A quick Poll

Date 03-27-2009 13:23

One of my recent inspection jobs was a 5 million gallon water tank in Hesperia, CA. All of the vertical seams for the tank were done with a downhill progression using FCAW and had all of the proper documentation to D1.1. These were CJP welds and were to receive RT following completion. The contractor is very reputable and international.

By Lawrence (*****)

Date 03-27-2009 13:38

Thanks for the input Blazer

I have family in Hesperia The high desert is very nice.

Was that FCAW self shielded?

By BLAZER

Date 03-27-2009 22:55

Yes, E71T-8, Lincoln NR232.

By OBEWAN

Date 03-27-2009 13:49

My former boss at a D1.1 shop had some vert down spray procedures for 1/2" girders. I never had faith in them. They were too touchy. While I do not think he cheated on his WPQ's, I think the shop did not often follow the WPS. When I was an inspector, I used to shut down the production line for it. I once pulled a large girder off the line as a reject. When they questioned me, I grabbed a guy with a torch and said "Cut this joint right here". He cut through the weld, and it had about 50% Pen and was hollow in the middle. They had to splice that girder, but they never questioned me again after that.

By Lawrence (*****)

Date 03-27-2009 13:53

That's kinda what I suspect... It's doable, but very tight process controls and a high operator skill level are required. But if any variables change, like mill scale or poor fitup, rushed operator etc. Than fusion issues are going to much more likely than in flat or horizontal welds.

By OBEWAN

Date 03-27-2009 14:18

Yes. Operator travel speed is the big one. There is a temptation to rush, and the wrong torch angle can kill the weld.

By jarsanb (***)

Date 03-27-2009 14:49

Lawrence, I used to work for a company that fab'd hydraulic tanks of various sizes. 10, 12 and 14 ga. For speed purposes The T-joints on some of the designs were welded with spay transfer in the virtical down position. Leaks were extremely rare. The welds were cancave, but not overly so, so cracking was not an issue. It was a proven process in that application. No they were not pulsing and these were not to D1.1 - obviously. Amps were high. Wire feeds, if I remember correctly were near 550 ipms. Voltage was on the low side for spray to maintain a fairly small arc length. 98Ar2O2.

By Ke1thk

Date 03-30-2009 10:58

Lawrence,

I use spray transfer downhill with my robot. I don't like it but in certain cases it's almost the only option. Also, the weld is only a fraction of the total welds on the part.

Good Luck,
Keith