Date:         Sat, 9 Aug 2008 22:38:19 -0400
Reply-To:     Allan Streib <streib@CS.INDIANA.EDU>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Allan Streib <streib@CS.INDIANA.EDU>
Subject:      fuel tank de-rusting
Content-Type: text/plain; charset=us-ascii

I had very good results at removing the rust from my fuel tank using
the electrolytic method.

For explantion, google or see here....

  http://myweb.tiscali.co.uk/andyspatch/rust.htm

I had just about decided to buy a new tank when I discovered this
method.  I had already tried cleaning the tank with a wire brush,
naval jelly, and paint stripper, the latter of which was fairly
expensive and none of which worked very well.

For the reaction tank, I built a wooden crate big enough to hold the
gas tank vertically, with a few inches all the way around, and lined
it with a single sheet of heavy poly film (sold in rolls for use as a
moisture barrier, etc).

For the electrolyte, I tried to find washing soda but was
unsuccessful.  I used lye (NaOH), sold as drain cleaner.  Careful with
this stuff, it's nasty in its pure solid form.  It does not take a lot
to get the reaction going.  I used about half of a 16oz bottle added
to about 70 - 80 gallons of water in my tank.

I used some scraps of steel "strap" that I had lying around for the
anode material, and a battery charger on the 2 amp setting for the
power source.  I used 4 anodes, one on each side of the crate.
Probably would have been good to have one on the bottom and top as
well, but I thought it would be easier to just rotate the tank a
quarter of a turn about halfway through the process.

I let it sit, energized, overnight and today found that all the rust
had been removed, and the paint/undercoating had been loosened
wherever there was rust bubbling underneath, and it scraped easily
away.  I removed the loosened paint with a putty knife and went over
the whole tank with a wire brush and it looks really good, no rust to
be seen anywhere.  There is of course some pitting in the surface
where the rust WAS, but this process did remove all the rusty metal.

Next steps are a good coat of rust-oleum primer, then a top coat of
rust-oleum paint, and then a spray coat of automobile undercoating.

Just thought I'd share this, for anyone wanting to remove rust this
seems like a really good way to do it...

It was still a lot of work, and somewhat messy, but all in all I think
it was easier, cheaper, and much more effective than manual
scraping/wire brushing, or chemical strippers.

Was it worth it compared to the cost of a new tank?  Probably not if I
consider my time, but on that basis nobody should own a Vanagon
anyway.

Allan
--
1991 Vanagon GL