compressor oil

This is ancient, I got it out of a skip probably 30 years ago, so it's probably due an oil change. It is mounted straight on the end of the electric motorAny idea what I should use. There are no makers marks anywhere as far as I can see. Tellus 37 would be good as I've got a tin, but I'm prepared to buy the right stuff if need be

Edited By duncan webster on 28/10/2022 23:07:16

Ancient rescuee of unknown history...

Hmm, I'd be inclined to worry about the state of the reservoir as much as the right oil.....

Ah the res is a lot newer, and I'm pretty rigorous about draining it off

Screwfix and Toolstation both sell compressor oil by the litre.

I tend to use Pennine Lubricants, as I used to live in Sheffield.
Their product page has a download link to a datasheet giving the spec.
https://www.penninelubricants.co.uk/product/ultracomp-h4000-d46/

Bill

Most hardware store compressor oil is basically ISO 32 hydraulic oil. Both will have an anti-foaming additive these days. Not sure if the old Tellus oils have that? Data should be available on the net somewhere.

A compressor is an engine without a sprk plug ! Almost any light engine oil or hydraulic will be fine ! Noel.

If possible stay away from motor oils, which have detergent additives to keep the innards of the engine clean. Compressors are prone to condensation particularly if they only run for short periods, so mixing condensation with detergent and oil gives a lovely brown frothy custard.

FWIW

Simon

I have a compressor with tank which I sourced many years ago for my father, I then later inherited it. It had not much work done. So after running in circles for corect oil, I manage to source manufacturer, which informed me 30 oil is good, I had no idea what was in it.

Screw fix it is then, thanks to all who replied. Looks like this oil would be good for your ml7 as well.

Does anyone do an occasional hydraulic test for the sake of safety, peace of mind etc?

I'm thinking of the style where you fill the tank brim full of water then pressurise to (say) 1.5 x max working pressure. Ought to test the operation of the pressure relief valve at the same time.

Properly such activities are pre-planned and set out in the Written Scheme of Examination.

Any takers?

Duncan,

Your Tellus 37 should be perfectly adequate for an old compressor. We used to use either DTE light (Mobil equivalent) or medium in the dozens of compressors around the site

Simon,

Yes. My receiver is, I think, ‘60/70s. It only costs the water and grease (to raise the pressure). Well worth the confidence that the receiver will not rupture @20 Bar. Many use their pressure washers, to jack up the pressure, these days.

It looks like a COMPAIIR air compressor, just like mine.

I rescued this one from a dark and damp barn nearly 20 years ago, after rolling the dirty scabby looking thing out of my way many times while working in the barn. At first I thought the lump was a home made bodge up of a pump grafted onto an old motor, until one day I finally took a closer look.

I replaced the thin circular flat steel crankcase cover with a nice Alluminium cover I machined up, the air filter has just been removed while I make up another adapter to take a different type of filter.

When I stripped down the pump I found it was in perfect as new condition, not a single mark on the Alluminium alloy piston or cast iron cylinder bore. The conrod is steel and uses a sort of self aligning ball race big end bearing.

I use straight SAE 30 oil in this little compressor, and in my other larger compressors.

Edited By Lathejack on 30/10/2022 19:51:19

That's it exactly, but no plate or name on the inlet filter. Following NDIY advice I've used Tellus 37. It only holds about half a cup. One of these years I'll treat it to a pressure switch