Stick welding fundamentals

WWW.THEFABRICATOR.COM MAY 2009

May 26, 2009

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With instruction, some mild steel, the right welding rods, and a cracker box, the hobbyist can begin stick welding, also known as shielded metal arc welding (SMAW). Novice welders can learn more about the process by reading this article and by visiting the links shown at the end.

Stick Welding

A great way to bust into stick welding for a hobby is with a cracker box and some mild steel plate. A cracker box, or buzz boxfor the buzzing sound, is an inexpensive, usually AC-only machine that is good for small projects. You can buy a stick welding machine for around $300 these days.

The main welding processes are stick, MIG, flux core, and TIG. To be acronymically correct, that would be stickfor shielded metal arc welding or SMAW; MIGfor gas metal arc welding or GMAW; flux corefor flux-core arc welding or FCAW; and TIGfor gas tungsten arc welding or GTAW. Put that together and it spells SMAWGMAWFCAWGTAW.Next time you're at a cocktail party and someone asks what you do for a living, tell them you're a SMAWGMAWFCAWGTAW technician. Note to new readers and greenhorns … I'm kidding.

Before I continue with stick welding fundamentals, I want to give a shout out to Jeremy and Liz and everyone at their middle school way up there in Oregon. They like my crazy stories, and I've neglected to include one in my last couple of articles. Let's see, something funny, dumb, or stupid that has happened to me? No shortage of material there! Here's one that helped me to learn how important it is not to use something you aren't familiar with, such as stick welding.

Avoiding Stupid Mistakes

I was about 14 years old and had been begging my dad to let me ride a motorcycle. So he finally rented a Yamaha Twinjet 100, which was one sweet bike for a 14-year-old back in the day.

I'll always remember Dad, who hadn't even ridden on a bike, driving that thing out into the country for me to learn on. Instead of gradually starting out nice and slow, I headed right up the first small hill I saw. I drove up just fine, hit the top, and then saw an almost straight-down drop-off. I flew up about 3 feet in the air, came down straddling the gas tank, and hit my—well, you know—really hard.

I somehow managed to control the bike and rode it down the hill while sitting on the gas tank with my legs dangling off the side like some kind of nitwit. I parked that sucker, climbed into the back seat of the car, and curled up in the fetal position, vaguely aware of the howling laughter coming from my 11-year-old brother. That day became famous in my family as the day the word wheeliebecame balliefor some reason.

I had no experience with and did not give the motorcycle respect; it cost me. Using equipment you aren't familiar with can cost you or someone else … dearly. It's just as important to emphasize safety with a little cracker box as it is using an industrial machine. Small machines can hurt or kill you just as easily, and in some cases easier, than industrial equipment. Most industrial machines are pretty well-maintained; most cracker boxes are not. Many are bought used and have been modified or tampered with.

When researching this article, I ran across an OSHA reportabout a guy who was killed a few years ago while using just such a machine that had been messed with. Follow ALL safety regulations, don'tmodify the machine, and be careful.

Select the Right Consumables

Stick welding requires rods. Good choices for a cracker box are 3/32-in.- and 1/8-in.-diameter rods if the machine will pull up to 120 amps (heat). You even can go smaller and use 1/16-in. diameter for welding really thin material, but that's like welding with a toothpick.

I recommend 6011 and 6013 (for the thin stuff and also as a good learning rod) and 7018 for the hobbyist. 6011 is similar to 6010, but the flux is a bit harder to chip, and it doesn't run as smooth. But 6010 is used only with DC, whereas 6011 runs with AC or DC. 7018 also runs on AC or DC, and some rods are specifically designed for AC. Quite a while back I wrote about the 6010, 6011, and 7018 rods.

Yamaha Twinjet 100

Know Your Metal

Mild steel is the most commonly welded metal used in stick welding in both manufacturing and construction. You can make all kinds of projects and artwork with it, plus it's easy to find and purchase. Mild steel is a ferrous metal,meaning it is iron with a very small amount of carbon (0.33 percent).

Carbon is what makes steel hard, and it doesn't take much at all to change the hardness. Increase the carbon minutely (0.5 percent), and it is considered high-carbon steel. Mild steel is ductile, meaning it can bend without breaking. A pocket knife blade is high-carbon steel, which is harder yet more brittle. It is not ductile; bend it and it will break.

Working With Cast Iron

I get asked a lot about how to weld cast iron. Cast iron is high-carbon and needs preheating and a controlled cool-down to room temperature to keep it from being susceptible to longitudinal cracking—a crack right down the middle of your weld or steel running lengthwise with the direction of weld. Sometimes the steel cracks ahead of you as you weld, which is quite irritating. An old trick is to drill a hole at each end of the crack, weld it, and then fill the holes. The best thing to do is preheat it to a certain temperature and then control it in an oven to room temperature.

However, not too many people have an oven in the hobby shop, so as long as you're not welding a critical piece, you can guesstimate the heat treatment by heating the metal somewhat with an oxyacetylene rig. Then after welding, you can continue to heat it just slightly with your torch less and less to keep the material from cooling too quickly.

I told a buddy he needed to do that before he welded a cast head on an old tractor he was rebuilding. "Nah!" was his smug reply. He welded it and it looked pretty danged good for cast welding. Then it cooled and made a loud pop!as it cracked right down the middle. This would have been a perfect time to explain to him the properties of cast iron, but instead I laughed at and made fun of him for not listening to me.

Cast iron requires specific rods with nickel in them that don't produce a very visually pleasing weld because it's hard as heck to distinguish the weld pool from the molten flux. These rods run on both AC and DC machines. It's usually best to weld an inch or two, and then peen it to relieve the stress. (Peening is tapping the just-made weld with a ball peen hammer to relieve stress. You have to watch out though because peening also can make the cast iron more brittle.) Be sure and bring a lot of money with you when buying cast-iron rods. You can, thank goodness, buy them a few at a time.

Remember, this is for welding noncritical pieces only; otherwise you should let a professional shop do the work.

Here's a good article about cast iron.

Learning Stick Welding

You really need to take a class at your local community college to learn the fundamentals of stick welding. If you absolutely cannot take a class, the next best way to learn is to watch all the videos you can, read all the literature you can—both of which are abundant on the Internet—and then start out with the 6013 rods I mentioned for thin steel. As I've said many times, when it comes to welding, I do notlike or recommend self-teaching, because you don't have anyone to correct you when you develop a bad habit.

That said, a basic class, a cracker box, and a handful of rods will get your stick welding hobby going!

Some good tips from equipment manufacturers can be found at these links:

Understanding processes

http://www.millerwelds.com/products/helpmechoose/

Amp setting chart

http://www.hobartwelders.com/products/electrodes-wire/electrode-chart/

Arc welding fundamentals

http://www.lincolnelectric.com/knowledge/articles/content/arcweldfund.asp

Electrode selection tips

http://www.esabna.com/EUWeb/FM_handbook/577fm1_1.htm

You also can find many articles about welding on thefabricator.com.



High School Career Center in Texas

Marty Rice

Contributing Writer
High School Career Center in Texas
Marty Rice is a welding instructor at a high school career center in Texas. He is an honorary member of the Ironworkers Local 263.

 

Questions for the author can be e-mailed to vickib@thefabricator.com

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