Quote Originally Posted by shadetreewelder View Post
WTF do you need with a 15 gallon tank???

The Miller coolant are not designed to be diluted. If you are looking for algea protection. And the system has had, microbial growth in it before. Fill the tank with a strong bleach (1-2 ounces per gallon) with tap water and recirculate for 15-60 minutes. This will kill any live organisms and spores. Flush well with tap water, then rinse with just enough distilled or DI water as needed to get the system to pump. Dump the rinse water and refill with distilled water or DI water. I would not worry about freeze protection if your shop never get below freezing. Goto the nearest water bed store and get some biocide/fungicide combo for waterbeds and use it to treat your system. The chemical they use is a quaternary biocide, it is a broad spectrum biocide and if is sold in the concentrated from one pint will treat 1,000 gallons of coolant, typically the solution is already somewhat diluted so read the label for the dose rate.

As far as Distilled or DI water just go to the grocery store and buy what they have as DI or distilled, it will be just fine.
Re: "WTF do I need with a 15 gallon tank?" I have two cooling units. One is a home-brew 15 gallon circulator with a stainless steel tank that is extremely well made. I inherited this when I bought my former Lincoln. It uses a Procon pump with a 1/4 hp Emerson pump drive motor. Typicaly it is run half full. I don't need 15 gallons. So to answer your question. That's "WTF" I have a 15 gallon tank for. Some other guy built it and, since I don't need the money I'm keeping it.

The other cooling unit is a Bernard (now ITW) 3500 SS with 3 gallon capacity and a Procon pump. According to the instruction manual that came with the machine, distilled water is just fine unless you live in a cold area.

Both units work perfectly. The Bernard has a radiator on it so it can get by with three gallons.

Happy Trails!