French Polish

[David Lay]

Thank you.  I calculated 50g/200ml = 2.08  lb./gal(US).  

[SteveS]

23 hours ago, David Lay said:

Thank you.  I calculated 50g/200ml = 2.08  lb./gal(US).  

It can take a few days for the shellac to dissolve completely - I keep mine in a sealed jar.

 

Baby food jars are ideal for keeping small quantities of shellac.  To make a 1/2 cut divide in 2 and add the same quantity of alcohol (meths) again to one of the halves - then repeat for 1/4, 1/8 and 1/16 cut. 

 

Ed. once mixed, the shellac/alcohol has a finite shelf-life, so it's best to make as much as you think you'll need for the job at hand.

Edited February 8, 2023 by SteveS

[Richard Mellish]

22 hours ago, David Lay said:

Thank you.  I calculated 50g/200ml = 2.08  lb./gal(US).  

How many concertinas are you planning to French Polish?

[RogerT]

The problem with using a rubber to finish a concertina end is that the polish tends to get snagged in the fretwork. Mark Lloyd-Adey (concertina spares) told me he sprays on the shellac to get a good finish, and this is how I do it, and it gives consistently good results and is much faster and easier than using a rubber (well, I find it easier…I use a rubber to finish old melodeons so I do know how to do basic French polishing). I have an air brush (I don’t have a compressor..just a big can of air). And the trick is to dilute the button polish or shellac with meths…but you have to experiment to get the right dilution. And obvs do it in a ventilated place, wear a face mask and do not light a match nearby. I think you can actually buy spray cans of shellac in the US but I couldn’t find any in the UK. I think my air brush cost about £25. You don’t need anything particularly fancy. 

[David Lay]

1 hour ago, RogerT said:

The problem with using a rubber to finish a concertina end is that the polish tends to get snagged in the fretwork. Mark Lloyd-Adey (concertina spares) told me he sprays on the shellac to get a good finish, and this is how I do it, and it gives consistently good results and is much faster and easier than using a rubber (well, I find it easier…I use a rubber to finish old melodeons so I do know how to do basic French polishing). I have an air brush (I don’t have a compressor..just a big can of air). And the trick is to dilute the button polish or shellac with meths…but you have to experiment to get the right dilution. And obvs do it in a ventilated place, wear a face mask and do not light a match nearby. I think you can actually buy spray cans of shellac in the US but I couldn’t find any in the UK. I think my air brush cost about £25. You don’t need anything particularly fancy. 

This is the spray shellac I see most often.  It says it is a 3 pound cut, so a bit heavy.  

https://www.amazon.com/Rust-Oleum-Zinsser-408-Bulls-Shellac/dp/B0009X8HWG/ref=mp_s_a_1_2?crid=KNHM9DLG159V&keywords=shellac+spray&qid=1679529912&sprefix=shellac+spray%2Caps%2C158&sr=8-2

[Wally Carroll]

Just be aware that shellac may not be suitable for all players' hand chemistries (particularly those whose hands perspire while playing).  I suspect it would be better suited to English concertinas where there is less hand contact on finished areas and maybe less physically intensive to play due to less bellows reversals on average.  I tried shellac when I first got started and it looked beautiful for a couple weeks but then started to deteriorate.  Maybe there are modern formulations that are more moisture resistant, but in general, nitrocellulose lacquer yields a similar look with better durability.  Of course, this usually involves having a more extensive setup involving spray equipment and it may not be legal in certain areas due to VOC content.  Another good alternative is the gun oil product sold under the name Tru Oil.  It is a polymerized linseed oil that fully hardens and can be built up in layers.  Guitar makers use both of these alternatives to shellac.