Anyone run into this before?

Okay, I need a bit of advice from my Tumblr followers, I know quite a few of you build some terrific bikes, maybe you’ve ran into this. This is a pic of the inside of my tank, bear in mind I’ve already flushed it out with muriatic acid once and let it sit in Evapo-Rust for 24hrs. As you can tell from the pic, part of the tank looks brand new while other parts have these really heavy deposits (I rotated the tank during the cleaning process to ensure even coverage). My question is does anyone have any other cleaning remedies? If I can’t get it clean will Red Kote tank sealer work on a tank in that bad of shape?
Thanks, mikey







