As a DIY Welder and Metal Fabricator, you should at least be familiar with the different common types of welding machines and processes. Check out this post for common welding acronyms and what they mean in plain english.
Let’s work through these definitions with the help of our friends Wikipedia and Amazon. Click on any of the pictures or Wiki links for more information.
SMAW – Shielded Metal Arc Welding
Also known as ‘stick welding’. This is the simplest and cheapest method of welding to get into. basically it consists of a welder, positive and negative leads and a stick of metal covered in flux. Because of the flux, no welding gas is needed. If you are on a tight budget and only need to weld occasionally, or have the need to weld different metals like aluminum or cast iron then this is a good option. Light duty SMAW stick welders are generally pretty cheap and you can buy welding rod to weld just about anything.
These welders used to be big, heavy, and full of copper like this one. They can put out up to 225 amps to really burn into some thick steel. Also known as a ‘tombstone’ because…well it looks like one:
But now they are ‘inverter’ powered. Lets just call it working smarter not harder. Therefore are 1/4 of the size and typically cheaper until you get up to the higher amperage units, then it is cheaper to go with the above ‘tombstone’ type.
GMAW – Gas Metal Arc Welding
FCAW – Flux Cored Arc Welding
I am going to lump GMAW and FCAW together, because they are both forms of wire feed welding (commonly called MIG welding). This means that there is a spool of wire inside of the welder that travels through the gun and out of the tip as you are welding. The difference between GMAW and FCAW is that GMAW uses welding gas that also travels through the gun and out the tip to protect the weld, where FCAW uses special wire that has a flux core in it therefore no welding gas is needed. Other than that, they are pretty similar processes.
Today, GMAW is the most common industrial welding process, preferred for its versatility, speed and the relative ease of adapting the process to robotic automation. – Wikipedia
Wire feed welding is good for just about all positions, is fast, and with flux core wire (FCAW) you can weld outside or in windy conditions. some disadvantages are that if you want to weld aluminum for example, you would need a welder that is compatible with an aluminum spool gun. The reason for this is because the aluminum wire is too soft to travel through ~8 feet of hose, so you have to use a smaller spool of wire located on the gun.
Below is a small homeowner type 110V input welder. It still has the capability for welding gas. You can save ~$100 and go with a unit that doesn’t have the welding gas capability, but it would not be fun if you decided that you didn’t want to keep using flux core wire at some time in the future. Keep in mind, the units that weld with welding gas are backwards compatible with flux core wire, but if you have a flux core only machine, it will never weld with gas.
Here is a medium duty welder like the one I have in my shop. 99% of everything I weld is 1/2″ thick or less and this size unit works well. As an added bonus the unit below includes an aluminum spool gun (though you will need two different kinds of shielding gas, one for steel and one for aluminum)
What is the big deal about shielding gas? The shielding gas protects the weld area from contaminants in the air specifically oxygen and nitrogen that make for a porous weld. Flux core wire will also provide this protection, but creates more spatter/smoke due to burning the flux.
GTAW – Gas Tungsten Arc Welding
Also known as TIG welding (Tungsten Inert Gas) uses a tungsten electrode to make the weld instead of a consumable wire or stick. TIG welding as far as I know always uses shielding gas, though what type of shielding gas you use, depends on what type of metal you are using. According to Wikipedia, TIG welding is most commonly used on thin sections of stainless steel and nonferrous metals like aluminum, magnesium, and copper.
In my opinion, this is definitely one of the hardest welding processes to master. I have dabbled in it from time to time with my combination welding machine, but haven’t really gotten good at it yet. You create a spark between the tungsten in the gun, and the metal you are trying to weld. Once the base metal of the piece you are trying to weld gets hot and starts to melt, you move the torch in a small circle while adding metal with an appropriate type of filler rod as needed. When done properly, it can produce very high quality welds.
I have and use a combo machine made by (imported by?) Everlast Welders. They aren’t going to be as good quality as a Miller or Lincoln, but you really get a lot of bang for your buck. With one machine I can TIG weld, STICK weld, and PLASMA cut. So far my only failure has been a pressure regulator and a finicky TIG foot pedal. Click on the pic below to at least check them out while looking for your welder, you might be surprised by the reviews.
If you made it this far, congratulations. I hope you learned something about the different common welding practices. Check out the Wikipedia articles for more information, and click on the pictures to check out some of the different welding units and their prices on Amazon. Now go outside and build something! Till next time, Paul.