FCAW Shop vs. Field

Date 06-25-2009 04:21

Well recently we have started using outershield (specifically Lincoln Ultracore 71C 0.052") For shop fabrication of moment frames and Seismic Structural Fabrication. While its a sweet running wire and qualifying the shop welders was super easy. Its become a pain in the rear when re-work has been required in the field.

With the metallurgy being completely different welding over the outershield wire with a self shielded wire (NR-232 0.72") is impossible and the previous shop welds need to be completely ground down to the parent metal before a field weld can be made over the outershield.

While 90% of the time this is NO BIG DEAL its the 10% of the time that makes it a PAIN IN THE REAR. Besides the obvious thoughts of getting a better detailer (I WISH I COULD!) and riding the shop fabricators like a 3 legged pony to keep their tolerances and quality control on top, How are people dealing with this problem?

Previously we just welded everything shop or field with a E71T-8 wire (Coreshield-8 or NR-232) but with our short term exposure to the E71T-1C H8 (Ultracore 71c) and its super fast travel speeds and rate of deposition were sold on it. Its the incomparability that's making the transition difficult

By jeffery19677 Date 07-14-2009 03:38

Any possibility of only letting your best welders use the ultra core? If you let the most concientious welders use the ultracore, you might eliminate 50% of your field reworks.
Put the best on any difficult-to-repair welds. Might cost you a .25 cents an hour premium for ultra-core welder. Then again, it might not be worth using ultracore.
Good luck.
Jeff

By spots

Date 07-14-2009 11:27 Edited 07-14-2009 11:29

We are using 71-T1 Dual Shield 710X .045" (ESAB) with up to 35 CFM 85%CO2 15%AR shielding gas in the field with excellent results. I am sure you could adapt it for shop use quite easily. Not sure how the chemistry stacks up to your brand of choice though.

According to their literature you can get a 6.8 lb/Hr deposition rate. Our welders do not seem to have much difficulty passing a bend test if they have passed a 7018 stick test.

Best of luck.

By Duke

Date 07-14-2009 12:13

What do you do when the wind blows?

By spots

Date 07-14-2009 15:02

"Hooch up" as they say.

A small wind break to get the air speed down to 5 mph in the area of the weld is sufficient.