I own 2 old aluminum 80 scuba tanks that I can no longer fill because the batch of aluminum used to make them was flawed and was causing tanks to explode...So i would like to re-purpose them as fermentors. My first concern is the aluminum being exposed the PH of fermenting beer. I was wondering if there would be a good way to line the inside of the tanks so i could use them as conicals. If I can line them it should be easy enough to remove the valve and install a new one and a yeast catcher. Also, I am sure I could create some kind of lid, but first I need to see if lining the tanks is even possible.