how long weld 6 inch sch 40 steel pipe GTAW

Irishapprentice · Sat Jul 18, 2015 11:26 am

Hi all, just finished up at pipe welding school and on work experience at a local shop,
all my experience so far is in welding school I am trying to get a feel on how (Bad/good) my work rate is,
I'm welding 6 inch sch 40 carbon steel pipe, GTAW complete, about 50% is in the 1g position, rest is 2g or 5g, in a fab shop, butts are pretacked for me and I'm getting 5 finished completely in 7 hrs work time,
any advice for me on how far off the mark this is?,
foreman at the shop reckons i should be getting a lot more than this done, but not sure if he is just trying to keep the pressure on as I'm a newbie or if he is going to fire my ass next week!.
Thanks for any help in advance

Rick_H · Sat Jul 18, 2015 7:17 pm

Are you following a WPS that has temp restrictions? How many passes are you doing? I'm assuming walking the cup? What's your settings...

Speed comes with seat time or torch time;)

Irishapprentice · Sun Jul 19, 2015 5:29 am

Thanks for the reply Rick
The WPS states amps between 100 and 140 , 3 passes, I'm putting the root in at aprox 130 depending on gap, then 140 for fill and cap,
I'm free handing the 3 runs( walking the cup is not allowed on the cap ) and to be honest I have very little experience walking the cup as in school we were required to freehand all the time, but im working on that in my free time.

Coldman · Sun Jul 19, 2015 8:07 am

All fairly high amps and three runs only is fairly fast already. The only thing to slow you down now is a big gap and or wide bevel angle. If you have a say in the prep see if you can go for a laywire root that Jody demonstrates in his utubes if you are not doing so already. Its the fastest way to lay a root pass . Try to keep the bevel angle between 30* and 35*. Less filling required.

Irishapprentice · Sun Jul 19, 2015 10:25 am

Thanks Coldman, ill have a look at rhe the vid on jody's channel and try it out,
I don't really have a say as to the prep, its a little bit hit and miss, sometimes 4mm, sometimes a little over 2.5 :/.
But at least I know now im not a milllion miles off the mark tho with time, ill try and speed up the root and walk the cup with the fill and see if that gets me the extra speed I need to keep the bossman happy

Rick_H · Sun Jul 19, 2015 12:48 pm

Walking the cup will actually be a little slower then standard dabbing and stepping forward. Sounds like they are aiming for a 3/32-1/8" gap. I run my root around 90-100, 110 hot pass and 120-130 cap.

I use the laywire technique and walk the cup most of the time on 4"+ diameter piping. I wonder why your not allowed to walk the cap? What size filler are you running?

5g sucks...

Irishapprentice · Sun Jul 19, 2015 3:27 pm

I think its to do with leaving scratch marks on the weld from the cup, bit extreme i would think but that's how they want them, ill blast that question to the one of the senior welders tomorrow and find out for sure,
I'm using 2.5(3/32 i guess

) filler wire and dabbing very often as its so hot,
that's basically why I'm scratching my head trying to figure out how I'm going to save any more time, if i go by the foreman's numbers id have to complete a weld in 42 min with no time in between welds to fetch new butts to weld,
that's almost exactly half the time I'm doing them at the moment :/
maybe I need a crate of energy drinks and some heavy metal on the mp3

Rick_H · Sun Jul 19, 2015 3:51 pm

It could be the marks not every one wants to see them... You need a TIG finger helps with all that heat when your scooting forward, I find it very useful.

WWW.weldmongerstore.com

Irishapprentice · Sun Jul 19, 2015 3:55 pm

TIG fingers on the top of the 'to buy list', first pay check in more that a year will arrive next week, so ill be heading straight to the the weldmonger store

wheresmejumper · Sun Jul 19, 2015 5:06 pm

I think an hour per butt would be a good time to be aiming for,for now.
with tig you can only move as fast as the amps allow,to a certain extent.the faster welders ive worked with would root 6 inch at +140 and fill at 180 (wps dependant)

Irishapprentice · Sun Jul 19, 2015 6:21 pm

Thanks a mil wheresmejumper, ill see how far I can push the amps up, hopefully my hands will keep up

gnabgib · Sun Jul 19, 2015 9:37 pm

Think 1 an hour is good.

gnabgib · Mon Jul 20, 2015 2:03 am

Second thoughts, that's a total of almost 1.5m per weld.

TRACKRANGER · Mon Jul 20, 2015 2:59 am

Irishapprentice wrote:...
foreman at the shop reckons i should be getting a lot more than this done, but not sure if he is just trying to keep the pressure on as I'm a newbie or if he is going to fire my ass next week!.
Thanks for any help in advance

Without being confrontational in any way, you might ask the foreman for some tips on how he recommends reducing your welding time. Tell him you want to improve. Maybe ask him to do one for you so you can see how to improve your time. You might pick up some good speed tips, or the foreman might find out that it takes longer than he thought.

Just be careful not to rock the boat. Don't wait until he comments about your time and then use the above in reply. It's best if you instigate the discussion, tell him you want to improve your performance, ask for advice and practical demonstration.

Trev

Irishapprentice · Mon Jul 20, 2015 2:51 pm

Thanks for the reply's fellas,
took all the advice and managed to get my welding time down to 62 minutes per butt today , still a way to go but the foreman seamed happy enough with today's Improvement.
I'm still a bit sloppy on the cap but i guess the hand just needs to get used to the extra amps, thankfully ill sleep better tonight