Newbie- Can I use Motor oil (synth) as coolant?

[alexccmeister]

Hi guys,

Very new to coolant and stuff. Just installed CNCfusion kit #4 on my X2 mill. Now I am looking into building an enclosure which I know how to do but as for flood coolant, instead of using the type used by alot of people here, can I use synthetic motor oil as coolant? Since its synthetic, it shouldn't smell after long use. Any reason why no one is using it?

I have read M oil is a good lubricating medium for cutting steel. Also in th epast when I was working in a hardware store, I have cut thread before with a theadcutting machine for water pipes. Old technology but we use a stream of oil for cutting the thread. Its messy but isn't the same with the other type of coolant? Thanks.

Alex

[cam1]

Hi: Motor oil is not formulated for metalworking applications. It's also very expensive and messy.You could start with a mist coolant sytstem (Noga for around $100), which uses compressed air/water/coolant. Just make sure to vent the fumes (cheap vacuum or suction fan with discharge going outside). The primary purpose of motor oil is to reduce friction on rolling and sliding surfaces. Metalworking coolants are designed to reduce friction, but primarily to cool the tool and to wash away the chips. Water is the best medium for cooling, and the oil is added to prevent rusting of the machine, and to reduce friction. Yes, motor oil can be used to thread pipe (it's better than nothing), but for heavy threadcutting, re-sulpherized oil is used, that just happens to look like motor oil.

regards

[alexccmeister]

Hi Cam1,

Thanks for your reply. The reason I am looking into oil as coolant is because I can't get the right coolant for milling job where I come from. I need to order online and I am sure custom here won't allow liquid to be shipped here.

When you say coolant, is this something similar to the coolant used for car radiator? Its antirust. I can mix that with water as well.

Thanks.

Alex

[cam1]

I suppose that could work, but the coolant I was referring to is cutting fluid that is a combination 97% water and 5% +/- soluble chemicals.
Let's see if someone else has any comments on using Automotive coolant.

regards

[alexccmeister]

Hi Cam1,

Thanks. Would love to know. I can get lots of these.

Alex

[AbsoluteZero]

The fumes from automotive coolant would be a lot to handle even with an exhaust. If you can't get metalworking fluid i suggest mineral oil. You can use it straight or with a air blast. I even have seen vegetable oil used to machine molds.

[budP]

Make your own
Use 18gal water---2gallons veg oil or corn oil---enough laundry soap to emulsify the mix

budP

[LeeWay]

I think straight water would be better than automotive coolant. The smell alone is enough reason not to use it. I tried it instead of Koolmist 77 for a very short time. 2 jobs. Then I cleaned it all out and went back to Koolmist. The best things about it is no smell or rust and it only takes a little. Mostly water.

Some automotive coolant is poisonous too. Best not to be used for machine coolant. I also noticed that it smoked. This tells me it wasn't cooling very well, but burning instead.

Whatever you chose to use, make sure you can't ignite it with a torch. I have seen some of my endmills glow bright red while being drenched with coolant. (Way too fast of a speed setting) A flammable source in this instance might just explode on you.

[alexccmeister]

Thanks guys. Will hear from more people and decide what to do next. I might end up looking for a source of coolant online and try to have teh stuff shipped here. Thanks.

Alex

[Geof]

If you are machining aluminum you can use automatic transmission fluid as a cutting fluid; this is Dexron (sp?) ATF. It works extremely well, just brush it on ahead of the tool.

When cutting steel a coolant/cutting fluid is not essential but sometimes it can help with getting good surface finish especially on manual machines. Try using ATF here, it may help a bit.

[alexccmeister]

Originally Posted by Geof If you are machining aluminum you can use automatic transmission fluid as a cutting fluid; this is Dexron (sp?) ATF. It works extremely well, just brush it on ahead of the tool. When cutting steel a coolant/cutting fluid is not essential but sometimes it can help with getting good surface finish especially on manual machines. Try using ATF here, it may help a bit.

Hi Geof,

I am thinking of flood coolant with this stuff. I can get the stuff and use them over and over again. I can make a recirculating system for the coolant. I am surprise you are saying its not essential for coolant when cutting steel. I have always thought it more crucial to have coolant for cutting steel.

Alex

[LeeWay]

I think coolant or mist really helps out the hobbiest. It extends the tool life and speed error to some extent while also adding a touch of lube. With flood, it also helps remove chips from the cut path.

Coolant isn't required for mild steel. I milled many parts out by hand with only a drop of oil every few minutes. It got hot, but didn't effect the carbide tools much.

I have seen many video's on Youtube where no coolant is used on many different metals.

I personally use it for everything on the mill, just because it's there and I find it helps me from lack of experience.