:laughing:    I had to go read the thread you may be talking about
Is this it?   
http://www.tractorbynet.com/forums/build-yourself/164738-mig-welder-how-thick-can.html
     Or is it a different thread?
     I am not a believer in 110 vac welders-( except maybe small stuff on a budget)  and never owned or used a 110 only unit.
  Seems to me that 230 vac is pretty much a given to have the power available to put heat into a weld when needed-
  especially over 1/4" steel let alone anything  1/4"+ of Aluminum,   the welders i have owned were 230 volt   except my old victor Oxy-Acetylene
    For many years my  mig was the only electric welder  -and although it did weld 3/8  steel,  was never comfortable with making  multiple passes at max amperage (hoping) for  really good penetration /fusion.
 Never tried flux cored wire either, just dug out the old tombstone while I had it, for outside welding unless it was dead calm.
      Have always believed that a person needs to use what he has to get the job done- but may have to add an exception for 110 volt welder built trailers... 
   In that case keep the small welder and buy a 230 volt one with enough amperage and duty cycle for the bigger jobs-(trailer building)  
      May have to go get my flame  suit out now, for the heat possibly coming my way - showing me the wonderful 110 volt welder built  trailers.