Ralph,
  Your plan sounds good to me.  When I replaced mine about 3 years ago, I
used a generic can of spray-on bedliner from a FLAPS.  Holding up well.  If
it is really unpainted, I would wipe it down with acetone to remove any oil
that may be there to prevent rust.  If there is paint, alcohol would be
better.  Since the spray goes on kind of thin, I used multiple coats until
the can was empty.
  Like someone said, don't neglect the top; I had a tank rust thru on the
top on an '80 I owned once.

Larry A.

On Thu, Jun 20, 2013 at 1:02 PM, ralph meyermann
<ralphmeyermann@gmail.com>wrote:

> Hi all me again! Ive got a question about my new fuel tank. My fuel tank is
> bare steel would it be wise to coat the exterior with some form of paint/
> bedliner stuff to prevent external rust or would that cause more rust?
> Thanks again!!
> Velma 82 na diesel westy
>