Cutting oils

[FulmenParticipant @fulmen]

Do I really have to defend a DIY-solution on a home shop forum?

As far as I can tell sulfurized oils are still in use: https://www.schaefferoil.com/odorless-cutting-oil.html

And they appear to be perfectly safe and non-toxic. I only use it neath for work like tapping and threading so bacterial growth isn’t an issue either. But I understand these kind of solutions aren’t for everyone.

[JasonBModerator @jasonb]

I think RTD also contains some sulphur. You have to buy the “cleancut” version if you don’t want sulphur. Same with CT-90 which I think Dave mentioned that he uses?

[PeteParticipant @pete41194]

No there should be no need to defend a simple home made solution and I found your post useful Fulmen. There’s loads of different concoctions of cutting lubes in old machining books. Some fairly benign, and some we now understand would be dangerous. While Dave’s mostly correct about what he’s said, and I don’t use it as an all round cutting product. I do use pure baking lard while reaming, and it’s worked better than anything else I’ve tried. However it just wouldn’t work in a proper industrial environment for multiple reasons. That still doesn’t mean it’s worthless, or that there is or isn’t anything better.

I’m careful to keep it frozen unless it’s being used, and I’m quite fanatical about spotlessly cleaning the reamers and work pieces with dish soap, hot water and re-oiling the reamers. Rancid animal fat in even a minor cut isn’t anything I want to experience. For anyone not willing to do the same every single time it’s used, then I definitely wouldn’t recommend it. And for some obvious reasons, bacon fat isn’t something I’d use instead.

[JasonBModerator @jasonb]

my first metal work teacher at school was in favour of tallow when threading and I think he akso used it to slick back his white hair instead of Brillcream. Still available today and popular for threading pipe.

I used milk when threading teh hollow stays in my Traction Engine boilers which worked well.

I’ve only done metal spinning with steel but the Bacon fat is said to be good when spinning non ferrous.

Sparey that a lot of people recommend as a good read mentions whale oil.

[Author]

Posts