I am thinking the only thing I can do is the Lincoln MIG-PAK 10 Welder ... it's only 100 amps though .. it states up to 1/4 inch in one pass, but can I really believe that is the question? .. specs below
Unit Includes (Canadian model only): Magnum 100L welding gun and 10 ft. (3.0m) cable assembly with .023-.025" contact tip and gas nozzle installed, 10 ft. (3.0m) work cable and work clamp, factory installed gas solenoid valve, 2 lb. spool .025" SuperArc L-56 mild steel MIG wire, 1 lb. spool .035" Innershield NR-211-MP mild steel self-shielded flux-cored wire, six spare .023-.025" contact tips, welding handshield with #10 filter plate and clear glass cover plate, and instructional video. Note: K1606-1, CTC Product No. 58-8133-0, Shielding Gas Regulator/Hose Kit Sold Separately.
• 30-100 amps output.
• Welds up to 1/4 in. steel.
• Ready to weld with MIG on mild steel. Shielding gas and gas regulator/hose kit sold separately. Also welds .035" self-shielded (gasless) flux-cored wire.
• Plugs into 115V, 20 amp outlet.
• Gun trigger safety feature keeps welding wire electrically "cold" until trigger is pressed.
• Compact, portable, lightweight and easy-to-use.
• This combination wire feeder/CV power source is recommended for .023-.030" solid wire MIG (gas-shielded) welding of virtually any light gauge, mild steel or stainless steel material (stainless steel wire sold separately). Install K664-2 Aluminum Welding Kit to expand the MIG-PAK 10's capabilities to include .035" solid wire MIG welding of aluminum.
• Welder settings reference chart conveniently located inside wire feed section door makes it easy to set the MIG-PAK 10 for mild steel welding jobs.
• Fan-cooled for long life expectancy.
• Three year warranty on parts and labor. (90 days warranty on gun and cable).