View Full Version : Coolant Question

12-18-2005, 10:59 PM
I picked up a Jet 7x12 bandsaw (big improvement over the 4x6 that I have been using for the last six years) this weekend and have a coolant question. I am placing an Enco order this week and am looking for a general purpose coolant that I can use in the saw and on the Bridgeport mill that will not skunk out too fast. I work with a mix of mild steel and aluminum mostly, but it is not uncommon to play with a little stainless. Any help would be appreciated.

12-19-2005, 11:11 AM
The "skunking" of coolant is mostly attributed to tramp oils. If you can keep the tramp oils out, (usually done with a skimmer), the "skunking" may not be as bad, or as frequent. There are coolants that have some resistance to "skunking", as well as additives you can add to coolant prevent the same.

Coolant selection can be broken down into use categories, sawing, grinding, and milling/turning, as well as specific application depending upon metals used with.

Each one being formulated for a specific criteria of use.

I use Valenite VNT 700. I only use it in a mill though, no sawing.

Hope this helps some, BTW, no expert in coolant.

Robert Duncan
12-19-2005, 10:20 PM
I have been using ATF (cheap stuff, like $7/gal) with just a touch of Marvel Mystery oil added, maybe 6oz. Has been fine in my 7x12 for two years now.

12-20-2005, 02:03 AM
I use Koolmist #78 in the mill, drill press and bandsaw. I also mix it rather strong.
No odor in the coolant tanks!
It will rust bare metal overnight however if you let it sit.
I also use the way oil on the bare metals in the shop sparingly.
Enco number is 505-2074 from the last invoice.


12-20-2005, 02:19 AM

You're using straight oil? What do you do about the inevitable coolant/oil on the floor?

I concur that skunking is caused by tramp oil, on the old bandsaw I used Astrocut and it never skunked but with the power hacksaw and mills the Astrocut skunks because of the way oil and tapping fluid. Skimming helps alot. I get poor toollife on my CNC with Koolmist in the mister so I hooked up flood coolant and used a heavy concentration of Astrocut, speeds doubled and tool life about tripled. I'm gonna move the mister to the manual mill since I don't like the way BP tables drain flood coolant. I also filled the sump on my big Polamco lathe the other day, 0.300 DOC on the radius with a TMNG insert, no more getting burned by the clinky chips that manage to get airborne.

While we are at it I've been welding a lot of aluminum lately and kicking on the overload on my Tig, I dumped a bottle of Water Wetter into the chiller and it seems to have increased my weld time, no hard data though.

-Christian D. Sokolowski

Robert Duncan
12-20-2005, 10:37 AM
<font face="Verdana, Arial" size="2">Originally posted by rsr911:

You're using straight oil? What do you do about the inevitable coolant/oil on the floor?


A strategically placed plastic kitchen container catches the drip I get from the front left corner of the saw. The only other mess is when the cutoff falls off and hits the floor. My floor is painted, so that wipes up fast with a paper towel.

If I am doing a batch of small cuts I put a bucket down for them to fall into, taking the mess with them.

12-20-2005, 11:50 AM
Aluminum coolant-flood, water and corn oil.. It works great, but the mice love to chew on the machine afterwards.

mace tyler
12-20-2005, 10:52 PM
I found a very good coolant through my machine shop supplier. It's called Rustlick 370R
This stuff works great. absolutley no rust on the machine. No staining. and it leaves a very thin film of oil behind when it dries.

And it does'nt go rancid very easily.

Also the cut quality is good.