The three most common welding processes for stainless steel are stainless metal arc welding, tungsten inert gas welding, and metal inert gas welding. Each of these processes offers individual advantages --- SMAW is great for beginners, while MIG and TIG tend to offer finer levels of control and minimize post-weld cleanup. All of these procedures have specific guidelines for obtaining optimal results when welding your stainless steel.
Clean the base metal before welding. Use degreasers to remove surface oils, and remove debris from the surface with a stainless steel brush.
Bring the base metal to room temperature, 60 to 75 degrees. If welding stainless steels that are particularly thick, contain a high degree of carbon, are ferritic (containing a high degree of iron) or martensitic (containing a high degree of chrominum, with a hardened crystalline structure), you may have to preheat the steel before welding. Preheat the steel in an oven to 250 degrees Fahrenheit.
Use jigs, if necessary, to keep your base metal in place while welding. Create an arc between the welding tool and the base metal, by striking the electrode on the base metal or igniting the welding torch, and create a welding pool by melting the metal.
Add filler metal to the center of the welding pool, so it will act as a shield. Dip the filler metal into the welding pool, without allowing it to drip.
Move the welding torch over the surface of the stainless steel. Move your entire body along with the welding torch, rather than just moving your hand, in order to obtain a steady and constant weld.