Prop install

[Skywalker]

Quick question.

When you install your prop, do you put grease on the contact area?

My local prop shop recommended I do this to minimize salt and corrosion that would make it difficult to remove the prop.

Any thoughts?

Chris

[edwardc]

Makes sense to me. You use TefGel ( or synth grease ot Lanolin ) to seal screws & fittings above the waterline for the very same reason.

[Al Schober]

I think a little grease in this area is a good thing. The prop may slip back against the nut with a hard reverse, but that's what the nut is for. Our shafts use a taper of 3/4" per foot (16:1) which can be quite secure, but it takes a good push to get it on tight. Use the thick nut to get the hub tight on the taper, then remove it and then install the thin nut first. Run both nuts up hand tight, back off the big nut a little to install the cotter, then jam the thin nut back against the thick one.
Just for a point of perspective, there are commercial ships running around with no propeller nuts or keys, but these shafts/hubs use a 20:1 taper. They use hydraulic pressure between the shaft and prop to expand the hub while they use hydraulic pressure to push the hub forward. They bleed off the interface pressure then ease off on the push. A relatively thin plate gets bolted on to seal the aft end of the shaft. To remove the prop, they just pump hydraulic fluid into the interface.

[Skywalker]

Thanks.

The last PIA issue with the prop is the since. I have around 5/8 -3/4 of an inch between the the deadwood and the prop.

My prop shop will cut zincs to fit for $5. I'm splurging on this! I am tired of doing what seems to be an easy job - that never is. I put the darn thing in my vice, get a nice, new hacksaw blade, but it is always a hack job (pardon the pun).

Maybe I can invent a sleeve that fits between the prop and the shaft to insulate the two.

Chris

[Al Schober]

Chris,
It's been done - I've got one on my Tartan 30. Made by Globe Marine, it's a Drivesaver #353. It will move your shaft aft 11/16". Bought mine at Defender.

[BadaBing]

I have the same adapter. It provides a little give to the coupling. A good addition IMO for any well loved vessel.

I noticed 2 seasons how much the standard doughnut shaft Zink was intruding over my indigo shaft hub. Given the indigo is already rather small I decided to modify one of the more sharply () zincs. Same reason, restricted space between prop face and countless bearing. I uses a vice and a recip saw. Your correct, it could have been neater. Next time I'm going to spin the zinc on a wood dowl in an electric drill and use the recip saw.

It seemed, could be subjective, to allow the prop a better flow or bite.

[Skywalker]

Hmm. That's a intriguing option. That would give me a little more room, too.

[hanleyclifford]

Just one additional thought for this discussion: if you do grease the shaft as suggested ensure the grease has no metal component so that you do not set up a galvanic cell.

[Al Schober]

Hey Hanley,
Any grease put in there is going to be squeezed out and washed away. The only galvanic couple to worry about is the prop and the zinc - unless there's something really screwy going on.
Have no doubt - the shaft and the prop are going metal to metal. The grease won't keep them apart. The grease will only help to exclude sea water from the interface.