coolant evaporation question

My manufacturing lab doesn't have classes every quarter, so
sometimes the CNC lathe and mill will go a while without use.

I discovered today that the 42 gallon sump in the lathe had evaporated
down to about 5 gallons. I sucked it out with a shop vac. My question
is whether it is possible to mix it back up with water and reuse it. It is
Blaser 2000, with about a pint of way lube thrown in. No smell, and about
the same color as the original concentrate.

If it is a bad idea to reuse it in the lathe, I'll just keep it around for
mixing up cold saw and bandsaw coolant.

Clearly I need to come up with a plan for keeping the lathe topped off
during periods of less frequent use.

Thanks,
-- Ralph

nah

why take a chance. if the shop vac was 100% clean and you got rid of the way oil then sure. but how much money are you saving? you have other good use for it. Hope this helps

If the lathe was working hard and long hours, it will evaporate a fair amount of water in short order, even if it were used only one day in the distant past.

I would redilute a cupful of it with a couple of cups of water and see how it mixes up. Then test it with a refractometer to see how potent it really is. Dilute as required. It may be that the sump only was half full and not as much is gone as you might have guessed. Let the sample age a day or two and see how it smells.

RalphStirling said:

My manufacturing lab doesn't have classes every quarter, so
sometimes the CNC lathe and mill will go a while without use.

I discovered today that the 42 gallon sump in the lathe had evaporated
down to about 5 gallons.

Click to expand...

This brings up a good point about coolant: You can calculate the amount of water needed to get a certain dilution percentage, but the minute you use the machine (or let it bake in the sun over the summer like we do at our lab), the oil percentage goes up; WAY up.
In your case, my biggest concern would be the stink factor. We have a real problem with this for our CNC machines.

I would start over some coolants will lose additives over time and standing, aswell as hard water, bacteria and hard water soap formation. If it did mix up nicley it maybe lean in pH and or rust inhibiotrs and other problems not worth. better idera is run tank as low as you can kinda like a dry sump then when its time to sit bucket it off for other shop use.
bruce

706jim said:

This brings up a good point about coolant: You can calculate the amount of water needed to get a certain dilution percentage, but the minute you use the machine (or let it bake in the sun over the summer like we do at our lab), the oil percentage goes up; WAY up.
In your case, my biggest concern would be the stink factor. We have a real problem with this for our CNC machines.

Click to expand...

Fortunately, our Blaser Swisslube 2000 doesn't stink, even after sitting for months
and evaporating all the water out.

I ended up cleaning the sump out good and mixing up a fresh batch of coolant. I'll
use the "used concentrate" I sucked out to mix up cold saw coolant (after we fix the
cold saw...).

I'm thinking about getting a plastic drum and pump out the sump when I expect it
to sit for an extended period. I also need to get a refractometer so I can check
the concentration regularly. I see $40 refractometers on ebay, but they seem to
have scales for wine or battery acid or other such stuff. It looks like I have to spend
$100+ for one from the coolant dealer.

Thanks for all the advice from the group!
-- Ralph

RalphStirling said:

Fortunately, our Blaser Swisslube 2000 doesn't stink, even after sitting for months
and evaporating all the water out.

I ended up cleaning the sump out good and mixing up a fresh batch of coolant. I'll
use the "used concentrate" I sucked out to mix up cold saw coolant (after we fix the
cold saw...).

I'm thinking about getting a plastic drum and pump out the sump when I expect it
to sit for an extended period. I also need to get a refractometer so I can check
the concentration regularly. I see $40 refractometers on ebay, but they seem to
have scales for wine or battery acid or other such stuff. It looks like I have to spend
$100+ for one from the coolant dealer.

Thanks for all the advice from the group!
-- Ralph

Click to expand...

If you look hard enough, you can get a coolant refractometer from Ebay for $40, pay attention because some are temp compensated and some are not.

Here's ya go, comparison shop the same features for the best deal http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370158893673


As a side note, I've been wondering about evaporation control. The use floating balls in vats of plating chemicals to control evaporation, I wonder how well it would work in the open areas of the sump?

I also run a manufacturing lab and I have gone away from coolants in volume because of evaporation, stink, contamination and the bio hazards of germs ect that can bite me with a kid who gets some rash. The final consideration was disposal. Non- sumped out coolant beiong disposed is costly, probably several times more costly than the original mix.

I posted a question about using cutting oils like transultex and such, may go this way. costs quite a bit on the front end, makes a bit more mess, but I will ahve to put a bit more shielding around the work area on the open mills among other things.

Since this is a "school lab", you need to think about this - do you really need the coolants at all, what can be substituted, can a squirt bottle with coolant work rather than a flood (we would all love flood coolant). Blazer also makes an oil based coolant, but I would stay away from the "canola" based oils as I have found out they tend to get sticky to a high degree if left on steel surfaces for a long time when un-used.

Blaser Blasocut coolants contain emulsifant additives to mix the oil with the water, and they are very picky about how you mix the product.

In fact, they only want you to use their little venturi mix tool which creates some sort of sonic shockwave at the mixing zone to ultra-micro-emulsify the stuff. It costs like $500 of course. Everything for a CNC machine costs $500.

I use a pail and a paint mixer tool in a hand drill. They tell you if you're going to mix the coolant manually, put the oil in last.

Have the old stuff picked up for disposal. It's not the same any more.

I'd call Blaser and ask them what to do to keep the coolant stored for long periods of time. They probably have some procedure for that.