Thin wall cutlass bearing - Maritex vs white metal

[big_s]

Hi all,

I have a Samphire 26 sailing yacht built in the 1970s.

A survey flagged the cutlass bearing as badly worn and, on removal of the propeller shaft, I found that the original white metal bearing had pretty much worn out.

I am considering replacing it with a composite bearing e.g. Maritex. rather than using white metal again.

The cutlass bearing housing has internal diameter of approximately 1 9/64" (seems an odd value but the most accurate I can measure with my kit). The original bearing was approximately 3.5 inches long. The propeller shaft diameter is 1 inch.

The cutlass bearing wall thickness would therefore be thin at approximately 1.8mm. Does anyone have experience of a Maritex bearing with similarly thin walls?

Talking to a Maritex bearing supplier, they want to know if the cutlass bearing will have water on either side of the bearing. I presume even a small tolerance in the gap between bearing and propeller shaft would allow water ingress to the stern tube and so I presume yes it would. Is this thinking sound?

Does anyone have any idea what a ballpark price might be for a Maritex and/or white metal version of the bearing in the UK?

Many thanks for any insight.

 

[DinghyMan]

Some similar info with similar issue here: Replacing the white metal bearing in the Stern Tube – Nicholson 38 Owners Group

Finding someone to do white metal bearings these days will be an issue

Best bet is probably to talk to H4 Marine

By "having water on both sides" probably means "is it in a P bracket" so has water on both sides rather than "is in a stern tube" with water only on the outside

Would be better, and probably longer life, to replace with Maritex, Vesonite, or similar, bearing wall would probably be too thin for some of the plastic options

Other option may be to remove cutlass bearing housing and get it machined out for a standard cutlass bearing? Smallest standard one for a 1" shaft is 1 1/4" which is only just bigger than your measured 1 9/64"

 

[Snowgoose-1]

Some similar info with similar issue here: Replacing the white metal bearing in the Stern Tube – Nicholson 38 Owners Group

Finding someone to do white metal bearings these days will be an issue

Best bet is probably to talk to H4 Marine

By "having water on both sides" probably means "is it in a P bracket" so has water on both sides rather than "is in a stern tube" with water only on the outside

Would be better, and probably longer life, to replace with Maritex, Vesonite, or similar, bearing wall would probably be too thin for some of the plastic options

Other option may be to remove cutlass bearing housing and get it machined out for a standard cutlass bearing? Smallest standard one for a 1" shaft is 1 1/4" which is only just bigger than your measured 1 9/64"

Can't improve on the above, particularly moving away from white metal bearings. Faced the same as yourself onetime. I was fortunate to find a conventional cutlass bearing that fitted . Just had to drill and tap for the grub crew. Getting the housing machined would probably work out cheaper than the cost of a bespoke white metal bearing.

 

[Tranona]

Another vote for machining the housing to take a standard cutless bearing. I have done this n 2 boats, the first was a Stuart Turner housing wwhich sounds similar to yours - same length and similar ID but a rubber lining . At the inboard end it had white metal and a "leaky) stuffing box so again machined the ID to take a cutless and the OD to take a Volvo seal. Did similar on the current boat changing from 1" shaft to 30mm and machining the inboard end to take a cutless as extra support for the rather long shaft. again OD to take a Radice seal.

 

[vyv_cox]

Two accounts of fitting non-metallic shaft bearings here Stern gear. Bottom of the page.