Mig advice sought

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Hi all,I am in the process of building a solid fabrication table 1200 x 1200 x 20mm thick and having sides extending down 200mm, also 20mm thick all round. I want to machine the top and 4 side faces true and square and have fixturing holes on all faces.I am looking for advice for welding the table prior to machining as I haven't done a lot of heavy fabrication. I want to have a minimal weld bead to reduce machining costs and have good penetration for strength. I was thinking of welding the sides onto the top plate with a 3mm gap and a light chamfer ground on both edges, say around 2mm for the butt weld and fillet weld the inside. Does this sound reasonable? Also, what would be a ballpark amperage to start, I own a Esseti 320 amp synergic pulse mig. I will probably try welding it in single pulse to start with.Thanks
Reply:Do you really need to machine a fabrication table ? 20mm plate should be flat enough, to fabricate nice square sides in relation to the top.Pulsed GMAW is ideal, however for 20mm plate fillet welds you are going to need at least 160 A / 22V to successfully weld in flat positions with 200 + A / 22 - 24 V better.For positional work Vertical down parameters as for flat welding aboveVertical up work - 140 - 180A / 22 - 24V Cheers