pinhole leak in fuel tank of quattro - suggestions

[Tayo de Boer <tdeboer@ibm.net>]

to the list regarding leak on '875kt CD quattro

	I've got a very small leak in the gas tank along the forward edge of the
tank. Since the car is a quattro getting easy access to the problem area,
let alone removing the entire tank for repair is a real itch.
     I've been considering two methods of repair and I'd like feedback on
either - pro,con,other..
in both scenarios there is a minimal amount of fuel in the tank - well
below the seam line. My aim is to remove all the fuel if I have to.

1.       the first option is to do the repair from the outside: it
basically involves using a Dremel with various wire wheels to clean the
seam for about 4" / 100mm in the area of the leak, this I would follow up
with sandpaper to obtain a smooth and clean area as possible. The area
would then be sealed with a fine mesh fiberglass strip that just covers the
seam top and bottom, with following larger layers finishing up the job.
It's a basic fiberglass job.The biggest drawback is that I can't see what
I'm working on; what if I'm not successful the first time? 
2.	the second option would be to seal the leak from the inside. The main
reason for this method is that if sealed with a flexible material, the
force of the fuel against the seam in the tank should make a permanent seal.
	I would jack the front of the car up to make the remaining fuel pool at
the "bottom"; this fuel can then be siphoned out to have the absolute
minimum fuel in the tank.
	After inspection of the tank wall that no other problems, coat with at
least two or three layers of butyl type product applied with plastic shims
commonly used in body work. The front seam would be sealed in a similar
manner to applying gypsum to drywall joints with each layer wider than the
next.
	Would this also be a good time to check the condition of the pump filter
or should I leave well enough alone; What would indicate that the filter
needs attention? Is it normal to find a lot of crud on the bottom of the
tank, what about this reference on the list to fuel tank coatings flaking off?
	Add on a small point; the trunk lid should be secured to a joist or other
with suitable material. No surprises from trunk lid. Must remember to
replace existing struts with stronger ones - should be in the archives?

GEE...think I prefer option 2?     whichever I do I've got to organize
before it gets too cold.

	all opinions, other options considered, please.
regards,
tayo