This is a series of articles/videos entirely focused on helping a person make good welds with 7018 electrodes.
An Introduction to the Series
How to Read the Puddle
The most important skill to develop is the ability to look at the molten puddle, and interpret what it is doing. This is at the very core of a good weld.
The following videos should give a good clue as to what to look for, and where to look for it.
If you can, I highly recommend watching these videos in Full Screen 1080p Resolution. There’s a lot of fine detail in the puddle, and it requires good video quality to see it.
Don’t believe in editing videos, so it takes a couple of tries to get it right. PITA really 🙂 . Mostly forgetting to say anything while I’m doing the welding 🙂 . Then gotta do it over again to make sure to actually talk about what’s going on.
The Dreaded Uphill Fillet
Everybody seems to think there’s some sort of mystery concerning the uphill process. There is no mystery, really.
Setting your amps
Because you’re working with a close, tight arc…..you should be set high enough to prevent drowning the arc, but low enough to prevent excessive burn-off. Excessive burn-off results in a puddle that’s too heavy, and hard to control (run hot, and you have to run faster to keep from spilling the puddle).
Generally, because most people, including myself, prefer 3/32 for uphill………somewhere in the 85-90amp range is a good starting point. About the same amps as you’d use when doing a flat weld.
1/8 rod should start out somewhere in the 105-115 range. Adjust accordingly. 1/8 rod will be your go-to with thicker plate, or longer welds, where you don’t want to have to continually do starts/stops because you run out of rod before the joint is completed.
These settings will vary with machines, and your ability to control the puddle. Often, starting at a lower amp setting allows you to learn the puddle characteristics. After a break in period, you’re ready to run the rod at what it should actually be run at.
The puddle should be fluid, not ropy. The undercut should be pronounced (penetration). And the arc should be easy to maintain. It all gets better (to a point) at the higher settings.
A quick note about machines. The small transformer welder will do an adequate job, but because the arc on these machines is somewhat rougher, you can expect a rougher appearance in the finished bead. It’s not a bad thing, it’s just technology. Inverters (good ones), and higher end engine drives, will give smoother beads, but then is it worth the money?????? It’s your choice. The main goal is to weld the material, it’s not the Miss America Pageant.
Rod Angle and Head Angle
I like to face the joint, looking at it dead on at a 90 degree angle to the root. Bear in mind THAT THE PUDDLE IS HARD TO SEE AT THIS ANGLE. The rod gets in the way.
If you’re having trouble seeing the puddle around the rod, it’s ok to view the puddle from off to the side. But you have to remember……because you’re offset, it’s possible to have some undercut issues on the toe which faces you. Mainly because you can’t actually see the undercut at this angle. Also…..it’s harder to run a nice uniform, equal width, puddle when looking from the side. It’s an alternative when starting out, and when you’re forced to look from the side due to obstructions.
Stringer vs. Weave
It’s no secret……..I like a nice tight stringer. 2x the rod diameter. It works for me, and I religiously stay away from weaving. More control over overall heat input, better heat at the root (in my opinion), and it’s more pleasing to the eye (in my opinion 😀 )
Others feel the same way I do.
(Update 10/7/15) I was at an equipment auction today, and was admiring this scraper.On closer inspection, I spotted a failed weld. Which happened to be a wide weave (about 1 1/2″). Just a quick example. Whether it was a poor repair weld to begin with, or the design of the joint was improper, it was a failure.
I’m just one person, with one opinion. Don’t take it to heart.
So….Let’s See It
Keep an eye on the tight arc, economy of motion in the side-to-side motion, and the steady progression.
Gotta say, this was a messy deal. I’m trying to film while wearing a camera, with reading glasses perched on top of the POV camera, then the hood (and a limited viewing portal) on top of all that. OOOOOMPH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Had to do a few of these before it all came together in a viewable package. Camera too high, camera too low, hood lens in the way, glasses in the way, etc. OOOOMPH!!!!!!!!!!!!!!!!!!!!!!
And A Myth Trashed
I like the internet, I’m out there on it, so I better like it 🙂 .
But…………I just can’t tolerate some of the stuff I hear. It’s absolutely BOGUS.
So………gonna do a different take, with a different machine. Going to use the Ranger this time. I’m tending to shy away from the Ranger for most of this, because it has a stronger arc that drowns out your view of the puddle. The camera simply can’t compensate for the brighter arc. Doesn’t do either of us any good if you can’t see the puddle. But for this clip I wanted to show a difference between machines….The little transformer welder (AC/DC 225/125), and the more powerful machine (Ranger 250 GXT).
I hope this helps. I hope it helps to dispel the myths. And I hope you’ll be better at it than I am. Some good people helped me along, so it’s up to me to pass it along.
The Horizontal Stringer
This is a confidence builder. I really know of no other reason to practice these types of welds (other than possibly a need to master the 2G horizontal groove joint). BUT YOU WILL LEARN TO KEEP FROM SPILLING A PUDDLE. Handy thing to learn really 🙂 . It’s the foundation for overhead welding.
7018 is a fill-freeze rod. In other words………..it’s sort of runny. It will not fast freeze like 6010/6011. You have to learn how to use surface tension, gravity, and rod manipulation techniques to your advantage.
TRAVEL SPEED: Horizontal stringers will teach you a safe travel speed which prevents you from spilling the puddle down the cuff of your pants. Slow enough to build a bead profile, but fast enough to keep from adding too much filler to the puddle (the spilling thing).
AMPS: It has to be enough to keep the arc from drowning in the puddle (this will become important when welding overhead). Ideally………at the same, or higher, amperage than what you’d use for a flat weld. If you’re running 3/32 at 85-90amps on the flat, it’s a good bet that it will run good in the horizontal position at the same amperage. If you experience arc outages, or sticking, then turn it up a bit. I know it’s counterintuitive, but it is the real deal. It has to do with arc force.
ROD MANIPULATION: You’ve no doubt heard that 7018 is a straight drag rod. Well, it is………..mostly 🙂 . There are times when you have to add a little flair ( 🙂 ) to your motion. You gotta smoogie it a bit. In this case, you will find it a good thing to add a small circular motion to your travel. Why?????????? Gravity, and undercut. (Best explained in the video).
The overhead fillet weld is the first true overhead weld.
Reading the puddle, and the ability to keep the puddle from spilling, were the prerequisites for this stage of the game.
GRAVITY: This weld actually depends on gravity for its success. At this point you’ve learned to defy gravity with the practice on the horizontal stringers, and now it’s time to use gravity now that you’ve mastered it.
ANALYZE YOUR WELD SITUATION: Think, ahead of time, just how gravity will affect the puddle. In this case the tendency for the puddle to droop is a good thing. The lower toe of the weld will be formed by gravity. The upper toe will require a technique to control the natural tendency to droop. The video will explain………
If I get a chance, at later date, I’ll redo the video. I’m sorry about the camera angles. Still getting used to this stinkin’ camera 🙂 .
Three Pass Overhead Fillet
FIRST PASS: The first pass is a fillet, like above.
SECOND PASS: More of a flat overhead stringer, bisecting the first pass on the toe closest to the vertical plate, with the other toe falling on the overhead plate. This pass provides material to stack the 3rd pass on.
THIRD PASS: A fillet spanning the distance between the top of the second pass, and the vertical plate.
It’s better to see it than try to explain it.
Throughout the series, there’s been some attention to rod manipulation. I feel that a certain amount of oscillation, and slight weaving, has its place when running a stringer bead. It helps fill the toes, and distributes heat across the face of the weld.
Is it a departure from a drag technique???? I suppose it is, but then it’s also a real world solution to real world problems. Try making any out of position weld without some motion. You’ll see why some motion is necessary.
Speed when welding overhead is a killer. A straight drag requires a faster speed, and causes underfill. (Smaller beads). The toe on the overhead plate also suffers……it can be too narrow. The filler material has to be massaged in order to make uniform width fillets.
HOWEVER………………… Don’t let your tiny circles, and weave, escalate into whipping. Any time you leave, and return, to the puddle is whipping. Pushing the arc back into the slag zone is also whipping (a technique used to fill wide gaps in a bad situation). You will get slag inclusions in your weld if you go this route.
I don’t have any immediate plans to cover groove joints (flat/overhead/vertical) until I encounter these type of joints in my daily work. I hate to cut up thick plate simply for a demonstration. I’m pretty sure these types of welds will pop up in the future though. And I figure on documenting the process at that time
I Hope It Has Helped
I’m, by no means, the last word on this stuff. It’s just my take on working with this particular welding process. It’s worked well for me in every day applications, and I feel confident enough to pass it on. I hope I’ve done a good job of it, and it benefits at least one person. If it does, I’m a happy camper 🙂 .
(TO BE CONTINUED)