Dented tank...ideas?

[Alex E]

Haha way to contradict myself "is not hard but it's hard", you guys know what I mean!

 

[VAhasnoWAVES]

Think about it. If the tank is full, there will be very little air in the tank, and even then the vapor pressure will be high and above the ignition point. How do you think they run an electric pump in the tank.

The pin welder does not penetrate the skin of the tank, especially when the other side is cooled by gas. A pin welder also does not normally cause any arcing. It simply heats up the junction of the pin and the metal until the pin melts and bonds to the tank.

i may be wrong but i think there has to be an arc. your not applying a heat source hot enough to melt steel, which is about 2500*. your also not applying enough pressure to generate that kind of heat. i would think there is a resistance arc in the gap between the pin and thin metal, much like a spot weld. this does of course imply that the arc is on the outside of the tank. id agree that itd be better to use a full tank of gas to insulate the the heat, and reduce the amount of fumes in the tank. i still wouldnt personally do it...

id opt for pressurizing the empty tank using an inert gas. farrrrr away from any heat source or especially an open flame. dont use oxygen or compressed air from a compressor. also, releive the pressure slowly.

 

[Alex E]

True, I'm not sure I have the balls to weld to a tank full of gasoline but I agree, a full tank is much better then an empty one. Think of the fuel sending unit and how it's a potentiometer aka variable resistor-I'm sure those spark sometimes but the ratio of fuel and oxygen is to far off to allow combustion...not to mention its a very low amp circuit so the spark probably isn't hot enough to promote combustion.

 

[Alex E]

For some reason I just remembered a Mythbusters episode I saw years ago where they were trying blow a car up by shooting the gas tank and IIRC they were unsuccessful.

 

[rockclimber]

Think about it. If the tank is full, there will be very little air in the tank, and even then the vapor pressure will be high and above the ignition point. How do you think they run an electric pump in the tank.

this part is true... and sounds great on paper... but is still a terrifying thought.


although, if the tank was out of the rig and sitting outside somewhere away from other fuel sources, the worst that would happen is it would burn for a while.

gas does not explode like it does in the movies unless there is a ton of vapor and very little liquid.

and as long as the container is not pressurized it wouldn't explode (think sobe-bomb)

A pin welder also does not normally cause any arcing. It simply heats up the junction of the pin and the metal until the pin melts and bonds to the tank.

not even remotely true.

there is arcing, you just can't usually see it.