Weld strenth

[Eric Walter <ewalter@domain.elided>]

The best thing to do, (even if you're experienced) is to try and
recreate the exact welding circumstances with a test part. A couple of
pieces scrap held in the same position, (its cheating to test rightside
up when real part needs to be welded upsidedown), run an inch of weld,
not around a corner, then bend it back and forth in a vise with a big
adjustable. When when the base metal breaks (not the weld), you're ready
to go.
One hint on arc welding (not mig welding) is angle the rod back toward
where you've been and travel at a speed that leaves a puddle of molten
weld metal the size and shape of a fingernail.
When mig welding thick metal, point vertical or forehand, and weave back
and forth. The strenth of mig welds are often limited by penetration or
porosity, if you see bubbles in the weld, grind it out completely and
try again. Porosity often comes from a breeze blowing away the shielding
gas or dirty metal (grease, paint, etc).
Eric