That's what I'm talking about. Going to do that. Thanks for the write up of the processGet a gallon or 2 of apple cider vinegar, fill up the tank, shake it well, let it sit 10-15 minutes, do it again as many time as needed until satisfied.
I did this to mine when I first got it and it had sat for 13 years. Cleaned up very well until there was only some light pits I could see. Cleared up like 95% of the rust in the tank and any larger chunks came loose and came out when rinsed. When I was done with the vinegar I removed the petcock and made sure to rinse the tank out well, and all the rust bits came out from where the petcock mounted.
Fairly inexpensive DIY tank cleaning I would try before getting a tank.