Scott Grandstaff wrote:"What exactly have you been feeding this cat?

"If ordinary soaps or solvents wont "take it off" then the surface of the 
paint has been damaged.
"Every old school auto parts sells rubbing compound and polishing 
compound for rubbing out paint damage..."


My first reaction was similar to Scott's, but not exactly the same.  I thought
"What is cat barf anyway?"

I don't have a specific answer, but the basis is clear enough: cat (or any )
barf is degraded fragments of food plus the highly corrosive liquid designed to
degrade them much further. Traditional japanning in particular has a lot of
organic materials in its composition, just the sort of thing digestive fluids
are supposed to break down. It is likely that what you are seeing is not an
incrustation that can be removed, but is damage and destruction to the japanning
itself.

I have no experience with this kind of damage, but Scott's advice seems the way
to go. Rubbing compounds will depend on having a thick layer of original coating
(paint or japanning or whatever) and abrading away the surface until the paint
below the damage is exposed. This will have the secondary advantage of leveling
the surface, so that there is no ghost image from cratering of the paint.
However, if the barf-corrosion went so deep that there is little or no paint
under it, using a rubbing compound might expose the base metal. In this case the
japanning may have to be built up in some way, and it might be better to do this
before starting the rubbing. Using a magnifying lens, not just a 2x desk
magnifying glass but something more like a 10x jeweler's loupe or even a little
hand-held 30X lighted microscope, might be a good idea before starting to use
the rubbing compound.

That's all I got. Take it for what it's worth, which is free advice from someone
who's never dealt with the problem and has no responsibility.

Tom Conroy
Berkeley