Nylon as a shaft bearing

[CassidyNZ]

Originally Posted by Epicurean

I'm not sure how I could tell if they didn't just use nylon. Is there a way to tell the difference, other than a mass spectrometer or perhaps a density check?

You could always supply the material yourself. Quality guaranteed and probably at a better price. If it’s available to the engineer, it’s available to you.

[Chotu]

Originally Posted by Jim Cate

for a cutless bearing? did you machine grooves into the ID for water ingress?

Jim

That’s what I get for going on the forum in the middle of the night when awake for an hour.

No, mine was for rudder shaft bearings. Not cutlass bearing.

Sorry. Good catch.

[Epicurean]

I found a bearing that had neither a brass outer covering nor anything else. lt's solely vulcanized rubber. I learned a lot from this thread and thank all those who offered advise!

[MCOS]

At max of 3 % change due to water absorption, nylon could be considered for your bearing application if you do not have the other material available. You will be most likely machining grooves the length of the interior surface to allow water to pass through to lubricate and cool the bearing. The minimal expansion should not interfere overall. If the more exotic materials the other posters have mentioned are available, use them.

[MCOS]

Many of the "exotic" polymers mentioned are available on line, Delrin for example is available through the Walmart on line site at a very reasonable price.

[Scaramanga F25]

Johnson non-metallic +- 45$.

[DanielF]

Originally Posted by Epicurean

I need to replace the shaft strut bearing on an aluminium strut. There’s only brass/bronze backed rubber bearings available here and no fibre backed which is what’s in there now and I would prefer, to avoid the possibility of electrolysis. The mechanic has proposed machining a bearing out of nylon. I’m not familiar with that as an underwater bearing, only the rubber cutlass type. Does anyone have any knowledge about that? He says he’s used that on large ships.

Thanks.

I use this one. It's good!!
https://www.skidim.com/products.asp?dept=1119

[mikecambrai]

n my first yacht I had a lignum vitae bearing (special wood), then progressed to Nylon, then when the nitrile rubber ones came out I switched to them. The life of the Nitrile rubber far exceeds the wood and nylon presumably because the shaft vibrations would not be absorbed so easily by harder surfaces. With a well-aligned shaft and Nitrile rubber, I have never had to replace one.
My solution with an aluminium hull would be to either used a brass /rubber bearing and remake the brass housing with a more compatable material or better still if you search for Nitrile Rubber shaft bearings you will find some made only of nitrile which would solve the anodic problems once and for all..

[Maclir]

Nylon is not a good idea for this application. Contact T Norris marine, London, he can supply phenol case cutless bearing, highly recommended

[wannacat]

Mine is made of Duralon. Don't know if that's just another trade name or a different material?

[Cheechako]

There are non nylon plastic types that don't swell up much. But dont use nylon.

[Ivansgarage]

Originally Posted by Epicurean

I need to replace the shaft strut bearing on an aluminium strut. There’s only brass/bronze backed rubber bearings available here and no fibre backed which is what’s in there now and I would prefer, to avoid the possibility of electrolysis. The mechanic has proposed machining a bearing out of nylon. I’m not familiar with that as an underwater bearing, only the rubber cutlass type. Does anyone have any knowledge about that? He says he’s used that on large ships.

Thanks.

Delrin best for wet stuff Delrin really machines nice...

https://www.craftechind.com/top-5-ma...etal-surfaces/

[Cadence]

Originally Posted by Epicurean

I need to replace the shaft strut bearing on an aluminium strut. There’s only brass/bronze backed rubber bearings available here and no fibre backed which is what’s in there now and I would prefer, to avoid the possibility of electrolysis. The mechanic has proposed machining a bearing out of nylon. I’m not familiar with that as an underwater bearing, only the rubber cutlass type. Does anyone have any knowledge about that? He says he’s used that on large ships.

Thanks.

Delron would be better than nylon if in fact it is a good idea?

[lamadriver]

don't use Nylon

Vesconite is good if used in the correct application.

Delrin ( acetal) is perfect and readily available for this kind of bushing. easy to find, easy to machine

[Cadence]

Originally Posted by lamadriver

don't use Nylon

Vesconite is good if used in the correct application.

Delrin ( acetal) is perfect and readily available for this kind of bushing. easy to find, easy to machine

Pardon my misspelling of Delrin. As I recall it is considered self lubricating whereas nylon is not. I'm glad to see he found a sleeveless rubber bearing.