Types of Welding Electrodes

There are many types of welding electrodes. This article will cover a “mild steel electrode.”

Welding electrodes are metal wires with baked on chemical coatings. The rod is used to sustain the welding arc and to provide the filler metal required for the joint to be welded. The coating protects the metal from damage, stabilizes the arc, and improves the weld. The diameter of the wire, less the coating, determines the size of the welding rod. This is expressed in fractions of an inch such as 3/32″, 1/8″, or 5/32.” The smaller the diameter means it requires less current and it deposits a smaller amount of filler metal.

The type of base metal being welded, the welding process and machine, and other conditions determines the type of welding electrode used. For example, low carbon or “mild steel” requires a mild steel welding rod. Welding cast iron, aluminum or brass requires different welding rods and equipment.

The flux coating on the electrodes determines how it will act during the actual welding process. Some of the coating burns and the burnt flux forms smoke and acts as a shield around the welding “pool,” to protect it from that air around it. Part of the flux melts and mixes with the wire and then floats the impurities to the surface. These impurities are known as “slag.” A finished weld would be brittle and weak if not for the flux. When the welded joint is cooled, the slag can be removed. A chipping hammer and wire brush are used to clean and examine the weld.

The metal-arc welding electrodes may be grouped as bare electrodes, light coated electrodes, and shielded arc or heavy coated electrodes. The type used depends on the specific properties required that include: corrosion resistance, ductility, high tensile strength, the type of base metal to be welded; and the position of the weld that is flat, horizontal, vertical, or overhead.

Welding electrodes must be kept dry. Moisture destroys the desirable characteristics of the coating and may cause excessive spattering and lead to the formation of cracks and weakness in the welded area. Electrodes exposed to humid air for more than a few hours should be preheated before use and when in doubt as to how long they were exposed they should be re-dried by heating in a suitable oven. (See Electrode Rod Storage Recommendations for proper time and temperature charts.) After they have dried, they should be stored in a moisture proof container.

The American Welding Society’s (AWS) classification number series has been adopted by the welding industry. The electrode identification example below is for a steel arc-welding rod labeled E6010:

“E” indicates “electrode” for electric arc welding
The first two (or three in some cases) digits (60) indicate tensile strength in thousands of pounds per square inch
The third (or fourth in some cases) digit (1) indicates the position of the weld. An “O” indicates that this classification is not used; “1″ is for all positions; “2″ is for flat and horizontal positions only; 3 is for flat position only
The last two digits together (10) indicate the type of coating and the type of power supply required, 10 organic coating and DC current with reverse polarity.

Therefore, a welding rod numbered E6010 indicates “E” an manual arc-welding electrode with (60) a minimum strength of 60,000 psi., that can be used (1) in all positions and (10) DC reverse polarity is required.

Please review all of our welding rod ovens for the proper storage of your welding electrodes.

Fundamental Tips to Improve Stick Welding Skills

Shellfish can make you a better welder. Simply think about CLAMS: Current setting, Length of arc, Angle of electrode, Manipulation of the electrode and Speed of travel. If you’re just learning the Stick process, technically called Shielded Metal Arc Welding, remembering these five points will improve your welding technique.

Before leaping into the “how to weld” information presented later in this article, take a minute to review the following advice, especially if you’ve never struck an arc or are still debating which machine to buy.

Q: What type of Stick welder works best for all-around use?

A: A welder with an AC/DC output, whether its an electric arc machine like Miller’s Thunderbolt or a gas engine drive like Miller’s Bobcat.

DC welding offers advantages over AC for most Stick applications, including: easier starts; fewer arc outages and sticking; less spatter/better looking welds; easier vertical up and overhead welding; easier to learn “how to weld” and a smoother arc. DC reverse polarity (electrode positive) provides about 10 percent more penetration at a given amperage than AC, while DC straight polarity (electrode negative) welds thinner metals better.

Q: Does an AC output have any advantages?

A: Yes, if you need to weld on material that’s become magnetized from friction, such as when hay, feed or water constantly rub against a steel part. A DC output won’t work because of “arc blow,” where the magnetic field blows the molten filler metal out of the weld puddle. Because an AC output alternates between polarities, it enables you to weld magnetized parts.

Q: How big of machine do I need?

A: A 225 to 300 amp machine handles almost anything the average person will encounter, as most Stick welding procedures require 200 amps or less. To weld material thicker than 3/8 in., simply make multiple passes – this is what professionals do, even when welding on 1 in. structural steel.

Q: I see the word “duty cycle” on product spec sheets? What does that mean?

A: Duty cycle is the number of minutes out of a 10-minute cycle a welder can operate. For example, the Thunderbolt XL creates a 200 amp DC output at 20 percent duty cycle. It can weld continuously at 200 amps for two minutes, and then must cool for eight minutes to prevent overheating.

Duty cycle and amperage are inversely proportional. Operating at 90 amps, the Thunderbolt has a 100 percent duty cycle, meaning you can weld without stopping. This inversely proportional rule is true of all Miller machines but does not apply to all machines made by other companies.

Q: What type of rod should I use for hardfacing?

A: Hardfacing rods can provide impact resistance, abrasion resistance or both depending on the application. Because the type of rod required depends on the type of soil or aggregate in your area, contact your local welding supply distributor and ask for their expert opinion. If you don’t know a distributor, call 1-800-426-4553 and the operator can automatically connect you to the nearest Miller distributor. You can also locate distributors through http://millerwelds.com/wheretobuy/ ENDPARA]

Q: What type of rod should I use for general work on steel?

A: Common electrodes used for general work include 6010, 6011, 6013, 7018 and 7024, each of which has specific properties: 6010 electrodes penetrate deeply, while 6013 electrodes penetrate less. For much better bead appearance and work on higher strength steels (say for a hitch), use a 7018 rod. For better penetration on thick material, grind the joint to a 30 degree bevel (leave a nickel-width land on the bottom of the groove) and make multiple passes. Alternatively, make the first pass with a 6010 rod, then make a “cap” with a 7018. The 7024 rod is perhaps the easiest to use. Also known as a “drag rod,” this electrode’s thick flux automatically maintains the correct arc length, which allows you to drag the rod directly along the work piece.

Q: Do I have to remove rust or oil before welding?

A: Stick welding is more forgiving on unclean conditions, but it never hurts to clean parts with a wire brush or grind off excess rust. If you prepare well and have average welding ability, you can make a sound weld. However, even great welding skill cannot overcome poor preparation, as it can lead to cracking, lack of fusion and slag inclusions.

Do It Yourself for Carpet Installation

DIY carpet installation

Described below are the procedures for installing your own carpet.

First, nail in your tack strip around the entire perimeter of the area to be carpeted, except any doorways. Leave a gully between the tack strip and the wall the width of the new carpet’s thickness. Then spread out your underlay with the smooth side up, ensuring it is the right type recommended for the carpet you’re planning to install.

Once you’ve got your underlay down, trim away the carpet’s factory selvage (the edge of a carpet that is woven so that it will not fray or ravel) as recommended by the manufacturer – usually this is about 2 cm from the selvage (if necessary).

Roll out your carpet and let it relax before putting it in place. Before and during installation make sure there is proper ventilation in the area where you’ll be laying your carpet and be sure to keep the area dry.

If you are planning to use hot melt tape to seal the fresh cut seams of your carpet you’ll need to use the carpet stretcher to condition the carpet for the non-stretchy hot melt tape. For tufted carpets you should use either tape and latex, hot melt tape, electric tape or pin tape. For most woven carpets, only hand sewing and pin tape are recommended.

When using the power stretcher follow the manufacturer’s instructions for its use. Only apply the degree of stretch required for the particular carpet type. Then hook the carpet onto the tack strip and trim the excess. When using a wall trimmer be careful to leave enough excess carpet to tuck into the gully and don’t staple your carpet to the tack strip.

Carpeting stairs

If you are installing new carpet to a staircase you should make sure the stair nosing’s are well rounded to prevent unnecessary damage to both your carpet and underlay. For a good fit, cut the underlay about 3 cm narrower than the width of the stairs so you’ll be able to turn the carpeting edge under. You may also need to install tack strip on each step to maintain proper tension in the carpeting.

Attach tack strip on each tread and riser with pins on the steps aiming toward the riser and having the pins of the riser tack strip pointing down toward the tread. The gully you leave between the treads should be a little less than twice your carpet’s thickness.

Then:

put down your underlay
use a knee kicker or stair stretcher to install your carpeting
fit your carpet to the tack strip tightly, pushing it into the gullies between the treads and the risers using a stair tool
make sure the carpeting lays smoothly over the stairwell’s steps.

When you’re done remove the excess trim and vacuum. You’re now ready to enjoy your new carpet.