Replacing the white metal bearing in the Stern Tube

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April 1, 2011 at 18:19 #5061
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Keymaster

This is a companion to the other post entitled “how to remove the cutlass bearing”, which includes a link to the drawing for the white metal bearing (open the PDF from here)

Neil Younger at H4 marine saw that post, and contacted me with information about using Maritex composite material as a replacement for the white metal bearing. This is from his email:

Quote:
You can replace the white metal bearing with a [Maritex] composite water lubricated shaft bearing without any need to change the stern tube/bearing carrier, we can supply these finished to suit most carrier and shaft sizes, the white metal is cleaned out and the new bearing is bedded on epoxy as a clearance fit (easier to remove)

This is the same bearing used by many commercial vessels as a direct replacement for nitrile rubber bearings and has some advantages over this material.

I asked Neil for more details, and he responded with this:

Quote:
If we have the shaft OD and bearing carrier ID we can make up bearings and ship them [to the US in my case], we normally melt out the old white metal and then dry check fit and then fit the Maritex with low temperature epoxy (araldite 2011) They can be finished any size or length as required.

List Price
34.93 x 42.85 x 140.00 shipped from UK
£77.20 excluding delivery/shipping costs

Quote:
We’ve helped out a few old yachts with this type of bearing over the past few years, we also replace standard rubber shaft bearings and Delrin/vesconite type materials. Maritex is a premium bearing material, we don’t compete on price but the bearings last longer and run smoother with less deflection especially as the temperature increases.

So we’re thinking about this because we do need to replace the bearing, and wonder if anyone else has gone with a composite material such as Maritex, rather than finding someone who can machine a white metal bearing?

The contact details for H4 Marine rep:
Neil Younger, W: http://www.H4marine.com, E: neil@H4marine.com, T: + 44 (0) 1822 852466
7 Richmond Terrace
Yelverton
Devon
PL20 7LU
Also look at our Suppliers page, because they are offering a 10% discount to forum members.

August 7, 2011 at 21:09 #9901
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Keymaster

We finally replaced our white metal bearing, with another white metal bearing. It did not work out for us to use Maritex composite (as discussed above) because the bearing has to be fit to the shaft wear. The separation between us (in Seattle) and H4 Marine (in UK) was too far to try this.

Instead, we worked with Port Townsend Foundry, whom I strongly recommend to anyone in the US, particularly the Pacific Northwest. You can read all about our replacement process on our blog here. On that page, I’ve included detailed steps on how to do it, as well as some photographs. We’re happy to answer any questions on this process for whomever needs to take on this task next.

Marilyn

August 7, 2011 at 22:15 #9951
Arild Jaeger
Arild Jaeger
Participant

I’m impressed with how quickly you managed to do this! Also interesting to see your new propeller.

August 8, 2011 at 21:04 #9971
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Keymaster

Yes – the white metal bearing replacement was done so quickly compliments of Pete at Port Townsend Foundry. He not only knows what “white metal” means, he had enough in stock to make the casting on short notice. He then machined the new bearing to be a precision fit on our worn shaft, which meant it was quite tight while slipping it over the larger diameter area between the taper and the shaft wear area, but then the shaft slips into the “sweet spot” just right. He charged us seven hours of shop time, during which he produced this new custom fit bearing, made a new shaft key, and cleaned up the shaft. Keep in mind, I called him about noon on Thursday, and by Friday at 5:30PM we had the new bearing in hand. Friday morning, before he made the white metal bearing, he explored whether a composite would be the better solution because he said people who know what “white metal” means are getting harder to find. But after finding the leadtime on getting composite material shipped as well as the cost of it, he decided it was financially most prudent for us to sit on the hard only one day while he used the white metal he had in stock. We just got lucky with his schedule because he said his calendar was fully booked the couple weeks after this job, so he knew he had to get it done on Friday else we wait for sometime. We felt well cared for during this whole process!

If anyone needs the services of a foundry, I strongly recommend Port Townsend Foundry. Pete is extremely knowledgeable about sailboats, and great to work with.

Regarding our new prop – yes, that’s an Axiom prop. We’ll give a full (generally positive) report on our experiences with Axiom once we get a chance. Van is currently still working on our leaking injector pump problem…

Marilyn

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