How to MIG Weld like a Professional
It is important to keep your welding skill sharp, but do not forget a welder’s repertoire is not only about clean welds. It’s about the whole welding process from start to finish, setting up your machine, setting up your metal pieces, welding, and finally your final touches, such as painting.
Machine Settings
First up, in order to start welding we need to tune our welder for the task at hand.
Electric Arc Welders – there are two settings which require adjustment. The power setting and a speed setting. (Applicable to both MIG & TIG welding)
The power setting is what adjusts the amount of volts/amps being dished out. An increase in electrical output causes your wire to melt faster.
The speed setting determines how fast your wire is thrown out of your gun.(For TIG the speed will be how fast you feed the rod with your hand)
First, we will discuss the power setting which ranges from A-K, A being the lowest power and K being the highest. The power setting is solely based on the metal thickness you are working on. Your highest setting will vary depending on which electric welder you have purchased. The ones with higher letters are more powerful and more expensive.
This can easily be measured using a tape measure or caliper. There is a diagram typically on the inside of your electric welder or on the manual that came with your machine. The chart will look like the following:
Once your power setting has been configured, you will need to tweak the speed setting. The speed range is between 1 and 10, 1 being the lowest speed and 10 being the highest speed option. Unfortunately, the speed setting is not as simple, the setting is dynamic.
This setting can be balanced out by your hand movement speed, the slower you move your hand the higher the speed should be. Most welders have their own sweet spot for their hand movement speed, so this setting can vary from person to person.
The intended setting for this would be the higher your power output the higher the speed setting should be. Since it melts faster it requires you to feed more wire in a shorter amount of time. Yet it cannot be too high because then it will cause you to make a hole through your metal. Too much wire melting in one point causes the metal to heat up more than normal and it melts it away.
Note: If you are using gas with your electric welder, your gas psi gauge should read 20psi.
Metal Preparation
Mark your metal
Once you have your welder’s setting setup for the project, you’ll want to start to arrange your metal. You will need to look at your project blueprint. If you do not have one, you will need to make one, this does not have to be “engineered” made. It’s important to have the measurements of each individual part, and have a general idea of where each part will go.
Keep the blueprint close. Grab all the metal pieces you will be working on, and begin to mark them with a marker according to the blueprint. You will mark down all the places where cuts and welds will be necessary. Make sure to write down the length in inches or feet on the metal, to save you time from constantly checking the blueprint.
Keep in mind, you need to deal with heat distribution. You need to weld in sections, each section being a maximum of 4-6 inches, depending on how fast you are welding. The faster you are welding, the longer it may be. Try to zig zag your welds as well, weld from one side, then for your next section, weld from the other side and so on. Moving back and forth, from each side, until you reach the center.
The way you have a good placement of your welds is by always starting from each end with one section on each side. Then placing one in the center of the two(50%), then another two in the middle of each side to the center,(25%) &(75%) respectively.
Smoothing out the Edges
Now that you have all your metal marked, start to remove the rough edges by sanding them down.
Place your disc sander or file sander, at 45 degrees on the edge, you will only need a tap, or a quick pass from side to side.
Do the same on the opposite edge. The sides will be mostly diminished and rough, but that is okay, the first pass was simply to give it its round shape.
You will now choose one side to start from, does not matter which side, and do the same thing, slightly faster.
When you reach the end of the first side, tilt your sander to 85 degrees and work your way back. Then tilt your sander to 95 degrees and give it a quick pass. Lastly, set your sander to 135 degrees and bring it back.
Your result should be a nice round smooth edge. You may need to give it a feel with your hands the first couple of times, and sand down any deformities. Since the pass with the sander is pretty fast, it’s easy to change the degree of the disk when going over it.
Create good Connection
Before you put your sander away, pass over all your previously marked welding locations.
This will remove all the dirt and oil in the area and ensure a strong connection is established when you weld. It might seem a bit exaggerated at first, especially since, well, it will still weld without doing this, but that is only because, after you have applied enough heat, it burns the dirt and oils off the surface. So why do it?
Prior to you being able to apply sufficient heat, your wire will stutter to make contact. In other words, you will get sparks flying out before you get a nice sizzling constant burn.
These “sparks” are actually pieces of your wire melted. The ones which do not cool off in the air, typically the ones which land closer, will stick onto your metal. Some of these can be taken off by hand, others will require you to tap it with a chisel or using the edge of a sander/grinder’s disk.
So it is clearly a win-win scenario. Always sand down your welding location prior to welding, it saves you clean up time, makes it easier when welding, and you will be able to see the welding location more easily.
Placing your Metal
Start to put in place where each metal piece will go.
Use a right angle and a level to make sure everything is placed nice and straight.
You will be placing tic-tacs where all your marks for welds are, this will hold everything in place. Tic-tacs are small balls of welds. A couple of these will not only hold it in place, but be able to withstand hammering. To top it off, what makes them your best friend, is the fact that individually they are easily taken off.
Begin to Weld
Finally, you can now begin to weld. Go over each tic tac location, which was previously placed in your marked locations. Remember not to weld from one side to the other non-stop. To prevent warping of the metal, work in sections and in a zig-zag form.
Make it Presentable
In order to make your work really pop out and give it that manufacturer look you will need to give it a nice coat of paint.
Preparing the Surface
In order to get a nice even coat of paint that will not break, you will need to smoothen out your metal’s surface. Grab a sander disk and pass over the whole surface, it does not need to be 100% even, as long as you see a nice clear shine on your metal that is fine. The wheel patterns leftover will not affect how your paint responds.
Primer
For this next part, we need to determine what will be the use of the project being constructed. Depending on its purpose, you can apply its respective primer:
Primer | Intended Use |
UV-Resistant | If you project will be in direct sunlight for a long time |
Rust-Oleum | If your project will be in a humid area for a long time |
Heat-Resistant | Great for Barbeque Grill, Engines. Something that produces a lot of internal heat |
Self-Etching | Good for project with deep veins of rust, it ensures your primer coat goes to the top of the surface |
Note: If you are not using a primer All-in-one and want UV protection. The primer type does not matter, you will need a UV-Resistant paint or a clear UV-Resistant coat. UV protection must be applied in the outermost layer for it to have any effect.
How much you would like to spend on the painting process is up to you, but for the best paint application you should apply two coats of primer. The first coat is a very light coat, applied at approximately 1ft away(in a low wind environment).
Applying it to the whole surface, you may still be able to see patches of the metal’s color, which would be fine for the 1st coat. The pattern in which it is applied does not matter, since it will not be visible. You can go up and down, side to side.
Let it sit for 5 minutes to make sure it completely dries. Then begin applying your second coat. Your spray can will be about 6in away from the metal when spraying. You want to be able to see a nice wet coat as it lands on the metal. Make sure to increase your distance if you begin to see it wanting to drip.
Note: If it drips, use a rag/napkin to soak it up. If it has dried then you can sand it down. Debri flying around might have also gotten stuck. Make sure your end result is nice and smooth.
Painting
Before you begin to apply your paint, make sure you have let enough time pass for your primer to fully dry. Once you are sure it’s dried, you can begin to apply your first coat of paint.
Unlike your primer, your first coat will be applied more heavily than your second, this is because you now have a smooth surface underneath. You will keep your can about 7 inches away and move in a side to side motion, working in a square section at a time.
Let it sit for about 7 minutes, then apply your 2nd coat. This coat will be applied at about 6 inches away, but at a rate 3.5x-4x faster speed. You will also not work in sections anymore, but rather from one side to the other side non stop. This will help blend any lines previously left over, and give you a nice clean finish.
Note: If you wanted to use a paint with gloss but were unable to find one with your color, you can apply another coat of clear gloss on top. Likewise, if you wanted to apply a layer of sun protection, simply add a UV-Resistant clear coat.
Looking at your finished result now, it would be hard to believe it was DIY made.
Although you might feel something is still off, and that is having an authoritative figure behind it. In order to fully imitate a manufactured metal part, you’ll want to add a “brand name”. It doesn’t have to be an actual existent brand, it can be whatever you want. Depending on how big your project is, you might want to consider using multiple colors. 2-3 colors will make it look more visually appealing.