My particular backup problem is that when I do a full backup on some transaction-heavy databases that have their recovery models set to Full, the first hourly transaction log - .trn file - after the full backup is almost the same size as the .bak file. 

Subsequent hourly .trn files are nice and small.

I wanted all the .trn files to be small, to conserve drive space, so I tried setting the recovery models to bulk_logged, then do the .trn backup, then setting the recovery models back to Full, but this three-step approach seems to either take forever, or fail.

Any ideas would be appreciated.

 Thanks, Mike