Well I’m glad you brought it up, because I hadn’t thought about it that far out and that deep honestly, didn’t even have a tank until today. Found one my grand dad converted into an air tank years ago. I’ll use it, it may be rusted out though only one way to find out. Hammer test it and then cut it. Way I would do it is fill it with water and torch the top out then make the cut with an angle grinder. I have to build a frame and weld me some d rings on it as well. Make a notch for a pour spout. Build me some angle iron molds I have a few hundred pounds to clean and process. It’s another project o have yet to find the time to start.