Plug Welds

Date 09-15-2016 17:15

I will admit, I have not done a bunch of plug welding in my almost 9 years of being self employed. I had the opportunity to repair some trash, on some trash where when the trash was first built they didn't do plug welds. Had to locate the metal within the trash then cut out holes to do plug welds.

Get holes cut, cleaned and since I have never experienced "plug welds" my initial reaction was shock. :eek:

In my minds eye I saw a plug weld as a hole with the inner metal immediately behind the opening where you could weld inner base metal to exterior base metal. I wasn't expecting the inner metal anywhere from 3/4 to 1 inch away from the exterior base metal. I raised the question, WTF???? The short answer was, "That's how it's done" or "That's how it's always been done". My reply, "Hmmm, never did a test where I build out a weld thru open air for an inch before I can even touch what I am welding too". One and a half inch stringer bead, clean, run another, clean, run another, clean, talk about annoying! :mad:

Was like putting a 12" pipe standing up on the ground then putting a 10" pipe in the center with plastic spoons on the edge of the 12" to support the 10". Gave the whatever look, engineer approved and moved on.

So, my opinion was, Farm Code all the way but was wondering is this the norm? Since I have no flippin' clue what plug welds "shall" look like I figured I would come here and ask some of the more seasoned members.

By Lawrence (*****)

Date 09-15-2016 20:27

Sounds like you are in the farm code zone

D1.1 2015 Says this:
5.21.1.1 Faying Surface. The separation between
faying surfaces of plug and slot welds, and of butt joints
landing on a backing, shall not exceed 1/16 in [2 mm].
Where irregularities in rolled shapes occur after straightening
do not allow contact within the above limits, the
procedure necessary to bring the material within these
limits shall be subject to the approval of the Engineer.
The use of filler plates shall be prohibited except as specified
on the drawings or as specially approved by the Engineer
and made in conformance with 2.11.

By Cumminsguy71 (*****)

Date 09-15-2016 21:11

Thanks Lawrence, I kind of figured I had stepped out of the truck and onto the ranch! 1/16th of an inch, wow! I had a few that were like that, was like a breath of fresh air, filled quickly, others, not so much.

We had a gap where the pipe was offset(one in the center of another) and the gap was almost three inches. The guy in charge and the engineer said, "We figure you'll just have to fill that in with weld".

I laughed and said, no chance in h-e double hockey sticks. Told them they needed to figure something out. I ended up coming up with the idea for the engineer to approve, lol!! Fill in almost three inches of air space with weld, I resisted the initial reaction of falling over and laughing while rolling on the ground!

By Tyrone

Date 09-16-2016 11:57

Ackkk! 3" of air?!! Hope that Engineer knows what he's doing/approving.

You would not believe how much I hate plug/slot welds! It's one of my pet peeves. They seem to always have some type of weld defect, mainly lack of fusion, that causes field failures.

I've told the Design and Weld Engineers not to use them on our products.

Tyrone

By Cumminsguy71 (*****)

Date 09-16-2016 23:27 Edited 09-16-2016 23:32

We resolved the 3" of air with my design idea, engineer approved it. That's the funny part, dumb welder comes up with the repair and engineer runs it thru his 'puter to make sure it'll work..... :roll:

Whole thing was welded like this as well as a second and third one all in the same area. Most hideous attempt at welding that I have ever seen and I've seen some sorry stuff. Pictured was their attempt at running wire. I know this because I found wire sticking out all over. Apparently that wasn't enough of a hint that something was not quite right. Keep piling it on, it'll be a-ight.