Making cutting oil? out of motor oil?

[Gunther45]

I thought I read somewhere about making cutting oil out of motor oil and kerosene ( seems dangerous to me but? )

I only buy synthetic 10w30 motor oil and usually only Mobile 1 but with the economy and the fact that my car has over 100000 miles on her, I have been buying whatever full synthetic is on sale , I usually have to buy 5 quarts and only use 3 1/2 ( Actually I use 4 because I use about a 1/2 to help flush the engine of the old stuff ) either way I end up with 1 quart of extra oil and I don't like mixing brands of oil in my car. Other than use it for lubricating gears in my machines is there a good use for it elsewhere in my workshop such as making cutting oil or something to that effect?

Might sound like a stupid question but I have a few quarts and am at a loss of how to put it to good use.

[wildwestpat]

I would think about the economy after you have read the safety warnings for the actual oils you have. The composition of 'synthetic' oils vary a lot and can cause skin problems with prolomged exposure. The makers of cutting fluids have formulated their 'oils' to reduce the effects of long term risks to the skin of the operator.

If you look on the web there are recipies for mixing minertal oil with soda soap to make a thin white milky fluid. Cracked skin v savings is no contest in my book.

It is safe to mix oils of the same spec but you will need to check that the oils you have to hand are all manufactured to the same one. Obviously there are a whole raft of synthetics hence the caution.

Regards

pat

[HuFlungDung]

On your next oil change, buy 24 quarts of one type of motor oil. That seems like the most obvious economics.

Motor oil is stinky stuff when it gets to smoking, which is likely to happen with occassional machining. It really doesn't do much more than water would, except it shocks the hot tool less than water does.

You could likely flog your existing stock on the local classifieds. Some guys could care less about mixing types so long as they are compatible. I am one of them. I run my vehicles til they die a rusty death Nobody, and I mean nobody gives you a premium on your old heap just because you changed oil every 100 miles, if its got 100000 on the odometer.

[peoplepillars]

Hi,

Motor Oil is made from various base oils including SN 500, SN 150 and other Synthetic formulations. Emulsifiers are used to make oils soluble in water i.e. Water soulble Cutting Oil. Because of high viscocities of motor oils these oils cannot be used in watersoluble formulations. Therefore they can be used only in Straight Formulations or Rust preventive formulations with addition of some additives.

[CalG]

Motor oil makes lousy cutting oil. Worse than nothing in my opinion (That is I would rather machine dry.
Canola oil on the other hand, secreted away from the kitchen) works very well.

Don't be afraid to mix that good oil and use it in your engines!