How to Weld - MIG Welding Home Sign Up!

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How to Weld - MIG Welding
by noahw on June 6, 2007
Table of Contents
intro: How to Weld - MIG Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
step 1: Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2
step 2: How the Machine Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
step 3: Safety Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
step 4: Prep for Your Weld . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6
step 5: Laying a Bead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
step 6: Welding Metal Together . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
step 7: Grind down the weld . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
step 8: Common Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
step 9: Wire Fuses to Tip/Change the Tip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
step 10: Replace Wire Feed to Gun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
step 11: Other resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Related Instructables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
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Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
http://www.instructables.com/id/How-to-Weld---MIG-Welding/
intro: 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).
step 1: 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)
step 2: How the Machine Works
A MIG welder has a couple of different parts. If you open one up you will be able to see something that looks like what is pictured below.
The Welder
Inside the welder you will find a spool of wire and a series of rollers that pushes the wire out to the welding gun. There isn't much going on inside this part of the welder,
so it's worth it to take just a minute and familiarize yourself with the different parts. If the wire feed jams up for any reason (this does happen from time to time) you will
want to check this part of the machine out.
The large spool of wire should be held on with a tension nut. The nut should be tight enough to keep the spool from unraveling, but not so tight that the rollers can't pull
the wire from the spool.
If you follow the wire from the spool you can see that it goes into a set of rollers that pull the wire off of the big roll. This welder is set up to weld aluminum, so it has
aluminum wire loaded into it. The MIG welding I am going to describe in this instructable is for steel which uses a copper colored wire.
The Gas Tank
Assuming you are using a shielding gas with your MIG welder there will be a tank of gas behind the MIG. The tank is either 100% Argon or a mixture of CO2 and Argon.
This gas shields the weld as it forms. Without the gas your welds will look brown, splattered and just generally not very nice. Open the main valve of the tank and make
sure that there is some gas in the tank. Your gauges should be reading between 0 and 2500 PSI in the tank and the regulator should be set between 15 and 25 PSI
depending on how you like to set things up and the type of welding gun you are using.
**It's a good rule of thumb to open all valves to all gas tanks in a shop only a half turn or so. Opening the valve all the way doesn't improve your flow any more than just
cracking the valve open since the tank is under so much pressure. The logic behind this is so that if someone needs to quickly shut off gas in an emergency they don't
have to spend time cranking down a fully open valve. This might not seem like such a big deal with Argon or CO2, but when your working with flammable gases like
oxygen or acetylene you can see why it might come in handy in the event of an emergency.**
Once the wire passes through the rollers it is sent down a set of hoses which lead to the welding gun. The hoses carry the charged electrode and the argon gas.
The Welding Gun
The welding gun is the business end of things. It's where most of your attention will be directed during the welding process. The gun consists of a trigger that controls the
wire feed and the flow of electricity. The wire is guided by a replaceable copper tip that is made for each specific welder. Tips vary in size to fit whatever diameter wire
you happen to be welding with. Most likely this part of the welder will already be set up for you. The outside of the tip of gun is covered by a ceramic or metal cup which
protects the electrode and directs the flow of gas out the tip of the gun. You can see the small piece of wire sticking out of the tip of the welding gun in the pictures below.
The Ground Clamp
The ground clamp is the cathode (-) in the circuit and completes the circuit between the welder, the welding gun and the project. It should either be clipped directly to the
piece of metal being welding or onto a metal welding table like the one pictured below (we have two welders hence two clamps, you only need one clamp from the welder
attached to your piece to weld).
The clip must be making good contact with the piece being welded for it to work so be sure to grind off any rust or paint that may be preventing it from making a
connection with your work.
Image Notes
1. This is the spool of wire that feeds the welder. The wire comes off the spool, is
pushed through the feeder wheels and travels out to the welding gun.
2. Advanced control settings. These are not present on all models of welders.
3. These are the rollers that pull the wire off of the spool and send it out to the
welding gun.
Image Notes
1. Tension adjustment for the rollers.
2. The wire is fed through the rollers.
Image Notes
1. These are the regulators for the tank of argon gas. The argon shields the weld
as it is being formed.
Image Notes
1. This is the positive electrode wire coming out of the tip of the gun.
2. Laying some test beads.
Image Notes
1. These are the negative clamps that go on to the table to complete the circuit.
Clamp the negative lead from the welder onto your project, or in this case, the
entire welding table. There are two pictured here because we have two welders,
but you will only need one.
step 3: Safety Gear
MIG welding can be a pretty safe thing to do so long as you follow a few important safety precautions. Because of MIG welding produces lots of heat and lots of harmful
light, you need to take a few steps to protect yourself.
Safety Steps:
The light that is generated by any form of arc welding is extremely bright. It will burn your eyes and your skin just like the sun will if you don't protect yourself. The
first thing you will need to weld is a welding mask. I am wearing an auto-darkening welding mask below. They are really helpful if you are going to do a bunch of
welding and make a great investment if you think you will be working with metal often. Manual masks require you to jerk your head dropping the mask into position
or require to use a free hand to pull the mask down. This allows you to use both your hands to weld, and not worry about the mask. Think of protecting others from
the light as well and use a welding screen if it's available to make a border around yourself. The light has a tendency to draw on lookers who might need to
shielded from being burned too.
Wear gloves and leathers to protect yourself from molten metal splattering off of your work piece. Some people like thin gloves for welding so you can have a lot
of control. In TIG welding this is especially true, however for MIG welding you can wear whatever gloves you feel comfortable with. The leathers will not only
protect your skin from the heat produced by welding but they will also protect your skin from the UV light produced by welding. If you are going to be doing any
amount of welding more than just a minute or two you will want to cover up because UV burns happen fast!
If you are not going to wear leathers at least make sure that you are wearing clothing made from cotton. Plastic fibers like polyester and rayon will melt when they
come into contact with molten metal and will burn you. Cotton will get a hole in it, but at least it won't burn and make hot metal goop.
Do not wear open toed shoes or synthetic shoes that have mesh over the top of your toes. Hot metal often falls straight down and I have burned many holes
through the tops of my shoes. Molten metal + hot plastic goo from shoes = no fun. Wear leather shoes or boots if you have them or cover your shoes in something
non-flammable to stop this.
Weld in a well ventilated area. Welding produces hazardous fumes which you shouldn't breathe in if you can avoid it. Wear either a mask, or a respirator if you are
going to be welding for a prolonged amount of time.
Important Safety Warning
DO NOT WELD GALVANIZED STEEL. Galvanized steel contains a zinc coating that produces carcinogenic and poisonous gas when it is burned. Exposure to the stuff
can result in heavy metal poisoning (welding shivers) - flu like symptoms that can persist for a few days, but that can also cause permanent damage. This is not a joke. I
have welded galvanized steel out of ignorance and immediately felt it's effects, so don't do it!
Fire Fire Fire
Molten metal can spit several feet from a weld. Grinding sparks are even worse. Any sawdust, paper or plastic bags in the area can smolder and catch fire, so keep a tidy
area for welding. Your attention will be focused on welding and it can be hard to see what's going on around you if something catches fire. Reduce the chance of that
happening by clearing away all flammable objects from your weld area.
Keep a fire extinguisher beside the exit door from your workshop. CO2 is the best type for welding. Water extinguishers are not a good idea in a welding shop since you
are standing next to a whole lot of electricity.
Image Notes
1. Button this up before starting to weld otherwise your neck will get burned!
step 4: Prep for Your Weld
Before you start welding make sure things are properly setup at both the welder and on the piece you are about to weld.
The Welder
Check to make sure that the valve to the shielding gas is open and that you have around 20ft3/hr flowing through the regulator. The welder needs to be on, the grounding clamp
attached to your welding table or to the piece of metal directly and you need to have proper wire speed and power setting dialed in (more on that later).
The Metal
While you can pretty much just take a MIG welder, squeeze the trigger and and touch it to your work piece to weld you won't get a great result. If you want the weld to be
strong and clean, taking 5 minutes to clean your metal and grind down any edges that are being joined will really help your weld.
In the picture below randofo is using an angle grinder to bevel the edges of some square tube before it gets welded onto another piece of square tubing. By creating two
bevels on the joining edges it makes a little valley for the weld pool to form in. Doing this for butt welds (when two things are pushed together and joined) is a good idea.
Image Notes
1. He should be wearing gloves - but it's ok because this picture is staged...
Image Notes
1. Bevel the edge on your metal before welding.
step 5: Laying a Bead
Once your welder is set up and you have prepped your piece of metal it's time to start focusing on the actual welding.
If it's your first time welding you might want to practice just running a bead before actually welding two pieces of metal together. You can do this by taking a piece of scrap
metal and making a weld in a straight line on its surface.
Do this a couple of times before you start actually welding so that you can get a feel for the process and figure out what wire speed and power settings you will want to
use.
Every welder is different so you will have to figure these settings out yourself. Too little power and you will have a splattered weld that won't penetrate through your work
piece. Too much power and you might melt right through the metal entirely.
The pictures below show a few different beads being laid down on some 1/4" plate. Some have too much power and some could use a little more. Check out the image
notes for the details.
The basic process of laying a bead is not too difficult. You are trying to make a small zig zag with the tip of the welder, or little concentric circles moving your way from the
top of the weld downward. I like to think of it as "sewing" motion where I use the tip of the welding gun to weave the two pieces of metal together.
First start laying beads about an inch or two long. If you make any one weld too long your work piece will heat up in that area and could become warped or compromised,
so it's best to do a little welding in one spot, move to another, and then come back to finish up what's left in between.
What are the right settings?
If you are experiencing holes in your workpiece than your power is turned up too high and you are melting through your welds.
If your welds are forming in spurts your wire speed or power settings are too low. The gun is feeding a bunch of wire out of the tip, it's then making contact, and then
melting and splattering without forming a proper weld.
You'll know when you have settings right because your welds will start looking nice and smooth. You can also tell a fair amount about the quality of the weld by the way it
sounds. You want to hear continuous sparking, almost like a bumble bee on steroids.
Image Notes
1. These settings are pretty good.
2. Not enough power, not enough wire feed.
3. Good wire feed, not enough power.
5. It takes a little while to get comfortable, don't be afraid to make some test welds
to get a feel for it.
Image Notes
1. These are similar power and feed settings, but tested on a much thinner sheet
of steel plate. As you can see the weld has penetrated very deeply and is starting
to deform the piece. You can see some curling on the sides of the plate.
Image Notes
1. Here the weld has completely melted through the thinner steel plate. The
welder is set way to high here.
step 6: Welding Metal Together
Once you've got your method tested out a bit on some scrap, it's time to do the actual weld. In this photo I am doing just a simple butt weld on some square stock. We've
already ground down the edges of the surfaces that are going to be welded so that the seem where they meet makes a small "v".
We are basically just taking the welder and making our sewing motion across the top of the seem. It's ideal to weld from the bottom of the stock up to the top, pushing the
weld forward with the tip of the gun, however that isn't always comfortable or a good way to start learning. In the beginning it's perfectly fine to weld in whatever
direction/position that is comfortable and that works for you.
Once we finished welding the pipe we were left with a big bump where the filler came in. You can leave that if you like, or you can grind it flat depending on what you are
using the metal for. Once we ground it down we found once side where the weld didn't penetrate properly. (See photo 3.) That means that we need to have more power
and more wire to fill in the weld. We went back and redid the weld so that it was properly joined.
Image Notes
1. This was our first try. Not a bad weld, but we could probably use a little
more gas and a little less power. This weld penetrated pretty deeply.
Image Notes
1. This side of the square stock wasn't welded with enough power because the
weld didn't penetrate all the way through. Notice the blue hue to the metal around
the seem. That means that we were pushing too hard with the angle grinder when
we were grinding down the weld. Remember to keep the disc moving and to resist
the urge of trying to cut corners while griding. It's sometimes a slow process that
requires patience.
step 7: Grind down the weld
If your weld isn't on a piece of metal that will show, or if you don't care about how the weld looks, then you are done with your weld. However, if the weld is showing or
you are welding something that you want to look nice then you will most likely want to grind down your weld and smooth it out.
Slap a grinding wheel onto an angle grinder and get started grinding on the weld. The neater your weld was the less grinding you will have to do, and after you have
spent a whole day grinding, you will see why it's worth it to keep your welds neat in the first place. If you use a ton of wire and made a mess of things it's ok, it just means
that you might be grinding for a while. If you had a neat simple weld though, then it shouldn't take too long to clean things up.
Be careful as you approach the surface of the original stock. You don't want to grind through your nice new weld or gouge out a piece of the metal. Move the angle
grinder around like you would a sander so as not to heat up, or grind away any one spot of the metal too much. If you see the metal get a blue tinge to it you are either
pushing too hard with the grinder or not moving the grinding wheel around enough. This is can happen especially easily while grinding thing sheets of metal.
Grinding welds can take a while to do depending on how much you have welded and can be a tedious process - take breaks while grinding and stay hydrated. (Grinding
rooms in shops or studios tend to heat up, especially if you are wearing leathers). Wear a full face mask when grinding, a mask or respirator, and ear protection. Make
sure that all your clothing is neatly tucked in and that you don't have anything hanging down from your body that could get caught in the grinder - it spins fast and it can
suck you in!
When you are done your piece of metal might look something like the one in the second photo pictured below. (Or maybe better as this was done by a few Instructables
Interns at the beginning of the summer during their first welding experience.)
step 8: Common Problems
It can take a good amount of practice to start welding reliably every time, so don't worry if you have some problems when you first stop. Some common problems are:
No or not enough shielding gas from the gun is surrounding the weld. You can tell when this happens because the weld will start splattering little balls of metal,
and will turn nasty colors of brown and green. Turn up the pressure on the gas and see if that helps.
Weld is not penetrating. This is easy to tell as your weld will be weak and won't be fully joining your two piece of metal.
Weld burns a while right through your material. This is caused by welding with too much power. Simply turn down your voltage and it should go away.
Too much metal in your weld pool or the weld is globy like oatmeal. This is caused by too much wire coming out of the gun and can be fixed by slowing down your
wire speed.
Welding gun spits and does not maintain a constant weld. This could be caused because the gun is too far from the weld. You want to hold the tip of the gun
about 1/4" to 1/2" away from the weld.
Image Notes
1. Lots of weld splatter here. Possibly caused by incorrect wire feed speed.
Image Notes
1. These settings are pretty good.
2. Not enough power, not enough wire feed.
5. It takes a little while to get comfortable, don't be afraid to make some test
welds to get a feel for it.
Image Notes
1. Here the weld has completely melted through the thinner steel plate. The
welder is set way to high here.
step 9: Wire Fuses to Tip/Change the Tip
Sometimes if you are welding too close to your material or you are building up too much heat the tip of the wire can actually weld itself onto the tip of your welding gun.
This looks like a little blob of metal at the tip of your gun and you'll know when you have this problem because the wire won't come out of the gun anymore. Fixing this is
pretty simple if you just pull on the blob with a set of pliers. See photos 1 and 2 for visuals.
If you really scorch the tip of your gun and fuse the hole closed with metal then you need to turn the welder off and replace the tip. Follow the steps and the overly
detailed photo series below to see how it's done. (It's digital so I tend to take too many pictures).
1. (Photo 3) - The tip is fused closed.
2. (Photo 4) - Unscrew the welding shield cup.
3. (Photo 5) - Unscrew the bad welding tip.
4. (Photo 6) - Slide a new tip into place.
5. (Photo 7) - Screw the new tip on.
6. (Photo 8) - Replace the welding cup.
7. (Photo 9) - It's now good as new.
step 10: Replace Wire Feed to Gun
Sometimes the wire gets kinked and won't advance through the hose or the gun even when the tip is clear and open. Take a look inside of your welder. Check out the
spool and the rollers as sometimes the wire can become kinked in there and need to be re-fed through the hose and the gun before it will work again. If this is the case,
follow these steps:
1. (Photo 1) - Unplug the unit.
2. (Photo 2) - Find the kink or jam in the spool.
3. (Photo 3) - Cut the wire with a set of pliers or wire cutters.
4. (Photo 4) - Take the pliers and pull out all of the wire from the hose through the tip of the gun.
5. (Photo 5) - Keep pulling, it's long.
6. (Photo 6) - Unkink the wire and feed it back into the rollers. To do this on some machines you have to release the tension spring holding the rollers down tight on the
wires. The tension bolt is pictured below. It's the spring with the wing nut on it in it's horizontal position (disengaged).
7. (Photo 7) - Check to make sure the wire is properly seated between the rollers.
8. (Photo 8) - Re-seat the tension bolt.
9. (Photo 9) - Turn on the machine and depress the trigger. Hold it down for a while until the wire comes out of the tip of the gun. This can take 30 seconds or so if your
hoses are long.
Image Notes
1. Kinked spool
Image Notes
1. Tension bolt and spring for rollers
step 11: Other resources
Some of the information in this Instructable was taken from an online Mig Welding Tutorial from the UK. A bunch more of the info was gathered from my personal
experience and from an Instructables Intern welding workshop that we held at the beginning of the summer.
For further welding resources you could consider buying a book about welding, reading a knowledge article from Lincoln Electric, checking out the Miller MIG Tutorial or,
downloading this beefy MIG Welding PDF.
I am sure that the Instructables community can come up with some other great welding resources so just add them as comments and I will amend this list as necessary.
Check out the other how to weld instructable by stasterisk to learn about MIG welding's big brother - TIG welding.
Happy welding!
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Comments
50 comments Add Comment
view all 127 comments
salemsgt says:
May 4, 2009. 6:30 PM REPLY
I just came into possession of a Chicago Electric 90Amp wire welder, non-gas. I have no operations/ owners manual. Does anyone know where I can get
one? And, I have heard of a spray that helps limit spattering, what is it and where can I get it? Yep, I'm a rookie, just trying to learn.
I'll appreciate any help anyone may offer. Refer to valaw@cox.net
Thanks a million
DANE1111 says:
May 1, 2009. 12:11 PM REPLY
man this is a great informational site.I am leaving for trade schoo in a couple weeks and taking welding and glad that I know the basics and so much already.
Thanks to all those who put there time and effort into these sites.
jkauwe says:
Apr 20, 2009. 7:09 PM REPLY
I just go some new welding resprators made by 3M. They are brand new but, I can still smell the zinc or, other gases thru the metal. any ideas or tips?
darnocpdx says:
Mar 28, 2009. 7:56 AM REPLY
Galvanized steel is nasty stuff. You can get zinc poisoning with it's exposure. It is inert until it burns. It's the zinc in the smoke that will make you sick.
You can taste it as you get it when welding (a weird kinda taste in the back of your mouth can't really describe it real well). And since your body has no way
to get rid of it, it actually builds up in your system and it gets easier to get with future exposures.
Trust me it's no fun, being a welder I get it from time to time. (Sometimes it too hot outside and I'd rather take the chance on poisoning than wearing a
respirator all day long).
Also it can be quite frustrating to weld through. If your just starting out with welding, don't practice on galvie. It's not going to be easy, the zinc resists not only
water/air but electricity too. And you'll be have a hard time getting a good weld.
Even if you get it going, the zinc will weaken the weld in that it will contaminate the weld with zinc, reducing the structural integrity of the the weld.
Don't use galvanized steel unless you have too. And then it's only really needed for things that are going to be exposed to the elements constantly. I wouldn't
use it for anything that wasn't structural, other than a perhaps dune buggy frame or say the support frame to water tanks or something of that ilk.
dmcodwhy says:
Mar 25, 2009. 12:14 PM REPLY
From my teachers "always open your valves all the way". The valves are designed with a seal at 100% open too. (as cox_gene said)
Muscelz says:
Mar 15, 2009. 5:42 AM REPLY
ahh uhm no disrespect but the role of the the gas is to sheild the arc from the atmosphere (nitrogen & oxygen to be exact) so it doesnt "burn" or "plasmaize"
is some respect, without gas "fusioning" process doesn't occur propaply and will leave the weld bubbly and ugly and in some cases wont even weld
ncblu says:
Jan 5, 2009. 8:48 AM REPLY
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
Beausejour says:
Mar 14, 2009. 6:08 PM REPLY
HI There Can you tell me how close i should hold the tip from my work.
ironandwine says:
Jan 8, 2009. 9:53 AM REPLY
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.
stallsworth says:
Mar 13, 2009. 6:57 AM REPLY
miller
ncblu says:
Mar 13, 2009. 6:40 PM REPLY
2nd that - they're worth every bit you pay for them
ncblu says:
Jan 8, 2009. 3:09 PM REPLY
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 http://www.millerwelds.com/ 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
ncblu says:
Jan 5, 2009. 8:54 AM REPLY
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.
stallsworth says:
Mar 13, 2009. 6:53 AM REPLY
dude u suck at welding u need to get ur wire speed right and lurn how to put a proper beed down im only 16 and weld better than you and i have a job at a
big welding shop in ar. if ur going to put a how to up at least do some thig u no like sucking at life
flatcurve says:
Mar 6, 2009. 9:32 AM REPLY
I would recommend wool as well as cotton, because wool is naturally fire resistant.
weldinman#2 says:
Feb 26, 2009. 1:25 PM REPLY
I think that this is a blast I just started like 2 weeks ago and I love it
rivetgeek says:
Dec 22, 2008. 10:59 AM REPLY
Heres an old welders trick for mig spatter, cooking spray. Just spray the whole area with pam or some sort of non-stick cooking spray and the tiny beads
wont solidify on the metal because they vaporize the spray on contact with creates a tiny gas shield under the bead as it cools.
As an added bonus, welding now smells delicious.
trailleadr says:
Jan 28, 2009. 5:33 AM REPLY
That welders trick is for the inside of your gas cup. If you spray the surface to be welded then you'll ruin the gas coverage. When the cooking spray burns
off it will not allow the shielding gas to do it's job which will create porosity and weak structured welds. Always keep your welding surface clean!!!
So your added bonus will be that your weld looks like hell, performs like crap, and smells like burnt oil.
Mechanical Advantage says:
Feb 6, 2009. 8:41 PM REPLY
True - I wouln't spray it directly on the area to be welded. But it might be handy if you sprayed it on the surrounding area, if you were concerned
about splatter sticking to the rest of the peice.
Mechanical Advantage says:
Feb 6, 2009. 8:38 PM REPLY
Very informative! This gives me a little more confidence to try my hand at welding. Thanks!
kaboom05 says:
Jan 25, 2009. 8:53 PM REPLY
hey i am a boily welder by trade and just wanted to say nice introduction to welding =]
i have to say if u ever get the chance at some hardened steel welding using an iner shield welder it blows ur mind with the difference between the mig and
inner shield but is alot harder to learn.
keep up the good work
and continue to weld
ps slow down ur welding and hold the nose alittle closer or tilt the nose on more of an angle
good job =]
ncblu says:
Jan 5, 2009. 8:33 AM REPLY
welding sounds......
when i run hardwire, i can prep it to a point where you hear nothing, the only time you hear bacon sizzling is if you're running fluxcore or your metal isnt
clean.
magworks7 says:
Jan 24, 2009. 10:22 AM REPLY
This information I am giving may be a little advanced,but may help.There are 3 different types of wire transfer-(wire to parent metal) when it comes to
running MIG.
Static Transfer-(Bacon Frying Sound),Globular Transfer-(Some Sound),and Spray Transfer-(No Sound).The way you achieve each type of transfer is by
adjusting your voltage control from lower settings-(static) to higher levels-(Globular),Highest voltage tolerance-(without burning back to your tip) will
achieve your spray arc.What type of transfer used is determined by what the thickness is of the metal your welding on,and your rate of travel speed.
When you are using a solid wire,and using a spray transfer,I would highly recommend using 95/5 gas-(95%argon,5%oxygen) as well.This gas will help
you run a bit hotter,and will help you produce a better weld by bringing more impurities of your parent metal-(work piece) to the surface.
On a personal note,I agree with ncblu.
-Adding a comment,...a properly done finishing pass (at times) can improve the final overall appearance of the weld job without negatively affecting weld
quality .
kenbob says:
Jan 23, 2009. 12:30 PM REPLY
Thanks. You provided some good tips here. As an amateur welder, the grinder is my friend. My last project (posted) was especially difficult for me as it was
my first where the final structure was bigger than I could move. You could do a great supplement on magnets, bracing, squaring, etc.
benthekahn says:
Jan 21, 2009. 6:26 PM REPLY
It seems like there is a lot of build up on the cup in these pictures. I found these MIG pliers help a lot.
ohament says:
Jan 12, 2009. 11:06 AM REPLY
Thank you for the informative article. I have a MIG/TIG welder and only used a handful of times. I always wondered why I got brown beads and splatter so I
avoided having to plan projects requiring welding. You have restored my confidence and I'm beginning to plan my utility trailer upgrade which will require
some welding!
jayrak says:
Jan 8, 2009. 4:55 PM REPLY
YouTube videos on MIG welding:
http://www.youtube.com/profile?user=TheLightningStalker&view=videos
ironandwine says:
Jan 8, 2009. 12:23 PM REPLY
hey ncblu, looking at the hobart 140. question is, my platform is 5/16 diamond plate, this welder is rated to work with up to 1/4 inch. would it do the trick or do
I need to bump up to a 220 unit if I'm going to be welding on 5/16 material?
BlessedWrath says:
Oct 14, 2008. 11:54 AM REPLY
I am searching for the best type of welding for a very specific application, and have questions.
One: The application requires fine detail much too intricate for any sort of flame welding at all. It's down to MIG or TIG at this point, unless there's something
else out there.
Two: The application requires butt-welds between two ends of wire (I'm sealing the joins in tiny metal rings, and want a solid ring as an end result)
Three: The material is stainless steel wire ranging from 20gauge to 12gauge in thickness, and the rings will be in close proximity to one another (they will be
joined with other rings in a very tight pattern).
It is my belief that MIG is the way to go, but I'm seeking confirmation from those who know. Unless I attend a class, my only option to learn is to buy one and
experiment. I don't have money to waste, so I only want to do it once.
So how about it? MIG? Yes? No?
mattstruct says:
Jan 6, 2009. 10:30 PM REPLY
It sounds like you're making chainmail from jump rings. I've a fair bit of experience making chainmail from various gauge wires, in various ring sizes, and
unless using wire more than 1.5mm thick, I think you'll find an oxy/propane or oxy/acetylene torch is the best way to go. Jewellers typically use
oxy/propane, and very small hand torches. Search for "the little torch" to get an idea of one frequently used handpiece. This will happily allow you to weld
jump rings of up to 1.5 mm wire thickness, and I've successfully made chainmail bracelets from 0.5mm diameter silver wire, wound around a 1.6mm
former.
A standard sized oxy torch will work nicely for chainmail made from anything from 1mm up through about 5mm wire. Anything larger than that might
require a TIG welder.
If you search jewellery making sites like ganoksin, you'll find many people using oxy/fuel torches to make chainmail.
eosha says:
Oct 27, 2008. 5:08 PM REPLY
I know that many of the people making welded chain mail use a simple spot welder. AZON makes commercial-sized machines for that purpose, but there
are some other ideas out there for home use.
jholder73 says:
Oct 27, 2008. 4:11 PM REPLY
Tig would be best for thin stainless, another good option would be to stick weld it.
ncblu says:
Jan 5, 2009. 8:31 AM REPLY
i'm a welder. if you try running a bead in small circles, you will likely get fired if someones paying you to do it, what you get is undercut because you're not
laying enough wire down and spreading the puddle out too far and not getting the right penetration. straight line passes are the only way to properly weld and
if you have to make more than one pass - your welds will look better and be stronger. if i read the instructable correctly it states that you move from the top
and weld downward - dont!, you get minimal penetration and all you are doing is laying blobs of metal down which will likely end up at your feet. always weld
from the bottom and proceed vertically, no weaving, circling or sewing.
recon506 says:
Oct 4, 2008. 12:03 PM REPLY
What do you think? 1/4" GPS steel plate, first time welding. I'm guessing that my regulator was not set high enough, judging by the little brown halo
surrounding the weld, but I really like the concentric circles my weld has.
Any comments/suggestions are more than welcome - I have a test on this in a week!
Black Cat says:
Jan 1, 2009. 1:52 AM REPLY
dont forget that the angle on the gun is very important too for a good weld.
dj_nme says:
Dec 17, 2008. 2:00 AM REPLY
This isn't too bad for your first weld bead.
I hope that you went OK in the test.
You might want to either turn up the voltage slightly or turn the wire-feed down slightly to flatten the bead out.
Also, you could try holding the torch with two hands: dominant hand gripping the handle and your off hand cupped underneath to help both with the
weight of the torch and to move at a more constant travel speed.
The bead going from narrow to wide and back again is showing that your travel speed is uneven.
The brownish stuff around the weld doesn't matter, the real indicator of not enough shielding gas is a bubbly looking weld bead.
The ideal amount of gas is a flow rate of between 15 to 20 litres per minute.
The inert gas regulator should have two dials: one showing the cylinder pressure and the other showing the flow rate.
Another couple of causes of bubbly welds are:
Tipping the torch over too far (too much lead angle) and causing a venturi effect which sucks in air.
Too much gas flow (over 20 litres per minute), the same problem is caused.
StarBlades says:
Dec 12, 2008. 9:54 PM REPLY
you should turn your gas up. or use a wire brush to clean off the brown stuff :)
sgwires says:
Dec 24, 2008. 10:19 AM REPLY
sgwiresWe are a manufacturer of MIG Wire & SAW Wire located in faridabad, India pls tell which tests should be done on the wire to confirm its aws
odonnghaille says:
Dec 23, 2008. 6:15 AM REPLY
The Australia Govt. is funding a science project at the moment on the effects of cocaine on Bees, So imagine how self important he feels.
tzhauling says:
Dec 20, 2008. 7:26 PM REPLY
A tip to avoid spatter from sticking from the tip it to dip the tip into liquid flux before welding, and a few time during welding if welding for a long period.
tzhauling says:
Dec 20, 2008. 7:20 PM REPLY
Just another tip about the sound. My teacher always say to listen for the eggs frying.
melds says:
Dec 16, 2008. 11:46 PM REPLY
Check out http://www.sperkoengineering.com/html/articles/WeldingGalvanized.pdf and http://hazmap.nlm.nih.gov/cgibin/hazmap_generic?tbl=TblDiseases&id=69 on galvanized steel.
I did however find warnings on NiCd welding rods and Fluorite in some fluxes. I don't know anything about welding, though.
WikiPedia has an article on heavy metals does not list zinc in the toxic metals category and also discusses Zinc Shakes.
jschmadeke4life says:
Again, awesome job and very informative. Thank you.
Dec 16, 2008. 7:55 PM REPLY
jschmadeke4life says:
Dec 16, 2008. 7:35 PM REPLY
Great Instructable! I appreciate you taking the time to put this together :P
rick450 says:
Jul 10, 2008. 7:53 PM REPLY
The welding shown here would be considered defective welds. When welding tube or pipe the tubing is beveled at 47 degrees +/- 5 degrees with a 1/8th inch
landing applied to the ends and its an open v groove weld separated by 3/32 or1/8 th inch and a full penetration weld is required..followed by a hot pass and
filler passes. His grinding show incomplete fusion of the weld. The weld should be stronger than the metal thats welded not become the weakest point. A mig
welder is not like a glue gun. Also the gas mixture that gives the best results is 75%argon and 25% carbon dioxide also known as 75/25.
gnose says:
Dec 15, 2008. 12:34 AM REPLY
we're...beginners
tercero says:
Sep 6, 2007. 4:48 PM REPLY
Thanks for this. I purchased a 220v Lincoln Mig last year for a project, and never got around to using it. I've yet to weld and it's $500 just sitting there
collecting dust. After reading this, I feel like I should go and give it a try this weekend. I just wished there was somewhere local (in Barrie) that taught a basic
welding course.
stasterisk says:
Mar 2, 2008. 7:50 PM REPLY
Did you give it a try? How did it go? Welding is something you really can do on your own - you could be the person in Barrie teaching a basic welding
course!
Just treat MIG as though it's a big metal hot-melt glue gun, and you're in the right mindframe, and know everything you need to know. Hit the "on" button,
and you're welding!
tercero says:
Mar 3, 2008. 6:00 AM REPLY
I'd forgotten all about this thread, :)
I welded my Saturns exhaust last year. I swapped out the engine cradle and had no choice but to cut through the exhaust just forward of the cat. So, I
welded the exhaust. I burned a couple of holes through, but I got it back together. I sealed the exhaust with auto cement and a flat band exhaust
clamp. I next used the welder to weld a broken sway bar on a Dodge Caravan. The sway bar had broken where the bar attaches to the stabilizer bar
link. I used the correct liner and wire, and did a nice neat job grinding off any excess and sealing the final job with tremclad metal paint.
My projects for the spring (after the snow goes) is to build a small bike carrier and weld a bike frame.
StarBlades says:
if you weld and make a huge hole, try to do small little welds around the hole and you can patch up the hole.
view all 127 comments
Dec 12, 2008. 9:59 PM REPLY

How to Weld - MIG Welding Home Sign Up!

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