Shellac is giving me a shellacking

[COWW]

I recently finished building a small Jewelry box for my daughter.

Had lots of firsts for me:

Bolivian Rosewood - Beautiful, brittle

Completed everything except resawing with meat power.

Hand cut dovetails - Turned out... ok

Shellac "Rubbed out" finish

This last item is kicking my butt.

I brushed on 6 coats of a 2lb cut of garnet shellac sanding with 320 between coats.

I waited a week for the shellac to totally cure.

I then progressed through 400,600,800,1000,1500 grit paper followed by medium pumice. I would have progressed through fine pumice and rottenstone, but at this point I realized something was wrong. After the 400grit I noticed some dullness on the outside corners of the carcase, I continued thinking that the rubbing out process would fix it. Most of the box looks great, the figure in the rosewood really pops, and it's so smooth, it makes you just want to touch it. However the dull spots on the outside corners I now realize are still dull, because I sanded through the shellac with the 400 grit

Before I brush on more shellac, do I need to "rough up" the carcase with say 220, or can I just apply several more coats of shellac then level with say 600, and progress back up through the grits to "rub out"?

Thanks,

Chris

(COWW)

[TimV]

No, you do not need to rough up the surface for shellac. The denatured alcohol allows it to "melt" the prior layers and bond into one layer. The only reason you would sand between layers is to clean up imperfections in the surface.

You really don't need to sand very much with each grit, just a light touch will do when progressing up to polish like you're doing.

Tim

[bois]

I rarely if ever sand between coats of shellac (to Tim's point the only reason you'd do this is if you had nibs or dust you needed to remove). Each subsequent coat of shellac partially dissolves the coat below it, so there are no adhesion issues at hand. I also think your progression of sand paper on the final rubbing is unnecessary. I am typically trying to bring the natural glossy finish of a shellac top coat down to a satin, meaning I am just trying to dull the surface slightly. Going down to 400 grit is not only risky (you saw the results) it's not necessary. Go right to the 2F pumice if you're looking for a satin finish, progress to 4F for a simi-gloss, and then keep going up to the rottenstone if you want a real high-gloss finish (some folks continue on to automotive polishing compounds). Make sure to use a lubricant, and clean off the prior grits well to avoid cross-contamination. Think of this process as taking a relatively high gloss (but imperfect) top coat slightly back to a satin and then progressing back to a high sheen from there. The good news for you is that sanding through the shellac won't result in witness marks when you re-apply new coats (if this same thing happened with a poly, you'd have to sand the entire thing back to bare wood and start over). Good luck.

[COWW]

Cool,

Thanks for the replies guys.

I've been sanding between coats to sand out the brush marks. I guess since it's not flowing out well enough to self level the brush marks I guess maybe the cut was a little heavy, or possibly I brushed over a section in which the shellac had partially dried.

I just mixed up another 2lb cut, If I'm still getting brush marks I might thin the mixture on successive coats a little this time.

Chris

(COWW)

[bois]

I typically start out with a 2 lb cut to build up a finish, but when I get to the final few coats I'll switch over to a 1 lb. cut. You want to brush that final coat on using the highest quality brush you have, and do the same kind of airplane landing / take off technique you'd do with a french polish and a pad. The quality of the brush plays a much more important role here than you might think. I would even suggest going to an art store and getting a nice flat ended nylon bristle brush for the final few coats. Look for brushes for water-based finishes, not oils. Apply thin coats, using the airplane take-off / landing technique you'd use for a french polish using a pad. You'll be amazed at the difference in the quality of the final finish (and you'll understand why you should only need rottenstone for the final rub).

While I didn't record the entire finishing process, I did discuss my approach on a recent blog video I did. This still might help (and you can see the final results of my finish).