Removing Existing Weld and Rewelding 1

[Banks]

I have a client that placed a beam in the wrong location. It's only 1" - 2" away from the right location, but I'm a little concerned about them trying to torch off the old weld and re-weld 2" away. Is this a valid concern or am I just being overly worried about something that wont' be an issue? Is there something more I should write in there other than "provide extreme care when removing weld?"

I should mention that the beam is supporting only the horizontal wind load from the glass curtain wall and is spanning about 14 feet.

 

[connectegr]

NO TORCH!!!!

Are the existing welds fillet welds? Arc gouge the existing weld and grind.

http://www.FerrellEngineering.com

 

[metengr]

I would strongly suggest you have a surface NDT performed of the area on the beam that was previously welded and blend ground to ensure no base metal defects.

 

[Banks]

Thanks for the input!

We have fillet welds for this area - 3/16" for this connection.

I'll also make sure that the surface of the beam (and column) are inspected thoroughly. That was really my big concern with them possibly torching it (what kind of swiss cheese beam and column would I then have?) - I like the idea of arc gouging the existing weld better than mechanically cutting, but I guess I'll let them decide that in the field.

Thanks again!

 

[connectegr]

A torch can be used. But the cutting should be away from the weld surface to remove the beam and connection material. Then the remaining material can be removed with a grinder/cutting wheel. In most cases, cutting the welds with a torch will damage the welding surface. This can be repaired, within reason. Air arc gouging can remove the welds with more control. For 3/16 fillets this is not difficult.

http://www.FerrellEngineering.com

 

[Guest102023]

By the sound of it (3/16" fillet), the section thickness(es) involved are small, so go with flame cutting. It's quicker and neater and almost any welder with have the knowhow and equipment nearby. Arc gouging makes an unholy mess and the equipment, air, and consumables may not be readily at hand. Cut parallel to the plate you wish to preserve, and grind the rest flush. If you cut no nearer than the fillet, you should have no worries about thermal effects to the base metal. Grind off the rest, and perform magnetic particle testing on the area.

For the other member you have cut, if it can be reused (i.e., it is not now too short), grind back until the end is square. Mag particle and you are good to reuse it. Any thermal effect of the cutting will be wiped out by the rewelding.

 

[MiketheEngineer]

If it is just a short 3/16'' weld - I am thinking it could be ground off or use a cut off blade to cut through the weld parallel to the beam??

 

[racookpe1978]

For a small weld use a hand grinder and wheel.

Where the fillet is "visible" (accessible to the grinder without removing the shield) use a thin wheel (0.040 thick). For other place/corners where you can't see easiely how the wheel is cutting, use a 1/8 thick wheel and cut with the edge of the wheel.

The very thin wheel can break if the grinder is twisted while cutting when the wheel is "inside" teh thin notch. A thick wheel takes longer because you are grinding more material away, and the thick wheel requires you change the wheel when its corner becomes rounded, but the thick wheel will not break/shatter as easily.

Once the weld is cut through, use a tiger paw or surface grinder to smooth the old weld remnants and dye penetrant test the surface to be sure no flaws have been exposed. Then re-install the steel and reweld. Re-NDE.

Charge the company that put the steel in the wrong place for ALL appropriate time lost!