Well flying for the winter is a great idea...if your a duck, I used to use a 5 gal. bucket which was no big deal to dump when done for the day but when I started doing bigger work I got an old wooden wine barrel and cut it in 1/2 and use one half as my slack tub, the barrel was around 70 gal give or take, so I have around 35 gal or more slack tub, so dumping it isn't really an option.
I had thought about a heater but really want to keep from raising the elec. bill any, which is why I also decided against putting air from the compressor into it for bubbles.
Dish soap doesn't really protect too low....I don't think any way, anybody know how low? Which is why I ended up at the rv anti-freeze, and it isn't designed for cooling purposes, just for freeze protection, plus no enviromental issues. But as I said, I'm not sure what if any affect it would have on the quench.
welder19