Yard Welding Fundamentals
Introduction: Form Whom this Book is Written and Why:Edit
This book is written for the guy who wants to learn to weld but can't do it in a formal setting. It is for the guy who just bought a welder and now wants to make good use of it. Because I am that guy.
I write this to pay down a debt. The debt I owe is to a machine shop in the Arcata Bottoms. They know who they are. In exchange for my doing a little yard work around the shop, these otherwise shrewd businessmen let me run a welder just outside one of their shop doors. For them, it must have been like having a half-witted step-brother living under the porch steps.
In my defense, I did my best to keep out of the way. It was a busy shop. But every once in a while, one of the crew would stray too close or linger a little too long in conversation, and an invaluable lesson thereby would be extracted. After this happened a couple times, I asked one of the partners about leveling the balance sheet, because quid-pro-quo is a lot better than charity. The deal we hit on was a good one: Whatever I learn from them, I pass it on. Hence, this book.
What is a Yard Welder:Edit
I say "yard" welder because to distinguish myself from tradesmen. This is out of respect for the trades. Picture an old asphalt lot bounded by brambles and weeds. There, tucked in a corner behind a rusted-out concrete mixing truck is the Yard. It is about as sophisticated as a bulldog's behind.
Tips for Getting Started:Edit
1) Get a fan.Edit
Smoke in your helmet is annoying and distracting. You don’t need that when you are trying to lay in a weld. And you can’t just count on whatever the breeze is, either. All that heat and gas coming off your work can swirl around you, even when you are lined-up with the breeze. So get a fan. A big, nasty-powerful fan, and practice working with it in different settings.
2) Take positioning seriously.Edit
Sometimes you have to be your own jig. So get in the habit of making dry runs before lighting the arc. You will be focused on other things when welding, so take a moment to settle yourself with the position and motion that you will be using as you weld. Do not just fold yourself into the first way you think the position should be. Give yourself a minute to experiment. Hold yourself in different ways and place the electrode along different angles in the holder to find what works best.
3) Experiment Freely, Continuously Challenge YourselfEdit
Always be varying your distance, position and weld direction when practicing. Run left to right then right to left. Run at a distance and up close. Run from up high and down low. Run horizontal, vertical, flat, overhead beads. Always use the hole electrode so you are forced to stop and start again on the same weld. Use both pushing and pulling techniques. In short: do not just run the same weld in the same direction from the same position over and over, unless you are just getting started. Try butt, fillet, lap, and other joints. Get in the habit of experimenting without boundaries. Keep yourself out of repetitious patterns. Boldly go...
To weld, you have to know your machine. How well? A machinist I know calibrates his welder by ear. He knows so well the engine driving the welder's generator it speaks to him like a radio playing music. He just sets the tune.
That kind of perception comes by applying attention over time, and that is why care and maintenance of the machine also are the welder's solemn work. Every day, before you even hook onto the machine, give it the same kind of go-over you would if you were riding for the pony express and the machine was the horse. Lavish it with attention, even if only briefly. Let your eyes and hands travel all over it--taking note of even the faintest signs of wear or excessive play. Check your fasteners, wipe any smudges, and fret over every blemish. Always check the oil before starting. Then start it up and listen to it run while it comes up to temperature--all the time taking note of what you hear.
You don't have to name your machine, but you should know its personality.
First pick the material you want to work with. I started with 3/16” mild steel. Then pick your electrode type. The crew at the machine shop said 7018 was what they mostly worked with. Once you have picked out an electrode, go to its manufacturer specs and learn everything you can about how the rod was designed to be used. Also determine what diameter you need for the amps/material that you will be welding on.
I chose 1/8” for the rod diameter. That rod was advertised as effective from 90 to around 160 amps. The next step was to fire up the welder and start experimenting. Here is what I learned.
1) 7018 is not “fast freeze” flux. Therefore, a finished bead tends to have more elongated ripples in it. So if you read somewhere that a bead should looked like a series of “stacked dimes,” the writer probably was using some other rod or process. My 7018 stringer beads were never “dimey,” even though I spent a lot of time trying to make them so.
2) 7018 is made to run low and straight. Once you get your machine dialed in, the rod will do most of the work. Most all you need to do is to gently hold it against the leading edge of the puddle and just let it lay itself into the weld.
3) The natural width of a puddle, once you have one going, largely has to do with the voltage at which the rod is running, and that is not something you control. You can dial up the amps you are using, but that just increases the penetration. So unless you just camp out over a spot and let the rod pool, the width of a stringer bead is just whatever the rod was designed to produce at whatever voltage the welder sets to maintain the amperage at which the machine is set.
4) To find a baseline, I adopted the adage: Set amps so you can run a tight arc (just enough), then run a tight arc. Another adage that helped was to add 1 amp for every .001” of electrode diameter. With 1/8 (.125) diameter rod, 120 amps of current worked allright for starters.
5) The hotter the metal gets, the more it resists the flow of current. At some point, if the piece you are working on gets too hot, the machine will have to raise the voltage in order to maintain the target amperage. That means more watts on the work. More wattage is more heat. So unless you pause to cool the piece off, from time to time, be prepared to lower the amperage setting to keep the electrode and the work from melting too fast.
6) You will find yourself experimenting with different machine settings as well as different travel speeds, electrode angles and heights, etc. It is mostly learning by trial and error. At some point, it is of tremendous benefit if you can get a professional welder to look at what you are doing. You don’t want to be practicing bad technique and sometimes there is no knowing for sure if you got it right. Get a pro to give your practice welds a glance. That can save you weeks of guesswork.
Reading about welding can help you understand how to be a better welder, but only to the extent you are able to put what you read into practice. This is because the act of welding largely is kinesthetic. If you have every played a sport, then you know what it is like to teach yourself to move in certain ways. You start by thinking your way through the move to get an idea of how your muscles will need to work together. Then you practice until it all starts to feel natural. When are you done practicing? Never. You are always seeking to improve your technique. Even your breathing can matter.
To teach myself a move I take three steps. First, with the welder offline and my helmet off, I’ll size up the path I need to follow. I first try to determine how best to place my lower torso. Then I grab a loaded stinger, take a position, and experiment working the electrode along where I will draw the puddle. I want to get an idea of how I am going to have to move as I draw the weld. That gives me a place to start. I make adjustments, fire up the machine, and the rest is just trial and error until your muscles obey without your thinking and the puddle you trace is smooth and even.
***add something about practicing always to meet changing conditions...every weld is unique.
You’ll need a good back-handEdit
To be a welder, you can’t just go left to right. You also have to go the “other” way. That means pushing when you might normally pull, moving across the body instead of away, and using the backhand muscle (the tricep) instead of the forehand (bicep). The forehand was the more natural, at least for me, because that is how I learned to write. The backhand (or cross body) motion took more practice. Here is what I learned.
Using your backhand often means you draping the electrode cable over the "other" shoulder, standing with the "other" foot forward, and switching to using the "other" side of the electrode holder, etc. It feels very "other" and may take some practice. At first, I was gripping the electrode holder way to tight. I needed to practice letting my hand relax. I watched a guy explain his badminton backhand technique on Youtube, for insight.
After a day or so, you find your control with the new set of muscles you are using and it becomes just another technique to practice and refine. Read the section on Seat Time if you have not already.
The eyes follow the puddle and the body follows the eyes.Edit
This is a kind of simplifying mantra, or maybe it is an incantation. I started saying it right before I strike an arc. It works because, after you have picked your electrode, dialed in the machine, and practiced your technique, when the arc lights, all the things that came before were just to help you draw a good puddle. So don’t just keep an eye on the puddle, lock it in the cross-hairs of your concentration. Gear everything you do to keeping it stage center, uniform, and looking like you want it to. Your world rotates around that weld puddle when the arc is lit.
The Welding Circuit:
Back to music as the analogy: Think of the welder as a set of bag pipes. The engine/generator combo is what huffs out the bag, and the circuit is the part where the sound comes from. Every welder should be familiar with the circuit he is welding on. I use a Lincoln Electric Welder from the Ranger class. These are called "choppers" by some. A chopper first routes the AC output from the welder's generator through a rectifier to produce DC current. This current is then routed through a control board with a microprocessor running at tens of thousands of cycles per second. This is a time scale far beyond the reach of human perception. In a single beat of your heart, the welder might send 10,000 or more pulses (or pulse gaps) of current, each one tailored toward keeping the weld current constant, in the aggregate.
What they don’t tell you in the brochure.
In a way, it runs just like a light bulb. You don't notice it, but
By "familiar" I mean you should at least understand how the components The circuit I weld on is called a "chopper." different
the the musician and the welding circuit would be the instrument.
place holder for book