I need to repair a flat sheet fabrication in 3mm steel without distortion. It's had two slots 6mm wide x 70mm long the semi-circles of a 13mm hole at the mid-point put in it. Slots are lengthways-on near each end.
Sheet is 660mm wide and 1700mm long, with angle-iron reinforcement around the edges.
Want it to be smooth so easy to scrape clean - used in dewaxing autoclave of lost wax foundry.
Cut out a piece of metal which as closely as possible fits each slot - same 3mm thickness.
Cut some say 12mm plate about 120mm long and 50mm wide and attach with a series of shot tacks to the underside. Big enough to hold the sheet flat but small enough that tightly restrain the weld area.
Pack height from workbench so can hammer in that area
Weld the "filler" in place fast, highish current, small bead - then hammer the weld immediately afterwards to counteract shrinkage
Cut off thick restraining plate with angle-grinder.
Turn over - seal weld that side too in same way.
So that's my idea - how should I really do it?
Thanks in advance