GMAW

Gas Metal Arc Welding (GMAW), often times referred to as Metal Inert Gas (MIG), is a semi-automatic or automatic welding process. In this process you use a consumable wire electrode that is continuously feed through a wire gun along with a shielding gas to protect the weld. With the GMAW process you use a constant voltage, DC power source most of the time. Constant Current Systems, as well as AC can be used for some metals.

The equipment involve in GMAW is a welding gun, a wire feed unit, welding power supply, an electrode wire and shielding gas supply.

The wire electrode is feed from the wire feed unit into the liner of the welding gun. The liner keeps the wire from binding up inside the gun while being feed to the work piece. As the wire passes through the contact tip it becomes electrically charged. Once the wire touches the grounded work piece it then makes the arc and you can begin welding. As you are welding, the gas nozzle is used to evenly distribute the shielding gas over the weld zone. The larger the nozzle the more shielding gas will be distributed over the weld area. So, if you are going to be using wider weld beads then a larger nozzle would be needed.

GMAW torch nozzle cutaway image. (1) Torch handle, (2) Molded phenolic dielectric (shown in white) and threaded metal nut insert (yellow), (3) Shielding gas diffuser, (4) Contact tip, (5) Nozzle output face
The major advantage that GMAW has over other welding processes is that it is fast and pretty clean. You rarely have to stop with the GMAW process too. Where as in GTAW or SMAW you have to stop when you run out of filler rod.

On the flip side, it is difficult to use in hard to reach places because of the size of the nozzle.

Technorati

Trying to get linked up on technorati.com. If you are a blogger and you don't know about it you should check it out. It is a site where you can register your blog with them and hopefully it will help you get more traffic to you blog. After you get signed up you have to put your blog address in your profile and follow the steps to get it authorized. One thing you have to do is put in a verification code in one of you blogs. I'm going to put it in this one at the end of the blog. So the letters and numbers at the bottom will be this code I am talking about. Anyway, thought I would try it out and see how well it works. I will have that blog on the "mig" welding process posted shortly. Bare with me.

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SMAW

So let's talk about the SMAW process of welding. SMAW, also commonly known as "stick" welding, is one of the most portable and wide spread ways of welding. It is a manual arc welding process that uses a consumable electrode coated in flux to lay the weld. You can use either direct current or alternating current for this welding process. To get the arc started between the electrode and the base metal you put your electrode into your electrode holder, which is connected to your power supply, and slightly scratch the electrode on the base metal. As you are laying the weld the flux will turn into vapors that protect the weld pool from atmospheric contamination. A layer of slag will also form on top of the weld to protect it while it is in the molten stage.

 In my experience with welding SMAW is the easiest to get started with, but one of the hardest to prefect. There are a lot of starts and stops with this process because you are using a consumable electrode. Tying into the starts and stops is a little difficult at first, but it is very important in this process. I've found that if you start a little in front of where you stopped and work back into the weld you get a better tie in. This helps prevent a cold start and possible defects in your weld.

The process is used primarily to weld iron and steels (including stainless steel) but aluminum, nickel and copper alloys can also be welded with this method.

That pretty much covers the basics of SMAW. If anyone has anything to add please leave a comment and we can talk about it. The next blog will be on the Mig process. I will include both FCAW and solid wire in the blog.

Let's Talk Welding

I would like to start this blog by talking about what I want to acomplish on here. I want this to be a place where people new to welding can get good information and learn a thing or two. I also want this to be a place where people that have been in this field for a while can talk to others and get ideas if they need it. I don't want to restrict this to only welding processes. I want this to be a place where we talk about anything to do with metal working. Lets get some good content on here that people can use in the "real world". My next post will be about the SMAW process, also know as "stick" welding.