I am in the process of building a fuel tank out of .090" 5052 and have a
couple of questions about welding set up and testing for leaks. There is
only one welding symbol on the plans so I am looking for advice on the rest
of the seams etc. I will be using a Lincoln Squarewave 175 for the welding.
I am very comfortable welding thinwall steel tubing and understand some of
the differences of welding aluminum. I certainly could hire the welding out
but I would get more satisfaction if I could do the welding myself.
The bottom of the fuel tank is to be made from three pieces. The main piece
is 51" long and is bent in the shape of a trough. The front edge is about
6" high with a 1/2" flange bent along the entire top edge. The rear is
about 4" high with the same type of 1/2" flange. There is a 24" bottom
between the front and rear ends. Two other pieces are supposed to be welded
on each end of the trough to complete the bottom part of the tank. Should
the end pieces be cut for an open filet weld or should they be a lap joint
with an inside filet or some other option?
Could I run a bead on the inside and outside of each corner?
The top of the tank is filet welded along the length of the 51"x1/2" flange
on the front and rear. I have heard/read that tack welds can become a
source of leaks. How often should I place a tack along the 51" weld? How
can I reduce the amount of distortion that might show through to the top of
the tank as it will be exposed?
What is an acceptable method to check for leaks? If a leak is found is
there anything special I would need to do to seal the leak? Can I go back
over the area with the electrode?
I know some might be thinking I should just hire out the welding and believe
me I am not opposed to that but would like to give it a try if it's within
my skill set.
- posted 15 years ago