Oil for sintered bearings

[wd40addict]

Does anyone have any thoughts on the best oil to use on 'oilite' style bearings?

I have a Brenell and a Cossor on the bench at the moment, both in need of some lubrication.

Obvious candidates are 3 in 1 and sewing machine oil, but maybe there's something better?

[Boater Sam]

Clock oil.

[Nickthedentist]

Are you sure? Sam?

AFAIK, clock oil is designed not to migrate, whereas for these, I understood that you need something that does creep into all the pores etc. Rightly or wrongly, I use sewing machine oil.

OTOH, any oil will be a vast improvement on running dry, which is what tends to happen in equipment that's been neglected.

N.

[Boater Sam]

As I understand, oilite bearings they are originally impregnated with a grease compound.
Which is of course a non migrating oil form.
I have seen them soaked under vacuum if that helps.

[Richard]

I was taught to and have always used 10/40 engine oil.
Modern engine oil has various additives that make it stable, friction reducers, etc etc, have literally done 100s of small motors, never had a problem.

Soak the bearing in hot oil, this expands the air in the bearing, as it cools the oil is drawn in, or a vacuum if you have the equipment.

Richard

[emeritus]

I still have the instruction manual of the old "ADA" washing machine (1953 Coronation model) that had been left for me in my first house. It had sintered bearings for the wringer rollers which the manual recommended oiling every week with "a good class medium machine oil". It does not say what is meant by this. I used to use W20/50 engine oil.

My understanding is that general purpose grease is simply a mixture of lubricating oil and a soap, the soap serving to keep the oil in place. When grease has dried out, it is because the oil has evaporated, leaving the soap behind.

[The Philpott]

I think any of the above.. Gear oil is also something i have used on sintered bushes.

[dseymo1]

Be careful of gear oil - I understand that some hypoid types can attack and damage yellow metals.

[paulsherwin]

The speed at which the shaft rotates in the bearing is an important factor. You don't want a relatively viscous oil like 20/50 if the shaft will rotate at high speed. 5/30 semisynthetic would be fine for most jobs.

Remember that you can make an oil in a range of viscosities by mixing 20/50, baby oil and paraffin/kerosene in various proportions. There are all sorts of witches' brews if you search the net, but I find a cheap and effective light machine oil is:

40% 20/50
40% baby oil (cheapest you can find, check the significant ingredients are just mineral oil)
20% paraffin

Increase the proportion of 20/50 for a medium machine oil or if using 10/40. The baby oil may be scented so the mixture might smell a bit strange.

Neat 20/50 is fine as a heavy machine oil.

[Radio Wrangler]

Avoid EP extreme pressure gear oils like the plague (the ones associated with hypoid tooth shapes) They contain particularly nasty additives it's true that they will attack brasses, and you don't want them on you. AND the smell will go on and on. Better the scented baby oil brew.

If the bushes are out, dunking them several times in hot oil is good.

A lot of the additives in engine oils are fierce detergents to handle carbon and acidic combustion products. If you're not oiling an engine, best not to use engine oil. One good alternative is automatic transmission fluid (also used in power steering and some manual gearboxes) it avoids a lot of the aggressive additives. These are oils for clean environments and are readily available.

David

[paulsherwin]

I take your point about the additives in engine oils, but I've never found them to cause a problem in practice. Each to their own I guess.

[Refugee]

Modern engine oil has to be reasonably safe if it gets past the piston rings and out of the exhaust pipe due to the vehicles being used in built up areas.

[Graham G3ZVT]

Originally Posted by paulsherwin

40% 20/50
40% baby oil (cheapest you can find, check the significant ingredients are just mineral oil)
20% paraffin

I've got the ingredients and I might make a batch.
I'll label it "Oil of Sherwin".

[wd40addict]

Wow plenty of thoughts there!

I am nervous of over viscous oils after once lubricating a Columbia wind-up gramophone motor with Hammond organ oil. It could no longer reach 78! I had to wash it out and replace with 3 in 1. Hammond oil is not particularly viscous either, allegedly SAE 15.

Presumably a multigrade will perform at the winter viscosity, so 5 for the 5w/30?

Does anyone know the viscosity of 3 in 1?

ATF is another interesting idea, I think I need to check my garage and see what I have 'in stock'!

As regards speeds this is for the idlers and belt tensioners etc, not the motors.

[paulsherwin]

Lots of people distrust 3-in-1 because the ingredients aren't made public, but it's basically light machine oil with some additives. Some people claim it goes gummy after a while.

Originally Posted by rambo1152

I've got the ingredients and I might make a batch.
I'll label it "Oil of Sherwin".

Credit where credit's due, I didn't invent that mixture. I found it on the net years ago, I think in a modelmaking forum. I can't remember the details now.

[emeritus]

An advertisment for 3 -in-1 oil that I saw in a pre-war tool catalogue said that it was a mixture of animal, vegetable, and mineral oils (hence the name, presumably) , but didn't identify the oils or their proportions.

[paulsherwin]

All these branded household oils will have been reformulated many times. Before the war they were mostly castor oil, sperm oil being too expensive for everyday household use. They are all mineral oil based now as that is both cheaper and more effective than vegetable oils.

I have a prewar can of Wakefield (aka Castrol) household oil which is castor oil based. The name Castrol comes from castor oil.

[Radio1950]

Hi there,

are you sure that your bearings really need oiling?
And how did you intend to do it?

Most sintered porous bronze bearings are factory lubricated for long life.
It is not quite intuitive, as you think they always look as though they need a drop of oil, which probably will achieve little.

Unless you think that the old bearings have had a very long life, like 4 hrs a day for ten years, AND the manufacturer had a suggested lubrication schedule for the device, then I would leave it alone.
Is there undue shaft wobble? That's a different issue.

Better to replace if possible if you think the old lube has gone too hard.
Most small bushes are still available.
Make sure you get the correct type, as there are plain bronze, and sintered porous bronze bushes.


You can flush out the old lubricant, and then relube.

In ye olde days, eg for plain pre-oiled type bushes, the bushing is removed, warmed, flushed with kerosene by squeezing both ends between finger and thumb after dipping the bush and fingers into the kero, withdrawing, and observing the gunk being flushed through the bush.
The fingers act as a pump.
The bushes are porous.
Then alcohol is used to flush the kero.
The bush is warmed.
Then oil is squeezed through the bush in the same manner as flushing.
Continue until oil is freely oozing out, after displacing the alcohol.
This process must be carried out with the oil going through the sides of the bearing.
Just pushing oil through the bush along the axis of the shaft achieves nothing.
Almost no oil will enter the bush.

One problem with bushes is that the actual bearing surface of the bush can be damaged by peening or scraping when eg a punch and hammer are used for removal, or rough handling.
This closes up the porous openings.
Some bushes are quite thin.
Better to use eg an old bush rather than a punch to assist the replacement process.
Better to have an old bush untouched and working with 90% lubrication, than to damage things with attempted lubrication or replacement.

Caution with cylindrical bushes with an end flange bearing surface, as these should be removed and replaced with constant pressure in a press type operation, not with hammer and punch raps.

Plenty of info on the web, and on oil types.
Whatever you do, do not use WD40 for this application.

Anyway, very good luck to you.

[Craig Sawyers]

I'd agree with the above. But I'd fall short of actually removing the bushes.

Personally I use a single weight, soap-free, Comma "Classic" https://www.commaoil.com/passenger-v...ducts/view/260 for slow rotating bearings, such as a turntable. I use sewing machine oil (much thinner) for motor bearings.

Craig

[Nickthedentist]

Re. post 18: what an informative and useful post, thank you