[JohnToner]

Since water evaporation will become a concern, I will need a method for testing the concentration of the coolant. Are any of the refractometers sold by Enco worthwhile?

[WOTDesigns]

Since water evaporation will become a concern, I will need a method for testing the concentration of the coolant. Are any of the refractometers sold by Enco worthwhile?

Yeah, they are all the same (aside from the spread on the scale. You want 6-8% concentration so getting a 0-10 scale is easiest to read.

You just set a baseline with just tap water by putting a drop of water and adjusting the screw until it reads zero. Then wipe it off and drip a drop of coolant on. It only needs to be close. No point spending more than you need to. A case with it is nice, but other than that a cheap one will read more accurate than required.

Brian
WOT Designs

[LeeWay]

Yeah. ATF is worse. What we all need to be using is an approved metal working fluid. There are pro's and cons to every single one of these products. Some will effect certain individuals only. Some only work well with a certain type of metal being machined. I suggest if you have any issues at all, try others recommendations. Rust would certainly be an issue with water based coolants.
I don't see much of that with Koolmist. I do clean my tray out daily now rather than weekly on the older Torus. Still it only had minimal rust. I do not need a second step for cleaning parts before I powder coat them. I have not seen any rancid characteristics with Koolmist. No health issues either. The one main con is that it gets into polycarbonate and deteriorates it. Fast. I can live with that.

All MWF's have at least one thing in common. No or at least very high flash points. Using alcohol, engine oils, tranny fluids and latern fuel really should be avoided. They all have relatively low flash points. I have turned a carbide end mill cherry red in a matter of two seconds while being flooded with Koolmist. Using one of the above non approved fluids in such an instance could cost you or someone else their life.

I do use oils on my manual lathe. I have seen guys use oil when tapping with cnc. I think those uses might be okay. To start with, there is very little oil present when tapping. Doubtful you could ever turn a tap cherry red unless you run it in reverse. Then it would likely break anyway. On a manual lathe, you have more control over the oil and speed. Just because it might be okay in small amounts for some aspects does not mean it's okay to keep a tank of it under the machine and start throwing mist into the air when flood or mist cooling. That is simply begging for a fire.

I was a Maintenance manager for a couple of furniture companies locally. Both used unleaded gasoline tanks colored with paints and tar as stains. 250 gallons each tank. They had 4. I warned them repeatedly about it. They could not keep workers dipping furniture for very long due to heath issues. They wore full protection, BTW.
Both plants burned to the ground and it did so quickly.

One was just after quitting time. The other was during lunch time, so both plants were relatively empty. By the time the FD's got there, there was nothing to do.

I was fortunate with the fire in my machine. We had it nearly under control from a fire extinguisher and water hose by the time the FD got here. 17 minutes.
Please just give some thought to what you choose to use.

[WOTDesigns]

Poorly phrased on my part. Using dirty baby diapers would also be worse

I don't even consider 'random liquids people use as coolants' when I think of coolants.

Brian
WOT Designs

[JohnToner]

Brian,

The Castrol arrived yesterday, and this a,m, I swapped out the regular oil. Everything was clean but it still was a PITA. I think I'd rather have been water boarding. I mixed 10:1 but my refractometer only read 6%. Maybe b/c I didn't use distilled water.

[SCzEngrgGroup]

Brian,

The Castrol arrived yesterday, and this a,m, I swapped out the regular oil. Everything was clean but it still was a PITA. I think I'd rather have been water boarding. I mixed 10:1 but my refractometer only read 6%. Maybe b/c I didn't use distilled water.

If you've mixed it correctly, just make a note of the refractometer reading you got, and aim for that in future mixes.

Regards,
Ray L.

[WOTDesigns]

Brian,

The Castrol arrived yesterday, and this a,m, I swapped out the regular oil. Everything was clean but it still was a PITA. I think I'd rather have been water boarding. I mixed 10:1 but my refractometer only read 6%. Maybe b/c I didn't use distilled water.

Didn't see your post, sorry. Ray is right. Refractometers never read the quoted mixture because of irregularities/other stuff in the coolant that isn't readable. I keep mine between 6-8% reading on the refractometers

Brian
WOT Designs

[Kenny Duval]

The stuff I am using came with both the suggested ratio and the approximate refractometer reading indicated in the specs.