I'm looking for a recipe for lard oil used in machining. I want to turn some threads and noticed the first time I tried the threads were somewhat gnarly. In the book "How to Run a Lathe" it mentions using lard oil.
I have a recipe for GIBBS (half ATF and half lacquer cleaner) but darned if I remember what it's used on. I'd appreciate it if someone could refresh my memory...
Thanks,
Dave Young
Penetrating oil.
Lard oil, AFAIK, is bacon grease (essentially triglycerides) with the glycerin seperated, IOW fatty acids (steric acid, etc.). I don't remember the process for that; boil with water? In the mean time, try fat dissolved in kerosene, paint thinner or a similar solvent.
Tim
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It might be hard to find in recent times. Look in the plumbing section in a hardware store for the sulfurized thread cutting oils they sell for plumbing use. They have a yellow cast to them and work pretty well. It the only thing I ever used for a thread cutting lube.
Gnarly threads can result from too deep a cut. On most lathes you can feed .010 once or twice, then .005, then .002 or so to the finish. If it is still tearing drop down to .001. The tool is pretty heavily loaded when threading.
And then there is dull tools...
If a thread is gnarly and you run the tool again with no more infeed and it smooths up, you are probably needing a sharper tool and/or a lighter cut.
And then there is crappy material. No cure for that. :>)
Lard oil is lard oil, it's not a mixture of anything else. Pressed from lard. You can get mixtures of lard oil and other stuff, "cutting fluids" is what you'll want to search on. Or you can get the real stuff, Buttercut is the stuff I've been getting from MSC. My granddad was a plumber, all he'd ever use for cutting threads on iron pipe was lard oil. It's good stuff, but I'm sure there's as good or better things available now. The magic phrase "bio-degradable" along with "all-natural ingredients" applies, though. Doesn't stink as much as the dark sulphurized cutting oil, either. If you're doing steel threads, the dark stuff works well, use a lot of ventilation, though. The plumbing dept. at the local hardware store should have some.
Gibbs is supposed to be some kind of super-penetrant, I've been using LPS 1 so I don't need it.
Stan
Stan
Yeah, nothing starts easier or threads worse than cold rolled steel with a little taper on it.
The gang here recommends leaded, free machining steel. Sounds good. We never had any in the college shop that I knew of.
Yours,
Doug Goncz (at aol dot com) Replikon Research
Replikon Research researches replikons, which are self-reproducing configurations of non-living matter in environments that support replication, analogous to organisms living in ecologies.
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