Thread: Cutting and welding fuel tanks

done the above I tend to run the gas through for an hour before touching,prefer welding diesel tanks which I have done the odd one that is full with diesel got to keep the machines going

Most shops have a CO2 or Argon/CO2 mix in cylinders for mig welding, that is why I suggested it. Many would have to go and rent a nitrogen cylinder.

the method taught at tech was the one scouse mentioned.....

drain and rinse the tank with lots of water.......drain and connect to a cars exhaust for about an hour.....
this gets the tank nice and hot and evaporates off any fuel or water that may be in tank......




simply rinsing with water then hitting with the oxy is how people get hurt......
fuel floats on water......the water drains out but the fuel sticks to the tank.....
then the oxy heats it up....it turns to vapour......and....if you are lucky you will wake up.......
in intensive care.......

20 odd years ago there was a guy killed at enoggerra in qld welding a diesel tank while running exhaust fumes thru it if my memory serves me correctly. it works most of the time, but not all of the time.

Originally Posted by George130

How hard is it to cut and reweld fuel tanks? I want to cut a section off and weld a new plate over that section.

DONT weld or cut a fuel tank without doing the following (BTW Diesel is more VOLATILE than petrol when hot) :- Get a drum with a lid, half fill it with water, place it on a heat source, run a hose from the drum to the fuel tank, have it setup so any residue can run out, boil the water , steam will disolve any residual fuel in tank, steam for at least an hour, longer if you can still smell fuel in tank, run clean water thru tank and look for any fuel in the water, use some detergent if you find some residue, as a final safety tip almost fill tank with water, just enough not to wet or submerge your work area, if in doubt DON'T, Regards Frank.

Thanks guys. Spoke to a mate about it today and he sujested using a nibbler to cut it. The tanks would have been used for petrol but once finnished I plan to use them for diesel. The idea is to cut down some series long range tanks to fit into mine as sill tanks. Probably a lot of work for the gains. I would prefer at least one for water anyway so who knows.

I'm with Tank. If in doubt, don't!

my methods are similar when repairing a tank

fill and flush 4-5 times

fill and boil for an hour

drain and flush

add 1 l of vinager and about 300grams of sodium bicarbonate, seal the tank and shake it. (let it vent a little from the breather to purge any o2)

cut/solder/weld as required. and I prefer to use a non hot cutter, nibblers, drills or snips as opposed to oxy or grinders..