Watch out for debris!!!!

[Alumarine]

Re: Watch out for debris!!!!

As far as whether this can really happen or not, I have seen it. Don't have pictures of what I saw growing up, but here is an example:

http://www.wmi.org/multi_boards/other_topics/message.html?message_id=317046

The ones you have seen were they using jack plates?

 

[Expidia]

Re: Watch out for debris!!!!

I've seen this comment time and time again and I don't buy it. Even with a stainless prop, you'll bend or break a blade, break the shear pin or trash the hub before you bend or break anything in the drive.

Here ya go . . . this was copied off a prop repair shop's FAQ page. I don't want to show their name since Iboats I think has a link for prop repair through them.


Q: What are the pros and cons to stainless props versus the aluminium version?
A: The stainless prop, if it is exactly the same dimensions as the aluminium, will usually perform a little better because they can be a little thinner and are more efficient as they don't flex as much under load. A lot of the stainless props are designed for better top end than the aluminium props by having a higher rake angle and better cupping. Of course, the cost is higher, but the durability is a lot better. A concern with a lot of boaters is whether or not a stainless prop will cause drive damage if a strike occurs. If the prop hits a large rock or immovable object, then drive damage might occur. Usually the blades will bend or the hub will slip before this happens, but once in a while a shaft gets bent or a gear tooth does break even with aluminium props. Most boat insurance will cover any of this damage. Remember stainless propellers can be rebuilt to there original strength whereas aluminium propellers cannot.

 

[bekosh]

Re: Watch out for debris!!!!

Usually the blades will bend or the hub will slip before this happens, but once in a while a shaft gets bent or a gear tooth does break even with aluminium props.

The question is whether damage to the drive occurs more often with Stainless vs. Aluminum. I'm not convinced that it does and it appears that the engineers at Mercury agree. http://www.mercurymarine.com/propellers/about/how-to-choose/stainless-vs-aluminum/

Will a stainless steel propeller damage my lower unit in the event of an underwater impact? Mercury engineers, conducting underwater impact testing, found no substantial difference in the amount of torque transferred to the propeller shaft between an aluminum and stainless steel propeller.

 

[Expidia]

Re: Watch out for debris!!!!

The question is whether damage to the drive occurs more often with Stainless vs. Aluminum. I'm not convinced that it does and it appears that the engineers at Mercury agree. http://www.mercurymarine.com/propellers/about/how-to-choose/stainless-vs-aluminum/

Hmmm, now there's an independent source . . . Mercury! Might these be the same engineers that work for Mercury who also sell the more expensive SS props too.

And I'm conversing with a guy who even lists the names of his SS props in his signature . . . Hahaha . . . Just kidding and yanking your chain a little . But no really, you don't have actual names for each prop do you? There I go again, just kidding.

If my rig was larger I too would have SS props as they don't nick or bend as easily as aluminum. But I can remember years ago when I said to my BIL that I was thinking of getting SS for my 40 and he immediately said "don't do it". I really respect his advice. I've been boating with him for 45 years. He's taught me a lot about boating. He has had 4 large rigs, this last one is a 46 foot Bertram Sport Fisherman that we stay on. His tender is a Whaler with 90 or so Yammy. He won't put a SS on that. He was the one who told me aluminum will flex and potentially not pass the shock through the other parts of the lower unit.

So you might think its a myth. But that link I posted was from an independent prop repair shop, which was the first one that I googled. One would think he would prefer to see everyone buy SS as they cost twice as much to buy or repair.

So far my "real world" experience over the past few years proves my BIL correct. Twice I've whacked my aluminum prop. First time on a submerged piling that did not show on my GPS Navionics map (it was like 40 feet off) I know, I know . . . Don't use the Nav. chip for navigation. 2nd time on a rock which I hit when I cut across a bay which I knew I was supposed to avoid. it's like standing on the top rung of a ladder, the sticker says don't do it but we do it anyway as I fall to the ground and I'm still thinking of that sticker!

Both times I had to send the prop out to be repaired and there was no damage to the seals, prop shaft or spline gears. I had to also get the skeg repaired both times at a local welder.

I think its more of a situation where small motors have smaller components that would be more suseptible to impact of the transfer of shock of whacking your prop on a rock etc. From my experience, if I had a SS on my small 40 HP I'd have at least lost a few teeth off the prop shaft spline.

lastly, for me personally, an expensive SS prop is a target for thieves. Especially as I do a lot of trailering and leave rig in motel parking lots. I have a prop rod lock that locks through my transom saver but if a thief wants your prop he's going to get it anyway.

 

[Tagerman]

Re: Watch out for debris!!!!

I boat on a hydro lake in Chattanooga and I put a keel protector on the boat (also because in the river there are sandbars I like to beach the boat on and chill) because it is almost impossible to run up and down the lake without hitting something. $30 a season to have one of my props rebuilt and I'm good. My self created theory is if I see something at the last minute try to turn hard to one side or the other. The hull seems to be good at moving debris out of the way as long as I don't hit it dead on.

 

[the vision]

Re: Watch out for debris!!!!

Well turning would probaly have been the best bet, but the river was too narrow in the corner I was rounding. So slowing down was my only option.

 

[Campylobacter]

Re: Watch out for debris!!!!

So you might think its a myth. But that link I posted was from an independent prop repair shop, which was the first one that I googled.

Here is the only part of the link you posted that pertains to bent shafts: A concern with a lot of boaters is whether or not a stainless prop will cause drive damage if a strike occurs. If the prop hits a large rock or immovable object, then drive damage might occur. Usually the blades will bend or the hub will slip before this happens, but once in a while a shaft gets bent or a gear tooth does break even with aluminium props.


Not sure the prop material really matters.

 

[04fxdwgi]

Re: Watch out for debris!!!!

Comes with the territory of river cruising. I have the same issues on the Hudson River here in NY. Whenever we get a real hard rain it raises the water way above the high tide mark and this flushes a ton of logs, branches, pieces of peoples docks, metal 55 gallon drums, tires with the rims still in them etc back into the river.

Much of this debris is water logged so it travels down river just below the suface. In the Spring I've seen "entire trees" I mean like 30 feet long just criusing alone

Not much you can do about it other than wait a week or two after a storm or hard rain. The fishing is usually poor for me over the week after it rains anyway.

Usually if you hit a small log or branch on a river while you are on the move, since the log is not stationery you tend to pop over it and you hear this loud whack that scares the bejesus out of ya!
Damage is usually just a bent prop ear (maybe a bite taken out of it) since a log in the water has some give to it.

The worst is when you hit a rock or submerged piling (done both already) these types of immovable objects tend to whack the prop or take a chunk out of your skeg which is there to help protect your prop (skeg easily repaired by local welder for $50-75, done that twice already) Another good reason for using an aluminum prop, instead of stainless steel. Aluminum tends to bend or break, but for $30 sending in to an online prop repair shop, they can make it look just like new and ship it back all within a week!

This is why I always carry a spare prop, nut and several shear pins onboard and a prop wrench. A spare is handy too if you damage one and it's in the prop repair shop at least you don't lose a weekend of boating waiting for your only prop to come back.

Stainless steel does not give much and transfers the shock to your lower drive possibly breaking something or bending your prop shaft.

Just take a look at the boats being trailered as they go by on the h-way, check out their props and skegs, most are beat up. Some say "I've been boating for years and never nicked a prop". If my boat was in my driveway most of the season, my prop would be pristine too

Sure river cruising can be hard on props due to hard to spot floating or submerged debris . . . but that just adds to the adventure . . . hahaha

Agree 1,000% I boat in the Hudson also, putting in at Peekskill. After a storm and in the spring, it's like "running the gauntlet". Almost hit a full length telephone pole in the river last month. Tied up to it and dragged it ashore. Can't let your gaurd down for a second, but I do learn where the largest debris fields gather and avoid those areas.