Greetings to all! I am looking to experiment with building a conical custom made fermentation tank (1BBL). For a limited period I will have hands on an automatic TIG wire feeder and Tig machine, a turntable and a pair of rollers. Since I have access to super mirror polished sheets from my local shop (they will form cone, cylinder etc.), I wanted to ask the community of how to achieve the amazing exterior sanding lines we all see on tanks… My guess is that makers use a stationary belt sander and rotate the tanks but whether right or wrong, how do they equally polish the weld inside the tank? That last one is what puzzles me the most as for sanitation reasons is the most important! Any videos, photos, ideas will be much appreciated.