Homebrew cutting oil

[bill70j]

For steel I use 4 parts sulfated heavy cutting oil, 2 parts cheap light lubricating oil (like 10w30 motor oil

I like the idea of adulterating the good stuff with cheap motor oil (especially if it's used). I'm going to try it. Thanks for the tip!

I do mix used transmission/power steering fluid with kerosene in a 20:80 ratio for cutting aluminum.

 

[Dabbler]

I stay away from used motor oil unless it has been left to settle and refilter it, because the dark stuff can contain abrasive stuff, which I fear will lower cutter life. but clear used oil will prolly be OK!

 

[Ed ke6bnl]

I like TapMagic for nearly every cutting need.

What type of TapMagic there seems to be several varieties.

 

[Video_man]

Where does one even get trichlor any more?

Wish I knew. What they call "new old stock" and going fast.....

 

[pontiac428]

Where does one even get trichlor any more?

It is not banned. Chlorinated brake cleaner, QD electronics cleaner, and sometimes as parts cleaner, all in aerosol cans at the local quickie auto mart. Sometimes you want a strong solvent that won't start fire easily and has vapor degreasing qualities.

 

[Jimsehr]

I go with oil tested by professionals that are made for machining. I have used homemade oils and compared them to stuff like lard oil and checked time cards and the professional stuff worked much better. Time cards don’t lie. In a production setting where you have past results to compare. For one part does it matter?

 

[Dabbler]

@Jimsehr you are absolutely right.

However, From a hobby machining viewpoint, making chips is our fun. We aren't needing to do the job the fastest, or even get the extra 10% cutter life - for a price... Paying 26$ for tap magic 750 ml is insane if I can use three components I stock anyway; for about 3$ for the same amount. IF, of course the home concoction works effectively enough. Mine seems to.

I worked in machine shops and had the best of everything available, and all the pro lubes, coolants, etc are a godsend if you are machining 8-12 hours a day. For machining 6-20 hours per month, it just doesn't make a tangible difference, except in price.

 

[pontiac428]

Since there is no shortage of cutting oil packaged in small cans and bottles, I have never even considered a homebrew. I love reverse engineering stuff and doing it for pennies, but there's no penny to be saved here. Sure, when I read an ingredient list like Tap Magic (petroleum distillates, aliphatic esters, cinnamaldehyde) I see "medium solvent, soap, scented preservative", but at a few bucks a bottle, why bother?

 

[Video_man]

Since there is no shortage of cutting oil packaged in small cans and bottles, I have never even considered a homebrew. I love reverse engineering stuff and doing it for pennies, but there's no penny to be saved here. Sure, when I read an ingredient list like Tap Magic (petroleum distillates, aliphatic esters, cinnamaldehyde) I see "medium solvent, soap, scented preservative", but at a few bucks a bottle, why bother?

I think I dabble in this, not to save pennies, nor for any practical reason, but for the same reason I have thousands of dollars worth of machine tools sitting largely idle in my garage...I could buy the little things I make but I do it for the fun of it. Of course, if I were a business, I would not do this. But then it wouldn't be fun, either.

 

[GT-6 Racer]

I definately agree with Pontiac428. There are lots of commercial cutting oils That are highly engineered for their purpose. Depending on your choice of supplier, they can be a little spendy, but we spend a lot on this hobby already. I’ve tried them all. my oldest son gets migraines and is very sensitive to some odors. While making FRC robot parts, the oils I had made him nauseated so I went on a search for cutting oils that didn’t bother him. Turned out Cool tool II was his choice for everything not aluminum and tap magic aluminum for that. While he’s now off to grad school, I no longer keep all the options, I use tap magic ep extra, buy it by the gallon (73$) for most everything but aluminum, which is wd-40 or tap magic aluminum for more critical finish stuff and tapping. I tried tap magic pro tap, cuts nice but stains everything, very disappointed in that. For tapping steel, I haven’t found anything close to Relton rapid tap. I do have a gallon of sulfur oil, but it stinks the high heavens if you get it hot on the lathe. I cool trick hack I learned from an older old guy, was to use Go-Jo cream hand cleaner for surface grinding lube if you don’t have flood coolant. It’s fantastic. Even allows you to grind aluminum transfer bocks to a mirror. Smells nice too. For us hobby types water flood coolant is probably overkill on cost and amount of effort Except for band saws and grinders. But if you try machining with good flood it’s a game changer for more modern higher speed machines. My Hardinge turret has neat oil flood coolant which is fantastic for tool life and a giant mess. It only holds a couple gallons total, but fire is still a concern, but no rust for sure. It all comes down to what you want, just make sure it doesn’t harm the machines And have fun !