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Sure!

- Two coats of schellac (Zinsser Seal coat, like I mentioned). I now do this in all cases, not specifically on rosewood. I sometimes had some uneven colors when I was directly applying polyurethane on wood. Specially on cedar. Shellac resoved this.
- I then proceed with applying about 5 to 7 coats for the build-up using a foam brush, where I scuff with 400 grit between coats. I can give two coats a day, waiting about 7 to 8 hours between coats.
- Once the wood texture has disappeared everywhere on the guitar, I then wet sand with 320 quite heavily, taking special attention on runouts and drips (which I was never able to avoid during build-up). I will almost always sand through the finish on several places. I wipe on some shellac on those areas with a paper towel afterwards.
- I then apply what I call 'finishing coats'. I clip some paper towel folded in two over a foam brush, and proceed with applying my polyurethane with that. This little setup makes sure the coat is really thin and thus greatly minimizes runouts. I apply 5 coats, where I sand between coats. 1000 grit after the first and second coats (just light scuffing), 1500 after the 3d and fourth (appying myself a little more), and then finish with 2000 prior to buffing.
- I buff using a Stewmac buffing arbor, using medium and fine menzerna compound.
- Buffing touch-ups with colortone fine buffing compound and a soft rag.

I think that's pretty much it!

_________________
Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)