This is countered by clamping and fixturing, or post weld heat treatments and dummy beads. Sometimes over the course of a long seam (imagine a long U shaped trough) the whole assembly will want to distort. Once you start welding lap joints on the top of flat sheets then distortion starts becoming evident. On a simple shape like a box or say welding a rolled section to make a tube, distortion shouldn't be much of an issue. Now you have a continous water tight seam with little build up and little heat input. Once the first (or both) joints are done, pipe clamps will bring the angles back to square. To weld you would start at the top (if vertical down) and weld continously between the tacks which prevent the sheet metal from seperating, The numerous tacks mean the metal really won't warp or distortion while welding. The procedure is repeated on the other side and the unit is brought close to square. In the end it's "stitched" with about 3-5 tacks a foot. You repeat this process all the way down the seam. Now you'll proceed to move about 2-4" down the joint line it up again and tack. Tacks are generally done at hotter settings and the torch is cycled on and off as fast as you can flick the switch. Once the top corner is lined up perfectly you'll tack it. Unlike other welds fit up is very critical in fuse welding. ![]() ![]() It's impossible to line up both joints at once, so you start with the top of one joint and line it up perfectly. Most likely it would be pressed in to 2 L shapes with a square cut for the final side. If you are trying to make a square box with 5 sides and an open top lets say 3' to a side I'm not sure how familiar you are with sheet metal fabrication but I'll try to describe the general procedure for a box form there is little chance for distortion as the base metal does not get that hot. sheet metal is usually welded very cool around 45-60 amps in the vertical down processes at around 10-20IPM I.e a very fast and cool weld. ![]() Distortion is more a function of time and heat input. Finally while stainless steel is more prone to distortion than carbon steels. This is because there is very little restraint on the weld and the metal is relatively ductile in such thin sections. Stamping would only be economical on mass produced items such as "home" sinks and as such most smaller manufacturers will not have the capital or volume to produce units like that.ĭistortion control is actually extremely easy on stainless steel sheet metal. Following welding, joints are ground down and then "grain matched" if neccessary. The general weld procedure is Vertical down or flat, fuse welds with no filler. I worked at a company making resturaunt tables and equipment (hoods, lockers etc) and at a company making equipment for corrosive material handling.Įverything is generally cut via laser or shear then press braked followed by TIg welding outsides corners, square groove welds, Fillets or lap joints. In my career as a welder, I welded stainless steel sheet in the 16-20ga range with TIG.
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