"David H" wrote in message
...


Thank you for you input. My intent was to apply polyurethane as I had
in the past using either a brush or wipe on poly and build up the
finish with 3 or 4 coats. No matter how careful they are applied, the
last coat often contains small bubbles that break as it dries leaving a
less than perfectly smooth finish. What I was hoping to accomplish was
to sand the last coat as I had the others, removing all the
imperfections, and then applying a final thin bubble free coat that
only needs to be think enough to fill in the sanding scratches of 220
or 300 grit sandpaper.


Errrrrrr!!! Stop right there. You won't "fill" sanding scratches from 220
or 300 grit paper with a spray application. They will be visible after it
dries. Those are pretty darned coarse grits for a spray finish. If you are
going as far as to cut the previous coats down to flat with 300, then simply
work back up to 1200 or 1500 and finish it off with a rubbing compound. Go
from 300 to 600 to 1000 to 1500. Or better yet, start at 1000. You don't
need anything near as coarse as 300 to flatten a clear coat.


--

-Mike-