[DeTomaso] NPC (sort of) Tig Welder Recommendations

[burrid1 at netzero.net]

As far as I know Syncrowave is a brand name (mid 70's) given by Miller when they pioneered square wave technology for welding over existing sign wave. Square wave technology is not a requirement to make good quality welds in aluminum alloys with AC Tig. Tig welding on aluminum can be done with standard alternating current (typical home use type). Standard A/C current use a sign wave as it alternates between positive and negative. Squarewave is the AC output of a power source that has the ability to rapidly switch between the positive and negative half cycles of alternating current. This is accomplished with advanced circuitry. Where the normal AC sine wave is smooth, the sharp corners of the square wave represent the quickness of the change between polarities and can also be used to represent balance control (dwell time on each side of the half cycle). Greater amounts of Electrode Negative create a deeper, narrower weld bead and better joint penetration. Greater Electrode Positive values remove more oxide and create a shallower, wider bead. Transformer-rectifier Gas Tungsten Arc Welding machines can adjust Electrode Negative values from 45 to 68 percent. What is happening with square wave is you are going peek to peek with no falloff, as you would have in a normal sine wave. Also you can control the length of time your electrode is positive and negative. This allows you to be able to adjust your cleaning time, heating time and so forth.
 The faster and sharper the machine can switch between polarities the greater the chance is that the AC arc will remain smooth. When an arc breaks between the half cycles and does not reinitiate (this is called rectification) the welder experiences popping and lack of smoothness in the arc and reduced quality in the welds. Square wave machines have a couple of very useful features not available with ordinary sine wave machines. The Square Wave power source will help to eliminate rectification and provide balance control which is often needed when welding a variety of aluminum or magnesium alloys. Probably the most important factor is the ability to adjust the AC balance on the machine so that either the more positive or negative side of the cycle can be introduced depending on whether you are after more or less cleaning or penetration. Another benefit is the ability to introduce ramp up or ramp down and to use crater fill (These don't apply if you are using a foot or hand piece current control). If you're looking at a welding a large variety of different components, the square wave machine will offer flexibility the lesser machines just don't have. There are some jobs that a square wave power source with balance control can do that lesser machines just cant. My friends still in the welding business tell me the newer welding machines with hybrid wave inverters allow adjustable hertz control which gives greater AC balance control and in hybrid wave the ability to introduce DC wave into the AC wave for even greater flexibility. I've never used one of these machines but have great reports, and have had numerous offers to experience the difference, which they claim is substantial. Good Luck and NEVER EVER BUY A USED WELDER WITHOUT A DEMONSTRATION OF IT'S CAPABILITIES OR ACTUAL USAGE. 
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   As far as I know Syncrowave is a brand name (mid 70's) given by Miller
   when they pioneered square wave technology for welding over existing
   sign wave. Square wave technology is not a requirement to make good
   quality welds in aluminum alloys with AC Tig. Tig welding on aluminum
   can be done with standard alternating current (typical home use type).
   Standard A/C current use a sign wave as it alternates between positive
   and negative. Squarewave is the AC output of a power source that has
   the ability to rapidly switch between the positive and negative half
   cycles of alternating current. This is accomplished with advanced
   circuitry. Where the normal AC sine wave is smooth, the sharp corners
   of the square wave represent the quickness of the change between
   polarities and can also be used to represent balance control (dwell
   time on each side of the half cycle). Greater amounts of Electrode
   Negative create a deeper, narrower weld bead and better joint
   penetration. Greater Electrode Positive values remove more oxide and
   create a shallower, wider bead. Transformer-rectifier Gas Tungsten Arc
   Welding machines can adjust Electrode Negative values from 45 to 68
   percent. What is happening with square wave is you are going peek to
   peek with no falloff, as you would have in a normal sine wave. Also you
   can control the length of time your electrode is positive and negative.
   This allows you to be able to adjust your cleaning time, heating time
   and so forth.
   The faster and sharper the machine can switch between polarities the
   greater the chance is that the AC arc will remain smooth. When an arc
   breaks between the half cycles and does not reinitiate (this is called
   rectification) the welder experiences popping and lack of smoothness in
   the arc and reduced quality in the welds. Square wave machines have a
   couple of very useful features not available with ordinary sine wave
   machines. The Square Wave power source will help to eliminate
   rectification and provide balance control which is often needed when
   welding a variety of aluminum or magnesium alloys. Probably the most
   important factor is the ability to adjust the AC balance on the machine
   so that either the more positive or negative side of the cycle can be
   introduced depending on whether you are after more or less cleaning or
   penetration. Another benefit is the ability to introduce ramp up or
   ramp down and to use crater fill (These don't apply if you are using a
   foot or hand piece current control). If you're looking at a welding a
   large variety of different components, the square wave machine will
   offer flexibility the lesser machines just don't have. There are some
   jobs that a square wave power source with balance control can do that
   lesser machines just cant.



   My friends still in the welding business tell me the newer welding
   machines with hybrid wave inverters allow adjustable hertz control
   which gives greater AC balance control and in hybrid wave the ability
   to introduce DC wave into the AC wave for even greater flexibility.
   I've never used one of these machines but have great reports, and have
   had numerous offers to experience the difference, which they claim is
   substantial.



   Good Luck and NEVER EVER BUY A USED WELDER WITHOUT A DEMONSTRATION OF
   IT'S CAPABILITIES OR ACTUAL USAGE.