DIY Cutting Oil

EdCaffreyMS

"The Montana Bladesmith"
Hey Gang!

I do a lot of cutting/machining of not only damascus, but also Titanium. Which means I use a lot of cutting fluid to keep tooling cooled and lubricated during various processes. And with cutting oils/fluids being so expensive, I've played around with making my own and trying to save myself some money.....and think I finally have found a mixture I like, and thought I'd share my findings....

In a 5 gallon bucket.....
3 Cups of dishwashing liquid (I found Dawn works the best)
1 quart of cheap SAE 30 motor oil... OR if you want water soluble (which I do) use a quart of dark cutting oil

4 gallons of water
https://www.homedepot.com/p/Oatey-3...t+dln:{568036}+qu:{32+oz+dark+cutting+oil}:qu
I use a snap on lid for the bucket, shake it up well, and then fill spray bottles to use at the drill press, lathe, etc.
It works out to approx 50 CENTS per gallon, versus buying straight dark cutting oil at $21+ per gallon.


A couple of notes:
-If you use SAE 30 motor oil, expect a sticky film once the water evaporates from the mix. (why I like the dark cutting oil in the mix)
-I found that if using any dish soap other then Dawn brand, things separate in the spray bottles and clog the sprayers.

My biggest use of this cutting oil is in my large metal cutting band saw fluid tank...... and when I'm building pen barrels on the lathe or damascus and titanium.
 
Last edited:

J. Doyle

Dealer - Purveyor
Nice. That would add up to significant savings pretty quickly I'd think.

Is the water just to increase volume? Does it all (eventually) evaporate away? Meaning....would you just be able to replenish the mix with water if you needed to?
 

Chris Railey

KNIFE MAKER
Thanks for sharing that recipe Ed. Would the mixture offer any advantage over using shop oil (which is whatever oil I have lying around) for drilling holes in steel?
 

EdCaffreyMS

"The Montana Bladesmith"
Is the water just to increase volume? Does it all (eventually) evaporate away? Meaning....would you just be able to replenish the mix with water if you needed to?
Had to think on that for a moment..... once sprayed, the water will evaporate, and leave a thin film on where ever it's sprayed..... if the film is really thick and sticky, it means you used too much dish soap. The water doesn't evaporate in the bucket.....as I keep an air tight lid on it. Does that make sense?

Would the mixture offer any advantage over using shop oil (which is whatever oil I have lying around) for drilling holes in steel?
Personally, I like it better for drilling/cutting then a straight dark cutting oil, and like it far better then say straight SAE 30 or WD40...... plus, it's far cheaper then either.
 

J. Doyle

Dealer - Purveyor
Had to think on that for a moment..... once sprayed, the water will evaporate, and leave a thin film on where ever it's sprayed..... if the film is really thick and sticky, it means you used too much dish soap. The water doesn't evaporate in the bucket.....as I keep an air tight lid on it. Does that make sense?
Ahhh.......that makes sense.....I misunderstood the post.
 

springer82

Well-Known Member
Ed,,,, You use a mister to spray your coolant on what you are working on. No flood coolant? Do the corners of your endmills hold up.
 

EdCaffreyMS

"The Montana Bladesmith"
I don't use flood cooling.... except on my large mill.........my other machine are not setup for flood cooling, and trying to do it is just too much of a mess to clean up.....likewise with a mister. I use a plain old 32oz ace hardware spray bottle....or an old windex bottle....or whatever I have that will spray. :)
 

springer82

Well-Known Member
On a knee mill a mister is good. :)
You can get a mag base with a adj plactic shield that would help with the mess. That has saved me more then a few times. If you gave me your knee mill then you would not have to worry about it anymore!!! :cool:
 
Top