I don't think there is a simple cut and dry direct answer. Others here may have suggestions to add.New lathe user/owner here. I've been watching YT videos and sometimes cut are made dry. When is coolant recommended?
Thank you. Lots of food for thought thereI don't think there is a simple cut and dry direct answer. Others here may have suggestions to add.
Here is a list of Threads pertaining to the coolant subject that Texasgeartrain posted in another recent thread.
Some pretty good threads and an article here on PM:
Thanks for the 2Cs DonThat's a ball of worms right there. I would follow M-lud's advice and start doing some reading/youtubing.
Just a general rule of thumb. Never on Cast iron. Small jobs that are going to be quick and you're using inserts or carbide don't usually require it. Metals that hold heat like stainless are good candidates, and jobs that require real tight tolerances, require a lot of cutting and will expand from heat - then use it. Manufacturing and repair are different animals, and I'm only looking it at from the repair end. Just my 2C . Don
When I’ve used water soluble coolant in the past, it was for three reasons. 1) To maximize tool life. 2) To utilize the full horsepower of a machine – assuming it has enough horsepower to be relevant. 3) To control thermal expansion. In other words, when time is money.New lathe user/owner here. I've been watching YT videos and sometimes cuts are made dry. When is coolant recommended?
I like it!When I’ve used water soluble coolant in the past, it was for three reasons. 1) To maximize tool life. 2) To utilize the full horsepower of a machine – assuming it has enough horsepower to be relevant. 3) To control thermal expansion. In other words, when time is money.
If the time is your own, I would use a bottle full of cutting fluid and a little brush. Coolant for the occasional user can be problematic.
It tends to collect way oil or tramp oil which forms a layer on top. You then need a skimmer to remove the oil. If the machine tends to sit, the coolant will eventually separate, the skimmer will remove that and then you’re left with a diluted coolant. To avoid some of this you’ll need an aerator to keep the coolant mixed and the bacteria out. If you don’t keep up with it, you’ll have corrosion issues.
Anyway, it is not as simple as it may first appear.
In my shop I use coolant in a cold saw and zip/miter bandsaw.
Thanks markaIf you're a new lathe owner, i'll assume you are a hobbiest (like me). In that case, you might want to differentiate between coolant (primarily to remove heat) and cutting oil (to lubricate the cut). As others have said, the material matters as does the cutting tool. I use HSS almost exclusively and one of the main failure modes of HSS is for the material you are cutting to weld itself onto the cutting tool which tends to ruin the surface finish. Cutting oil (on steel) reduces this weld build up, extends tool life and improves surface finish. It does provide some cooling as evidenced by the smoke it creates but I think the primary purpose is to lubricate the tool. I just use a chip brush with oil on it for each pass. I have no experience with soluable cutting oils so i'll not speculate on those.
Do not use oil on cast iron, brass or bronze.
All good reasons to go with HSS but it seems to me that as a beginner I can start making things more quickly with carbide insertsHmmm; why use HSS exclusively...?
Well there's lots on contnet on YouTube extoling the virtues of HSS such as:
However, for me there is an additional factor and that is, I just find grinding tooling by hand to be both challenging and cathartic. It's rewarding to get the tool to perform the way you want it to.
- It's cheap
- It comes in many different sizes
- You can grind it to any form you want
- It's easy to resharpen and hone
- It's less brittle than carbide therefore less prone to chipping
- It pairs well with the old, slow machines I have