How much experience do you have welding? Particularly doing out of position welds? Remember that the strength and quality of a weld depends as much on the skill and knowledge of the welder as it does on the process used. (A defective weld made with TIG is no better than a defective weld made with stick.)
TIG is difficult and time consuming, in this case not needed.
If you have access to a MIG welder, use that.
I would recommend using 0.035" E70S-3 wire, with 85%Ar/ 15%CO2 shielding gas. Both of these are inexpensive. 0.035" is a good wire diameter for welding 3/16" thick material.
Set your Volts and WFS so you get good spray transfer. Note that spray transfer produced a quiet "crackling" arc with very little spatter. A noisy arc that produces lots of "popping" or "snapping" sounds, and lots of "fireworks" indicates globular transfer which is the least desirable method.
For horizontal welds with the 0.035 wire set 600 ipm with 28 - 30 volts. Starting at about 500 ipm, set the voltage to an initial setting of about 28 volts - lay a bead, then adjust the voltage for the correct sound of the arc - slight crackle. For vertical down welds with the 0.035 wire, set the wire setting at 500 ipm. Set 24 - 27 volts.
For vertical-up welds, short-circuit transfer should be used. Short circuit has a noisy crackling sound, but without very many "pops", and produces many small sparks, but far less than big, long-lasting, impressive sparks produced by globular transfer.
Adequate penetration can be a problem with MIG due to it's comparatively low heat input. A technique I like to use is placing a scrap of 1/16 plate between joints when tacking them together, then I pull the plate out before welding. This gives a consistent root gap to ensure good penetration. But if you use this method, I'ts important that your cuts are dead-on accurate. Measure twice, cut once.
Also be sure to grind your joints down to clean, shiny metal before welding. This is a sound practice for all types of welding and is guaranteed to increase the quality of your welds, by reducing weld contamination.