Distilled water

Can we use distilled water made for inverter batteries in the laser chiller ?
I am not sure if the distilled water made for batteries has some extra stuff in it.

If it is distilled water there is nothing else in it. It is actually recommended for use with co2 laser machines. Demineralized water is also fine, I use that.

What you run in the machine for a coolant is greatly based on where the machine is operating. If you are working outside above the arctic circle water may not be a good choice…

I ran distilled water in mine for about 4 months. De-ionized is the best from an electrical standpoint, but isn’t really useful as it returns to distilled water with air contact.

These are two manufactured coolants. The OMTech one is good to -31F. I would have picked the first if it didn’t have to be shipped from the UK, it’s non toxic.

OMTech has been sold out … I got mine from Amazon, but they also appear to be sold out… :frowning:

What type of chiller do you have?


For what it is worth…when I was an FSE back in the late 80’s for a large medical laser company we used Dowfrost in every one of our sealed tube CO2 lasers. I say sealed because back then the sealed gas tubes had just come out so used to be flowing gas lasers with premix and in those we used distilled always.
Dowfrost is basically Propolyne Glycol…and we never had issues. The only issue ever was in the first gen sealed systems the heat exchanger was copper core based and the Dowfrost reacted with the copper and it started to leach into the dowfrost so we had to field retrofit to aluminum core heat ex changers. Again been using it for 35 years as of now.
I used to have gallons of the stuff but tossed it all. I will add that later in my career I was an ET on large 3Killowatt lasers for aerospace and in those chillers we used a mix of Dowfrost and water.
Anyway not getting into anyone’s opinion on Dow Frost because well I don’t care about anyone’s opinion. We used it…engineers designed the systems and all our medical Co2 lasers were 30-100 watts so…take it as just info

Sounds good, until I looked to purchase some…

At first only in 55G barrels but I did location some 5G pails $580 … maybe I’ll buy a few :exploding_head:

There appear to be many ‘good’ coolants in this price range.


Sort of an aside, but distilled or reverse osmosis sourced water should not be used in contact with copper. The water in there forms has very low mineral content and will leach the metals out of the copper tubing/fittings over time, possibly causing eventual corrosion and leaks.

This is a reason to not use distilled water in automotive copper core radiators.

Just an FIY.

FWIW I run straight RV Antifreeze in my cooler and haven’t had any issues.

The problem with automotive antifreeze is it’s about as close as you can get to a conductor in liquid.

There are a number is cases that have had the hv jump to the coolant. This makes anything that conducts and exposed to the coolant at the hv voltage level…

Good luck with that stuff…


It’s been years with 2 lasers. Thanks for your concern though.

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