Ferris, what Scott (the allmighty admin) says is the way to solve your problem!

I use Mr. Surfacer when I don't wanna use the Tamiya cans. I use them to have better control because I can spray with the a/b.

Though you have to thin them with Mr. Leveling Thinner or with Mr. Color Thinner but with the add of the retarder.

Don't use only Mr. Thinner or the normal laquer thinner or you'll clog your a/b or get a grainy surface.

Try them out correctly and you won't come back.

Another try could be Alclad grey primer....it's really a great product,cost a bit but fill the small scratches like anyone else does.

I could compare it to the Mr. Surface 1000 as for "grainy" finish.

I personally use the 1000, then fix the scracthes and the last preparatives then use the 1200 and polish a bit with a 12000 grit sandpaper or a cotton shirt (old preferably LOL LOL)

Cheers and hope it helped!