PM ET (US)            

quote:

---

I'd rather break off a "weaker prop" than a lower unit. I was lucky

---

posted 03-15-2009 04:03 PM ET (US)            

Anyway, depending upon finances, I might just finally make the plunge and soon go stainless with my Yami 60. If I do, I'd love to be blown away by the difference, but my little skiff is so quick and nimble right now with its stock Yamaha 15P aluminum prop, and she gets such incredible fuel economy, that I'll be amazed as well as impressed if I notice much difference.

posted 03-16-2009 11:09 AM ET (US)            

All
I have to give this crowd a hand for the intensity, articulateness and zeal of this conversations based around the relative implications of aluminum versus SS.

I am sure the stainless steel gets slightly better performance figure, but Elaelap's point that exactly what we mean by performance with BW work boats (the kind of work I like: fishing, cruising, hanging, bringing kids out), should not be confined to WOT speeds, or 0-40 planing speeds.

Tom W. Clark however needs some informal logic lessons. His entertaining tale of his boating experiences--given to establish credibility about his claims--creates two myths of its own:

1) I used lots of aluminum props as a youth, thats when I broke them, and that's what informs my knowledge of aluminum props

Sorry Tom, prop breakage is not just an excess of youth. Sometimes it happens to us older, maturer folk and not just the yahoos.

Plus if your experience with aluminum props only occurred as a youth maybe your raging hormones at the time clouded your judgment?

2) The one time I bent a SS prop it was a strange substantial form of plankton

Your one empirical example of a SS prop that was damaged was hitting an unidentified floating object.

The hunch, hypothetical, analogy, lived experience around aluminum props saving you from more serious lower gear drive damage is hitting a stationary object that shears the aluminum prop quickly and does not lead to an impact like Ray Lewis and Brandon Jacobs

Elaelap and others who are interested in changing props at sea.

My experience with changing props comes from my first boat and learning the ropes around a very rocky area. I broke a few aluminum props ( I was always able to get home put putting when I didn't have a spare prop). You need some proper pliers for the pin, a big wrench the size of the nut on your prop, and a 12 inch piece of a 2" by 4", or even better a 2"x 8." You raise the anchor to its maximum height.
Depending on the waves and how cold the water is you can either lean out over the engine or sit on the transom or the swim platform. Remove the cotter pin by squeezing the bottom and pushing and pulling it out. Insert the block of wood between the prop and the engine so the prop doesn't spin. Be careful that the block of wood doesn't fall into the ocean. Loosen the nut. As you take the nut off make sure the nut doesn't fall into the ocean. Put the nut in a safe place. carefully pull the prop free and with throw it into the ocean in a fit of pique or store it away. Replace the old prop with the spare you have cleverly stashed somewhere on the boat. Don't drop the prop into the ocean. Don't drop the woodblock into the ocean. Don't drop the nut into the ocean. You will do alright without the cotter pin until your next trip. I do have rather long arms and I much prefer to do this when I somebody is with me but it can be done alone.

posted 03-16-2009 11:41 AM ET (US)            

You missed the point. I damaged a lot of aluminum propellers in my youth not because I was young but because I used aluminum propellers back then.

posted 03-16-2009 12:30 PM ET (US)            

1. It can be done.
2. You probably won't like doing it.

Having a buddy boat is the single best (safest, warmest) way, however, a buddy boat may not be very interested in the business end of your skeg pointed at his hullside in a lumpy sea.

Most Whalers do not have transom ladders/platforms.

You will want a lanyard for your tools and the spare prop, prop nut, etc. That is why prop wrenches come with a hole in the handle - for a lanyard.

FROM THE BOAT:
Anchor with bow into the waves, if possible/safe. Tilt the motor all the way forward. Put on a PFD. Tie yourself to the leaning post so you can lean out over the transom and not fall in (I use a dock line and cushion my belly with a square throwable cushion or another PFD. Use lanyards for all items until the very moment you need them. Tie the lanyard to your PFD or your belt - not just wrapped around your hand/forearm.

FROM THE WATER - BRR!
(Make sure the water temperature is safe!). All needed items go into the splashwell. Tools are clipped to the transom eye so they can't be lost. Tilt motor until the prop is JUST out of the water. Put on a PFD and jump in.

I keep a spare prop and TWO spare prop nuts, thrust washers and SEVERAL cotter pins aboard the boat so if I lose something overboard while changing, it is not the end of the world.

Go slow and deliberate.

Good luck.

posted 03-16-2009 12:52 PM ET (US)            

I have struck bottom one time and I had to replace my lower unit. But I am still using my stiletto (ss prop). That was an expensive evening.

posted 03-16-2009 04:05 PM ET (US)         

Any takers? The closer to Augusta, Maine, the better...

posted 03-16-2009 08:34 PM ET (US)            

Tony

posted 03-16-2009 09:06 PM ET (US)         

How so?

posted 03-17-2009 08:16 AM ET (US)         

From what I have gathered, the alleged knock on stainless steel propeller damage to lower units from underwater contact is that when the propeller encounters a significant obstruction, and that obstruction prevents the propeller from continuing to spin. Since the engine is still applying substantial force to spin the propeller, something has to give, and that would be in the drive components, likely the gears. However, with the advent of modern hub kits and other bushings, the likelihood of this happening is remote. It is also hard to believe that a propeller alone, stainless or otherwise, would play any significant role in tearing a lower unit off of a motor.

posted 03-17-2009 08:46 AM ET (US)         

In our case (I was not the skipper BTW) we had a very small nick in the skeg about 2" up from the bottom, nowhere near the gearcase itself. All 3 prop blades were folded back about 1", the propshaft and driveshaft were bent and, according to the mechanic, in all such cases he has seen the gearcase casting itself is bent out of alignment, so it was replaced. That's only one mechanic's opinion, but certainly the insurance folks didn't give us any grief about replacing it.

This was with a 2004 Yamaha F200, which I would consider a fairly modern motor. So maybe the possibility is remote, but I'd say "not remote enough."

BUT we still don't have an example of anyone doing the same type of thing with an aluminum prop and experiencing no damage to the driveline and gearcase, so we have no way of knowing if that would be better.

posted 03-17-2009 09:04 AM ET (US)            

A couple of times a year (I do it once, but you have an extended season!) - remove the propeller and use BRP Triple Guard Grease (or equivalent) to lubricate the splines on the drive shaft and inside the hub of the prop. Don't be stingy!

That keeps the prop nice and easy to remove/replace when necessary.

This grease is waterproof and clings really well to the metal components....and it is difficult to wash off. It should last at least 100 hours on a trailered motor. I have not experience with a moored motor; but would suggest that perhaps you need to increase the schedule, as with most things on a moored vessel.

posted 03-17-2009 09:51 AM ET (US)         

We still have a (new) stainless prop on the Yamaha, and both the props I have for my Johnson are stainless. The mechanic said aluminum would have been no better, but I have no direct evidence to back that up.

I guess if someone could prove to me aluminum would save my driveline, I'd consider switching over - especially if my brother in law is going to keep driving the Yammy!

posted 03-17-2009 11:56 AM ET (US)            

Again, I love it. Hope to see some folks at the BW get together around the Statue of Liberty in June.