Welding is the most practical way to join two metal pieces together, and the two most common choices for welding are stick welding and MIG welding. Both of them work on a variety of metals and can get you a nice strong weld bead.
If you want to know whether stick welding stronger than MIG for your specific application, then read on…
Which is Stronger? Stick Welding or MIG Welding?
To answer this question accurately, we need to evaluate several factors that impact weld strength regardless of which welding method you use. We will compare stick arc welding (SMAW) with gas-shielded MIG welding (GMAW) in this article.
The first consideration is welding efficiency. In other words, how much material is transfered into the weld pool, and whether it is delivered consistently enough to build a strong weld bead with good penetration.
In most stick welding situations the machine uses straight DC current, as opposed to AC. Straight DC keeps a constant polarity (either positive or negative). This makes it easier to maintain a constant, hot stable arc with faster electrode melt. DC current allows metal to transfer well from the electrode into the weld pool.
However, one of the challenges of stick welding is it’s low efficiency compared to MIG. Only about 60-65% of the material in the electrode stick will be deposited as metal weld bead. The rest burns off as shielding gas, flux and slag. This makes stick welding inefficient froma weld strength standpoint. It is both difficult to see the weld with the smoke and spatter constantly coming off, and to control the weld bead consistency due to all the exothermic activity happening around the weld pool.
In comparison, gas MIG welding (GMAW) has around 90-98% efficiency. That means the great majority of the electrode wire is deposited as weld bead material. This makes it easier to create a strong weld bead with MIG, especially for beginner-to-intermediate welders. This assumes the proper machine settings, of course.
Another consideration for welding efficiency here is the welding position. MIG welding efficiency drops in overhead welds, vertical-up welding and at odd angles. An arc welder will often deliver strong welds more efficiently in everyday positions where it’s impossible to flat weld.
Generally speaking, due to higher efficiency, a MIG welder will generally produce a stronger weld faster than a stick welder can, particularly in the flat weld position.
Type of Metal
Now, let’s compare whether stick welding is stronger than MIG by type of metal using carbon steel, chromoly and aluminum.
Mild Carbon Steel (up to 0.3% carbon)
There is little or no difference in weld strength between stick and MIG welding on mild carbon steel. Both stick welding and MIG welding have equivalent weld strength with the right electrode stick or wire, and the right machine settings.
Chromoly steel presents a particular challenge for both stick and MIG. To get sufficient weld penetration and tensile strength with chromoly pieces thicker than 1/8 inch, the chromoly must be preheated to 400-600 degrees Farenheit before and during the entire weld. Unless you heat the chromoly properly you will get cracks and weld failures.
Basically, the strength of a weld on 4130 chromoly depends more on proper heat preparation and the use of the correct electrode stick or wire than whether it’s done with a stick welder or MIG welder.
For stick welding, you can use a torch to heat the metal, plus an E-7108 low hydrogen electrode stick. Or you can use an application-specific electrode like ESAB Atom Arc 4130 which heats the base metal correctly as part of the process.
Likewise, for MIG welding you will need to heat the metal to 300-400 degrees F and use ER80S-D2 or ER70S-2 wire with 75% argon/25% CO2.
For both stick and MIG methods you may also heat the welded area later to stress relieve it and strengthen the weld.
Is stick welding stronger than MIG when welding 6061 aluminum? With the right metal preparation, stick or wire/gas, and machine settings, there should be little or no difference in weld strength between stick and MIG when welding 6061 aluminum.
Aluminum presents challenges for welding due to its high oxidation rate which can lead to brittle and crack-prone welds. Preheating thicker aluminum pieces can substantially reduce the potential for stress fractures in and around stick or MIG welds.
To MIG weld 6061 aluminum you need to use ER5356 or ER4043 wire, 100% argon shielding gas and the MIG machine set on DC reverse polarity. A spool gun to feed the malleable aluminum wire is also helpful to ensure smooth wire delivery.
To stick weld 6061 aluminum you will need 4043 electrode sticks such as Lincoln Electric Aluminweld 43 or Harris 26 Aluminum. The stick welding machine should be set to DC (DCEP/DCRP).
Metal thickness is a big factor in weld strength between stick and MIG welding.
Thick metal is where stick welding shines in terms of weld strength. When you need better and deeper penetration on thicker metal, the SMAW or stick welding method with E6010/11 rods will do the best job. It will deliver a stronger weld than MIG with deeper penetration and flat joints. The constant vaporization and expansion of shielding gas around the weld allows stick welding to penetrate deeper than MIG welding on thicker materials. Stick welding rods are also available in greater thicknesses than MIG wire, allowing substantially more amperage and heat delivery into the base metal.
The only downside of stick welding thick metal is the spattering — you’ll need to grind off the spatter afterward if you want a clean-looking weld area. This adds another step to the process which slows things down and increases costs.
For thin materials (1/8 inch or less), MIG welding generally produces stronger, more precise welds. The MIG welding method is perfect for sheet metal, where you need less penetration but a strong weld. The reason is the hotter arc from a stick welder, combined with expanding flux gases and smoke, make it very difficult to control the weld and not blow through the material with a stick welder. MIG welders have more heat control and it’s much easier to precisely guide the weld bead where you want.
For MIG welding thin sheet metal you’ll use a gas mixture of CO2 and argon, or pure argon (for aluminum alloys). For the filler metal, it’s best to use a .025 electrode for light and thin metal. It will give you a spatter-free and clean weld bead for a strong joint.
On an equally clean, bare metal surface, there is no real difference in weld strength between stick and MIG welding. But stick welding can give you strong welds on dirty surfaces when you cannot clean the metal beforehand.
MIG welding requires careful preparation of the work pieces to achieve a strong weld. All dirt, oil, rust and paint must be removed from the metal to ensure the weld is not contaminated.
In comparison, a stick welder can create a strong weld even if the metal is not cleaned first. The hot arc and expanding gases from the flux-coated electrode rod push impurities away from the weld pool, allowing good penetration through rust, oil, dirt and even thin paint.
In a controlled indoor environment there is little difference in weld strength between stick vs. MIG. But stick welders will almost always make stronger welds outdoors than a MIG can. A stick welder can produce a strong weld in the wind, rain or snow. MIG welders cannot because the shielding gas blows away in the wind and cannot push away water from the weld.
Due to the relative ease of use, a MIG welder will generally produce a stronger weld in the hands of a beginner. This advantage quickly goes away with welder skill, however. Stick welding produces equally as strong welds in the hands of an experienced welder.
MIG welders are generally much easier to use for beginners and intermediates. The automatic wire feeding mechanism alleviates the need to control the electrode speed with your hand. MIG arcs automatically start when the wire touches the base material with the gun trigger depressed, whereas with a stick welder you need to “strike an arc”. Both of these things take more skill with a stick welder.
Workability vs. Weld Strength in Different Situations
Stick welding is the most versatile method for working anywhere, outside or inside. You can weld upside down and in tight spaces without losing weld strength. It doesn’t require a separate gas cylinder, so you’re free from having to drag a cart, gas cylinders and hoses around from one workplace to another. You can work with a stick welder in heavy wind or even rain.
MIG welding requires a controlled environment with no wind to get a high quality weld. It cannot be used in rain or wind because the gas shield gets pushed away from the weld. MIG welding can also be more difficult in close quarters or at odd angles, which leads to lower quality and weaker welds.
These factors can make a significant difference in weld strength in a variety of real-world situations.
Is Stick Welding Stronger Than MIG?
Bottom line, if you mostly weld in controlled indoor environments on thinner materials, or are a beginning welder, then MIG welding is a better choice for getting strong welds. If you weld in a variety of indoor and outdoor environments, have more welding experience and weld thick materials, then a stick welder will deliver stronger welds.