I got an email from a fella the other day asking if it was possible to use a tig welder as a plasma cutter....and if it was possible to use a tig torch for cutting metal, how it was done.
Well the answer is yes and no. Yes you can actually do some decent metal cutting with a tig machine on certain types of thin sheet metal...but NO... it wont be as good as a plasma cutter.
For thin aluminum sheet metal in the .063" and thinner range, you can actually surprise yourself at how well a tig torch can cut.but for stainless steels, you are in for a lot of grinding to prep the cut edge.
But... if a tig torch is all you got, if you dont have a plasma cutter, if you dont have a grinder with a bunch of slitting wheels, if you dont have a metal sheer, if you dont have a sheet metal nibbler,......If all you have is a tig machine and you need to cut something really bad, it can be done.
Her is how its done...
first you need to find a really small tig cup, like a #3. or #4 the smaller the better.
a 1/8" electrode usually works best, sharpen it, but not like a needle
we are going to need a lot of argon screaming out the end of your tig torch. (just think of that huge burrito you ate followed by a bran muffin and hot cup of joe)
Set the flowmeter to max.
The tig machine settings will depend on the type of tig welder you have but for the most part, just set the welder like you would to weld steel except for amperage,
I have found that the more amperage used the faster and better the cut....but 200 amps will work ok too if thats all you have.
250 amps worked pretty well for my tests. 200 amps just went slower.
If you are using a foot pedal, you can set the machine to give you all the amperage at once, or you can just floor the pedal manually.if using a torch switch, just make sure to turn off the upslope or set it where there is no upslope time....you want a burst of amperage.
the rest of the instructions are pretty much like using a plasma cutter. Clamp a straight edge on the sheet for a guide and just drag the tig cup along just like you would a plasma cutting torch...basically as fast as you can while still maintaining consistency and not outrunning the cut.
Remember ,this cut will not be nearly as good as a plasma cutter, but in a pinch, its another tool in the box you can whip out when you need it.
So here is the summary of how to use a tig welder for cutting metal...
* use a 1/8" electrode with a bluntly sharpened tip
* set argon flowmeter to max
* set amperage to 200-250
* use a #3 or 4 tig cup
* recess the tungsten about 1/8" below flush with the tip of the tig cup