[rdsi]

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 ...

[Steve Seebold]

I haven't used anything but Blazocut 2000 Universal coolant in my machine since I got it in July 2011, and it still has all the paint in it with the exception of a few scratches.

[widget_maker]

The stuff I bought from Tormach a few months back is called "Reladyne premier 600 synthetic coolant" and seems fantastic to me diluted at 20:1. Doesn't foam, I leave the machine wet - no corrosion issues.

[shred]

I used to use the Premier but it tended to lose it's anti-rust properties rather suddenly. If you were diligent about replacing it, it would probably do ok.

[MichaelHenry]

I stopped using the Premier coolant when I noticed paint peeling off the back of the saddle and in the chip the area where coolant dripped off the table. My mill is >8 years old though, so that may be a factor. Both the age of the mill and the paint on mine might be different than what Tormach is currently using.

[adamvs]

I stoped using it also. I do alot of work in copper alloyed aluminum, eg, 7000 series and 2024, and was finding after a while Premier would stain the material if left unwashed. I'm using a soluable oil, Koolrite 2290. I'm finding rust and staining is a thing of the past. It has better lubrication properties, so I can pocket more aggresively, tapping and reaming also seem to be working better.

[rdsi]

Thanks for the feedback.
I guess Tormach cannot explain whats going with their DURAKUT product?
I have been eying the Blazocut 2000 Universal but its not readily available.
There is a long history with this product but it's starting to look like there might be better ones.
I like what what I'm hearing about Koolrite 2290 (thanks adamvs) and it's available everywhere.
So it looks like after I blow through this DURAKUT stuff I'll reload with the Koolrite.

[Steve Seebold]

Thanks for the feedback.
I have been eying the Blazocut 2000 Universal but its not readily available.

Blazocut can be delivered by UPS.

[rdsi]

Tormach finally came thru & explained that the documentation incorrectly states the refractive index as 1.0 whereas it should be 2.8.
That explains everything. I guess not to many people use DuraKut and/or do not check the concentration level.

Oh well, maybe they'll fix all the documentation but I've already moved on...

[wtopace]

Tormach finally came thru & explained that the documentation incorrectly states the refractive index as 1.0 whereas it should be 2.8.
That explains everything. I guess not to many people use DuraKut and/or do not check the concentration level.

Oh well, maybe they'll fix all the documentation but I've already moved on...

WOW! This explains so much, my refractometer came in earlier this week and I'm at 3.75% with a refractive index of 1. I was wondering why I couldn't get the concentration to go up very much. Looks like I'm at about 10.5% right now with 2.8 index.

[CNC-Dude]

How do you change the index? A new refractometer?

[rdsi]

The refractive index is just a multiplier that you apply.

For instance, if the mfg states an index of 1.0 the refractometer would indicate the concentration level directly or 1 to 1.

If the index is something other than 1.0 it's just a multiplier to the reading obtained using the refractometer.

So in this instance my low reading needed to be multiplied by 2.8 to obtain the correct concentration level using the DuraKut product.

Note: All coolants have different index numbers and you need to know this in order to measure the concentration level using a refractometer.

Tormach's failure is that all their documentation assumes an index of 1. This may have been correct at one time when they were using a different product. Their new offering is DuraKut by Falcon Industrial. The problem is that Falcon Industrial states an index of 1 in their data sheet & that is apparently wrong. The index should be 2.8 according to Tormach.

No, you don't need a new refractometer, you just need the correct information!

Hope that helps...

[CNC-Dude]

The refractive index is just a multiplier that you apply.

For instance, if the mfg states an index of 1.0 the refractometer would indicate the concentration level directly or 1 to 1.

If the index is something other than 1.0 it's just a multiplier to the reading obtained using the refractometer.

So in this instance my low reading needed to be multiplied by 2.8 to obtain the correct concentration level using the DuraKut product.

Note: All coolants have different index numbers and you need to know this in order to measure the concentration level using a refractometer.

Tormach's failure is that all their documentation assumes an index of 1. This may have been correct at one time when they were using a different product. Their new offering is DuraKut by Falcon Industrial. The problem is that Falcon Industrial states an index of 1 in their data sheet & that is apparently wrong. The index should be 2.8 according to Tormach.

No, you don't need a new refractometer, you just need the correct information!

Hope that helps...

It helps a lot! Thanks for the detailed explanation. Was completely oblivious to the fact that I am supposed to use a factor when computing coolant ratio.

[wtopace]

The problem is that Falcon Industrial states an index of 1 in their data sheet & that is apparently wrong. The index should be 2.8 according to Tormach.

This was exactly my problem. Unfortunately, I trusted the manufacturers documentation to be correct, but it seems that it wasn't. Did Tormach mention if they were going to get a hold of Falcon to get it fixed?

I actually have been liking the Durakut 4010 quite a bit, although it's the first flood coolant I have ever used. Previously I have mostly used the no-spill cups, oil and an acid brush for my manual machining. The Durakut 4010 seems to have a pleasant smell and doesn't mind sitting for a week or two at a time in my case. I also like that it is mostly clear and I can see what's happening while the cutting tools are engaged.