How do i get rid of this black oxidized stuff?

My new boil pot fresh from welding. After using flap discs, flapwheels, bar keeppers friend and elbow greese, i cant seem to get this stubborn black residue free from the nooks and crannies of the weld. Im wwondering if acid or soaking for a longer period of time would work. Any suggestiions?

TIG over the top of it.

I thought about that. The tank is really tall and i dont think it would be easy to reach way down in the bottom with welding gear. I wonder how that wwould affect the outter side of the tank where it was orgionally welded from?

I would rather clean the inside

use a stainless brush on it. but you’ll just have a hard time keeping the inside weld clean. what’s the ID?

The stainless bruss is a good idea. The inner diameter is 8the inches. This is a 30 gallon pot. Keeping it clean isnt too much of a concern since its preboil. However, my fermentors are of the same construction. I would like to have a sanitary weld there so no bacteria can hide.

TIG might be the call. Welding from the insidde to get a super clean sanitary weld where there are no bumpy or jagged surfaces. Thanks for the advice

it’ll be kind of a pain to reach in, but lay the pot on its’ side to weld. you doing this or a local shop?

how’d it turn out?