Ping Tribologists

[T i m]

Hi all,

Another but different question on the 'Silent' piston compressor.

Talking to the manufactures today it seems they 'now' supply / recommend a fully synthetic oil, over presumably a semi or purely mineral oil?

Mine suggests it should take an SB-46 but that could be the older spec.

The new spec stuff seems to be this:

I think the 46 refers to ISO 46 (SAE 15W?) but I didn't know if that was enough to determine the spec?

So, if we know it should be ISO 46, fully synthetic, low detergent etc, could I use anything that fits that spec, as the branded stuff seems quite expensive and prices for ISO 46 oil seem to vary wildly?

Is there something 'special' with this compressor oil or could I use a fully synthetic 15W motorcycle fork oil for example?

Cheers, T i m

[newshound]

Don't know what the SB stands for, but as you say 46 cSt is one of the standard ISO grades. However Googling SB-46, the first obvious oil reference (apart from Bambi) is a biodegradable fully synthetic made by Morris.

So your Bambi *might* just be that, re-labelled.

In the domestic world, a lot of people use cheap mineral oils (as sold for compressors by Machine Mart, Screwfix, etc).

In industry, high performance oils are usually specified because these compressors are expected to have a long life or high annual hours. A good example would be Shell Corena which actually comes in five different formulations (each in two or three viscosity grades).

Since you have had problems with carbon deposits it is certainly worth going for synthetics. I wouldn't use a motorcycle fork oil (probably has additives to improve the viscosity index).

Aircon compressors often use a particular type of synthetic called poly alkylene glycol (PAG) which degrades without forming carbonaceous deposits, so that might look like a good fit for your compressor. However I was interested to find it does not seem to be used in air compressors, although the other main types of synthetic such as diester and poly alpha olefin (PAO) are.

The safest answer is probably to bite the bullet and use the Bambi product.