//Welders left on now use up fuel, but lets not have them run out quite that fast
if(1)
if(icon_state != "welder1")	//Check that the sprite is correct, if it isnt, it means toggle() was not called
force = 15
damtype = "fire"
icon_state = "welder1"
if(prob(5))
remove_fuel(1)

Above is what I meant, and they also do indeed cost 1 fuel for every use.

Also my bad default welders have 20 fuel not 30, which makes it even more limited.