Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum gloss finishes before lacquer

Thanks everyone
I have also heard of "spirit varnish" which is somewhat like shellac but with added resins . It will dissolve with alcohol.
Kamin.....black shellac I have not tried. What is added to it to make it black? a pigment or a dye?

Usually, a black dye called nigrosin was and still is used to blacken shellac.

Back to your original post: there are different methods of rubbing out and polishing shellac. One was a final rub with only the palm of the polisher's hand using extremely fine rotten-stone and sulphuric acid to remove the polishing oils.

Thanks all for the informations, and Jurgen it is probably what we see in the film, then.

We use similar products once the shellac is hard. So the difficulty. For stripping old black pianos may relate to an old cellulose film (the top clear coat is often more recent and is easier to strip)

Yes nigrosin for alcohol, a powder, also known as "chemical black"

The commercial names use for those yet modern finishes makes it difficult to know exactly , but at last shellak based products can be home mmade, certainly not cellulose based if you want to avoid to put everything on firre...

I tried to provide information on wood finishes prior to nitrocelluous laquer. What I state is accurate. There is no validity in quoting the website of a commercial product pushing a brand name. Wiki is just about as accurate. Nitrocelluous lacquer was invented in the twenties by Dupont. Prior to that, there was Shellac, Varnish, and Lacquer. They are what they are, and what is in each is what is in each. All consist of a resin disolved in a solvent. I also stated that there were various recipes used all the time.

Go quibble amongst yourselves. Since knowledge and comprehension around here is not as important as opinion or false conjecture, this whole thing is worthless.

Spirit varnish is not a solvent; it is a top coat. Could you please provide a source(s) showing where it is/was only a solvent, not a solvent with resins dissolved in it (including shellac) to be used as a finish?

Edit:
Sources:
piano finishes in the 19th century
http://www.google.com/#hl=en&su...8957d2&biw=1280&bih=550&bs=1

shellac as spirit varnish
http://www.google.com/#hl=en&su...e1960d58e8957d2&biw=1280&bih=550

spirit varnish vs oil varnish
http://www.google.com/#hl=en&su...e1960d58e8957d2&biw=1280&bih=550

Will I have to read this whole thread to find out which ego won?

One either strips a piano and refinishes it, or keeps the old finish and tries to keep it authentic.

Of course, knowing what finish one is working with helps.

Knowing what manufacturers used a hundred years ago? The stripper tells you. Every time.

And if you choose not to strip and keep the original finish, there are plenty of places where you can test new products that work very well.

End of my rant.

I really cannot help with English names but spirit based (alcohol) products can be either only shellac or mixed shellac and cellulose, which is more resistive to alcohol , dry fast, shine soon and more, but tend to crack in times when it harden too much.

first quality flakes of shellac (with minimal wax) alcohol and a small quantity of black. That black shellac is very sensitive to alcohol when rubbing it, and the top coat is a transparent one once the wood is well blackened (same as for cars , in the end)

Black shellac is an excellent product that allow us to repair old cases, some training is necessary but it is a simple method, variations happens depending of temperature and moisture, so one have to develop a feel for that.

Well done, the surface is like a mirror (means a first class sanding and preparation)

Just to be clear, Marty, Dupont say:

DuPont, seeking diversification based on its nitrocellulose experience, bought the International Smokeless Powder & Chemical Company, a manufacturer of both explosives and pyroxylin lacquers, in 1904.

Pyroxylin is a generic name for nitrocellulose compounds that form a film when dissolved in a mixture of ether and alcohol, from which plastics can be produced.

See: http://www2.dupont.com/Phoenix_Heritage/en_US/1904_b_detail.html#timeline

As you say they came up with the quick drying finish destined for automobiles in 1920.

Victory at last ! DuPont (Nemours) is a French name (I knew that )

The last time I baught collodium the chemist thought I wanted to make explosives !

DuPont representatives are very kind people, as when I asked them about the quality of micro fine Teflon used in pianos, they send me a 1KG sample so I could do some "testing"

(that one is used in anti-robbery inks, that explode to the face of the robber, and the ink traces can be located on his cloth even a very long time later, the shape of the particles is very uneven , so it stay well within the leather/escain)

An update The base coat seems to be an animal glue. As I am removing the bottom layer I find that it has that "special" odor and gets soft with water. This is only on the parts with the veneer. In traditional hot glue veneering, both sides get glue on them so this may be the reason??? The black may be a varnish as solvent do not seem to soften it.

hello Thanks gor the update. That seem to be a standard from those times. the glue is probably rabbit skin (mixed with a powder)
used after the veener is glued, not at the time of gluing I believe, (?) or the cauls have to be rubbed with tallow. the surface is moistened wth hot water for what I know of the process and probably not for all kinds of veener.


to make a refinishing or repair the black french polish is the "easy" solution. and you get a shine as polyester ( may be more glossy)
but it is dfficult to learn to do it well.
and it is a fragile finish, when one think of what will be done on it after.

it is better to sand and if not cracked you have your undercoat.

those jobs are to be done with modern finishes today. nobody want to spend the time to make a finish that can be so fragile.

but it may be authentic more than a PU or poly.

I worked that as a mean to make repairs. it also allow once you made your "hand" (in the end the eye is also important of course) , to use faster methods with filtered shellacks.
temperature and moisture play a large role in the easyness.

what will you do as refinishing ?

I have seen skin glue or rabbit skin glue used on the hard wood parts as well