So, I will be starting a new thread on building a custom cooler for my new TIG machine, as I seem to be stumbling across the parts I will need to get the thing built faster than I'm coming across the funding to buy my new EVERLAST 250LX. So here's the question. Why does a cooler have to be made of either stainless or copper? More specifically I recently read, and I can't for the life of me find the source, I think it was a website for coolant fluid, but it specifically said that a TIG cooler must NOT be made of aluminum, or have any aluminum in the plumbing, cooler element, or anywhere else in the system. Could somebody tell me why? The reason I ask is that I had initially planned on using a factory transmission cooler from a Ford f250, but to the best of my knowledge, it's aluminum. Now I'm in the process of finding a heater core, custom core, or even a small radiator, so long as it's brand new and made of brass, stainless, or copper. Just wondering why no aluminum?