Hello mightymoe, don't know that I know of any "tricks" right off-hand, however, if you can include additional information such as process, parameters, thickness, mechanized, hand-welded etc. I am sure that myself or others might have information that could be of help. So, if you can try to provide just a bit more info. After rereading the post I believe some things don't add up here. 1/4" 304 tube is "really" small to be calling out such a large gap and if hand-welded would certainly be a buggar, I believe butted and welded with an orbital tube welder would be the way to address this particular joint. I could certainly be mis-understanding what you are describing, my appologies if that is the case. Corrections requested. Best regards, Allan
EDIT: rereading again, are you saying 1/4" thick tube? What diameter? Purged? Filler wire diameter? Joint configuration: bevel angle, knife-edge, land/thickness, Etc.? Sorry just a little confused.
By bozaktwo1
Date 04-24-2011 00:55
Edited 04-25-2011 16:53
In light of the information already posted, the only advice I have is to keep your root to a minimum, cap your tube and use a metered release for the purge, allowing the pressure in the tube to prevent excess backside build-up. This is tricky, as you'll have to continually adjust the pressure as the root is closed up. Leave it going the same as when you start, and you'll blow out. For my 2 cents, I'm with these guys: machine welds all the way.
EDIT: ROOT GAP TO A MINIMUM.