Finish over waxed shellac or not - very confused

[Ryan Gustafson]

Recently refinished a fruitwood desk with shellac. I used non dewaxed Zinnser Amber shellac cut 50/50 with denatured alcohol and a few drops of dye. I applied 4 coats with cheesecloth and then two coats with clear non dewaxed Zinnser shellac (50/50 again no color). Love the way the finish looks and didn't apply more coats worried that I may ruin what already looks good.

It has been two weeks or longer since the last coat. While applying a handle on the desk it moved a bit and scratched the finish. It was small but obvious. Easy fix, but made me think I may need a harder top coat as it scratched so easily and so obvious. I have read many people's advice about a topcoat and am very confused so I am reaching out to you all.

Here are my questions.

1. Should I put more coats of clear shellac to prevent this issue??


2. Should I topcoat with something else. If so what?

I have read I can use non ploy varnish directly over non dewaxed shellac. - I don't want anything to yellow too much over the years.

I've read that Zinnser Seal Coat (dewaxed) will just melt into the waxed and essentially become waxed.

3. Is there something else I am missing with my issue or anything else I could do?

Thank you in advance.

desk.jpg

[Michelle Rich]

if your shellac is waxed, you will have to get rid of the wax, before you use poly or lacquer. The problem down the line is, poly or lacquer are hard to fix when they get scratched. So your pick is easy to fix shellac or harder to fix poly, etc.

[Prashun Patel]

If it were me, I would not yet throw the baby out with the bathwater.

I would repair the shellac. Repairing shellac becomes quite straightforward with a little practice. I have found my shellac pieces to be more durable than I originally anticipated. in fact, with use, I've found some things get naturally 'rubbed out' so minor scratches don't appear as readily as the first.

I would wait for a year and see if you still feel the same way.

The downside of putting a poly on top of shellac (apart from the effort) is that there's a chance it won't look as clear and thin and natural as your shellac. Poly can look like plastic if built up to any protective film.

If you DO decide to topcoat with more protection, consider a non-poly wiping varnish that can be applied over the waxed shellac. If you want to topcoat with a waterbased finish or poly, then you may want to shoot a coat of Zinsser Sealcoat (or a dewaxed shellac) to prime the surface.

[Jim Becker]

I will add that with Shellac, the "ideal" finish, unlike with varnishes, etc., is as thin as possible. It's actually not a good thing to build up the finish to any kind of thickness. So I would try to avoid building up any more. And as Prashun mentions, shellac is easy to fix since it will re-dissolve merely with some alcohol. If you do want something on top...go with a non-poly oil based varnish and, if possible, wipe it on for thin coats.

[Howard Acheson]

If you like the way it looks now, STOP. More woodworkers end up messing the finish up by applying "one more coat".

Shellac is a hard finish. However, what most don't realize is that the harder the finish, the more easily it can be scratched. The reason varnish and poly varnish is more scratch resistant is because is it a relatively soft finish. Soft finishes resist scratches.

Finally, too many coats of shellac can cause problems. Two to four coats is optimal.

You can always easily repair shellac but oil based finishes are much more difficult to repair.

A final note, waterborne finish can not be applied over a non-dewaxed shallac.

[John TenEyck]

I've been applying GF HP Poly over Amber shellac four 5 years w/o any problems.

John

[roger wiegand]

Over a period of 30 or so years before I "knew better" I routinely finished over non-dewaxed shellac with a variety of finishes including various polyurethanes, wiping varnishes, and poly/tung/BLO concoctions and never experienced any problems. It seems only recently has de-waxing shellac become essential.

[Jerry Olexa]

Shellac is easy to repair... A padding w DA and a little shellac should blend it together...also agree: with shellac, a thinner even coat is the goal..Not built up.