Last week I thought I'd easily finish up the snake's gas tank as well as
all of the things I'd taken vacation time for. Naturally I grossly
under estimated how much time non Cobra related stuff would consume.
For some reason my wife didn't feel getting my car on the road belong at
the top of my priority list while we were on vacation. At least I
managed to get the exterior surface tinned; or at least as much as is
likely to ever get tinned. The coverage is considerable better than
before I pulled the tank out, but the whole operation was very time
consuming and iterative. If I'd know what I was doing to begin with, I
would probably have ended up with much better results and finished in
about 1/10 the time. As it was, each new technique I tried created more
work. Not only that, it was difficult to see all of the spots that had
been missed during the rather messy process so I ended up tinning areas,
cleaning them off, finding missed spots, re-prepping them, tinning them,
and then going through the cycle again. Finally I decided to
concentrate on areas that would be exposed to moisture and to live with
the coverage on the rest of the tank. Since the tank had already
survived about 15 years with several large spots of minor surface rust,
I figured it would survive a few more with the considerably improved
protection I'd added.
Even at this point I figured I'd be able finish before my vacation was
over; it was Sunday and I didn't have to be back to work until Tuesday.
I scrubbed the tank down with a mixture of Simple Green, ammonia and
baking soda (to neutralize acids). I was surprised to see how much
better the tank looked with the flux and and acid stains removed. Even
so, I found a few spots the tinning hadn't adhered to so I ended up
doing some touch-up tinning here and there; finally, by the afternoon, I
was ready to start the interior prep. The tank sealer kit came with
concentrated etching solution to remove rust and to prepare the surface
for the sealer. Since this kit was for use on motor cycle gas tanks,
the bottle of etch only made up 2 1/2 gallons of solution. Since I have
an 18 gallon tank, this was kinda of on the minimal side to get coverage
on all surfaces, especially the baffles. The instructions suggested
rotating the tank to different sides every so often until all surfaces
were treated.
I started with the bottom since that seemed to have the most rust. I
checked after about 4 hours and could still see a few rust spots. I
decided to let it soak over night. The next morning I rotated the tank
to another side. By mid day, it was obvious I wouldn't be done with the
interior that day. That meant I wouldn't be able to slush the sealer
around until next weekend because the next day, Tuesday, I was scheduled
to go on an oft postponed business trip to Oregon. This time it was
absolutely positively on for sure. In a way, I was glad because this
would allow most of the week for the phosphoric acid do its work on the
interior surfaces I couldn't see. I would just change tank sides two or
three times a day.
Tuesday turn out to be very busy. I had a lot of work to get caught up
on after vacation plus having to get ready in time to catch an HP
corporate jet leaving San Jose for Corvallis early that afternoon; but
that flight got canceled and I had to make some quick adjustments to my
plans and drive the 50 miles to SFO to catch the last flight of the
night going to Eugene. It wasn't a particularly pleasant experience.
In all my rushing around I forgot to rotate the tank to another side
before leaving.
When I finally got back to the tank Thursday morning, all of the
surfaces not in contact with the etching solution had dried even though
every tank opening had an air tight seal. So now I more or less had to
repeat the rotation process to remove newly formed rust and the
crystalline deposits left by the dried etching solution. This seems to
be going well at the moment so I have high hopes of pouring in the
sealer tomorrow and having the tank installed by Sunday. It will be two
or three days before the sealer is completely dry, but I should be ready
to go by mid week.
Roland Dudley
cobra@hpcdcsn.cdc.hp.com
CSX2282
|