Is there a specific way to detail different welding types on drawings?
Such as TIG versus MIG welding - do they have the same symbol? If yes, should i add a note to the drawing?
There are letter designations for different welding operationes (MIG- GMAW) that you can add to the tail of the welding symbol if you absolutely must. However if all the welds on a drawing are of the same type than I would just make a note of it.
You might find this usefull: http://www.welding.com/weld_symbols_welding_symbols.asp
The weld symbol typically denotes joint type sush as fillet weld ot butt joint. If a specific process is required it can go in the tail of the weld symbol. Typically the required welding process and welding code used will be stated in the general notes or project specifications. Charts showing weld symbols can easily be found too.