SMAW (shielded metal arc) or stick welding, GMAW, commonly referred to as Mig welding (metal inert gas), and GTAW (tungsten inert gas) or Tig welding.
Stick or Arc welding.
The methods to weld stainless using an arc welder differ little to that of welding mild steel.
Generally a small gauge stainless steel electrode is used for arc welding stainless metals.
A safety note of caution, like mild steel there is a coating of slag left on a completed bead, with mild steel the slag needs chipping off, however stainless slag has a propensity to 'ping' off as it cools.
This can cause serious eye damage so always wear eye protection using stainless electrodes.
Using an arc machine is a relatively easy way to learn how to weld stainless steel Mig welding stainless steel.
Again a similar process used on mild steel.
Obviously you will need to exchange the mig welding wire for stainless steel wire.
This is usually available in 304 and 316 grades.
Use 316 grade stainless wires in high corrosion areas and for marine applications.
You will also need to use pure argon gas instead of c02 that is used for mild steel.
Mig welding is common in metal fabrication shops.
How to Tig Stainless.
This method is the most difficult to learn how to weld stainless steel, however in my opinion it is the most satisfying and offers a pure joint between base metal and filler metal.
Using a tig requires more skill but in a way is similar to using the Oxy-Acetylene gas process.
Tig welders use a small hand held torch that carries a tungsten electrode to create the arc.
Tungsten is used as it has an extremely high melting point.
The tungsten tip, when struck to the metal creates the arc and begins the fusion process; at this point a filler rod is introduced to add substance to the joint.
This is where the operator needs a steady hand.
Learning how to weld stainless steel comes down to using the correct equipment and choosing the best process for the job.
For basic welding of stainless the arc or mig process will suffice, however if you require a top quality finish or are constructing an item that requires a clean finish such as a commercial food mixing component the tig welder is the way to go.
As with everything using the correct process and practice will soon get you to expert status in no time.