Tig welders - discuss
LOL, an hour, ok, you may think you have something down but I guarantee you don't
I think some of the Miller machines are more plug and play, per metal application.
the Miller and other machines that have digital wave presets basically tell you to do whatever the chart says for each metal and thickness, much like a chart inside of the spool access door on a MIG.
I believe that with a digital preset, the machine probably took a lot of the bugs out of welding the working material. Ironically enough, this is the reason I did not buy one and opted for analog potentiometer controls.
A lot of the presets on the Miller machines are great and you can adjust them, but I felt that I would pay for a lot of stuff that I am simply not going to make use of, like pulse control. I think it can help with heat control, but after reading up on turning the frequency up on a pulse wave to emulate high frequencies that AC has for aluminum, even though it cuts down on heat spread, it makes the weld itself more brittle, which is already an inherent problem that a TIG welder gives.
Don't let that scare you away from a TIG. This is not a factor on a finished weld with the correct filler rod and penetration. The only time it affects anything is if you plan on beating the crap out of the weld. Why would you do that? Because planishing sheet metal requires it, for more involved panel fabrication.
With the exception of panel fabrication (big stuff, like joining large surface areas to to other large surface areas without a body line, butted for metal finish), a TIG is ideal, but not always necessary, depending on what you are looking for on the finished product.
I knew about the seperate grinder - my thought was a seperate wheel. My garage is rather tight and I'd hate to have a 2nd grinding wheel sitting around most of the time. I also understand each material has it's own personality. That's one of the things that concerns me...lol. I only "know" mild steel.
You will get more exercise changing wheels than what it's worth, or essentially lose a wheel on your grinder that will be living on it, especially when you are learning.
Every time that tungsten touches the work metal, you will have to grind the work metal off of the tip by resharpening it, or the arc will wander everywhere and have a ton of unfocused heat soak into the work. This is because tungsten steel melts at around 6000°F, whereas mild and even stainless steels melt closer to 2000°F.
The reason a TIG welder has such a focused heat range and high control, is due to the fact that the polarity is reversed. The reason the torch tip needs to be made from Tungsten steel with other high heat withstanding elements like thorium or lanthanum, is so the tip can withstand the heat of the arc that is coming from the positively charged work metal, into the negatively charged tip. The tip takes the heat from the current direction, even on AC, it takes the majority of the alternating current frequency direction, so when the tip touches the work metal, it actually takes part of the work metal with it, making the negative electrode weaker to withstanding and controlling heat.
This means, when you are working with the welder, you will do best to sharpen both ends of your tungsten rods and have a few on hand, sharpened, ready to go, in case you fumble. The grinder will be used a bit more frequently than you want to use it at first. It can get frustrating, but if you stick with it and really focus on distance and angle control, you will find that the pedal pulse and bead control will come with practice.
TIG welding is like combining torch welding with pinstriping. You always find a good rest for your hand to either prop on or drag against, out of the heat area as a guide and do a dry run to see how you will execute the pass without obstructions. This is how good tig welds look straight and consistent. Pulse control with pedal changes bead width as you amp soak each bead to melt, so it takes some practice on a mock up joint with the same material and angles.
The key to each weld made is to try it on junk metal, until you become familiar with your working material, angles, machine settings and techniques.
Here is what I would recommend considering, when buying a machine ~
- As mentioned, aluminum or not?
- What thickness of metals do you plan on welding? The number of the machine is usually given by AMP capability. 1 amp per .001", with the exception of stainless steel and moly, because they soak up and disperse heat, so 2/3 amp per .001" when working with those metals (not to mention a good mask, because chromium is deadly).
- Working environment? If you weld outside, forget it. You will never get the control you need with a TIG without excellent shielding cones and lenses, along with no breeze. You will want a collection of different ones for different jobs, along with a diffuser for lenses.
- How often will you be using it? Sometimes a few jobs would make more sense to hand out, rather than take it on. If you plan on fabricating a lot, look into jigs and various clamps to have repeatable results. This is also a huge part of a good looking weld. Cleanliness of the metal and orderly condition/ shape and gap consistency. It turns a frustrating trial in error into a job well done to be proud of, if you spend a little more time prepping the parts for fitment and cleanliness.
- TIG only sheepskin leather gloves. Would you drive an F1 car in mittens? Don't bother with Harbor Freight. Go to Northern Tool or someplace that sells thin, sheepskin welding gloves that fit you well and keep them nice. Don't use them for other things.
- A bench grinder with a cubby/ stand and a preset grooved guide for making tip sharpening quick. The first 12 times you will immediately screw up when learning, you will thank yourself for the hours saved, setting up a rig that makes this quick and painless.
- A good helmet that has a tig frequency or "TIG" setting. Most helmets don't. Frequency and pedal pulsing can jack with the time out on auto darkening lenses and TIG arcs give off unique light, even on DC, so be sure you can adjust tint and sensitivity. Don't bother with anything, other than an auto darken with a good setting ability.
- Finger and pedal amp triggers. Get both. I leave my pedal on for most work, but there are times when I'm not using filler rod for tac welding stuff for fitment. This is key for exhaust and other plumbing fab. A quick zap keeps it held together and its awkward to use a pedal in weird environments. A good workbench and a couple of body panel stands for most of your work is a good idea.
- Neodymium magnets. I use 3/8" squares and they keep me from having to guess. They work great in 3s or 4s for header tube mockup with filing the edges of my cuts. I can see how it will fit up, welded, without moving. Clamps work well for some work, but the magnets are awesome. I think I bought about 2 dozen. Try not to weld next to the magnets. You will kill them. Just tac the parts up 1 inch min away from each one and take them off quick.
- Tank dedicated to 100% Argon, possibly smaller one for adding Helium if you do cast aluminum. You can't use Co2. You want great shielding and you want clean metal on all sides for clean, uncontaminated welds. If it gets contaminated by lack of shield gas or too much turbulence from shield gas (small cone, high flow) it will look like garbage, even with the rest of your welding conditions on the money. I discovered that the hard way on a stainless tank I welded. Built new panels, changed the cone/ nozzle and gas settings. Did nothing else and it looks professional, now.
- Copper. Get lots of copper chunks. sheet metal, maybe a paddle, a good flat square bar... The bar works awesome as a hand guide and a heat sink. Especially on stainless and aluminum, but does well on mild steel, too. Clamp or drill it up to glue some of those neodymium magnets at each end and you've got a great welding helper. It also means you can set your hand closer to your work for better control and you will have a lot less warping.
TIG welders can be your friend with good work environment. Set the filler rod tubes up in holders, make your shop/ work area cozy. Think about the job and plan it. It gets involved. Think of a TIG like a high end kitchen, while a MIG is a microwave. MIG is great, gets the job done, you point it and shoot it and its all done. You can make awesome welds with both machines, TIG just takes some more thought, but if you can cook your own food, you can do this, too. There is a basic science to the work and some trial and error with adjustment is all it takes.
Look into analog controls as well as digital. I went analog. All my cars have sticks. I trade a bit of comfort for the control, because I like it, but that's me.
I bought an Everlast 185, because it has 110 and 220 input. I made my own pedal because I'm a nut case and I kept the hand arc trigger with a piece of velcro for a quick plug switch for tac work. If I find myself using it more, I have a dead lead in my pedal and I'll put it on a toggle switch.
The other analog machines I looked at had a good variety of pulse wave control, but I didn't need them. This one had AC balance and AC frequency analogs, which is all I was after, along with the max Amp analog. Gave me what I wanted without paying for stuff I didn't think I'd use.
If you buy a used machine, be sure to go through it and clean the gear up. A screwy potentiometer in a pedal or a couple of fried consumables in the torch could make a learning experience miserable.
