Spindle oils

And for those of us that actually use grease in our headstocks like my rockwell, I use Mobile SCH100 grease. Not a perfect match but the closest I could find.

Perhaps you could ask your friend for a suggested replacedment for these greases: Texaco Marfak #0 for gear train Texaco Starfak #2 for headstock

chuck

And periodically drain out the oil that is in there, flush, and re-fill. I get to this about twice a year.

Well. Not "answer." But at least it was 'suggested.'

:^)

Jim

================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================

I'm glad for the confirmation since that's what I had found by using the same oil in my lathe's headstock bearings.

Mark Rand RTFM

Well, I wouldn't call her my "friend," and I think I would be pushing it to call her for another lookup. She's an engineering executive and I only got to talk to her through a reference from another magazine editor. I have to be gentle with those networks.

If you call their tech line, though, I'll bet they'll have an answer for you right away.

Ed Huntress

I did that and I was told they don't have a close replacements. For example the recommended spindle grease has a viscosity of 64cSt. The closest they have is 100cSt. Since the SCH100 is a synthetic and the original grease was dinosaurse based, I figure its close enough.

They sent me to another company that might have a Marfax #0 replacement. I contacted them, but never heard back, so I figure they either don't have a replacment of don't care about me.

I picked up something from MSC that is listed as a forklift slide grease that sounded ok for the open gears, like the back gears and the gear train driving the QC. I think its called CB-2 Super-lith. It seems to stick to the gears which is the important part.

chuck

There is an engineering text (i.e. expensive) out called "Lubrication Fundamentals" by Pirro & Wessol ( ExxonMobil employees), Marcel/Dekker publishers. I have only read a little, but it looks like a good book for those who like to study a subject to death.

It turns out that crude oil is to lubricating oils as grapes are to wine. To make a lubricating oil with a given property, you need to start with crude oils from certain deposits. If you read between the lines, it appears that synthetic oils might be the only options for certain types of oils in the future.

I have found ExxonMobil tech support very good. They helped me find a grease to use on 100 year old flat belt driven shaper. Turns out there is a grease out there called semi-fluid that is commonly used in open gear boxes. It works quit nice on the low speed bull gear in the shaper. Not sure it would work well at high speeds though.

One interesting thing about calling Mobil tech support is you have to go through a long list of (phone) options to get connected to tech support. And then a different set of options to get to the sales people who tell you who the local supplier for a given product is. Why is this interesting? Because in the end I was connected to the same person.

Vince

Ed Huntress wrote:

Haha! I just love phone menus...not.

Thanks.

Being cloudy would mean that it has formed an emulsion: it contains little droplets of water, each surrounded by a monomolecular layer of detergent molecules which prevent the droplets from coalescing. You'd need some kind of mechanical mixing to form an emulsion -- you'd probably get one, for instance, by feeding both the oil and the water into the headstock bearing simultaneously. If you did get an emulsion, the next question would be whether those little droplets had any serious tendency to stick onto an iron/steel surface. Since the whole point of adding detergents is to prevent corrosion in engines, they probably wouldn't.

Saying that a detergent is hydrophilic, by the way, is only half the story: a detergent molecule has a hydrophilic end and a hydrophobic end. That is what makes it a good emulsifier.

Hygroscopicity is a related but different question -- it is the question of how much water absorption occurs merely through diffusion (of individual molecules), with no emulsion involved. Hygroscopicity is not a yes-or-no question, but a "how much" question. If you ask whether something is or isn't hygroscopic, the answer will depend on the answerer's personal threshold level. It's like asking "is it hot outside?"; a Thai will apply a different threshold for "hot" than an Eskimo will. This partly explains the different answers you got from different people. An exact way to ask about hygroscopicity is "what proportion of water will it absorb, if in contact with liquid water?" Every liquid will absorb *some* amount of water, however tiny. If it is a huge amount, it's fair to describe it as hygroscopic; if it can be measured only with very sensitive equipment, it's fair to describe it as non-hygroscopic; but in between there is a gray area.

The other thing likely to have caused confusion here is that a detergent itself is likely to be hygroscopic, but the detergent dissolved in a much larger amount of oil is likely to not be. If you ask about detergent oils, and ask whether the detergent is hygroscopic, some people will take that as a question about the detergent, and others will take it as a question about the mixture.

In any case, the precise answer doesn't matter hugely: even straight oil allows water vapor to diffuse through it, to reach the surface of the metal -- as anyone can attest who has put his fingerprint on a piece of clean steel, slathered oil on it in an effort to protect the steel, then come back after a period of high humidity to find his fingerprint etched in rust, the hygroscopic salts from the fingerprint having caught water molecules that diffused through the oil layer. An oil with a slightly greater proclivity for water will make that diffusion easier. But that is a matter of doing less to slow down a rust problem, not a matter of creating a rust problem.