I'm seriously considering anodizing an aluminum cabinet frame. It will be 2'x3'x3', made from 2"x2" aluminum rect. tube, TIG'ed together. I know to use 5356 rod (instead of 4043 rod), otherwise I will find all the welds come out black.

I plan to belt-sand the welds flat, then buff it all to a high shine. Any advice on what to do (or NOT do) to the aluminum prior to having it anodized? Is it okay to have the rect. tubes with open ends, or to they need to be "sealed" at both ends?

Thank you in advance for sharing your expereinces.