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Up Topic Welding Industry / General Welding Discussion / Arcing Time of electrodes
- - By rvraman0 Date 03-14-2016 11:56
Can someone tell me what is the standard norms for arcing time  i.e  how long a welder can weld without any hassles per 8 hour shift
Parent - By TimGary (****) Date 03-14-2016 12:06
There are so many variables that affect this, such as part complexity, weld size and amount, part size, weld process, power source duty cycle, etc., etc.

Perhaps if you provided some of this information, we could make a guess, but I don't think you'll find a "normal".

Tim
Parent - By Lawrence (*****) Date 03-14-2016 14:35
Welcome to the Forum Rvraman !

Your question is good and important.

As Tim mentioned wisely, to have a reasonable answer you must include many variables and fixed data as well to make an estimate.

There are many lean manufacturing models available, but few speak to welding and look deeply into the process control aspect of "waste reduction" in both manufacturing and construction...

**Reduce Weld Metal Volume
**Reduce Arc Time Per Weldment
**Reduce Rejects, Rework and Scrap
**Reduce Work Effort
**Reduce Motion and Delay Time.

Those are the big picture items that must be served by Engineering and Management to support the welders making more welds in the time they are given.

How long they can weld in a shift is important, but only a part of the equation to be efficient in production....

I use as a tool, a book called "Total Weld Management" by Jack Barckhoff P.E".  The best 200 pages you will ever read as a welding manager.

But tell us about:
1.  the process you use to weld
2. the material you are welding
3. the type of work being done, (pipe, structures, robotic, heavy manufacturing, job shop, etc.)
Parent - By WeldinFool (**) Date 03-14-2016 18:20
So, if you are asking what is an average "arc-on" time for a welder in an 8 hour shift, like these other guys said, there probably is no industry average.
I can tell you that for our shop, we had a third-party supplier perform a "productivity analysis" a few years ago. Surprisingly the average "arc-on" time for an 8 hour shift was just over 3 hours (much to the dismay of our upper management), which is about what I would have guessed. Our product line consists of hundreds of different parts, and a welder may work on several different parts in a day. Each will require set up and handling time in addition to equipment reconfiguration. This really cuts into "arc-on" time...
If you are asking if there is a limit to how many hours per shift a person can weld, I do no know of any such requirement.
Parent - By kcd616 (***) Date 03-15-2016 04:52 Edited 03-15-2016 07:46
8 hour shift
subtract 15 minutes for 1 break,
then we have to subtract time for bathroom breaks,
then we subtract for drink and fluid time, ie even if they have drink right next to them takes time to drink it.
other things come in to play, MIG mild steel with CO2,
run real fast and for a good amount of time you will freeze the flow meter (I have done it:eek::mad:)
have to get it thawed, takes time:sad:.
then you have to move yourself (can only reach so far and make so long of a weld)
and sooner or later move the material
then replace the material with the new part
and the harder and faster you work the sloppier and slower you get as time goes on
I personally have no experience at that type production work
my crews and myself never had any production work that wasn't precision work ie aerospace work
so everything I have ever thought about business wise was do it to print the first time and save time, material and $$$$$
(counting beans again flux:wink:)
all is IMHO
sincerely,
Kent
edit: forgot to add about heat and distortion
which is a whole new topic:cool:
in the old days days, used to ask about how long a welder had their hood down,
now with auto dark helmets can be 8 full hours:eek::razz::yell::twisted::evil:
if I was not old and half blind I would have a hood on everywhere but bed
used to wear cutting goggles 24/7:twisted::evil:
Parent - - By welderbrent (*****) Date 03-15-2016 06:17
rvraman,

WELCOME TO THE AWS WELDING FORUM!!

While you are dealing with all the well worded responses thus far and compiling more information for us to work with, it may be sufficient to say rare is the production welder who maintains an arc for more than a 4 hour period in an 8 hour shift.  If I remember previously performed studies by dependable personnel 3-4 hours is the average good production period of actual arc time. 

He Is In Control, Have a Great Day,  Brent
Parent - - By Lawrence (*****) Date 03-15-2016 12:30 Edited 03-15-2016 12:42
Hey Brent,  If you are getting 4 hours of arc time out of an 8 hour shift I want to sit at your feet !   Realistically most of the robotic cells I've been around aren't hitting 50% utilization.

For most production work in manufacturing (non-automated) 15 minutes of arc time per hour is considered a pretty good target...  This comes as a surprise to most managers who think they are operating at much higher rates :)

In fact... Challenge yourself (anybody who manages welders) and get a stop watch and sit for two days on your shop floor and find out the truth.. Most managers guess about 50% and when they are done measuring discover less than 15% actual arc-on time per hour in production.

I pulled down and sanitized a couple of reports I use every day to review OEE.  Yesterday was a pretty good day so I thought I would share.

The reporting is slick.  I can see any unit at any plant in the system real-time. I can see individual units or compare groups doing similar tasks.. Can view anything from individual welds to hourly, daily, weekly or monthly in the reports.

I won't venture to judge what anybody else should be doing as far as arc time per shift... But I know darned well what I expect :)    With this tool, I know when to ask questions and pretty much what kind of help is needed locally.

It may look at first like a "Big Brother" kinda thing, but its not like that at all...  The "bottle necks" are almost always things that just need a little attention and help.
Parent - - By TimGary (****) Date 03-15-2016 13:30
Nice post Lawrence.
Thought I'd add a little more for the guys to chew on...

This report shows average arc-on time, over a two month period, for 6 weld machines on a high volume GMAW production line.
It is covering only one 8 hour shift.
This shows that even with a line set up for high volume, using high deposition pulse solid wire GMAW, intelligent fixturing that requires no time for dimensioning or layout, and parts fed to the line within reach by material handlers, the fact that the weld sizes are small (3mm) intermittent fillets means little actual arc-on time.
I think that any more than 25% arc-on time for a manual application, regardless of other variables, is unrealistic.

Tim
Parent - By jwright650 (*****) Date 03-15-2016 14:00
At my previous employment, management had thought of trying to track the arc time and ran up against too many variables to give a realistic picture of welder arc on performance. One issue is that the welders and fitters are paired up as teams throughout the shop, so there is a lot of fitting and material prep time before any welding can take place. And then you have....time waiting on overhead cranes, waiting on punched material in the parts department, waiting for sawed misc materials (outriggers, channel, angle), waiting on answers to questions on shop drawings, stacking materials back up due to missing material, spreading out new materials, etc...all seem to hinder welder arc on performance when averaged in an 8 hour shift.
Parent - - By Lawrence (*****) Date 03-15-2016 14:25 Edited 03-15-2016 14:39
Tim,

I really agree with your notion that beyond 25% is unrealistic for anything applied by a manual operator.

Here is an admittedly cherry picked report over 30 days...  When I show something like this to the guys that sold us the power supplies they can't even believe it.   We do really well in some areas, but this is not representative of all workstations..  But is a goal we are working toward.

We work toward that goal by addressing the things John rightly mentions.  Operators getting guidance on unclear drawings, inefficient "kitting" of accessories to be welded, part flow:::Hoists, conveyors, Jibs etc., Plasma/Laser cut quality, gaps in fit-up...  It's a long list, but if addressed, this "upstream" stuff can be reduced and arc-on time increased.

John; Those barriers are exactly what you must run up against!  You may not like what you see at first, or at least it might not be what you expect, but the importance of recognizing and isolating those activities into your plan is what puts money in everybody's pockets, or keeps you working when the guy down the road lays off!

Most importantly, cleaning the shop floor of "WIP"  (Work in process)... When buffers are removed, the real bottlenecks present themselves like shining beacons!

Then how to sustain it becomes the critical factor!

But I'll tell ya what,,,  24% Arc-on time over a month in a factory running 24 hours a day is no small thing to sustain.

ONE MACHINE::::: 1,245 lbs. of solid wire.. @ about 12.5 lbs. per hour!

And we haven't even said a peep about making right sized welds yet and how that effects productivity vs arc-time !!
Parent - By jwright650 (*****) Date 03-15-2016 15:57
They started tracking time by task and shop order on each timecard( fitting, material prep, welding, etc... ) It helped as you said find bottle necks and where exactly all the time was disappearing to.
Parent - By Trackergd (**) Date 03-15-2016 12:20 Edited 03-15-2016 16:10
I'm going to agree with the 4 hours above with a possible extra hour.  In an 8 hour shift, our welders have a half hour lunch and two 15 min breaks, so that takes an hour out of the eight.  Moving material in and out of their hut, clocking in and out of their jobs, getting consumables etc probably takes up another two hours a day.  Bathroom, drinks etc and you are down to 4 - 5 hours.  Too much rushing, changing jobs mid stream and overtime (fatigue) tends to up the rejection rate in my experience.  It may seem odd, but I can tell when the Fab manager is rushing the day shift welders or if they have been goofing off on night shift, then rush to get their work done before they go home by the quality of the welds.  The quality improves if they take their time and can take breaks or get drinks when they need to.  It may drive productivity folks nuts, but the weld quality comes up and the rework goes down.  It does not save any time if you have to do rework.  As has been noted above, the material also plays a part, take the difference between prep and welding carbon steel and aluminum.  Another factor is skill set.  One welder may be a bit faster than another, but the quality of the work is the same.  All these lessons were hard learned in our case.  And to add my pet complaint...if the drawing has incorrect, missing or ambiguous weld symbols, there is a lot of back and forth with "Engineering" about what they wanted.  Sorry to be long winded... :red:

And WELCOME TO THE FORUM!

Edited to add....thinking twice, it would be more like 4 hours max.  Forgot about waiting for material from the laser or water jet...
- - By welderbrent (*****) Date 03-15-2016 17:56
OKAY, easy guys, I said 'RARE' is the guy who does so.  AND, as many of you pointed out there are so many variables: fit up time, pre-heat time, changing wire, double checking the fit up prior to welding-in the wrong place, grinding, cranes, rolling because the standard practice is to weld everything in flat/horizontal, bathroom, smoke, water, candy, clean lens, etc, etc. 

Now, it also means an average over weeks and months and years.  As opposed to one day in the week it may be entirely possible for at least one member of the crew to actually get over 4 hours of arc on time.  But it isn't about a one time occurrence,  it is about what to expect for an average to base shop rates upon over the long haul. 

I wasn't bragging on myself or anyone else, I was stating a fact.  RARE IS THE WELDER WHO WILL CONSISTENTLY PRODUCE AND ARC ON FOR FOUR HOURS PER DAY. 

Now, turn it around, what is the minimum the arc should be on in a day?  You can't predict that either.  What is the guys main duty? Fitting or welding?  What process is he using?  How much does he move parts around with the crane? 

The only fair labour calculation is are your guys being productive in whatever needs to be done and moving a proper tonnage of material per day?  As an average over a year.  Because not every day is going to see the same tonnage go out the door either.  How many parts were fit and welded to it?  How many fillet welds compared to CJP's on 2 1/2" thick continuity plates? 

It is a never ending battle, discussion, calculation, dilemma.

He Is In Control, Have a Great Day,  Brent
Parent - - By Lawrence (*****) Date 03-15-2016 19:07
Heh... Wasn't jumping on you Brent... :wink:

Was jumping on an opportunity to talk about something that interests me a great deal.

Here is a gem from today that hit 50% arc-on for four consecutive hours..  Just excellent.
Parent - - By TimGary (****) Date 03-15-2016 19:14
Sweet!
Hope he's got a 100% duty cycle power source...
Parent - - By Lawrence (*****) Date 03-15-2016 19:20
Actually its a 500 amp power supply...

So let me get my math straight here...

WPS current at about 260 amps at 100% duty cycle on a 500 amp power supply...

This means;   I can expect him to weld about 115 minutes out of every hour without causing the power supply to overheat...!!!!!

I can't wait to go tell him  :)
Parent - By Superflux (****) Date 03-15-2016 20:40
That should get you entered on the "Wall of Fame" in the last stall of the... uh-hem break room...
Parent - - By welderbrent (*****) Date 03-15-2016 22:24
Right, how to win friends and influence enemies eh Lawrence. 

Won't win many friends, especially around a union shop, telling them you now expect 10 hours of arc time for every 8 hour shift.  :lol:

I wonder how your WPS's would stand up to that??  :eek:

Brent
Parent - - By Lawrence (*****) Date 03-15-2016 22:31
Auditors love my WPS's..... Welders hate them (at first)

PM me someday and I'll tell you why :)

Can't give it all away for free !
Parent - - By ssbn727 (*****) Date 03-16-2016 15:50
Where are my waders??/ It's getting deep in here!:eek::grin::lol::wink::cool:
Parent - By Stringer (***) Date 03-16-2016 23:21
I think it's very nice and unusual for you to pay your welders for lunch, Trackergd.
Parent - - By kcd616 (***) Date 03-17-2016 07:30
Henry,
my very good friend
GREAT to see you post:yell::smile::cool:
sincerely,
Kent
Parent - - By Cumminsguy71 (*****) Date 03-19-2016 10:12
Man, if I only had the "arc on" for a total of 4 hours in a 8,9 or 10 hour day on most of my jobs I'd never get anything done! LOL!! I guess there is a big difference though in what most of you guys are talking about and me. Employees.
Parent - - By Lawrence (*****) Date 03-20-2016 21:02
You can't be serious
Parent - - By Cumminsguy71 (*****) Date 03-21-2016 12:09
Seriously. I can guarantee that the last job I was on that I had the "arc on" for a lot more than 4 hours in a 9 hour day. :grin:
Parent - - By jwright650 (*****) Date 03-21-2016 18:53
I "think" Lawrence is speaking of an arc-on time average per 8 hr shift for a year or more of data.....hard to gather materials, prep, and grind, fit, etc. and still average 4 hours per day arc-on average over the course of a year or more.
Parent - By Cumminsguy71 (*****) Date 03-22-2016 10:26
That would be the difference I think. My jobs everything is fit, ground, ready to weld. i fit a pipe job a week or so ago and welded, think I was lucky to get 2-3 hours of arc on in both of those days.
Up Topic Welding Industry / General Welding Discussion / Arcing Time of electrodes

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