Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic Welding Industry / General Welding Discussion / A general FCAW question to the forum
- - By jwright650 (*****) Date 06-30-2009 17:33
Let's give a little background info:

1" thick plate TC-U4b to a 3"+ thick column flange(nice, tight fit-up with zero to little chance of burning through on root pass)
3/32" FCAW w/ 100%CO2 @ 40cfh

carbon arc back gouge and refill second side

Now on to the question(s):
How many of you welders, here on the forum, would run straight stringers?
How many of you welders, here on the forum, would use a forward/backward motion whip? , if yes, how large of a motion will you apply?
Parent - By TimGary (****) Date 06-30-2009 17:46
Straight stringers only.
I never allow my welders to whip with FCAW, due to the chance of trapping slag.
Whipping is a GMAW sloid wire technique that some FCAW welders try to carry over just because they're used to it.

Just my humble opinion...

Parent - By mountainman (***) Date 06-30-2009 18:27
I would run straight stringers. However my experience is with .045, not 3/32.

Parent - - By pipewelder_1999 (****) Date 06-30-2009 18:43
I have never whipped FCAW and have done it with GMAW to show the scalloped appearance of the penetration on Fillet welds.

I have slightly whipped metal core years ago as thats how I was TOLD to do it filling in 3/4" groove welds in 3 passes (Not layers) . I told them it was wrong to carry that much metal but they were concerned with distortion. I spent a few hours repairing cracks and leaks on the same products welded prior to me getting there and Im sure someone probably had to fix mine later too.

Ripples do not add anything to the quality of a weld however I have seen people do some strange things to make them "look cool"
Parent - - By jwright650 (*****) Date 06-30-2009 18:56
Thanks for the replies thus far...still hoping for a few more before I spill where I'm going with this.

Need for this to be an unbiased question on my part, for this to work as intended on my end. :-)
Parent - - By Bill M (***) Date 06-30-2009 19:07
Is this horiz. welding 3/32" dia.  E71 T-1?
Parent - By Milton Gravitt (***) Date 06-30-2009 19:21
I would run straight stringers I have never had any luck doing the weave.

Parent - By jwright650 (*****) Date 07-01-2009 11:03
E70T-1...yes, flat, horz only
Parent - - By Lawrence (*****) Date 06-30-2009 19:32

We have several local players who use large diameter FCAW for draglines etc. and none of them would train their personell to whip with gas shielded FCAW.  3/32 lays a pretty wide bead without any tricks.

With 1/16 E71T-1 you can "weave" some vertical welds and not run into big slag problems but I've never even considered whipping.

What is the supposed benefit to a whipping technique with large dia. gas shielded FCAW ??????
Parent - - By jwright650 (*****) Date 06-30-2009 19:47
OK, I'll spill the beans. I had a couple UT'd welds where I found all sorts of entrapped trash in. The joints were right at 12" wide and I decided after trying to evaluate and mark up the first few inches of weld that it was easier for me and the welder if he just cut it all back out to half depth or so and start over because this same pattern continued across the entire length.

One of the top passes still had a fair amount of slag still covering so I chipped ever so gently at it to see just what was underneath and found that in every little whip there was slag rolled up under where it was impossible to get it all chipped without removing some weld material. I have two welders here who continue with this practice and I think it makes the weld cap look like crap.

All of my other guys all run straight stringers and have very little trouble passing my UT scans, unless they just plain missed a portion of the root while back gouging.

I was going to ask this question on here and then print out the replies to show them that nobody ever whips FCAW. I was hoping not to lead the question in any way so they could see that I'm not just blowing smoke or giving them a hard time over nothing. I've seen a minor forward/rearward occillation if the material is really thin(3/16 or 1/4"), but that is not the case with these joints at all.
Parent - - By reddoggoose (**) Date 06-30-2009 20:54
Back when I was a welder I had seen guys whip flux core. I was always told this was not correct as you can trap slag ahead and behind the weld.
Parent - By mightymoe (**) Date 06-30-2009 22:44
I'll don't whip FCAW but I'll weave it all day long.
Parent - By welderbrent (*****) Date 07-01-2009 01:17 Edited 07-19-2009 19:00

I do not care for 'whipping' FCAW in any wire size, especially larger diameters.  Working on heavy equipment or structural I find the welds consistently cleaner, on top, underneath and I also have found the root to be dependably burnt in better with smooth stringers as opposed to a wider weaving or whipping motions. 

In my shop, stringers only. Some light weave on cover passes.  No whipping.

Have a Great Day,  Brent
Parent - By raftergwelding (*****) Date 07-25-2009 02:50
i dont care how cool it looks as long as it holds. i'm not an inspector im just a welder i tyr my best to make them look slick and clean and thats all that matters but most of all it cannot leak or break and well not to brag mine dont. oops sorry jonh thats with stick i aint pulled many triggers please forgive me for intruding or not reading correctly
Parent - - By jrw159 (*****) Date 07-01-2009 12:09
straight stringers. :-)

Parent - - By 803056 (*****) Date 07-01-2009 13:15
I've done a considerable amount of FCAW, both gas shielded and self shielded varieties. Whipping out of the molten puddle (as is popular with E6010 or E6011 covered electrodes) is not a good idea, but some limited side to side weave produces acceptable results.

I use a tight triangular weave for the root pass of fillets to ensure fusion to the root and a sight backward motion then up to the upper toe (horizontal fillets) to obtain the proper leg size and then forward and down into the root again. The technique is very tight and within the molten puddle. It works well as evidenced by numerous fillet break tests that show good fusion to the root and no inclusions or porosity. Problems will crop up if the triangular weave becomes too pronounced, i.e., too large a fillet is attempted in a single pass.

I do encounter a number of problems when welders attempt to make large single pass fillets in the horizontal position with small diameter wire. The two most frequent problems are undercut along the upper toe and overlap along the lower toe. Welders that use a circular motion to produce large fillets typical have slag inclusions along the toe and incomplete fusion in the root of the joint.

I would recommend having the problem welders weld a fillet break test and let the test results speak for themselves. I love the fillet break test and I have it written into every project specification I am involved with. I don't care whether the welder passed a grooved plate test or a open root pipe test the day before they get on site, they are required to pass the fillet break test on the job-site. The failure rate for the fillet break test is unbelievably high until the welder is shown how to make the weld properly. Many welders have never taken the fillet break test, only the groove plate test and that leaves much to be desired. It's times like these that the ability to weld is a valuable tool for the inspector. My favorite comment is, "I'm only an inspector, if I can pass this test, then a welder that welds everyday for his living better damn well make a weld at least as good as mine."  That and my welded sample usually ends the snide comments such as "This is a waste of time, I've been welding for XX years and I've never failed a test yet!", "Dumb inspectors!", "Those that can weld and those that can't inspect!".

John, do any of the welds look like this?

Best regards -Al
Attachment: FilletwSlagandIF30Jun09.jpg (203k)
Parent - By jwright650 (*****) Date 07-01-2009 13:41
not exactly like that one....the forward/backward whip is more pronounced on the welds that I'm speaking of, that weld in your pic has a couple of issues going on. I'll try to snap a pic if I see one similar to the ones I had problems with yesterday.
Parent - By Fredspoppy (**) Date 07-01-2009 19:08
Sorry, but I can help making a comment.  The weld in this picture could not have been made by a qualified welding professional, could it?  If we could only get welders (and others influencing the work of welders) to understand that travel speed, "whipping", monsterous weaving, etc., have absolutely no impact on the production rates.  With a given requirement for a volume of weld, the only thing that makes a difference is the amperage (wire feed speed for wire processes).  With a given electrode diameter and amperage, there is little difference in time required to weld a given joint (or a given fillet weld size) if you use 3 smaller stringer beads or 1 larger weave bead.  Maybe a little bit of extra time for interpass cleaning is required, but potentially you come out ahead when you don't have to grind out 1/2 of the weld, due to slag entrapment.
Parent - - By PlasmaHead2 (***) Date 07-18-2009 16:54 Edited 07-19-2009 15:17
*Edit Again*
Well I kind of got the resizing figured out... if anyone wants a better picture, let me know and ill email you the full sized ones.
I rushed the weave a little bit and it came out smaller than I wanted, but I was doing this on lunch with a spool that was threatening to run out on me in the middle of a pass.
Next time I have to flux core something at work ill weld up another one without rushing it.
Also, I know I’m not even an amateur photographer so if anyone can offer any advice as to how to get a better picture of the welds, I’m all ears.
Parent - - By 803056 (*****) Date 07-18-2009 17:22
I'd like to see the photos you do have.

Regarding the triangular weave, this subject has been discussed before. I've attached a copy of the same sketch once again. The movement is essentially defined by the size of the molten puddle one can carry. In other words, the size of the fillet weld is not unlimited. The weld size is about 2 to 2 1/2 times that of a stringer for a given electrode diameter. If the size of the weave is made too large, that is if the movements are exaggerated, you can expect problems along the toes of the weld. Position plays a part in this. Welds in the vertical position using uphill progression can be deposited that are quite large compared to those deposited in the horizontal position.

Best regards - Al
Parent - - By 803056 (*****) Date 07-19-2009 18:23
From what I can see both the weave and multiple pass looks fine. I would recommend cutting the sample to verify both techniques are fusing to the root. That is a problem that comes up when qualifying the welders.

Best regards - Al
Parent - By PlasmaHead2 (***) Date 07-24-2009 22:51
I brought it back into work and cut it with a band saw and polished it as best I could with the 1" sanding disks I had which were the olny disks that went to 320 grit in the shop.
I can take some pics as is and post it, but I wanted to try and etch it.
The olny acid I have immediate access to is muratic, will that do the trick or will that be too much? And would you guys rather see it just cut or etched?
Parent - By PlasmaHead2 (***) Date 07-19-2009 15:18
*BUMP* Pictures are up
Parent - - By motgar (**) Date 07-01-2009 13:42

Are these particular welders using a forehand or backhand technique, with this whipping action?
Parent - - By jwright650 (*****) Date 07-01-2009 16:05
I think they are pushing it as they whip. I'll have to put my shield on and watch to be sure.
Parent - - By 803056 (*****) Date 07-01-2009 21:14 Edited 07-01-2009 21:23
I can not disagree with the statement that the deposition rate is dependent on the wire feed speed (amperage) and to a lesser extent voltage. However, given that a certain electrode diameter is available, there are circumstances where it is beneficial to use a slight weave, i.e., more heat input per linear inch, to obtain a certain microstructure if this conversation is limited to carbon and low alloy steels.

Most FCAW and GMAW electrodes should employ the backhand technique, i.e., pull rather than push, when welding in flat, horizontal, and overhead positions on all but the thinner base metals. For the most part, I have not seen acceptable results using the forehand (push) technique on most thicknesses.

Sorry Fred, I almost missed responding to your comment regarding "professional welder". These two welders had documentation signed by a CWI indicating both welders passed the flat position for groove welds using FCAW. Both welders were in their late thirties or early forties and indicated they had been welding "for years". The fly in the ointment was the owner didn't require third party inspection, so the apparent philosophy was "anything goes". "Professional welders" is a term I would contest. Had they been earning a paycheck and masquerading as welders? The short answer is "Yes". 

Best regards - Al
Parent - - By ZCat (***) Date 07-25-2009 01:58
3/32 wire at 29.5 volts? No wonder you got slag.

I used to weld pipe with .045 wire at 32 volts in 1G rolled.
Parent - - By 803056 (*****) Date 07-25-2009 03:14 Edited 07-25-2009 03:19
It's been my experience that staying within the manufacturer's recommended parameters produce the most reliable results with the widest array of welders.

There is a small percentage of welders that have developed techniques that produce good results using parameters that are higher or lower than those recommended, but the majority of the welders are going to have unacceptable results.

The bottom line is that WPSs are developed to produce consistent results, i.e., acceptable mechanical properties and acceptable workmanship to the applicable code. The WPS is of little value if only 2% (an arbitrary number pulled from my posterior) of the welders in the workforce achieve the desired results.

I don't know what electrode is being used at 32 volts, but it sounds quite high for 0.045 diameter E70T-1. Now if you tell me you are running 3/32 diameter E70T-1 electrode, 32 volts isn't unreasonable.

Best regards - Al
Parent - - By ZCat (***) Date 07-25-2009 05:47
We were using 80 series wire, this was in Alaska, they like the 80 wire. I don't know why, maybe the cold weather properties.

The QC crunched the numbers, the voltage was high, but the travel speed was much higher, too. He said the kilojoules were similar to what was in the WPS, so he let it slide.

The welds were smooth as glass, and the x rays were water clear.
Parent - - By 803056 (*****) Date 07-25-2009 16:18 Edited 07-26-2009 16:51
There are issues to consider other than heat input alone.

The transfer of various elements across the arc can be affected by the arc length and the time those elements have to interact with the gaseous shielding mechanism. The carbon dioxide decomposes in the arc and makes both atomic oxygen and atomic carbon available to react with various constituents of the filler metal. Some of the constituents, such as chromium, are easily oxidized as they transfers across the arc. The bottom line is that the chemistry of the weld deposit is affected by the type of shielding gas, arc length, presence of oxides (and other contaminates), and chemistry of the filler metal. There is also a relationship between the amount of diffusible hydrogen introduced into the weld and the arc length.

The chemistry and mechanical properties listed by the manufacturer in their product catalog or by the applicable AWS A5.XX filler metal specification are based on the results obtained when the filler metal is tested under the conditions described. All bets are off the table when the welder strays from the manufacturer's recommendations.

The WPS is no longer prequalified if the welder (or the WPS) disregards the recommendations of the manufacturer. Any weld made that is not within the established ranges of the approved WPS should be rejected if there is any danger to property or the well being of the user. I have fired welders that ignored my warning about working within the parameters of the WPS I develop. As a matter of fact, when I agree to manage the repairs on a major piece of equipment, one stipulation I insist on is that I have the authority to run off any welder that disregards my instruction. I typically sit down with the welders before the job starts and lay out the ground rules and review the requirements of my WPS. If I observe the welder not maintaining preheat, ignoring interpass temperature, disregarding the welding parameters I've established; it's "good bye Buckaroo", it was nice to meet you. I lay a blank check on the table and ask who's name is going to be printed on this "Good Bye" check? It gets their attention. I had one welder challenge me by saying, "I don't work for you, you're not my boss!" I paid him off on the spot. I set the welding machines in the morning and check them again after lunch. If the settings have changed the welder is gone.

If the employer qualifies the welding procedure using the parameters the welder has elected to use and it meets all the requirements of the applicable welding standard, God bless the employer and the welder. Until that time, the welder is gambling with the customer's well being and possibly their very lives.

So far, I'm not impressed, but rather dismayed when individuals, be they welders or staff, have a total disregard for the well being of others in their attempt to ingratiate themselves with their employers by only considering "speed" and disregard other factors. There is much more to welding than simply making a pretty weld bead as quickly as humanly possible.

In my early years as a welder, I never claimed to be the fastest welder around, but my welds passed UT and RT and I always stayed to repair the welds screwed up by the fastest welder in the crew. When all was said and done, at the end of the day, I welded as many or more accepted welds as anyone in the crew. I always asked the boss man why didn't he have "the man that screwed it up, fix it up?"

The response was always the same, "Just make it right!"

As for NDT; NDT does not provide direct information about the mechanical properties of the completed weld. A weld free of porosity, cracks, incomplete fusion can be as brittle as glass if due consideration is not given to other aspects of the welding process.

Best regards - Al 
Parent - - By 803056 (*****) Date 07-26-2009 18:52
Call it a power trip if you want, but when you take on the responsibility for the integrity of the welding performed, your reputation and business is on the line. A cowboy welder, disregarding the work instructions, can jeopardize the entire project. I'm not willing to allow one individual, i.e., the welder that thinks he knows more than me, to put everyone involved at risk including my business and my client's well being.

When the welder is an owner/operator and I'm not involved, he can do as he pleases. I just hope no one's life, well being, or livelihood is at stake.

I can, as can many other inspectors, write several pages of cases where contractors have ignored the drawing, the WPS, work instructions, and code requirements that have lead to disastrous results. Even when lives are not at stake, the economic cost of the consequences, lost time because the equipment was damaged or destroyed, the cost of repairs or replacement, lost wages to the workers that would have been operating the equipment, lost income to the owner, etc. far outweigh the "profits" the contractor made by ignoring the requirements, cutting corners, etc. 

As a matter of fact, much of my livelihood is dependent on contractors that don't know what they are doing. I've always said, "the less the contractor knows, the more profitable the job is for me". It's a cynic's position, but experience has shown that all too many contractors don't understand what they are dealing with, have little understanding of the codes they're working with, and are all too willing to place other people at risk for the sake of maximizing their profits. Were that not the case, the job opportunities for CWIs and lawyers would not be as plentiful as they are.

Don't misunderstand my position, there are contractors (including many fine welders) that have the knowledge and the experience to do the work correctly, but those aren't the contractors I deal with. My services are not required when the contractor does the work properly. My bread and butter are the less than qualified contractors that leave disgruntled owners in their wake. The less training the welders have, the less experience the welders have, the better it is for my business and my bank account. Unfortunately, owners are like everyone else, they pinch pennies forgetting that there are reasons the better qualified contractors charge more for their services. Like many of us, the owners pay in the long run by saving a few dollars and electing to accept the lowest initial cost.

I find myself preaching to the choir. Many individuals that participate in the Forum have experienced many of the things I've spoken of. My experiences are not unique. That's one reason many of us frequent the Forum. We answer questions to the best of our ability in hopes many of the mistakes we've seen in the past can be avoided in the future.

Did I stand a little too high on the soap box? Maybe, but if I did it was out of frustration and the desire to cause people to look at a situation from a different prospective and to consider all the factors that determine if a weld will perform as expected. Did I step on a couple of toes in doing so? Sorry if I did.

Best regards - Al
Parent - - By darren (***) Date 07-27-2009 08:42 Edited 07-27-2009 19:40
with regard to the first part of your first post, the guru i was taught by called it "boiling" the wire when you run too hot, the puddle gets to too high a temp and stays liquid too long and the properties change into who knows what because the elements get to mingle longer and find new dance partners rather than the ones the design engineer had intended them to pair up with.
stephan gave some awesome info on the co2 thing at higher temps and voltages.
with regard to the last part of your posts, bosses always "want" you to weld to the wps and then give you hell for welding too slow.
ive heard of understanding and reasonable bosses but i've also heard of the easter bunny, bigfoot, and a guy named santa; all of which i have more evidence of than the reasonable boss.
thanks for the awesome post and next time don't hold back...tell us what you really think ;)
*alright who gave me a one star rating for that fess up and give a reason ...yeesh*
Parent - - By 803056 (*****) Date 07-27-2009 14:45 Edited 07-27-2009 14:51
It is a common feature on many jobs that go bad that there is a direct supervisor involved that knows little about welding. He may have been a "rod burner" at some point in his life, but a "welder" he wasn't, isn't, and never will be. He's all about speed and little else weighs on his mind.

I've always told my apprentices and welding students that the boss isn't going to get fired when your welds don't meet the job requirements. When the poop hits the fan, regardless of the direction you were given by the foreman, you are the one that will get the bad reputation and you will be the one that is fired. Every weld you make is the same as your signature on a piece of paper. The completed weld will speak louder than you or your boss at the time of inspection. Whether it is accepted or rejected is dependent on the welder's knowledge and skills as a welder.

I've said it before and I'll say I again, never tell the boss man he's an idiot. That's job suicide. Do your job as you know it is suppose to be done. Where there is a WPS, follow it, where there isn't a WPS, do what you know to be right. If the boss man tells you to skip the preheat, if the boss man tells you you don't need a hot box for low hydrogen electrodes, etc. do what you know to be right without being in conflict with the orders given to you by your supervisor. There is more to welding than simply being able to burn rod. You have to understand the base metals your welding and how they respond to different thermal cycles, what filler metals are required, etc. Anyone can burn rod, but it takes a welder to know how to do it properly.

I was on a job once where the superintendent told me I was wasting time by preheating the connection. I didn't argue the point, I simply asked him to watch me to ensure I was doing it properly. On the next point I struck the arc and ran several inches of weld that looked liked sponge rubber. He looked at the weld, shook his head, pointed to the grinder and never told me how to make another weld. I didn't have to say a word. I worked with him on several jobs over the following years. When he needed a welder, I would get the call.

What was the cause of the porosity? The connections were assembled a day or two before they were welded. The evening dew wicked up under the plates overnight. The heat of the arc flashed the moisture off as steam, right into the molten weld. So, the preheat wasn't based on the base metal thickness, no, it was to ensure the moisture between the plates was evaporated before welding.

By the way Clif, you never told us how the weld roots looked. Did they have fusion to the root or was there a bit of incomplete fusion in the root of the fillets in the photographs?

Best regards - Al
Parent - - By PlasmaHead2 (***) Date 07-27-2009 22:11
I didn’t get a chance to take pics of them until I got home today. The 3 pass looks perfect, but I can see a tiny gap on the weave side.  I’ll leave it up to you guys to decide if its incomplete fusion, because it kind of looks like it could have been the gap between the 2 plates from the way I welded it. I ran the 3 pass first and that pulled the vertical plate to that side before I put the weave in. If muriatic acid will work to etch it then I’ll give it an etch and post those results up. 
Parent - - By Lawrence (*****) Date 07-27-2009 22:40
I'll leave the fusion at the root judgement to some more senior inspectors..

What I noted was a little imbalence of deposit, with one leg having significantly longer length than the other on both the single and the multi pass weld.

Horizontal fillets usually are the worst for this.. Verts are a bit easier to keep balenced.

Good work!

Keep em comming
Parent - By PlasmaHead2 (***) Date 07-29-2009 21:25
I noticed they were a little imbalanced, I was rushing.  Thank you though, and we are setting up for some more flux core work so I should get a chance to run another one soon.

I’ll try etching them, I have muriatic acid on hand and ill try and get to it tomorrow.
Parent - By DaveBoyer (*****) Date 07-28-2009 07:38
Try any acid You can get Your hands on, muriatic, car battery acid, vinigar, etc.. If none of those work get some ferric chloride from Radio Shack, if they stil carry it, or fom a "real" electronics supply .
Parent - - By CHGuilford (****) Date 07-28-2009 13:18
The fusion of the welds in the photos may or may not be adequate.  It looks close but OK in the photos, but the actual piece should be viewed before making a decision.  As you know, the fusion must make it to the intersection of the 2 legs of the joint but not necessarily beyond that.

As far as stringers or weaves - I just recently (yesterday) conducted testing in our shop.  In practice passes, I let the welders run the way they want to (mostly to avoisd later argument).  I can say that weave passes just did not work for a fillet test.  Slag inclusions/lack of fusion was scattered all along  the roots and edges of those fillet welds.  Neither did pushing the bead instead of dragging. 
I know there are many opinions on that but to those I say - run the tests and cut them to see.  In most cases macroetching is not evern needed to see unacceptable results.
Parent - By 803056 (*****) Date 07-29-2009 21:31
Nothing speaks louder or more clearly than physical results.

Best regards - Al
Up Topic Welding Industry / General Welding Discussion / A general FCAW question to the forum

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill