These are just some basic tips for tig welding steel, I am the first to admit that I am not the best tig welder out there but I know a few things about welding that I would like to share. There are many things that come into play when tig welding such as how clean your material is, how sharp you tungsten is, angle of tungsten, size of gas cup, gas flow, tungsten size, wire size, material size, and amperage.
The first thing I tell anyone about tig welding is that your material has to be CLEAN CLEAN CLEAN! No mill scale, all areas to be welded have to be ground down or sanded. I like to use the surface prep grinding wheels for a 4 1/2″ grinder, they are pretty much a scotch bright grinding wheel. If I do not have one of those I will use a flap disc but I try not to because they will take material away unlike the scotch bright pads do. If you have any deep grooves cut into your material you want to grind them smooth with a flap disc and some times when I am really feeling picky I will use a palm sander to finish it off. The reason why is because the arc and puddle flow smoother on a clean smooth surface. I also try to prep my material the same every time that way I know if the weld looks like crap it is not because of the prep I did.
Your tungsten is the next step, there are several different sizes and types. The most common used for steel is 2% Thoriated but I like to use 1.5% lanthanated because it will work for AC and DC. Hereis a link to Millers selection and preparation guide for tungsten.I would recommend buying the cheaper tungsten as a beginner because you will be going through more than normal. When grinding tungsten you first want a designated grinder for doing this because if you use one that has been grinding on other materials they will inbed themselves in the tungsten screwing you up. Next, when you grind you want to grind it with the grain not against it. Your grinding wheel should be spinning in your direction and be pushing not dragging it. The sharper the angle, the bead will be smaller because you are pretty much making your tungsten smaller. The smaller it is the less amps can travel through it efficiently and it will most likely ball up on the tip depending on how much heat you try to put through it. If you grind it at too much of an angle you can flatten the tip just slightly and that will widen the puddle up. Normally for thinner gauge material I will put a real sharp point on the tungsten but for thicker gauge I will flatten the tip a little. I used to have a special hand held die grinder but someone re-wired one of our outlets to 220v rather than 110v and it blew up. Now I just use a bench grinder with a cordless drill, this way I don't have to spin the tungsten by hand.
Your gas should be argon (not mixed) for steel and aluminum and should be set between 15-20 cfh, if you set it too high it will blow away from your weld which is bad. The tungsten should not stick out farther than the diameter of the cup, but I've had to do it before for tight spaces just not all the time. I am sure I have missed a lot and like the title says these are just some basic tig welding tips. I will be adding more later. Here is a link to a very informational how to website weldingtipsandtricks.com .
