Pressure test of header tank

Ran a pressure test on the newly minted header tank.  I did this by first capping off all inlets/outlets except for one, and attaching a schrader valve plus low-pressure gauge to the single open port.  I pressurized the tank to 5 PSI, and noticed a slight drop in pressure over time.  I then got out a spray bottle with soapy water and sprayed it all around the welds and fittings to find the leak.  Actually found two issues.  One was a small pinhole leak around one of the welds for a bung on the side of the tank.  The second was a tiny leak along an inner seam where the V-bracket was welded to the tank.

I removed all the fittings, then ground down some of the original weld material at the leak locations. I cleaned the surfaces and touched up those spots with the TIG machine by remelting the area and adding a little more aluminum filler material. The V-bracket inner seam was difficult to weld because of the corner that was formed by all the angles, so I changed to a smaller TIG torch and electrode prior to rewelding to get better access into the corner.

Once it was all touched up, I re-ran the pressure test.  I didn't see any drop in pressure, and I also gave it the soapy water treatment to see if I could find any bubbles.  Everything looks good.  I'm going to leave it pressurized for a day just to make sure there are no other slight leaks that I haven't found, but so far it's looking good. Hours: 2.5

Adding air to the tank to pressurize it

Tank with all fittings attached during pressure test