Welding tips, tricks, and shortcuts
The arsenal of welding weapons that can be deployed for battle for metal mending chores has grown exponentially over the years to include an alphabet-soup list of welders.
If you’re over age 50, you likely learned to weld with an SMAW (shielded metal arc welding, or stick) welder.
The 1990s brought us the ease of MIG (metal inert gas) or FCAW (flux-cored arc welding) wire welding, which retired a great many stick buzz boxes. More recently TIG (tungsten inert gas) technology has found its way into farm shops as an ideal way to meld sheet metal, aluminum, and stainless steel.
Now, the increasing introduction of multipurpose welders means all four processes can be utilized in one package.
Following is a welding short course certain to sharpen your skills for producing solid results regardless of the welding process you employ.
- READ MORE: Welding cart goes all-terrain
Commonsense Wire Welding Tips
Jody Collier has made a career of welding and educating welders. His websites, weldingtipsandtricks.com and welding-tv.com, are full of practical tips and tricks of the trade regarding all forms of welding.
Here are 10 of Collier’s tips guaranteed to improve your MIG and flux-core welding skills.
- Get a better ground clamp. This is probably one of the most important MIG tips! Ever heard someone light up with a MIG gun and it sounds like a drive-by shooting? You know what’s wrong? Bad ground! Now, it’s no secret that copper is the best conductor. That’s why copper ground clamps are better, especially ones that have a strong spring. To get a good ground, get a good clamp.
- Watch your stickout. Wire stickout is misunderstood. It refers to the distance from the welding tip (also called contact tip) to the arc, not the distance from the nozzle to the arc. Too long of a stickout softens the arc, making the weld pile up. A longer stickout works OK and can be a good thing on really thin sheet metal. For high-amperage spray transfer, a longer stickout is preferred, but if you want a good crisp arc using short circuit MIG on thicker metal, keep the stickout to less than 1/2 inch.
- Learn to weld uphill. Another of many important MIG welding tips is to weld uphill on anything thicker than ¼ inch. By pushing the weld, you can get better penetration.
- Be sure to match your contact tube, gun liner, and drive rolls to the wire size. Using .030 drive rollers with .035 flux core can make you want to quit welding.
- Clean the gun liner and drive rolls occasionally, and keep the gun nozzle clear of spatter. Replace the contact tip if blocked or feeding poorly. Buy a cutting torch tip cleaner if you want to make your tips last a little longer and ream them out occasionally. Keep a pack of new contact tips in your toolbox.
- Replace the gun liner when it needs it. Over time, liners get clogged with dust and copper from the wire. If you want to check the liner for feeding issues, turn off the machine, undo the spring clamp tensioner on the rollers, lay the gun lead out on the floor with the contact tip removed from the gun, and push the wire with your fingers. It should feed without having to force it. If not, replace it. A new one costs about $20 and will make a big difference.
- Always weld with both hands. Rest the crook of the gun neck in one hand and hold the part with the trigger in the other. Being steady when you pull the trigger is very important for good starts. Letting the gun be pushed away when you pull the trigger only makes for bigger than necessary tack welds and ugly bead starts.
- Keep wire feeder hub tension and drive roll pressure just tight enough to feed wire plus a little extra, but don’t overtighten.
- Use a big drop (extension) cord. If you must use an extension cord, use a big fat one and the shortest one possible.
- Get a good auto-darkening helmet. Moving even ¼ inch off the welding track when you nod your helmet down can screw things up. With a quality auto-darkening helmet you can see where your wire is pointing before you pull the trigger.
Changing MIG Gases
The go-to gas for MIG welding is carbon dioxide (CO2). While CO2 is economical and great for creating deep penetrating welds in thicker steel, this shielding gas may be too hot when welding thin metal. That’s why Jody Collier suggests switching to a mixture of 75% argon and 25% CO2.
“Oh, you can go with straight argon when welding aluminum or for MIG welding on steel but only on really thin stuff,” he says. “Everything else welds horrible with pure argon.”
Collier points out there are many gas mixtures on the market such as helium-argon-CO2, but they can sometimes be hard to find and expensive.
For most farm shop needs, on-hand gas supplies should include CO2 and an argon-CO2 mixture.
You will want to add two gas mixtures of 100% argon or an argon-helium blend for welding aluminum and a mixture of 90% argon, 7.5% helium, and 2.5% CO2 if you are mending stainless steel on the farm.
MIG welding penetration varies by the shielding gas. Carbon dioxide (shown at right, above) provides for a deep penetrating weld compared with an argon-CO2 mixture (left, above).
Cleaning Aluminum is a Must
Before you strike an arc on an aluminum repair, be sure to thoroughly clean the weld site to avoid failed welds.
Cleaning the welding site is crucial because aluminum oxides melt at 3,700°F., while the base metal melts at 1,200°F. Thus, any oxides (oxidized or white-looking corrosion) or oils on the repair surface will inhibit penetration of the filler metal.
Cleaning requires two operations: removing all oil and grease and then removing any aluminum oxides.
Eliminating oil and grease comes first. Then — and only then — should you remove the oxidized contamination. Don’t reverse this order, warns Joel Ort of Miller Electric.
Here are additional aluminum cleaning pointers.
- Remove oil, grease, and water vapor using an organic solvent such as acetone, non-chlorinated brake cleaner, or a mild alkaline solution like a strong soap. You may also use citrus-based degreasers, but be sure to rinse and dry the weld area before welding.
- Remove surface oxides with a stainless-steel wire brush combined with a strong alkaline or acid cleaner. Be sure the brush is used only for cleaning aluminum. Many welding suppliers sell oxide-removal solutions in spray or squeeze bottles.
- Remove all paint.
- If you won’t be welding the repair site immediately, cover the welding joint with brown kraft paper to prevent dirt and grit in the air from settling into the weld area.
- Keep the aluminum weld site dry and maintained at room temperature for a successful weld.
This Isn’t Your Daddy’s Stick Welder
Give stick welding another chance.
The tried-and-true buzz box welder got relegated to shop corners to collect dust with the popularity of wire welders in the 1990s.
But today’s stick welder has a place on the farm and especially in the field.
Unlike those old buzz boxes that were only alternating current (AC) affairs, the modern stick welder is both AC and direct current (DC), changing its welding polarity 120 times a second.
The advantages this rapid polarity shift provides are huge, including easier starts, less sticking, less spatter, more attractive welds, and easier vertical and overhead welding.
Combine that with the fact that stick welding produces deeper welds, excels in outdoor operations (where wind blows away MIG shielding gas), works gangbusters on thick material, and burns through rust, dirt, and paint. The welders also are portable and simple to operate, so you can see why a new stick or multiprocessor welder is worth the investment.
Joel Ort of Miller Electric offers the following stick welding pointers. Detailed information can be found at: millerwelds.com/resources/welding-guides/stick-welding-guide/stick-welding-tips.
- An all-purpose go-to electrode is an A6011, which provides a deep penetrating weld even in dirty, rusty, or painted materials. But keep some E7018 around as this low-hydrogen electrode is ideal for out-of-position welding and when welding on high-strength steel. If welding stainless steel, opt for a stainless 312 Plus electrode.
- To set your amperage, first determine the recommended amp range for your electrode type and diameter. Then pick an amperage within the range based on your metal thickness (thinner metal, fewer amps).
- Scratch start and tapping techniques to practice. Try either starting method to discover what works for you. With the scratch start, you drag the electrode across the workpiece like striking a match, lifting the electrode slightly after touching the work. If the arc goes out, then the electrode was lifted too high. If the electrode sticks to the workpiece, use a quick twist to free it. With the tapping technique, bring the electrode straight down on the workpiece and then lift slightly to start the arc. If the arc goes out, the electrode was lifted too high. Again, twist to free the electrode if it sticks.
- When welding a fillet, the leg of the weld should be equal to the thickness of the parts welded.
Hydrogen Kills Welds
Hydrogen is the leading threat in welding, contributing to delayed welding, a heat-affected zone cracking that happens hours or days after the weld is completed, or both.
Yet, the hydrogen threat is usually simple to eliminate by thoroughly cleaning the metal. Remove all oil, rust, paint, and any moisture as they are sources of hydrogen.
That said, hydrogen remains a threat when welding high-strength steels (increasingly used in modern tillage equipment), thick sections of metal, and weld areas that are heavily restrained. When mending these materials, be sure to use a low-hydrogen electrode and preheat the weld area.
Porosity: The Leading Cause Of Weak Welds
Sponge-like holes or tiny bubbles that appear on the surface of a weld are a sure sign that your weld suffers from porosity, points out Jody Collier, who considers the condition the No. 1 problem with welding.
Weld porosity can take many forms, including surface pores, wormholes, crater pipes, and cavities that are seen (on the surface) and unseen (deep in a weld).
Beyond its ugly appearance, porosity predicts a poor, weak weld.
Possible causes of porosity include:
- Inadequate shielding gas coverage (resulting from improper flow rate or from a draft blowing away the gas). Typical gas flow should be about 30 to 40 cubic feet per hour. “Some operators mistakenly think a pressure regulator is all that’s needed to assure proper gas flow and pressure,” Collier says. “But a pressure meter will not set flow. Instead, invest in a flow meter.”
- Lubricants, moisture, rust, paint, mill scale, and other contaminants on the base material.
- Excessive wire stickout, which prevents proper shielding gas coverage.
- Not following the wire manufacturer’s recommended wire stickout.
Collier also advises: “Keep the puddle molten for a longer time to allow gases to boil out of the weld before it freezes.”
Try Skinny Wire for a Good Weld
Although the most common welding wire diameters are .035 and .045 inch, a smaller diameter wire can make it easier to create a good weld. Try a .025-inch wire diameter particularly when welding thin material of 1⁄8-inch or less, suggests Karl Hoes of Lincoln Electric.
Most welders tend to make a weld that is too big, leading to potential burn-through problems, he explains. A smaller-diameter wire produces more stable welds at a lower current, which has less tendency to burn through.
If you keep your weld current lower, you will have a greater chance of success on thinner materials.
Be careful using this approach on thicker materials (3⁄16 inch and thicker) because a .025-inch wire may cause lack of fusion.
TIG Best Practices
Once only dreamed about by farmers wanting a better way to weld thin metal, aluminum, and stainless steel, TIG welders are becoming more common in farm shops because of the rising popularity of the multiprocessor welder.
Based on personal experience, learning to TIG weld won’t be as easy as taking on MIG welding, however.
TIG requires three-way coordination using both hands (one holding the heat source in a hot-as-the-sun tungsten electrode and the other hand feeding fill rod into the arc) and a foot (operating a pedal or torch-mounted amperage control for starting, adjusting, and stopping the flow of current).
My first attempts at TIG welds resembled bird poop on steel.
To avoid results similar to mine, beginners and those wanting to hone their skills can benefit from these TIG tips in the words of Ron Covell, a consultant with Miller Electric, from his “Welding Tips: The Secret to Success When TIG Welding.”
Find the complete version at millerwelds.com.
- Make sure everything is squeaky clean. TIG welding is not tolerant of any contaminants. Be sure to clean your base metal with a good degreaser, before you scrub it with a dedicated wire brush. (Do not use the same brush on different kinds of metal.) Wipe the filler rod down with degreaser, too.
- Get comfortable. Whenever possible, I like to be seated when I’m welding. Even in situations where sitting isn’t possible, any little adjustments to my stance or body position that make me more comfortable will have a noticeable effect on the weld.
- Look for ways to support your hands. Having good support for your hands or arms is crucial for moving the torch with precise control. I do my best welding when the base of my hands or my wrists are supported in some way. Often you can rest your wrists on the part being welded. I keep an assortment of wood and metal blocks near my welding bench, and I often can get better support by positioning a block to rest my torch hand on.
- Do a practice run (without power). Many professional welders do this before every pass. Get in the most comfortable position you can, with support blocks in place if helpful, and run your hands along the path they will traverse as you make the weld. You will often find that a slight adjustment of your position will allow you to make a longer pass, or to move your hands with less stress.
- Clean a contaminated electrode immediately! Every welder will contaminate the electrode at some point, but it’s essential that you replace a contaminated electrode immediately. I usually keep a group of presharpened electrodes right on my welding bench, so I can swap them out without having to walk to my grinder.