10) Finally Some Progesss

The tank is headed for primer!

Finally the gas tank has progress past welding and rewelding, the main wiring has been reinstalled, I have figured out how to wire the Harley ignition and various indicators into the Honda harness, completed the fairing mounts and mounted the coils. I actually have made some progress once the gas tank issues are finally (hopefully) behind me.

 I believe in my previous blogs I outline how the gas tank would be the foundation of the look of the bike as well as how the tank was to be the biggest challenge. Well no matter how I framed the effort to modify the tank it was an understatement. I know the person I had do the modification was becoming frustrated with it as was I. But there was a level of expected evolution in the chasing of pin holes. So after the tank was at the fabricators for a couple extra weeks I went an got it and figured I would take on the challenge. I mean I have some skills, right?

What a mistake. Right away I noticed the tanks was pretty tight except for around the flange for the level sensor. No problem, pulled out the Oxy-Acetylene tanks and proceeded to make a mess.

Once I got my technique back, (it has been awhile) I was able to fill the holes I made and ran some nice beads around the flange and I was happy. Until I heard the first pop. With a closer look I could see the crack at the root of my brand new weld. No problem, fired up the torch again and ran another well placed and formed bead over the crack. This time there were two pops. 

Ok, slow down, lets think about this. The flange is about 1/8 inch thick, the tank is maybe 18 gauge (or about 0.05 inches). As I try to remember back, hoop stress and thermal expansion may have something to do with this. So I welded up the new cracks and tried quick quenching which worked. Than I remembered how quenching will harden the steel making it more brittle. So I pulled out my rosebud (this is a very large Oxy-Ace torch tip) and carefully annealed the area around the flange to add some ductility back into the metal. This was working great until I heard it POP! Well now I am really getting a little frustrated.  Welded it up, quenched it and walked away.

The next day I installed the level sensor flange, pitcock and gas caps.  This was to allow filling the tank with water to make a final check for leaks and measure the flow rate through the pitcock. The first thing I noticed was the vented gas cap was working but not as well as I had hoped. I was only getting about 1 gallon in 8 minutes. Without the cap I could get 3 gallon in less than 4 minutes. So I made the decision to add a vent tube to the tank. More welding/brazing, but it did come out pretty good and works great.

During all the flow testing I noticed the level sensor flange had a slow leak. The best I could tell it was not leaking from the weld but by the gasket. After trying to tighten up the flange to seal the leak did not work a closer look revealed all the welding had warped the flange. So I did some initial grinding to try to flatten the surface and resorted to the magic of J-B Weld. Applied it as per the directions, sanded and lapped it flat and now I have a solid, flat and leak free flange.

     

 
I cleaned, etch and seal the internals of the tank with the Kreen tank sealing kit and covered all the welds with filler to give the tank a smooth finish. Once the filler is sanded and all surfaces are cleaned I will primer the tank and not look back (hopefully).

Next up is finish the air box, wire the fairing, mount the rear finder and about a million other things. Still having fun and may even finish this some day.