How to Weld Stainless Steel
If you want to weld stainless steel, there are few things you should know. First, stainless steel is not one metal, but a family of metals. An outer layer of chromium oxide makes them resistant to rust. They also come in different thicknesses. You have to know exactly what type of stainless steel you are dealing with before you start. Secondly, stainless steel is harder to weld than other metals because it warps and distorts under high heat. This can affect its strength and appearance. Electric arc welding is used, but there are several different kinds, so you must know which one is right for your project. The most common types for stainless steel welding are Stick (SMAW), Tig (GTAW) and Mig FCAW or GMAW.)
Step 1 – Safety
As with any welding, safety is very important. Welding produces fumes, sparks, and smoke that can be harmful. Don't skimp on your safety equipment, you might regret it. Make sure there is nothing flammable in the area. Look for pools of oil, scraps, rags, anything that could ignite. Make sure there is proper ventilation. Don't start until you completely understand your equipment.
Step 2 - Plan Ahead
Be sure that your pieces of stainless steel fit well before you start. Make sure the metal surfaces are clean. Plan which type of weld you are going to use. The five basic types are butt, corner, edge, lap & t. To prevent heat damage, clamp a piece of brass or aluminum behind the weld. This acts as a heat sink, so the steel doesn't overheat. Read and understand any instructions that came with the metal and the welder.
Step 3 – Practice
Just like getting to Carnegie Hall, it helps to practice before your big performance. Since stainless steel is trickier than other metals, even if you are an experienced welder you will want to try it on pieces you don't need before you do the real thing.
Step 4 – Weld
Make sure that the metal stays in place while welding. Use some kind of clamp or fixture if necessary. Stainless steel scratches easily, so don't let it move on a surface that will scratch it. Move the welding gun at a steady speed to keep it uniform. Keep your eye on the "puddle," the melted metal, to keep it under control. Be careful when you finish the weld to prevent the high heat from discoloring the steel.
Welding takes control and skill, so it's best to know what you are doing before you start the project. If you do it carefully and plan things out ahead of time, your project should look good and be useful and strong for many years.