Next Commander 6000 project . . .weld the neck back on??????

The previous posters have given you good advice.

If you do not have access to dry ice, many old timers simply adapted a hose from the exhaust of a car or other gasoline engine, put the hose in the tank and allowed the engine to run while welding.

Since you will be working on the filler neck, this might not be practical in your case.

Dean

I think silver solder was used on them originally. If you can tack on some tabs and solder it in decent, you can then over coat with a gas tank repair patch to make it tight.

jb

Diesel, wash the tank with soap and water (inside). Go to it. It is the vapors that explode, diesel has a flash point well above ambient temperatures, and thus no vapors. Now heat a puddle of oil to make oil vapors and you have your explosive condition, hence wash the tank out. Steam cleaning would be better.

Always did admire the 6000 after watching one pull at the county fair. Front end about 2 feet in the air, the operator tapped the brakes just so to keep it on target. He worked the throttle and shift gently to search out all the traction there was. He had spent some time in the seat of that tractor to know how much he could ask, and the machine delivered. 35 years ago.