lol........yeah I suppose, I guess maybe I'm wrong......I still believe it for some reason.........I think the best way is to wash it out like you said, but if there is no way to get the gas out(lets say) then I would go with a full tank.....or look at it this way, if it is going to explode anyways, I would rather die than get 75% of my body burnt away

I seen that on tv the other day, a guy got in a fire in his car, he had no skin left.......his face was sick, he had no nose or anything......wow......what a life.

 

Bradracer is right it would be safer than welding a empty tank . But still very dangerous . Fill the tank with water is even safer but still dangerous !
Only safe way to weld it would be in a inert chamber where there could be no combustion . also would eliminate perosity .
Yes they do weld those huge tanks full of gas they make sure they are full as possible most tankwelder want at least16" of fuel above weld .
Gas as a liquid wont burn it has to go to atomized or vapor . as long as the weld area is covered in liquid it wont ignite .
My first and last experience was working with a tank welder on a 80,000 gallon diesel tank when we arrived they were empting it . so we sat there on the clock until it was refilled over half way . . that was enough of that for me ! good money but not worth the stress~~
Same welder has and still welds gasoline tanks .
Ever watch a natural gas line being hot tapped????? they weld a metal fitting on a live mainline then they screw on a special valve and a drill that attaches to the valve . Then drill the bottom out of the fitting they welded on pull the drill up close the valve and remove the drill .

But Honestly as for welding a bike tank is it worth it????

As for cleaning then welding I worked in a fab shop and one of the guys there had a tank in a block cleaner then actetone steam cleaned sat out in the sun for 3 day he said it was odor less . touched it with a mig and blew him back about 15 feet he split the tank .
Not saying it cant be done just sounds scary ! I would at least purge it with inert gas

Heres a link from the eastcoast about welding gas tanks it's right above the refueling heading

http://www.umext.maine.edu/onlinepub...eries/2290.htm

Still safer to buy a new one! or Have Jessy James build it for you

 

finally someone agrees with me.......

 

Bradracer,
You are not stupid, you have just been dangerously missinformed. You are right that fuel will only burn in a gasious state, however, if you were to weld a gas tank with fuel in it, the heat would cause the fuel to boil. Inside each bubble are fumes. If one bubble were to ignite, the bubble would colapse creating a void which would be full of fumes. Also, the heated fuel would expand eventually causing the tank to rupture. You can immagine where it goes from there.

 

yep......back to step 1.......I suck.......lol.....