How often between prop removal & inspections

[Jimd1971]

I have a 4Cyl Ford Lehman powered displacement cruiser / trawler with a fixed 3 blade bronze prop.

When purchased 4 years (650 hours) ago I had the prop removed from the shaft as part of the purchase inspection and as a result the prop shaft and log bearing were replaced.

Since then I have only carried out inspections of the log bearing for movement wear and the castle nut and blades for damage on the two previous haul outs.

My questions is what is the service interval for the prop, i.e. how often should I be removing the prop from the shaft and inspecting the key way and re-greasing the taper etc. if no problem is evident.

Thanks in advance

Jim

[model 10]

Wow, you will get mixed opinions on "greasing a taper" around here. Good for you. You can wear out a bronze tapered hub if you remove and install it too often. That would be one reason to leave it alone for longer than 650hrs. Another reason would be a visual inspection would tell you a lot. And lastly, you are going to need a good puller however long you wait, so wait longer if it all looks good. The chance of getting intergranular corrosion in the shaft under the prop is pretty small. Then some people pull their prop shaft every year or so and polish it.

[fstbttms]

Never grease your prop and/or shaft. They are not designed to have anything, including lubricant, placed between them. Further, your prop is not supposed to come off easily.

[Jimd1971]

Yes, I like the "if its not broken, wobbly, or squeaking then don't stuff with it" approach.

It may not have been grease the surveyor lightly smeared on the tapper, could have been some sort of anti-seize after he polished it with a fine emery cloth but after 4 years I don't exactly recall.

Would 5 years be a good interval or do people generally run them until they detect a problem and hope its not while they are offshore?

Jim

[model 10]

Originally Posted by fstbttms

Never grease your prop and/or shaft. They are not designed to have anything, including lubricant, placed between them.

You are a crack up. I have wondered why, as a "professional" bottom service technician you don't have a wider understanding of the world of tapered shafts and propellers. I can only guess your area of expertise is limited to a few boats in SF bay and really not that much regarding propellers, tapers and the rest of the world.
There are reasons to use some sort of lube on a taper and perhaps some reasons not to. To say there is "never" any reason to put something on the surface, is clueless and no credit to your profession.

[fstbttms]

I repeat, never lubricate your prop bore or propeller shaft. It may be fine to do this in other applications, but anybody who tells you it's OK to do this on your boat is sadly misinformed.

[model 10]

Originally Posted by fstbttms

I repeat, never lubricate your prop bore or propeller shaft. It may be fine to do this in other applications, but anybody who tells you it's OK to do this on your boat is sadly misinformed.

Like the US Navy? Losers.

[mikereed100]

Originally Posted by fstbttms

I repeat, never lubricate your prop bore or propeller shaft. It may be fine to do this in other applications, but anybody who tells you it's OK to do this on your boat is sadly misinformed.

Why do you say this? My Kiwiprop installation guide specifies a thin coat of marine grease on both the hub and shaft prior to installation.

[fstbttms]

Originally Posted by Guy

Like the US Navy? Losers.

Maybe (in your rush to demonstrate to us what an expert you are), you could manage to keep the discussion about pleasure craft and not naval warships, hmmm?

Maybe you could describe a situation involving a boat that somebody reading this might own, in which it would be necessary (or even appropriate) to lubricate the prop or shaft prior to installation.

[fstbttms]

Originally Posted by mikereed100

Why do you say this?

I say it because of the prop installation I received from the manager of the largest propeller repair facility in Northern California.

[mikereed100]

Originally Posted by fstbttms

I say it because of the prop installation I received from the manager of the largest propeller repair facility in Northern California.

Excellent, but did he say why? For example, is there a problem with crevice corrosion if you add grease?

[SailFastTri]

I'm in the no grease camp.

Also your surveyor should not have used sandpaper on the taper. The prop hub should be lapped and fitted using a special abrasive compound that enables the two parts to work and conform to each other. Then they should be dry fitted. If they are properly fitted the key will not be needed to prevent the hub from slipping on the shaft, but it's used for "good measure ". The compression from the nut will force the two parts together very tightly and they will not slip.

[SailFastTri]

BTW I think 3-4 years is a good inspection interval, if you don't see any other reason to pull it.

[JstaRebel]

Originally Posted by fstbttms

Never grease your prop and/or shaft. They are not designed to have anything, including lubricant, placed between them. Further, your prop is not supposed to come off easily.

I have to concur with this post. I service my prop, cutlass bearing, and shaft every time I haul out. Two-three years max. It's just part of whats needed during this service. I'd also NEVER grease my shaft. They are water cooled. No grease is necessary. Everybody has their own ideas of course, and this is what I do.

[Sailmonkey]

If you grease a taper you are adding a measurable film between the bore and shaft, this is not how it was designed to fit.
Now on some types of merchant and naval vessels you'll float the prop on using a hydraulic float type of expansion fit......very different than what we use on small boats.


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