When welding verticle, why go up?

[bluesman2a]

When welding verticle passes, I haven't gotten the trick to vert-up yet. I understand the concept, but not able to do it satisfactorily. If I weld pushing DOWN the verticle fillet with a slight weave it LOOKs good, but we all know LOOKS can be decieving. (BTW, these are NOT structural welds, I've been doing).

So my question: why weld up verticle? I understand this may be a stupid question, but I'm trying to understand the reasoning behind it.

Thanks in advance... for your patience with a noob.

[morpheus]

how are you "pushing" down ?? you sure you're not pulling down ?

lots of good info from Dan in this thread, it greatly influenced my decision to put the effort needed into learning how to do it.
http://www.hobartwelders.com/mboard/...=&threadid=381

and just because I'm proud of myself a pic of my recent vert up efforts




using rocky's method:


- jack

[Roger]

Even if you have some welding manuals download a copy of Steelworker Volume 1 at the link below. Volume 2 might be more than what you need now but download it too. Great free manual. Vol 1, Chapter 7, page 18 covers vertical welding with illustrations of weave patterns.

http://www.tpub.com/steelworker1/

The reason to weld vertical up is more penitration over vertical down. Welding vertical down you are racing the puddle down as gravity tries to pull molten metal out of control with only arc force holding puddle in place. Welding vertical up the puddle sets on shelf formed by weld bead just layed, so torch can point 90 degree into joint and travel can be slower & with higher amps than vertical down. When you turn up the amps on vertical down, you must also increase travel speed so penitration doesn't increase.

The pictured weave patterns are simplistic as they don't illustrate the speed changes & slight pause at different points of the weave. You learn the speed changes by looking at side and back of puddle. They become part of your weave's rhythm.

[Seldom]

Hi Roger,
That Steelworker site is a dandy!
I don’t necessarily agree with every thing they say about mig (only thing I looked at) but it’s a very informative site nevertheless.

The “triangle weave” is also known as the “double-pass weave” and I’ve used it for many years. It makes a nice looking weld as seen in Jack’s photo above. There is one chronic problem with using that particular weave with mig-SC though. If the operator isn’t right on his toes with this weave, he’ll have cold-lap right where the edges of his puddle (lower two triangle corners) overlap. Especially if the welder skips the root bead! Adding a root bead to any joint when using this weave will help minimize but not alleviate the chance of getting cold-lap.

I’ve witnessed far more welder qualification coupons fail the face bends with this weave then the historically accepted mig weave. The failure will usually occur on the side of the weld in direct correlation to which hand he/she is holding the gun. Using the above photo as an example, the cold-lap would normally be on the right side of the weld as we see it if Jack is right-handed. The same welders switching back to the basic, inverted “U” weave will usually pass on retest.

In my opinion this weave is far better option for most folks when used with either stick or especially with flux core it’s great. I know of no training center or institution personally that teaches or recommends this weave with mig-SC.

[dseman]

Seldom,
Thanks for making that point. When I reviewed my material from Miller and Lincoln I noted that you were right on the money---only use a slight U or for cover/fill passes, a side-to-side weave when V-up mig welding.
Thanks,
-dseman

[Seldom]

Your welcome dseman!
I admit (because Iit was my favorite) the "double-pass" weave makes for a pretty cap with mig-SC. It sort of "combs" the base of the triangle and smooths the puddle out. Swweeettt!

In my opinion, if folks wouldn't try and carry so much metal and instead, put in one or two additional passes using the inverted "U" weave, those caps would look very nice as well. When using just about any process, thinner passes allows for more operator control so they usually will show nice looking caps along with a quality weld.

[JTMcCracken]

Hi Seldom,
When using the FEMA 353 approved flux-core wires, 203-N and 232, the wide triangle type weave is no longer acceptable in critical siesmic applications. In the early 90's this was the method taught, now passes over 3/4" wide are verbotten, the reason given is the reduction in Charpies. They won't even let you cap a AWS test coupon with a wide cover pass, the minimum is three and they really want four.
regards,
JTMcC.

[Sberry]

We used 203 on a space frame in Miami,,, its that thing with the glass prisims on it between buildings downtown. Some engineers tried to get us to use that triangle on some of the stiffners,, I didnt like it. They were not critical though. I welded some of the bearings on though and I did try to keep the beads fairly small,, about that,, 3/4 or so in some really big grooves on it. It was a real deal,,, some genius designed about 2000 joints with the bevel the wrong way.

[Roger]

Navy training manuals have always been slow to update. To help solve that problem they changed to more volumes or moduals to cover what was one book. Still big problem.

SW manuals are best free welding manuals I have found on the web. Army welding manual is 2nd best and covers underwater welding a little.
http://www.adtdl.army.mil/cgi-bin/at.../9-237/toc.htm
USN Steelworker rating is a Seabee. The ship board welders called Hull Tech (HT) gets great welding training but their manuals have much not related to welding and metalworking.

[morpheus]

Originally posted by Seldom
In my opinion, if folks wouldn't try and carry so much metal and instead, put in one or two additional passes using the inverted "U" weave, those caps would look very nice as well. When using just about any process, thinner passes allows for more operator control so they usually will show nice looking caps along with a quality weld.

Mike, thanks for your input on this topic. I must say I've learned quite a bit.

Is this the inverted "U" weave that you're refering to:

Especially if the welder skips the root bead! Adding a root bead to any joint when using this weave will help minimize but not alleviate the chance of getting cold-lap.

also, you say that adding a root bead will help minimize problems with the triangle weave. what do you mean by this statement ?
do you mean this in the context of making multiple passes with
the same technique or a simple "stringer" pass up the root of the weld ... please keep in mind that I'm just a hobbiest weldor so this might be a dumb question

- jack

[Seldom]

Hey, that’s a dandy sketch Jack! That’s it but with shorter legs of the “U” sort of like a crescent/U shape.

By adding a root bead lessens the 3-D of the puddle. Let see maybe this is a little better of an explanation- You’re not working your wire into the “depth” of the joint and back out. When using a root bead or extra passes you’re keeping the puddle more 2-D (less depth into the joint).

Let use a fillet weld for an example. You see when you don’t add a root pass foundation it allows some things to happen that most welders aren’t aware of and can cause either a poor appearance or poor quality. First the amps change because usually the welder allows his stickout to change as he runs his wire along the edge of the joint down to the bottom and out onto the other leg without him maintaining the proper stickout that he set his machine to.

Secondly, and definitely the most missed by many folks is that the deeper you go into a joint while making a pass (still with the fillet) most welders fail to recognize and alter the angle of their wire/gun in relation to the joint. As an example, a right-handed welder will always have his gun or electrode angled toward him, meaning he’ll usually get his intended fusion on the left side of the joint. The right side often gets missed and the deeper the welder has to go into a joint, the more chance he has of getting cold-lap as he comes back out with his gun angled away from the leg. Think about it, how many of you reading this are aware of this and twist your wrist to compensate as you weld vertical fillets or even grooves? It’s tough to do because it requires forethought and twisting your wrist outward isn’t easy to begin with especially if the deeper you have to come out onto the leg.

With the low arc heat of mig-SC is far less tolerable then stick or flux-core that inherently have a more penetrating arc. Though it’s been my experience that even with these two processes, most defects or discontinuities (slag entrapment as an example) will be found opposite the welder’s body because the angle of the arc is not perpendicular to the base metal so it’s more of a “washing” arc instead digging one. If when bend testing a mig-SC fillet weld and it fails, 9 out of 10 times, it’ll fail on the side opposite the welder.

Oh, I never was a “stringer” man except on horizontal caps, even on 6G’s (pipe on 45 degree angle) I wove everything except the root bead.

I hope folks find this explanation clearer then mud to understand because it was tough to put in words rather then physically show.

[morpheus]

you are a wealth of knowledge Mike, perhaps I've missed it but what do you or did you do since you mentioned all your stuff is in boxes ...

I can't take credit for the drawing someone else posted it and I just reused it here.

on the U/crescent technique maybe that's why my attempts at that technique didn't come out so well. I was just trying to duplicate that image ... I'll try it some more.

I understand what you're saying now. Especially the part about the electrode stickout. I had never given it much thought until a few weeks ago when practicing vert up I got to noticing that with the kinda large nozzle on the gun I was using that I had to keep it shoved into the joint almost hitting both sides to keep even a decent stickout distance at the root of the weld. Which made it easy to "skip" the root of the weld.

that's really interesting about the need to rotate your wrist to keep the angle of the gun the same throughout the weld. never heard or read that before. I can definitely see where it would cause problems though.

- jack

[Seldom]

Hi Jack,
Well I’m a twice-retired Senior Welded Construction/QA Specialist. After I retired from my career company, I had a consulting/trouble shooting business for several years that took me around the country representing different clients with welding or fabrication related problems and were in conflict with a fabricator. Last year I retired for good and boxed all my files, which I keep down in the basement. I enjoy trapping, hunting, and fishing so much that here I was retired and too busy to do what retired folks do! LOL
In addition, if a person isn’t keeping up with technology, he needs to step aside but if I know I’ve got an answer in the files or my head, I’ll dig them out for somebody.

I just stumbled on this site last week and find it very interesting and apparently I like to help folks but I never attest to anything unless I’ve actually done it myself or have the technical data to support it. I welded for over 20 years previously and was ASME certified in all processes and most all metals used in my old chemical plant. Mig-SC is/was my favorite process and I had the best mentor (he’s passed on now) I’ve ever come across in 40 years of being the welding field. I’m kind of passing some things on to others as a payback to him.

If and when you go back and try that crescent weave, I’d suggest only making a crescent shaped puddle about 1/3 of what is drawn and see how you like it. The twisting motion is slight but you’d be surprised to watch the amp meter while somebody is welding, you’ll see it! If you are just sitting or standing with your hood up and go through the motions you’ll think it isn’t possible but it’s what happens when the hood drops and you are focused on the arc.

[Sberry]

Despite not really knowing much about it I am a pretty slick SC weldor myself and mostly all I know is when its running right. Most of my stuff is light fab in the nature of repairs and I was welding a couple trailer house beams together a while back and the gaps in some of these joints were upwards of 1/4th of an inch on a web of about 10 guage or so. It was interesting that when I actually take the time to dial it in how much I could fill in a single pass, it was downhand but I was getting a kick out of seeing how much puddle surface tension I could keep there and doing 8 or 10 inches, the whole thing in one pass. It make a big difference to dial the machine right in, which most of the time I am too hurried to do and find it easier and faster to keep hot and let off the trigger for a second or so once in a while. Just some babbling during a coffee break here is all.

[HOT ROD LINCOLN]

WELDING VERTICALY CAN PROVIDE BETTER PENETRATION TYPICALLY 1/4 IN. OR MORE. THE TRAVEL ANGLE OF THE GUN IS A 5 TO 15 DRGREE DROP FROM THE POSITION. A SLIGHT WEAVING MOTION CAN HELP CONTROL THE SIZE, SHAPE, AND COOLING EFFECTS OF THE WELD PUDDLE.