TIG Welder inverters have a bunch of settings and if you don’t understand what they do, you will never get the most out of your inverter tig welding machine.
I have a friend who just had an opportunity to buy a big “old as balls” Miller 330 ABP for about 500 bucks. Those old things are Cadillac tig welders but the problem is the darn thing is as big as a refrigerator and weighs almost 900 pounds.
No matter how sweet it welds, or how sweet the deal is, if you are cramped for space, dont have adequate power service for a 100 amp breaker, and don’t have room for a refrigerator sized welder in your garage, its not a very good deal.
That’s were tig inverters come in.
With inverter technology, we can have a 300 amp machine that can easily be carried by one person or wheeled around the shop on a light duty cart.
And the really great thing about tig inverters is that the arc can be tweaked to your liking.
But only if you understand what all those freakin knobs are for.
So let’s talk about the main tig welding inverter settings. Some of the settings that you need to really get a handle on are:
• Amperage—pretty straightforward...but there is a simple rule of thumb that holds true up to about .125" thick metal. (3.2mm)...mainly carbon steel
one amp per one thousandths (thats about 40 amps per mm)
A little more than one amp for aluminum
A little less than one amp for stainless
once you get thicker than .125" the one amp rule starts to drift and not work as well
• A/C frequency—power from the power company is roughly 60hz in the USA and 50 hz in some countries. An inverter steps the frequency of the incoming AC power up before it even converts it to DC.
That’s why the transformer is so small light compared to an old tig welder…the A/C frequency knob allows you to weld with a much higher frequency.(HZ)
A higher HZ frequency setting stiffens and focuses the tig welding arc..pinpoints the heat more..and sometimes that’s a very good thing…like when you need to put one drop of filler metal on a pit in an aluminum injection mold. or when you need to weld near threads and you don’t want to arc off and damage the theads.
rule of thumb here is lower frequency for thicker aluminum and higher frequency settings for thinner aluminum...but there are always exceptions.
• A/C balance—Alternating current contains both electrode positive and electrode negative changing rapidly back and forth.
With Old school machines, you get what you get and roughly 55 /45 dcep/dcen due to something called rectification (ouch that sounds painful)…and you don’t always need all that cleaning action that you get from the dcep side.
But with most modern tig inverters, you can adjust the ac balance to more than 90 % dcen.
Rule of thumb: for nasty aluminum like a boat prop that has some corrosion, adjust the ac balcne to where you use more dcep .
For brand new clean aluminum diamond plate, set the ac balance to where you have around 67-75 percent dcen.
But some brands of tig welders have their AC balance knob where the higher number setting indicaties more cleaning so if you set the AC balance knob high and your tip of your electrode melts, try a much lower setting.
• 2t ---for using a switch on the torch handle…when you plug in the foot pedal or torch amperage control, most tig inverters are designed to bypass the 2t and 4t settings because the amperage control overrides all the upslope and downslope stuff.
The 2t setting pretty much turns the torch switch into a 2 position switch. Press the switch , you get and arc. Let off the switch, arc goes out.
uplsope and downslope can be set to taper up and down using 2t or 4t function
• 4t—the 4t position is most always used in conjuction with upslope and downslope settings…something like this…
o press the button and you get an arc.
o Let off the button and the arc upslopes to whatever the main aperage is set to
o Press the button and arc downslopes to lower amperage
o Let off the button and arc quits.
o Some machines are different but this is the general principle of 4t operation
• Tig high freq vs lift arc vs scratch start---tig high frequency lets you start the arc without touching off…the lift arc function lets you weld without high frequency if that’s important to you like if you are welding in an air traffic control tower….scratch start is basically the stick setting. If you are used to a plain jane dry rig, you might use scratch start.
• Pre-flow—the length of time the torch gas flows between the time you press the switch or remote foot pedal, and when you actually get an arc. No need to have more than 0.5 or ½ of second.
• Post-flow-- the length of time the torch gas flows after the arc terminates.
• Up slope—allows the current to climb at whatever rate you set…from start amperage to operating main amperage setting on the machine
• Down slope—allows the current to decrease at whatever rate you set on the knob so that you wont leave a defect like a fish eye or crater crack
• Start amps —allows for a really low amperage startup or a hot one
• End amps—determines the final amperage before the arc quits
• Pulse frequency---pps or pulses per second…you might think that once you get above 30 pps it would be like no pulse at all…you would be wrong. Higher pulse rates really focus the arc.
• Pulse percentage of background current or peak pulse percentage—lets you control the effect of pulse to limit heat input or just to agitate the puddle.
• Pulse % on time also called pulse width—the time the high pulse amperage stays on
Dang! Anything else!!??