Cutting Oil darkens machinery surfaces

[EOsteam]

Has anyone else noticed an issue with some cutting oils turning the steel on their machines a kind of light brown orange color? I think it might be the smoke that is doing it. My Kurt vice now has the surfaces nearest the end mill turned that color. It won't wipe off and hasn't seemed to cause any other surfaces to turn and that includes those surfaces where the oil has pooled. The same thing happened on my lathe when I was using a really thick cutting oil that is designed to stay in place. Pro Tap doesn't cause this but then again I can't tolerate the smoke from Pro Tap without coughing up a storm. I have an aerosol can that was purchased from Grizzly a few years ago that was labeled "Energy Release" that is one of the offenders.

If anyone knows how to remove the staining I'm very interested.

HJ

[10KPete]

I've never found a way to erase those stains. In my case, I've found that they are caused by cheap way oil ( I changed to Mobile Vactra and stopped those stains), and dark sulfurized cutting oil ( I don't use that any more ). By keeping the dark oils away from the machine the stains are starting to fade, but short of re-painting.....

Pete

[EOsteam]

It only seems to affect bare metal surfaces.

[John Hasler]

Real machines aren't shiny anyway.

[choprboy]

Presumably it is iron sulfide surface staining produced by a combination of sulfurized cutting oils, heat, and probably a little water/breakdown of sulfur forming acidic components. Sulfurized oils will readily stain non-ferrous materials, most likely does the same with ferrous over a longer term.

http://machinerylubrication.com/Read/29 ... utting-oil

Active cutting oils (containing active sulfur) should not be used for brass and aluminum, as they will stain or tarnish the finished parts.

Cutting nickel alloys: https://www.nickelinstitute.org/~/Media ... 11008_.pdf

When using oil, the high temperatures of cutting may produce a brown sulphur stain.

[John Evans]

I love and use high sulphur cutting oils ,i use what works the best. My machines are to work ,if they get stained toooo bad!

[NP317]

People TRY to get tan skin colors!
Consider your machined surfaces to be tanned...
~RN

[spro]

Same here. I want to see the stains and the evidence of the operations. Its going to happen anyway. A big turn-off is a pile of iron or grinding dust. New paint doesn't cure what that already did. I bit on that hook a long time ago with a 1933 South Bend 11". It was so cool and so original. And that "tool post" grinder was So big. and that bed and saddle was SO worn
How about a paint job? How about a new bed! Stains? Paint stains from proper lube and coolant? Man, if the operator kept the wipers clean and attended to lubrication/ protection, that's a level above paint.

[SteveHGraham]

Wait till you see what Moly-Dee does to iron.

[warmstrong1955]

Only problem I have had, was with KoolMist, but only under my vise.
Left the vise on for a few days, and when I removed it, had some grey stains on the table.
So, if I use flood or mist, after I'm done, I remove the vise, or anything else on the table.

Bill

[duckman903]

At the place I work we use Zurn Oil really great for tapping and threading but it leaves the chuck face with a tan finish, most will wipe off with some acetone but there is still a sheen of tan , to me it just proves I've been working , I find it's not the fumes but the mist when I blow the chips off the work if I wipe it off right away it doesn't get any darker , don't know what's in it but it smells nice and it's EXPENSIVE $25.00/gallon but they only sell by the 5 gallon pail plus shipping .

[Rich_Carlstedt]

Never ever use sulfur oil ( Pipe cutting oil) .
The only way to remove it is with a 'Fine" Cratex stick.
This is a extremely fine rubberized abrasive that removes the surface microns on the iron.
Rich