After searching flood coolant recommendation there seems to be lots of opinions. I decided to give Tormach's product, DURAKUT 4010 (P/N 31750), a try just to get the ball rolling. I guess at one time this part number used to equate to Premier 600 but has since changed.

Anyway, I picked-up a VEE GEE BTX-1 refractometer in order to evaluate the concentration level.

Upon mixing up a 20 to 1 ratio my concentration level is only a little above 2 and not the expected 4 to 6 reading?

So I started checking things... First, this product is made by Falcon Industrial and the data sheet is here.

This data sheet states the Refractive Index is 1.0 so the refractometer should be direct reading for concentration level. The data sheet also specs a minimum of 4%.

Since my refractometer is temperature compensating from a well known mfg and zeros for DI water, I believe it's working correctly.

Also, there is another thread about this very issue here: Brix reading for Tormach coolant, but there was no resolution discussed.

Both Tormach and Falcon literature states a 20 to 1 ratio should equate to 4% to 6% concentration.

So I fired off an email to Tormach. Their response so far was that volume-metric mixing was the most accurate way to prepare your solution & they would look into the concentration levels. No other response yet.

This kind of feels like a pacifier type answer and they don't know whats happening. OK I'm a newbie when it comes to flood coolant but my mentality drives me to make sense out of the available wisdom here. So when the consensus says maintain your coolant I get it, but this DURAKUT stuff is not behaving correctly.

So for the time being I'm running double the concentration, and then some, to keep the concentration level above 4%. There is no excessive foaming which I believe is a sign of too much. There is some sticky residue the day after but no rusting or staining so far.

Kind of a work in progress shot, the coolant looks clear on the table & has a slight blueish tint coming out the nozzle:

Attachment 272670

From the Falcon data sheet it looks like this product is only available in 5 gallon pails or larger volumes. Since the Tormach product comes in 1 gallon jug it looks like they maybe repackaging it or something?

Any ideas or coolant suggestions appreciated ...