Sheen after sanding

[Brian Penning]

This has happened a couple of time to me where I sand out scratches after applying the 1st coat of finish.
The areas where I've sanded never have quite the same sheen as the rest of the piece -usually duller where I resanded.
Anyone know why this happens and what's the fix?
TIA

[Steve Schoene]

That area always has one less coat of finish on it than the rest. Thus until even that area has been fully coated so that the entire surface can be properly leveled with 320 grit paper without cutting through the finish you are likely to have the problem.

This does emphasize the importance of proper preparation before finishing. One thing I always do is to wet the surface with naptha and examine the surface carefully with low raking light from several angles. That will allow you to catch all the scratches when you are supposed to --before the first coat of finish is applied.