Bacon Grease for Cutting Oil?

[nickel-city-fab]

just for referrence: brown&sharp in "practical treatise on milling and milling machines, 1913", recommends lard oil. they even give a recipie to boil lard oil, soda and soap for half an hour (p. 113).

That would be somewhat similar to today's soluble oils. I saw a similar recipie in "Practical Blacksmithing" dated 1881. Of course the cutting speeds and feeds were much slower back then, and I doubt their steels were very hard. I wouldn't mind trying the old recipie, after all my lathe was designed back then, by people who probably used that exact formula.

[dian]

just for referrence: brown&sharp in "practical treatise on milling and milling machines, 1913", recommends lard oil. they even give a recipie to boil lard oil, soda and soap for half an hour (p. 113).

[nickel-city-fab]

At work they had flood coolant on everything (good idea, they had some real idiots...)
At home I have the Dark sulfurized cutting oil, and a few gallons of surplus 90-wt
which works real good for parting off large diameters and things like that.
Had to use the 90-wt for something, I got tired of it sitting around.

I use the oils mostly when threading or parting off, especially with HSS. With carbide on roughing passes I usually go dry because I'm such a barbarian.

The machine oils is a different story -- I spent real money on the proper Vactra and DTE oils.

[JoeLee]

I got a small bottle of this a few weeks ago. I thought I would try something different for threading my 304 SS U-bolts. It seems to work OK. The threads are smooth, no jaggies, galling or streaking.
But...... not sure if it's my new die or the fluid. It seemed to work good for single pointing with a full profile insert too.

The only thing I don't like is it's very watery and usually drips off the spout as soon as I tip the bottle. So not sure if it's really coating the work like a heavier oil would.
This is where the comparison part gets difficult.

JL....................

https://www.mscdirect.com/product/details/00277012

[Tundra Twin Track]

A local Hutterite Colony that was big into Manufacturing SS products said nothing they tried would compare to Goose Grease for drilling SS.

[The Metal Butcher]

Over the years I've tried dozens of different cutting and tapping fluids. Honestly I could never tell if one worked better than the other weather it was extended tool life or surface finish DOC etc.

How would one actually compare all these different fluids ? I would think for starters you would have to pick a material and preform some various cutting tests. Milling, drilling, turning and threading.

There are so many variables involved that it would take quite a bit of time to accurately compare each of them.

I've used way oil, Rigid pipe threading oil, used motor oil WD-40 and even some of those fast evaporating tapping fluids that I hate because they run all over the place.

JL.......................

Project Farm in the video in the first post does a pretty good job. I'd start there and continue his work.

Now that I have a machine with flood coolant, I generally use that, or dry. I only use "oily oil" as Tom Lipton calls it for high load scenarios where I need a good surface finish lsuch as making radii. Even for parting I prefer the flood. I never use oil on long cuts as that just makes a smoke show, even with HSS. I do use it pretty often on the mill, and I almost always use it for drilling where flood is not available. Tapping gets oil 100% of the time (sans cast iron.) So for me the price of oil isn't a big concern, and I'll pass on the organic stuff.

[J Tiers]

I used to use any oil that came to hand. Now I have been using Harvey's, which is a darkish cutting oil for plumbing. It is sulfured, I believe, which helps a lot. I think it is now sold under the Oatey name.

It does for sure make threading pipe a LOT easier and better quality than non-cutting oils.

It also seems to help more than "just any oil" for both drilling and threading with taps. I cannot swear to the performance for turning and boring, but it appears to improve surface finish and reduce cutting force a bit. At least the flat belt Logan does better with the oil than without the oil.

Smell? I like the smell.

But I like the smell of other odd things, like the fumes from firing guns, and especially that smell mixed with "machine shop smell". The neighbor grew up on a farm, and says that my engine and garden shed smells like the tractor shed back home. I like that smell also, and regular barn smell. I'm not, however, big on cattle barn smell. Raw hay is fine, but after processing it is less so. Not cut out to be a dairy farmer.

[JoeLee]

Over the years I've tried dozens of different cutting and tapping fluids. Honestly I could never tell if one worked better than the other weather it was extended tool life or surface finish DOC etc.

How would one actually compare all these different fluids ? I would think for starters you would have to pick a material and preform some various cutting tests. Milling, drilling, turning and threading.

There are so many variables involved that it would take quite a bit of time to accurately compare each of them.

I've used way oil, Rigid pipe threading oil, used motor oil WD-40 and even some of those fast evaporating tapping fluids that I hate because they run all over the place.

JL.......................

[Video Man]

For what it's worth --- the active ingredient in bacon grease is oleic acid, part of the lard that is bacon grease. It was widely used in WWII for machining and there were drives to get people to save rendered fats to provide the needs of the war effort. True-- bacon grease has salts in it. A better alternative --- If you want to make a classic (and useful) cutting fluid, try this: buy grocery store unsalted lard. Heat in a double boiler to melting, and blend in two parts lard to one part mineral spirits. Let sit (maybe a couple of days) until a waxy white substance floats to the top. This is the other component, stearic acid, which seems to be useless. Skim it off (you can squeeze it in a cheesecloth and extract some more oleic acid). What is left is a pale yellow oil (Eureka! Oleic acid) and solvent. The solvent appears to keep the oleic from spoiling --- I have a bottle in my shop that's several years old and still going strong. It makes a very good drilling and tapping compound for steel.

[JoeLee]

Bacon grease will probably contain plenty of salt. Not good for metals.

my thoughts exactly.

JL....

[boats]

Rendered animal fats have been used as lubricants many years, some better than others. Machine lube you want to watch out for salt continent. High salts depend on the processing. Many years ago we carried tallow in Company ships deep tanks. Always pulled a quart size sample on loading held in case of a claim on discharge. Storeroom at the pier shelves lined with all kinds, labeled origin etc. Used to get all I wanted after claim time limit passed.

Best grade very good better than many commercial grease. Low grade would rust metal very quickly. Unknown origin I would be very careful.

Boats

[Ringo]

For me, there is only 1 place around town that has the dark cutting oil, and that is one place I try to avoid shopping.
Besides, dark cutting oil gets its smell onto my clothes, and wafts to the house and the SWMBO doesn't like that.
It's easier to use cooking oil than to listen to the wife complain

[millhand]

Many years ago I took a materials class and needed to do an experimental project that demonstrated material testing. I chose cutting compounds and performed two basic tests: extreme pressure testing using an Almen-Weiland lubricant tester (http://www.klueber.co.kr/index/image...nt-testing.pdf scroll down to page 41) and a tapping torque test. Bacon grease was heated in a beaker to drive off water, then filtered to remove organic debris, and placed into the tester. It was not the best EP lube, but I dramatically increased its EP lubrication by adding some flowers of sulfur and retesting. This combination was the second best material. The only material that was better was the 1970's cutting compound that was mostly trichlor solvent. I also did a torque test tapping 1/2" - 13 holes in steel. Again, bacon with sulfur performed very well; it was the second lowest torque with trichlor being the lowest.

[nickel-city-fab]

Geez guys,
just buy the proper stuff, its not gonna break the bank. A litre of cutting fluid a year in the home shop.
I mean, whats with cooking oil and bacon fat on my precision machine tool?
Its like the guys asking can they substitute 20/50 motor oil for way oil because they've got a pail of it under the bench.
Sure it'll work, but its not correct nor the best for the job.
Buy some way oil for $5 a litre.
Ditto the correct cutting fluid for the job.
FFS.

You have a true point, but some people actually *are* financially broke recently, and they did use lard a hundred years ago when there wasn't much else available.

Way oil in litre sizes is $9.50 plus shipping for me. I tend to use a lot of it, everything around and under the lathe is soaked. The dark sulfurized cutting oil I use, is the same stuff plumbers use in their pipe threading machines. $7 per litre. I cannot guarantee a time when I will be able to buy more, money is very sporadic at best for me. I'll be thankful if I can get more oil before the end of the year. This is in the USA, mind.

However, I found that parting off in a deep groove, it seems to go better with the surplus 90-wt gear oil I have on hand -- a mistaken purchase years ago finally has a use! My theory being the heavier gear oil clings better into the sides of the groove and stays around long enough for the parting blade.

[thaiguzzi]

Geez guys,
just buy the proper stuff, its not gonna break the bank. A litre of cutting fluid a year in the home shop.
I mean, whats with cooking oil and bacon fat on my precision machine tool?
Its like the guys asking can they substitute 20/50 motor oil for way oil because they've got a pail of it under the bench.
Sure it'll work, but its not correct nor the best for the job.
Buy some way oil for $5 a litre.
Ditto the correct cutting fluid for the job.
FFS.