Oh, and I haven't had any trouble with automotive anti-freeze; I used it in both coolers.
I've been working with coolers, torches and hoses a bunch in the past year or so and have found several newer torches that looked perfect, but had hoses that were crumbling internally leading to restricted flow, or no flow at all. They were all big name brand torches/lines and had the more expensive super flex cables. They all had one thing in common....automotive antifreeze was being used in them. I've even found them where you could run your fingers along the hose and find spots that there was so little rubber left it would collapse with light finger pressure....really weird. The bad thing is that the rubber crumbles into this sand like stuff that plugs up the smaller passages in the torch head and it turns into almost concrete...no way to clean it out that I've found using wires, rods, acid, etc.
I think there is something in automotive antifreeze that attacks certain kinds of rubber...probably the more expensive, supple kind based off what I've seen.
Years ago I was working with an engineer at Ford on a project and he told me that when the first deicing windshield washer fluid came out they found that it was causing a chemical in the rubber tubing that goes out to the nozzles to leech out and it was caustic to paint, so they were getting warranty claims for paint peeling off nearly new cars. They ultimately had to change the rubber compound to avoid the problem....after spending millions of dollars repainting car roofs. I think something like that might be going on with the torch hoses....I'm still trying to research it more.
I've gone through something like 20-25 coolers now and there has only been one other issue and that was a cooler run with tap water where the radiator developed pinholes in the copper tubing after a flush. All the others have been fine except the handful that were used with automotive coolant. It's not definitive, but certainly suspicious!
I normally use a 50/50 mix of this Cantesco coolant with bottled distilled water and that makes it good for down to about -15F. The price varies (Amazon doing it's thing) between $16 and $25 per gallon, so even for a big cooler you only need a gallon or two. It's a few bucks more than automotive antifreeze, but a lot cheaper than having to replace a torch that fails. They also have versions that are meant for higher temps and those are less expensive....you probably don't have to worry about single-digit temps there!
CANTESCO CF3-1G Cooling Fluid Low Temperature, -32 Degrees F, 1 gal Jug: Amazon.com: Industrial & Scientific
www.amazon.com
