Learning to weld is difficult enough when everything is working right. Learn to set your wire speed correctly and some of your problems could be eliminated or reduced.
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Making Your MIG Sizzle

There is logic to that buzzing sound

Text, photos and video by Tom Hintz

Posted – 2-15-2011

One of the nifty things about a MIG welder is that it literally tells you when you have the voltage and wire speed right. OK, very close to right but for new welders this audible indicator is a good learning tool. As your welding skills improve and your beads become more consistent you will find that fine-tuning the wire speed a bit faster or slower to get it “just right” for a specific job or position is almost second nature.

Some welding machines like my Lincoln Pro-MIG 180 come with charts or graphs that provide wire speed and voltage suggestions that match up well with material thicknesses. While these settings are a good place to start you need to learn what the sounds the arc are telling you to get your machine dialed in perfectly for the job. Getting the wire speed right makes the arc more stable and predictable, both of which are good things when you are trying to learn to weld.

Suggestive Sounds

The manual that came with your welder might describe the sizzle sound that generally indicates a good balance between the wire speed and the voltage setting. The problem is that they can’t actually demonstrate the sound generated by proper settings. Thanks to the video medium on the Internet I can. I can also demonstrate sounds that are not right and hopefully provide guidance on what those wrong sounds are telling us.


Many welders like my Lincoln Pro-MIG 180 have charts (left) that show wire speed and voltage pairings. These are usually very close but you might have to tweak them some depending on the job and material. Turing the dials just a little (right) can have a big impact on the welding so make small changes until you get more accustomed to these adjustments. Click images to enlarge

It is important to know that the sounds being made by the arc are only one indicator. A dirty nozzle or contact tip, low shielding gas flow, not-so-good ground and contaminated material can all impact the arc and the sounds that it makes. It is a good practice to check these things first when you suspect a problem. Then you can adjust wire speed with more confidence. As always, start with the settings suggested by the manufacturer. They know the capabilities of their machine and have a vested interest in providing settings that will help make you successful when using it.

Target Sizzle

The analogy of frying bacon is pretty close to the sound of a balanced wire speed and voltage. My bacon doesn’t maintain the steady sizzle that my Lincoln Pro-MIG 180 does when it’s set right but my MIG doesn’t taste near as good as the bacon.

When the wire speed and voltage are right for the material and position the sizzle sound is very consistent. Small changes in arc length do not alter that sound much initially but if you keep stretching the arc out you may notice that the sizzle starts slowing or sounding sharper. You can also hear the sizzle change back and forth if you are not consistent with the arc length. When everything is right the sizzle stays consistent, the puddle looks right and the penetration is correct if you are doing everything else right. Getting a good, steady sizzle at least lets you know that you have that part right.

Speedy Wire

The group of beads at "A" were tests. Bead "B" had the wire speed too slow. I tried to cover it up by slowing the travel but it still came out with the bead flat and narrow. Bead "C" had the wire speed too fast and the bead stood up more but had little penetration. Bead "D" had a very nice sizzle to it and made a nicely shaped bead with what appears to be good penetration.
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It seems that many new welders, at least initially use too high of a wire speed. The sounds made by welding with the wire speed too fast can mimic the right speed to some degree but it has a louder snap to it, almost an angry sound to the sizzle. Also, the sizzle may seem like it varies slightly in intensity or speed. Probably the most telling is the crackle that is mixed in with the sizzle.

In this case I will reduce the wire speed by one or two numbers and try it again. I like to work my way down to where it begins to sound like the wire speed is too slow. Then I can bump it up a touch and it is usually just fine. I look for the lower limit because I kept finding myself accepting a higher wire speed than was needed. Sooner or later I would have to lower the wire speed some. Since I used this procedure of finding the lower speed limit first then bumping it up a bit I have been able to continue using the wire speed it indicated.

When the wire speed is too fast you might also notice that the bead is standing up above the surface more. The wire is being fed into the puddle too quickly and even if you increase the rate of travel the bead tends to stay high because penetration is reduced.

Slow Wire

When the wire speed is too slow you can hear it stutter, almost pulse. I am told that this is caused by the wire burning away back towards the contact tip and distorting the arc. It sure sounds like that is what is happening so I have accepted that explanation. If the wire speed is just a little bit too slow it will sound OK but now and then pulse or stutter. Here again, reducing the wire speed just a little more can confirm that if the stuttering or pulsing worsens. Then you can raise the speed a couple of numbers as see if that cures it.

When the wire speed is too slow you may also notice that the bead looks very flat or even depressed. That is because there is not enough of the wire being fed into the arc to keep the bead filled normally. Remember though that your rate of travel can confuse this somewhat. I find myself trying to compensate for the lack of wire by automatically slowing my travel rate down. That helps the appearance of the bead some but we really need to get the right wire speed to put down correct beads.

Video Tutor

In this video I use the term "amperage" rather than the correct "voltage". tell you ears to hear it right and disregard me.

Making corrections in small steps is the only way to find the right speed until you get used to figuring out this setting. Large changes can have you going right by the correct setting and make this a more frustrating ordeal. When you get more consistent with your arc length and speed of travel dialing in the right wire speed is much easier.

Conclusions

Learning to manipulate the wire speed on your MIG welder is reasonably simple and gets easier as you get the other factors of your welding more consistent. Getting the wire speed right for the job makes learning to keep your arc length and travel speed correct much easier. It all works together and the more practice the easier it gets. Invest some time learning to adjust your wire speed for the situation and that is one more thing that will have less of a negative impact on your quest to learn to weld.

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