D1.2, Section 4.19.3

Date 06-12-2008 14:36

We are welding enclosures using 1/8" and some cases 3/16" 3003 AL using flush butt joints. The enclosures will carry no current nor load. The enclosures are stitch welded on the inside and welded out on the exterior. Per the code, the welds in the butt joints cannot leave reinforcement which exceeds 1/32". On 1/8" material, what voltage can be used to fuse the members and leave "1/32" reinforcement? Some of the enclosures are 10 feet long, 40 inches wide, with the longest sheet 6 feet long. Help!

By Kix

Date 06-12-2008 15:03

Are you in fact grinding your joint flush after you weld both sides? If not then you go by 4.19.2 and then you are allowed 3/32" reinforcement.

By brownhearl (*)

Date 06-12-2008 16:14

So you are saying to make the flush butt joint a groove by grinding the butted edges to make a groove in which to lay the weldment?

By Kix

Date 06-12-2008 18:29 Edited 06-12-2008 18:34

No, a square groove joint is just 2 pieces butted straight up, no joint prep at all. It is still considered a groove weld, hense the name "square groove". If you are grinding all the weld off flush with the base material afterwards, then it becomes a flush butt joint. You only get thrown into 4.19.3 category if you are grinding the weld flush after welding. If your not, then you go by clause 4.19.2 which allows 3/32" weld reinforcement because you are welding a sqaure groove joint. Hope this helps and if not, speek up. We might not be on the same page yet.;-)

By GRoberts (***)

Date 06-12-2008 19:44

Are you getting CJP on these joint, or PJP? If PJP, you could put a larger gap between the two pieces to have a place for the filler metal to go other than reinforcement. If you are doing CJP, you have to be more carefull with that so that you don't blow through.