Oil Lacquer in Turbomachinery Bearings.

The only place I have seen it on marine turbines is where oil leaks onto hot casings. Are you having problems with it getting thick enough reduce clearances or to peel off and contaminate the oil?

It seems to be a product of high temperatures. Keep your oil temp. below

As for a chemical description of the stuff try contacting your lube oil supplier.

Rick

Thanks Rick, no, I see it fairly often in Turbo machinery bearings. Shaft journals are yellow/brown (look like overheated but not in fact the case) ,the edges of bearing pads and inside surfaces of bearing carriers is coated to a greater or lesser extent. Apart from the discolouration it has never been a functional problem, but I might have come across a case where no other cause except for excessive laquer build up is causing high runing temp on a compressor bearing. So I'm looking for more background on the matter. Problem is, I don't seem to be having any luck searching for definitive answers. Thanks and regards.

Steve.

When deposited from fuel, that stuff is called 'varnish'.

This search was productive:

-Mike-

Thank you Mike, I shall review these documents.

Steve.