Field Procedure for thin GA to SS

By 542933 Date 03-07-2011 21:55

Hello-

The company I work for has a shop that welds some thin gage (14 and 16 gage) to thicker A36 members. I have qualified procedures for these situations using short circuit MIG and FCAW dual shield. We just got a job where the engineer wants to weld thin gage to 1/2" A36 in the field and I am wondering what a good process and electrode would be. We use SMAW E7018 and FCAW Lincoln NR-232 for our typical field welding, so we are very familiar with those electrodes. I never considered taking a gas shielded process to the field, I am at a loss. Any recommendations? Thanks.

Scott

By welderbrent (*****)

Date 03-08-2011 02:42

Scott,

WELCOME TO THE AWS WELDING FORUM!!

Hope you find all the help you need.

FCAW is used often in the field with a gas shield. Though you do need to be careful of wind blowing away the gas shield. D1.1 sets a limit on environmental winds. You may need wind barriers of some kind. You should be able to use the GMAW-S as well if it is protected from too much wind. Since you already have a procedure for using these I would give it a try.

You should be able to do it with SMAW 7018 or the NR-232 as well. Just may have to use smaller electrodes to keep from blowing through with every weld. Concentrate your arc on the heavier material and let it flow up and fuse to the thinner material.

To what code do you have your procedures qualified?

Have a Great Day, Brent

By 542933 Date 03-08-2011 16:32

Thanks for the input Brent. I qualified my procedures to D1.3 about 5 years ago. In our shop, we weld steel frames that attach to backs of precast concrete panels.... so we often have top and bottom chords that are 3/8" to 1/2 tube steel, and then we run vertical C-stud (14 or 16 gage)... The engineer wants to take this show to the field I guess. I am on the same page with you, I am recommending that we put up wind blocks around the welder for these specific welds and use our FCAW-G , shop procedure. I look at it like we're building a cubicle for the welder. Have a great day, and thanks for the response.

By welderbrent (*****)

Date 03-08-2011 16:56

Scott,

I should look it up but don't have time or codebooks handy at the moment.

Using D1.3, it should be pretty easy to get a new procedure using either the SMAW or FCAW 232. Then you wouldn't have to worry about the wind protection.

In fact, is the gas an essential variable? You may be able to use the FCAW with 232 in the field on the same procedure as your shop one. Or is that only on the welder quals, still need new WPS? Worth looking into.

Hopefully someone else will jump in a straighten me out. Like I said 'MAY BE ABLE', and 'Worth Looking Into'.

Have a Great Day, Brent

By jwright650 (*****)

Date 03-08-2011 17:02

The title to the thread threw me for a loop...when I read "SS" in the title...I was thinking that you were welding Gage material to Stainless Steel or visa versa....LOL, I'm guessing you meant Structural Steel by the SS?

By 542933 Date 03-08-2011 17:15

Yeah, structural steel.

Hey Brent,
My only concern with 232 or SMAW is blowing through the thin gage. When I qualified our FCAW-G procedures, I selected Lincoln Outershield 71M because they make it in .035" and it is an all position wire. I am only experienced with using our gas shielded wire in the shop, d you know of any good wind breaks that are made for field welding with gas?

Scott

By welderbrent (*****)

Date 03-08-2011 19:09

At most any welding supply you can get shields for either winds or visual break that are in single, double, or triple hinged units. The triples make for good wind breaks if you have room to put them. More stable and diverts the wind around.

Have a Great Day, Brent