Enahancing a finish with a new coat of shellac

[USlakeside]

At the advice of forum members, I think I would like to try to "refresh" the finish on my Edison Business Model D with a few coats of new shellac. Are there any special tips out there? How to deeply pre-clean the case first? Thanks!

[hillndalefan]

When I set out to do that, I start with just wood alcohol [shellac thinner] on a brush, which lifts dirt and also begins the amalgamation process. Often, that is all that is needed, but if you want to add a new coat of shellac, it's a good idea to rub it down with very fine wet/dry abrasive paper first, then remove any dust first. I've found it amazing how easily an old damaged finish can be restored that way.

[USlakeside]

Thanks. Going to do a gentle sand and then blow it off with an air compressor. This should be safe? Then the alcohol.

[gramophoneshane]

When I did mine, I actually started by giving the case a wash with mild soap & water & a well worn scourer from the kitchen.
I did one surface at a time, starting with a quick pass-over the surface with the scourer to wet the surface & soften the dirt & grime. Then I went over the surface again, but this time gently scrubbing the cabinet to shift the dirt. For these steps, I kept the scourer a little more than "damp" but not dripping wet, but you want it wet enough to penetrate the muck.
As soon as the surface is completed, wipe the sludge off with a damp rag (water only), and repeat with a second damp rag to remove any remaining dirt & soap residue.
Then wipe over the surface again with a clean dry cloth to remove any remaining moisture, and move on to the next side/surface.
Once the whole cabinet is finished, allow 24 hrs for it to dry completely. Once dry, you've got clean surface to work with, and you can see exactly what base finish you've got to work with.
Dont scrub the decal as you would the rest of the machine, but it should brighten up considerably with the 2 damp cloth pass overs. If not, you may have to give the decal a gentle rub with a little soap & water on a cloth, again rinsing any soap residue when done.

Now I know a few people will raise an eyebrow about using water & a scourer on a shellac surface, but each side from start to finish should take no more that 2 minutes max, so the water wont have time to do any damage to the shellac, and the worn scourer helps lift the dirt while smoothing out any lumps & bumps. You could use a cloth instead of a scourer, but I've found you'll need to do a lot more scrubbing, which also increases the time you're keeping the shellac wet. A well worn scourer wont leave the surface looking scratched either, but any minute scratches will be levelled off once you go over the surface with alcohol.
I apply the alcohol with a rag, and again have it a little more than damp. I only apply a single coat of alcohol, and it's a good idea to try to apply it to each surface in a single sweep. If you miss a spot here & there, wait for the alcohol to dry thoroughly & touch up the missed spots, otherwise a second sweep while the surface is still damp will act like a paint stripper & remove the rejuvenated shellac.
The trouble with "cleaning" the surface with alcohol is that sometimes as the alcohol is drawn into the dry shellac, it can draw in dirt with it. Also if you come across something like cockroach dung that requires a bit of extra scrubbing, you'll usually end up removing a lot of the surrounding area of finish before you remove what you want to.

If you do decide to try this, it might be a good idea to try it out on the underside (or inside) of the cabinet first so you get an idea what sort of pressure you'll need to apply with the scourer, and a bit of practice with the process & speed.
You'll be amased at how clean it becomes.

[USlakeside]

Thanks Gramophoneshane.

I have read online that you can clean it first with turpentine too? When I had access to it, I used an air compressor to clean the case, which was a good solution. It really blew a good deal of dust out of all the crevasses. I have read you should use a natural fibre brush for the application of the denatured alcohol, is there a reason a cloth is best? It does seem like you would have more control, less freak drips going off this and that way if you used an absorbant cloth. I fear that if I took soap and water to my finish, more of the shellac would come off than is desirable. If you were to look at one square inch of the finish, 50% of the shellac is missing. Its evenly missing throughout that one square inch, but its flaky. I would be more inclined to give it a gentle wipe down with just water first, let 24 hours pass, then start with the alcohol. Also, my decal is 95% missing, so Im not too worried. I will probably get a reproduction.

Thanks!

[USlakeside]

Also, I after the process, if the finish needs a new coat of shellac, is it better to use clear instead of a tinted shellac? Instinctively I would go with clear.

[hillndalefan]

I would advise using a clear shellac. The stains Edison used generally do
just fine as long as the original finish wasn't compromised. My Edison Standard type F had spent several decades in a barn and as a result had several areas without any finish or stain left. At the time [1964], I didn't
know better and didn't apply any dark oak stain when I refinished it, so it
needs to be re-done. I learned how to save the old finish some years later,
as well as the proper color. The earliest Edisons had a green stain on the case, but this was changed before 1906.