Picture of How to Weld - MIG Welding
This is a basic guide on how to weld using a metal inert gas (MIG) welder. MIG welding is the awesome process of using electricity to melt and join pieces of metal together. MIG welding is sometimes referred to as the "hot glue gun" of the welding world and is generally regarded as one of the easiest type of welding to learn.

**This Instructable is not intended to be THE definitive guide on MIG welding, for that you might want to seek out a a more comprehensive guide from a professional. Think of this Instructable as a guide to get you started MIG welding. Welding is a skill that needs to be developed over time, with a piece of metal in front of you and with a welding gun/torch in your hands.**

If you are interested in TIG welding, check out: How to Weld (TIG).
Remove these adsRemove these ads by Signing Up

Step 1: Background

Picture of Background
MIG welding was developed in the 1940's and 60 years later the general principle is still very much the same. MIG welding uses an arc of electricity to create a short circuit between a continuously fed anode (+ the wire-fed welding gun) and a cathode ( - the metal being welded).

The heat produced by the short circuit, along with a non-reactive (hence inert) gas locally melts the metal and allows them to mix together. Once the heat is removed, the metal begins to cool and solidify, and forms a new piece of fused metal.

A few years ago the full name - Metal Inert Gas (MIG) welding was changed to Gas Metal Arc Welding (GMAW) but if you call it that most people won't know what the heck your talking about - the name MIG welding has certainly stuck.

MIG welding is useful because you can use it to weld many different types of metals: carbon steel, stainless steel, aluminum, magnesium, copper, nickel, silicon bronze and other alloys.

Here are some advantages to MIG welding:

  • The ability to join a wide range of metals and thicknesses
  • All-position welding capability
  • A good weld bead
  • A minimum of weld splatter
  • Easy to learn

Here are some disadvantages of MIG welding:

  • MIG welding can only be used on thin to medium thick metals
  • The use of an inert gas makes this type of welding less portable than arc welding which requires no external source of shielding gas
  • Produces a somewhat sloppier and less controlled weld as compared to TIG (Tungsten Inert Gas Welding)
1-40 of 233Next »
DaveyH9 days ago

This sounds like a great place to start for me. I've heard how much money welders make and I wanted to get some sort of certification. If you say it's that easy, I'll have to look more into it and see if there's a class nearby. Do you think it's possible to learn this by myself though? I'd rather do that than have to go to some sort of school.

edanb1 month ago

I took a course on TIG welding a couple weeks ago and found it to be too difficult for me, I have since stopped welding, but after reading this I realized I should probably have started with MIG. Do you think it would make sense to take a month-long course? They are not so cheap and I don't want to waste my time. I was also told I should get a welding helmet, but wouldn't the instructor have to supply me with one? I'm a little concerned about the safety issues. Thanks!

Having just read the instructions for MIG welding I have to say it is a load of rubbish. Why do people think they can weld when it is very clear they cannot. I speak as a teacher of fabrication and welding (15yrs) my first year students after correct instruction would lay a weld 100 times better than what has been shown here. You guys out there that want to weld correctly, take the time and do an evening course at your local college.

Always clean your nozzle after every weld and when changing your tip. A clean nozzle prolongs the life of your tip and ensures a quality weld. A clogged nozzle also restricts your gas flow causing porosity.
JamesL192 months ago

struggling to choose my first welding equipment. Been searching the web for
reviews etc. There's plenty of pages like at here but I'm not sure if a
$300-$500 is good enough for my household needs.

DaveyH2 months ago

I've gotten burned before by a welder, and let me tell you, it's not fun in the slightest. It was actually a 3rd degree burn for me. Anyway, since then I learned then to wear gloves and be a little more careful.

ColinB43 months ago

I have written so many articles on welding procedures
but after reading this article felt like never knew anything about MIG welding.
Great job author.

This has been so helpful to me. I'm a freshmen in high school and I take welding class, I have gotten past my other 1st year class mates and I moved onto mig welding and this has helped me greatly.

AdeelR5 months ago


This article is best for newbies. A very good briefing on MIG welding basics; equipment, mechanism, technique etc. Find more on

ncblu6 years ago
i weld for a living. folks before you spend large amounts of money on a welder, make sure you are willing to spend the time practicing, thats the most important thing, practice, practice, practice. start running straight passes, no weaving or sewing or circling. when running a bead remember - where you point the tip is where the weld will be. if you're using gas, watch for porosity because you pulled the tip back too far and contaminated the weld. dont grind your welds - it's a bad habit, even if your welds arent pretty, they will be in time. speed is very important, constant steady speed. the welders you buy at harbor freight or walmart are fine for tack welding, but i wouldnt put it to use on a trailer or something that could have bad results if a weld cracks. if you run without gas you will get lots of spatter, even with anti spatter dip. prep is the most important, make sure your metal is clean and bevels should be between 25% and 50%. when making t-welds or perpendicular welds remember the metal will contract TOWARD the weld bead, not away from it ( i know this is contrary to popular belief and highschool science but it will happen ). never weld in a down direction, never drag the bead like you would in stick welding, always be pushing the puddle in the direction you want to go. most of all practice, practice, practice
ncblu ncblu6 years ago
one more thing, if you want to make a living as a welder, do not weave or circle or sew - you likely wont make it through to morning coffee break. also be prepared to weld out-of-position, this is welding on any surface that isnt sitting flat on a table ( which actually is harder to do properly than it sounds ). you might be welding upside down with hot metal dropping in your shirt.
GabrielleC1 ncblu6 months ago

thanks for all the excellent tips!! A few questions…is it possible to find a 110v MIG that actually penetrates? I am a home/garage hobbyist looking to weld materials averaging around no more than 3/16-1/4" thick, mostly for art projects, making lights etc…I have more experience with arc welding on thicker materials. I have heard that you can't really weld with 110 but I see a lot of machines out there… I am also considering going for a lincoln 225, I see a lot of them on CL, but I am not sure if that will be more power than I need. What do you suggest?

HI There Can you tell me how close i should hold the tip from my work.
I usually Lay the tip on the metal and angle it.
For solid wire you want the wire to stick out about 1/4 to 1/2 inch, for flux cored wire you want a 1 inch stickout.
I agree on all points except for the grinding of the welds in my line of work (chassis fabrication) grinding the welds to make a flat billet style appearance is mandatory as long as the weld was properly prepped and is not over finished there will be no ill effects.
Thanks for that "pushing" the weld info  I've been trying  to drag the weld. Not working very well either.  Probably not my only problem however. As I mentioned before all I've ever done is stick welding.
So what brand of mig welder would you recommend looking at? I'm a carpenter but my next job has a good amount of steel involved.
2nd that - they're worth every bit you pay for them
its kind of hard to tell you exactly what type. I use miller welders at work because they are industrial grade and allow for mig/tig/stickwelding in one unit. they use gas shielding and are 3 phase units. the best way to decide is to try this link at miller under the product menu, you'll see smart select, they ask you a bunch of questions to help you decide. once you found the type and specifics that will give you an idea if you want to try another brand. it all depends on the type of metal your welding, the size of metal, available supply voltage, will you want to use gas or gasless and the size wire you want 0.16 or 0.32 is best. the units at walmart and home depot are ok and they can be used in either gas or gasless mode but using gas shielding is always better, if you go gasless you will use flux-core wire and it doesn't work very well on thicker metal and it spatters alot. hobart makes a pretty decent portable welder but they're pricey. lincoln makes good welders also. as for helmets, what do you want, automatic or standard. i would go to a welding shop for a helmet, the ones at the hardware stores that you can get for 99 bucks are only going to give you sore eyes after a little while, they just aren't that good. i use both kinds, automatic for short welding and my standard helmet if I'm gonna be running passes for the next few hours continuously ( stay away from gold plated lenses in your manual helmet, if the gold gets scratched the UV will pas right through and burn your retina's) get a good pair of gloves that aren't tight on your fingers. while you're at it pick up a good chipping hammer and wire brush from a weld shop- the ones at the hardware store wont last and grab a container of nozzle dip, some spare tips an extra spool of wire and a pair of welpers ( pliers) i know it sounds like alot but it really helps make the welding go smoother and makes for cleaner better welds in the end

hope this helps
JanieK7 months ago

I'm struggling to choose my first welding equipment. Been searching the web for reviews etc. There's plenty of pages like but I'm not sure if a $300-$500 is good enough for my household needs

batonas9 months ago

good thing pictured doesn't radiate uv, and still I feel awkward when looking, would feel more comfortable with welding mask tough :D

Jan_Henrik11 months ago

Nice, thank you!!!

joshr1231 year ago
Your amperage was too high and slow the speed
Spudmuffon2 years ago
Check and adjust tension you should be able to squeeze the wire and prevent it from moving while not causing any kind of bird nesting by the drive rollers
Spudmuffon2 years ago
Except for all the splatter on the nozzle clean that up I would rather knock it out with a round file but a screw driver, small pry bar, scribe, pliers will work.
Spudmuffon2 years ago
When grinding run parallel to the work not side to side save that for corner sanding with a 9in. Take the welds down to about 3/32 or so and have at it with the 9 in sander you will have much nicer results
Spudmuffon2 years ago
Honestly leathers are overrated if you are going to be welding day in day out 10-12 hours a day then yes they are wonderful the average person no long sleeves made from a non melting cloth will suffice
jjjwat2 years ago
my question is just about the wire.....canu use meg wire for jewlery making safely?
mtudge2 years ago
MIG welding is one of the most popular forms of welding used along with TIG welding, and it is personally one of my favourite welding methods. Thanks for sharing this article and BTW a great welding company is -
louis854 years ago
We are a professional manufacture&exporter of all kinds of welding machine,plasma cutters and battry chargers in China,if you need economical MIG welding mahice,please contack me
Taizhou Genteck Electric Co.,Ltd.
Add:Eco.&Ind.Development Zone,Wenling,Zhejiang,China.
Office Phone:+86-576-86088668
Fax Number:+86-576-86088558
Online service: MSN:,
Yeah, don't buy their stuff.

They don't even have the proper data for their equipment on the website, all they are are cheap Chinese Knock-offs of ESAB equipment.
Most Chinese factories don't have a data base for the website, many of them even don't have a website, they only produce the cheap machine.And the reason the machines are cheap: lower costs of blue-collar workers, no extral cost for any other "useless and expensive " workes ( an IT crew for instance) at all
Calling a worker who makes vital information easily available to prospective customers "useless and expensive" is pretty short-sighted.

There are a whole range of factors that effect the price for this equipment. We could debate that concept all day. The fact remains that this equipment will be of lesser quality.
No, we don't have to debate, yes, many of them are lesser quality.
However, the difference between the quality is much more smaller than the difference between prices,that is why there are still so many people buying them.
Your are absolutely right about the "short-sighted" too, many factories are used to do the domestic trade, by which they can take the customers directly to the factory, to see the equipments,to get all information in need, they don't have the foresight of international trade, but the profit of international trade is so enticing that they still make the way to do it.
If you have the chance to come to China and see the factories, you will understand all I am saying.
You're just looking at the initial cost difference. Not the added costs in the long run. You can't sue a company in China if the welder ends up breaking after two days, or worse hurts someone.

Honestly I have no desire to go to China. Not until the country cleans up it's act on an industrial level.
When I said "lesser quality",it definitely doesn't mean that bad, the quality you were saying is back to the 80's ,that is a long time ago. The truth may hurt your heart a little bit: many parts are produced here in China, only reassembled to an unit then marked as "made in ***"
The factories don't have the foresight to do the international trade, and you ,sir, don't have enough experiences to judge.Bias blinds people.
You know what also blinds people? Industrial Grade Glycerine being marketed as Medical Grade Glycerine That was in 2007. I have no problem being biased, China as a country has done nothing to remove that bias.
Bahahaha you spelled battery, machine, contact, and machines wrong :D Lol Fail
1-40 of 233Next »