substitute for Tufnol as bearing material on rudder posts?

[Contorta]

My plans call for Tufnol as bearing material on my rudder posts. I am having difficulty finding the product in North America (at a reasonable price). Can anybody recommend a substitute?

[michael pierzga]

Many boats use Vesconite. Ask your designer.

http://www.xpcbearings.com/home

[Contorta]

Thank you Michael, I am sure your suggestion will work well. My designer is not in the habit of answering his Email.

[Tad]

The bearing material depends on load, in Prince George I'm guessing a trailerable boat? For that almost any medium to high density plastic will do. UHMW plastic is popular and available in tube or rod blank that can easily be turned to fit by anyone with a small lathe.......See the remainder bin at your local Industrial Plastics dealer.......

UHMW does swell a fraction in water so be careful to oversize slightly........

There's also a self lubricating version of UHMW called Murlubric....which is nifty

[michael pierzga]

Always Best to get the input from yacht designers and Plastics professionals. Many plastics are suitable for low tech applications like a rudder bearing. Water swelling, heat distortion and friction wear are well known and can be allowed for when you machine the bearing or wish project its useful service life. . A good plastics supplier should be able to advise you on available materials for your application.

[Tigawave]

A more recent development in bearing materials is a phenolic based self lubricating bearing material known as Maritex Aquarius. This has advantages over UHMW plastics in that it is non melting/softening and can support high loads with less distortion, it also has surface chemistry to resist marine growth. It is being used in everything from the Panamax project to new submarine shafts and dive planes, but is also available for shafts from 1" to over 22". It can be used with water, oil or dry.

It machines without dust or fumes and is dimensionaly stable over a wide temperature range. Clearance calculators can be found if you search for maritex aquarius calculator