Stainless steel is a fascinating metal to weld. I have spent many years welding different grades of stainless steel. Needless to say I have picked up a few tricks along the way to make the process a little bit easier and of course to produce better welds.

Welding stainless can be difficult if you don't know what you are doing. It reacts to excessive heat by warping and distorting once it cools. Everything shows up in stainless. What I mean by that is if you weld with too much heat you can see it by the heat marks left in the metal along with any distortion. It also scratches very easily so you must take care when welding on a metal table.

One of the best things to do when welding stainless is to use a heat sink such as brass or aluminum. I usually clamp a piece of 3/8 brass behind the seam of the weld. This absorbs the heat and also prevents any burn through. The trick with stainless is to put as little heat into it as possible, especially with thin material. It's worth the extra time to make sure you have the heat sinks in place before beginning your weld. This allows you to actually weld the entire seam without interruption.

Have you ever noticed that when you get to the end of the weld and you pull the heat off it always tends to turn a dark gray. That's because you are carrying all the heat with you and by the time you get to the end it's at its hottest point. A little trick that I discovered on accident is when you get to the end of the weld and you take your foot off the pedal. Wait until the weld pool solidifies and then touch the tungsten to the metal and hold it there till your gas stops flowing. You'll notice that the color will come back to the weld. Depending on how long you touch the tungsten to the end of the weld. You can actually get that nice salmon color back. You can only do this with a setup that uses a foot pedal. If you are using a dry rig system where you have to use a lift arc this is not possible.

I have built many stainless steel tables for commercial kitchens. We would add hat channels to give the table more stiffness. Any welding would be done on the channels and not the actual table. This keeps it looking clean.

Lets say you had a 5 sided box as a base. The bottom was open and you wanted to weld a pipe in the center of it. No matter how small you kept the welds, the base would still warp and twist from the heat. This depends on the material thickness. I am talking about 14 gauge material. You have to have a frame to keep the base from warping. I have tried several different methods using heat sinks and clamps but they have all produced some amount of distortion. The best way was to add either a few channels underneath or an actual frame with angle iron.