I’d say up to 10- 15%. Adds lubricity so that there is no need for tapping compound when ridid tapping up to about an inch. No stronger but I’ve had a lot of success in a wide range of stuff with that concentration. Aluminum to A-2/D-2
For what it’s worth… I’ve only ever filled a CNC machine up with tap water from a indoor garden hose. Cant say it’s ever been an issue.
Most shops I’ve worked use a 9-10%. Any higher and it will probably start to foam. Too low and you get rust.
I’ve always tried to keep it 9-12%. Of course most old machines leak oil into the tank and it’s 12% forever.
Exactly. Somebody suggested only using distilled water. I laughed. He must work for a rich shop.
That or a shop that has customer control specs for machining metals. Tap water has chlorine - bad for Titanium. Fluoride is another item. Other water impurities affect different materials.
This my experience in aerospace is everything is pretty anal.
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yeah, tapping is a bitch - especially trying to get a broken one out of the hole. We are running 9-10% in our machines, but the thing is to use a ‘peck’ tap with a full reverse. Problems (mostly in stainless) went away when we started doing that. Aluminum is not really a problem. Of course as an alternative you can go with a slightly larger drill bit than suggested - for instance for a 1/4-20 you can get by with a 13/64" (.203") versus the suggested #1 (.201) on a form tap.
Cool story bro. Also, wire EDM does that tap in pretty good. I’ve gotten some small ones out we didn’t think we could. Ever forced to use a cutting tap on copper? .05 peck all day lol. In die work we always go a drill size up so blocks can be adjusted.
Ive found some light commercial setups from the 500-600$ range.
The spec sheet says 4-10%, with 7.5% being optimal.
They also recommended topping up with 30-40% of the desired concentration, rather than water, to compensate for the differential evaporation.
The HAAS is being topped off with water, diluting the coolant. The pH was 7.4 when tested, rather than the 8.8 required.
We are effectively circulating dirty tap water.
Has anybody been in an environment where tap water was not used?
Is that for DI
Supposed to be RO.
This one does not come with a tank though
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I measured the pH of the coolant in the three machines that use it, the results are as follows
HAAS 7.04
Cold saw 9.03
Colchester 9.08
I calibrated against the standards in science.
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Let me jump in and say I think we’ve been discussing apples and oranges (at least by me). The only thing I care about in coolant is what is measured by the refractometer which measures specific gravity by how much the light is bent. Somehow this magically translate to how much lubrication we’re getting. Ideally 9-10%.
pH is the difference in acidity or alkalinity of a substance. Too much of one or the other hinders or helps bacteria growth. I can see where some think this is important only because you can smell the difference. Changing coolants ‘might’ help keep bacteria down, but be weary not to change the overall lubrication factor we need. Cheers!
====EDIT===
Sump Soda
A quick interweb search on coolant smells goes on to describe how bacteria growth equals stink. The simplest solution was to add sump soda. Here is the spiel:
Sump Soda™ is a simple, convenient and professional strength tank-side additive for metalworking fluid. It helps keep machine coolants fresher, cleaner smelling and lengthens their life. Upon adding an appropriate dose to an infected foul smelling sump, Sump Soda will immediately destroy existing bacteria and fungi in the system. In addition to this initial effect, Sump Soda will modify sump pH conditions by increasing the reserve alkalinity of the machine coolant, thereby inhibiting future growth of new bacteria.
what brix do you want?
Look at website, doesn’t say if it raises or lowers pH. But the term “soda” would indicate a base, which is the opposite of what the Lather and CCS need. They are too alkaline (pH greater than 7).
Added:
What pH should coolant be?
The acidity decreases and the alkalinity increases as the pH goes from 0 to 14. The recommended pH range for coolants is on the slight alkaline side, from 7.5 to 11. Anything at 11 and above would be considered too high. Tests that range from 6.0 up to 7.5 would be considered too low.
Does the Haas manual or any of the other state what is recommended? It would appear we are Okay. The biocides for controlling sludge and order may be what is needed.
we’re having a brixet.
BRIX is a unit of measurement of refractive index - the same thing the recractometer is telling us so 9-10. I think David is correct that it is probably adding alkaline which I think will stunt bacteria growth.
Did some reading. Apparently most of the bacteria is anaerobic and bubblers to increase oxygen will help. Some suggestions were and adding fine copper strands to the tank (works like anti-fouling paint on boats).
A decent biocide is probably what is needed for the Haas- I haven’t seen it bee a problem in the CCS or lathe, e.g. no bad smells.
the brix of the HAAS coolant is 2.75 ish.
The following is an excerpt from the trim mist spec sheet.
- MIST is not recommended for use on reactive metals like magnesium or zirconium.
- MIST is not recommended for use in recirculation systems.
- The recommended concentration is 5% on all materials.
- As spray mist systems are superior methods of cooling the work piece and cutting tool, they are most effective when all of the material evaporates.
Don’t forget the multiplier. You have to use the multiplier with the direct refractometer reading.
I didn’t I just reported the raw reading.
note this:
MIST is not recommended for use in recirculation systems.
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