[CNC-Dude]

I thought I would find the answer here and a quick search didn't show the answer I have been looking for.

But basically, I have two 5 gallon pails of old coolant I need to safely dispose of. In fact, one of them has been sitting on my shed for close to 2 years and whereas I thought it would have evaporated by now, it hasn't! I read on a different forum that apparently the oil goes to the top and creates a barrier preventing water evaporation. Apparently some people use an aquarium pump at the pail bottom and this helps considerably. I imagine this is to take the water in the bottom and send it to the top so it can evaporate.

The other stuff I found is for entities with ridiculously large amount of coolant gallons. More like barrels, not dinky little 5 gallon pails.

So, what do you do with your old coolant? Do you get it recycled somewhere? Do you evaporate the water and then take the oil to a respective recycling center? What other technique can you recommend?

[CadRhino]

Koolmist is suppose to be envirioentally safe and bio degradable.
The oils that accumulate in the tank is not.
First Skim off the large floating oil clumps.
Filter several times through layered fine 2 gal coffee filters in large funnel (from us plastics)
Repeat until all solids are caught and oil has been absorbed in coffee filters.
In my area chemical based coolants have to be disposed of at a special waste treatment facility that also takes antifreeze car oil and paint.

I thought I would find the answer here and a quick search didn't show the answer I have been looking for.

But basically, I have two 5 gallon pails of old coolant I need to safely dispose of. In fact, one of them has been sitting on my shed for close to 2 years and whereas I thought it would have evaporated by now, it hasn't! I read on a different forum that apparently the oil goes to the top and creates a barrier preventing water evaporation. Apparently some people use an aquarium pump at the pail bottom and this helps considerably. I imagine this is to take the water in the bottom and send it to the top so it can evaporate.

The other stuff I found is for entities with ridiculously large amount of coolant gallons. More like barrels, not dinky little 5 gallon pails.

So, what do you do with your old coolant? Do you get it recycled somewhere? Do you evaporate the water and then take the oil to a respective recycling center? What other technique can you recommend?

[Steve Seebold]

I have a hot plate and a 10 quart pot. I line the pot with aluminum foil, put the hot plate outside, pour in the coolant and boil the water off. Then I put the foil with the oil in a 5 gallon bucket. It takes a couple of days to do it, but the water goes away as steam and the oil is left behind to go into a 5 gallon bucket then off to the hazmat disposal site. It takes about 2 1/2 years to collect 5 gallons of the hazmat stuff. Then it's $20.00 to dispose of it.