Prop Shaft - To grease or not to grease ?

[Guest]

Having had a devil of a job to get the prop off, do I now grease the taper or not ?

If yes, what grease ?

I have Blakes seacock grease and Keenol.

Many Thanks

 

[Guest]

I dont know much about the subject but I can remember after having a simmilar problem being told that some grease acts as an electrical insulator which could interrupt the continuity between your propellor and the anode.
This would cause accelerated corrosion of the propellor.Sorry but I cannot recall the name of the correct grease to use

 

[Guest]

If you have a friction joint and tapered shaft to increase the contact area .....what the hell are you greasing for?!

Next time use the proper tool for getting the prop off

Just pop into your local auto bits shop and get a 4" puller ..2 leg about £12.50, 3 leg about £16.00 and then you can take your prop off as many times as you want!

 

[Guest]

If you have a friction joint and tapered shaft to increase the contact area .....what the hell are you greasing for?!..it goes on dry and clean!

Next time use the proper tool for getting the prop off

Just pop into your local auto bits shop and get a 4" puller ..2 leg about £12.50, 3 leg about £16.00 and then you can take your prop off as many times as you want!

 

[Guest]

I initiated a thread on this several months ago because of same problem. I was told authoritatively by at least 2 people claiming to be engineers that it was a definite no-no to grease the prop shaft. However - Nigel Calder in his well known book says quite casually something like " and don't forget to grease the prop shaft so its easier to get off next time"... Anyway I greased mine - no ill effects yet - but no idea if it will make it easier to remove in x years time. Incidentally the recommendation about the 'puller'(see below) did not work for me. The arms would not grip on the propellor blades

 

[Guest]

After failing to get mine of its inch and a quarter shaft on a previous boat,an old chap got it off in 2 minutes using 2 hammers.You dont try to hammer the prop off the shaft which will cause damage ,you tap the sides of the propellor boss simultaneously with the two hammers aiming the blows towards the center of the propellor shaft.

I dont know exactly how it works but it does.

I took great delight in using the method on a friends converted lifeboat prop after he struggled for some time.Unfortunately he had allready tried to hammer it off and had marked the propblades.

A puller is not allways possible if the boss is too close to the cutlass bearing to allow the arms to grip.

 

[Guest]

all that I can say to that graham is your shaft is a bit too short ...you should have enough room to get a puller on ...if only so you can get the damn prop off!

 

[Guest]

What I found when trying to use a puller(perhaps it was a too cheap and nasty one?) was that the lugs at the end of the arms simply would not grip the rear(forward end) of the propellor boss - just slipped off as soon as I began to wind it up. There was plenty of room - just something wrong with the angles involved so it would not grip properly.

 

[Guest]

sounds like someone has already knocked the corners off the prop boss!

 

[Guest]

Never EVER grease a prop shaft. It relies on a friction drive. The fact you cant remove it easily, means the tapers working correctly. By all means use a hub puller, but dont rely on just trying to pull it off with the puller. All you have to do is get the puller tightened up to apply some pressure. Then with a hammer give the end of the puller a sharp tap and hey-pressto it's off. I would advise that you leave the shaft nut screwed on a few turns or you may well end up with a sore foot when the prop drops on it? BTW most ships these days (including oriana etc) have neither keys or nuts to hold the props on,,,just friction, which is why they are fitted completely dry and clean)

 

[vyv_cox]

Don\'t grease it

I can claim to be one of the engineers who advised you previously, and I see that another has posted the same information. I think that Nigel Calder's book is excellent but I have found a few pieces of advice with which I disagree, and this is one of them. The propeller is driven by friction between the tapers, not by the key. Modern machinery practice is to eliminate the key altogether because it is a stress raiser, simply shrinking the female part on to the male. Greasing is detrimental to the friction.

On a purely practical note, I doubt very much whether any grease would remain anyway, after being subjected to high load and immersed in seawater for a few years. The advice given on use of the puller for removing the prop is good - I did exactly this last weekend when measuring the taper for my new Brunton Autoprop. I have owned this boat for six years now and never removed the prop previously. A few turns on the puller, one tap with a 2 lb hammer, and it was off. Definitely no grease present.

A tip for your problem of puller legs slipping off rounded shoulders - fasten a hose clip around the legs as close to the prop as possible. This should prevent them coming off.

 

[Guest]

A small amound of grifite grease will assist the propeller to slip into position without scratcing the shaft, will aslo prevent corrosion and will not damage the s

 

[Guest]

Use grafite grease to lubricate the taper shaft. This will prevent damages to the prop, threads and shaft and allow easy removal. Aircraft propeller shafts are lightly lubricated for the same reasons.

 

[johnt]

DONT USE GRAPHITE GREASE! ..what is used on aircraft isnt relevant ...they dont use a tapered shaft with a key.. they use a splined shaft..and it doesnt operate underwater!

 

[johnt]

Re: Don\'t grease it....

Im glad we agree on some things Vyv )

 

[Guest]

Thanks Chaps

It does now seem logical not to grease tapers !

Back to pullers for a mo

I hired one from a toolhire place - no good
Bought two others - no good again
Finally, bought one for £5 from the Chatham Jumble ( cheapo 2 pronged puller ) worked a treat. It just passed a turned rudder and just caught the boss lip.

Regards
Vic

 

[david_bagshaw]

Our props fit V close to a collar near the tube, so a puller was not used, however, the trick is to use a propane plumbers torch, ie wide flame, not aceteylene, to warm the centre of the hub to about 150 c then a few blows with a hammer.

Their (van der voorden of zalt bommel NL, manafacturers to barges ships & tugs etc)recommendation was definately do not grease tapers.

See my web site www.yachtman.co.uk