I am just assembling components to begin installation of my Econoburn 100 and am wondering about the possibility of using an old 30 gallon pressure tank minus the bladder as an expansion tank. I have 2 and would need the second when I eventually go to 500 gallon storage. It seems that the tank would be pretty easily modified and although the bladder would be nice I doubt that it would take the high temps. Any thoughts or experience would be appreciated.