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Just stumbled on this site and wow lots of info here. You guys rock.My question is I have a 2 or 3 g mig test coming up and want to make a few runs before i get their . I think it will be on 1/2 plate as thats what i used in a T joint test that they gave me in interview. Not sure if i should use the same or something thinner ?Next when I put the bevel on the plate what should the landing be ? Sharp like an axe, percentage of thinkness (1/4 on 1/2 plate) ? Is their a rule of thumb like 3 passes for 3/8 plate and say 4 passes for 1/2 From what I have got off this site im assuming 45 deg or sonot sure about the root opening but again thinking 1/4 or less with a backerThis is a production job and will be all heavy iron.Thanks for all the help
Reply:The exact dimensions for the joint will depend on the code you're testing to.  But these will give you some joint setups that should work for welding with MIG.  All this assumes you're welding 0.035 or 0.045" solid wire using short circuit transfer.  Spray or Pulsed spray will be different.1/2 or 3/8" plate will work for practice.  Try 30-37.5° bevel (total joint angle 60-75°).  Land 3/32", same root opening.  If using a backing strip, 1/4" to 3/8" thick 1-1.5" wide.  With a backer the land is 0" and the spacing between plates is 3/8" to 1/2".2G open root 1,2,3 beads (root, fill, cap) for 3/8" plate.  with a wider gap and backer, probably something like 2,3,4.3G up open root 1,1,1 for 3/8" plate.  With a backer 1,1,1 or 2 for a cap, bacause of the much wider root spacing.  Thicker plate will require yet more beads.good luck.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector