Quick question about TT bearing oil

[Darren]

I'm wanting to get my VPI HW19 Junior back on the road and I ordered some Audio Origami Booster oil from Analog Seduction. They have sent the wrong thing (silicone damper oil) and want this back before they send the booster oil..... which I get but... I was looking forwards to spinning a few discs this weekend.

Can I use some synthetic car engine oil instead? If so, approx how much?

 

[Vinny]

I am sure that TT bearing oil, not grease, is mostly witchcraft with a dose of deception.

Motor oil is going to hold a film over steel at crazy surface speeds and high temperature, as well as protecting a standing engine for quite some while.

 

[Martyn Miles]

No good for a turntable then ?

 

[Amber Audio]

Same outfit sent me the wrong thing in May, sent it back and never heard another thing. Was a cheap bubble level so gave up after a few messages trying to get a couple quid back.

 

[Tony L]

Can I use some synthetic car engine oil instead? If so, approx how much?

I’d tread very carefully as some modern synthetic motor oil is destructive to sintered bronze, which is likely what the bushings of your turntable bearing are. Far better to use a light sewing machine oil, even bog standard 3in 1 mineral oil as a stop gap. Whatever you use, the key is it has to be safe for sintered bronze (or whatever material your specific bearing is made from).

 

[Vinny]

I’d tread very carefully as some modern synthetic motor oil is destructive to sintered bronze

Sounds incredibly unlikely - do you have a link?

 

[trick cyclist]

Good question, and a couple of things you may wish to consider are the oil viscosity, and whether to use mineral or synthetic (I don't believe additives are worth thinking about, unless they actually cause more problems than they solve, as in Tony's suggestion above).
I use a very high purity molybdenum grease on my bearing, but it is an inverted Pink Triangle, and that was after checking in with Arthur.
Interesting thread here about changing ideas on lubrication from the VPI designer. In essence, try it and see what you like, for me the key is a trade off between viscosity/ drag, and stuff staying in place.
Oh and just to add, remember additives, some can cause seals to swell or disintegrate over time, including plastic bearing housings. Silicone (not silicon) additive is very bad for this.

 

[Jamie]

Or depending what you like the smell of, 2 stroke or Castrol R?

 

[Tony L]

Sounds incredibly unlikely - do you have a link?

There are other threads here and elsewhere dealing with it (it comes up around vintage Thorens, Garrard, Lenco, EMT etc where there is no ‘manufacturer’ to buy from). I don’t have time to google up examples now, but it is applicable in the vintage car community too, e.g. you don’t put certain modern synthetics in an old Morris Minor or whatever as it can damage the bushings. I did my research about 15-20 years ago so can only remember the conclusions as applicable to what to stick in a turntable, tape deck or whatever, not the information sources or science. The key thing as I recall is modern cars don’t have sintered bronze bushings (no idea what they have instead), so most modern synthetic oils are just not designed to work with them. Some modern oils are ok, but you need to be careful which.

PS For clarity: I’m not saying all modern synthetic oils are unsafe on sintered bronze, but some certainly are, so please do your research before sticking anything into a £2k turntable! My advice is always to use whatever the manufacturer supplies assuming they still exist.

 

[trick cyclist]

Just to second Tony again, I used to run a vintage Ducati, good quality mineral oils only.

 

[Chris]

Buy direct from John at Audioorigami. He´ll have it in the post today with any luck.

 

[Mike P]

I did some research on this some years ago and this is an old post I made over on another forum:

A number of high quality turntables rely on sintered bronze bearings, particularly many older turntables such as the Thorens TD124 or TD125.
Sintered bronze bearings are porous and when heated can be made to soak up oil like a sponge. This absorbed oil is then available for lubricating the bearing which gives them a degree of 'self lubricating' ability. However over time this absorbed oil is used up and the bearing dries out so it becomes important to re-oil the bearing periodically.

A badly worn bearing will create much more 'rumble' than a good one and so sonically it pays to keep your bearings in tip top condition.

Recently I've come across people recommending the use of automotive gearbox oil for lubricating the main bearing on turntables. While this may be perfectly O.K. for some turntables it could be potentially damaging for turntable bearings which use sintered bronze bearings.

Older gear oils often contained Sulphur or Phosphorous based extreme pressure (EP) additives which are well known to be corrosive to copper containing 'yellow metals' such as bronze.

Oil testing institutions test how corrosive a particular gear oil is to yellow metals by submerging a cleaned copper strip in the oil at a standardized temperature and for a set time. After the test period, the strip is examined for evidence of corrosion and a classification number from 1-4 is assigned based on a comparison with the ASTM Copper Strip Corrosion Standards. This copper strip test data is available for most commercial gear oils.

Modern gear oils of the type used in manual car transmissions usually contain a much less aggressive form of Sulphur EP additive which is not corrosive to yellow metals at low temperatures, often refereed to as 'buffered' rather than 'active' sulphur. This is why you can realistically get away with using a modern GL4 gear oils in a bronze TT bearing without any noticeable problems in the short term. However that doesn't necessarily mean that they can be considered safe to use.

In a gearbox the EP additives bond to the hard steel gears creating a sacrificial coating which prevents metal to metal wear of the gears. Problems can arise when a hard steel surface in in contact with a soft yellow metal bearing. What happens is that the EP additives form a coating on the yellow metal bearing. As this coating is worn off it takes with it a microscopic layer of bearing and so causes erosion of the bearing surface.

Gear oils with a higher number rating usually contain higher concentrations of EP additives so a GL5 oil has more of these additives than a GL4 oil.

Engine oil would be a safer bet for use in a bronze TT bearing. Car engines have bronze bearing surfaces (e.g. valve guides) so obviously engine oils need to be safe to use with yellow metals. However engine oils also contain other additive packages such as detergents which are at best of no use to a TT bearing and at worst may actually be undesirable. However given that most of us have easy access to engine oil it would be my default recommendation for the average owner.

An even better choice would be a high quality oil of an appropriate viscosity manufactured from a high quality base stock and containing no additives which may be considered harmful to a bronze TT bearing. Good quality air compressor oil would fit the bill perfectly.

If your TT bearing is a little worn it may be beneficial to use a higher viscosity oil than originally specified by the manufacturer. You need to aware though that comparing oil viscosity ratings can be a little confusing though. For example an 75w gear oil is actually about the same viscosity as a 20w engine oil.

Here is a useful comparison chart:

My personal choice of oil for my Thorens TD125 is a fully synthetic ISO 46 compressor oil which I believe is pretty much ideal. If you feel a thicker oil may be better then an ISO 68 or even ISO 100 compressor oil may be a good choice.

 

[JimmyB]

you don’t put certain modern synthetics in an old Morris Minor or whatever as it can damage the bushings

I think the thing about Moggies and older engines is that the viscosity isn't usually correct (need 20W/50) and especially on ones with higher mileage. I've only ever heard from other Moggie owners over seals being affected by newer oils but generally this hasn't been a 'thing'. There are modern lubricants made to 20W/50 encompassing synthetics etc. but it's a bit like putting high octane fuel in...it ain't ever gonna catch that Ferrari...(and I'd hate to try to brake afterwards using just the drums).

Having said that, I use Origami oil in my bearings because I lost my source of compressor oil that I was using before and there were no sewing machines to hand.

 

[Mike P]

I think the thing about Moggies and older engines is that the viscosity isn't usually correct (need 20W/50) and especially on ones with higher mileage. I've only ever heard from other Moggie owners over seals being affected by newer oils but generally this hasn't been a 'thing'. There are modern lubricants made to 20W/50 encompassing synthetics etc. but it's a bit like putting high octane fuel in...it ain't ever gonna catch that Ferrari...(and I'd hate to try to brake afterwards using just the drums).

Having said that, I use Origami oil in my bearings because I lost my source of compressor oil that I was using before and there were no sewing machines to hand.

The viscosity has to be right for older engines of course but it's the additives (or lack of) that make oils for modern cars unsuitable for old cars. For example, ZDDP (Zinc dialkyldithiophosphate) was widely used in older oils as an additive to prevent wear on components such as camshafts and tappets. However, ZDDP is harmful to catalytic converters and so modern oils do not contain any/enough to provide the right protection for classic verhicles.

 

[Darren]

Same outfit sent me the wrong thing in May, sent it back and never heard another thing. Was a cheap bubble level so gave up after a few messages trying to get a couple quid back.

That aint gonna happen here AA. It was Ebay so I opened a return case. Bit dopey of them - they dont ship very quickly as it is.

 

[Darren]

I’d tread very carefully as some modern synthetic motor oil is destructive to sintered bronze, which is likely what the bushings of your turntable bearing are. Far better to use a light sewing machine oil, even bog standard 3in 1 mineral oil as a stop gap. Whatever you use, the key is it has to be safe for sintered bronze (or whatever material your specific bearing is made from).

Thanks Tony. Does this stuff seem ok?

 

[Darren]

Good question, and a couple of things you may wish to consider are the oil viscosity, and whether to use mineral or synthetic (I don't believe additives are worth thinking about, unless they actually cause more problems than they solve, as in Tony's suggestion above).
I use a very high purity molybdenum grease on my bearing, but it is an inverted Pink Triangle, and that was after checking in with Arthur.
Interesting thread here about changing ideas on lubrication from the VPI designer. In essence, try it and see what you like, for me the key is a trade off between viscosity/ drag, and stuff staying in place.
Oh and just to add, remember additives, some can cause seals to swell or disintegrate over time, including plastic bearing housings. Silicone (not silicon) additive is very bad for this.

Thanks for finding that thread tricky. The synthetic motor oil would seem ok according to those guys. Obviously, I have no freaking idea what additives it has in it.

 

[Darren]

Big thanks to everyone for contributing. You have scared me right off the motor oil. Guess I'm waiting for the booster oil cock up to get sorted out.

 

[chartz]

I use Mobil Isoflex oil recommended by Revox for their capstans.
Prior to that I used Mobil 1 for years.

 

[Tony L]

Thanks Tony. Does this stuff seem ok?

I suspect it would be absolutely fine, old sewing machines, fans etc have bronze bushings, but by saying that if it was my deck I’d just ask VPI what they recommend and use that. To my mind it only becomes a variable with really old decks where there is no manufacturer around or direct equivalent to the original oil.