Sealers and grounds

[David Burgess]

I have about 50 pounds of de-waxed, charcoal purified flake shellac I'd be willing to sell if anyone's interested. I've latched onto various things, and when they looked promising, I tried to put in a lifetime supply to deal with potential supply problems and product changes.

I only use it for repair and polishing now, so holding back on the other 25 pounds or so should do me if I only live to be 200.

[Johnmasters]

I have about 50 pounds of de-waxed, charcoal purified flake shellac I'd be willing to sell if anyone's interested. I've latched onto various things, and when they looked promising, I tried to put in a lifetime supply to deal with potential supply problems and product changes.

I only use it for repair and polishing now, so holding back on the other 25 pounds or so should do me if I only live to be 200.

Do the dry flakes go bad? I recently had some bleached blond flakes and they made a gelatinous mess in alcohol. I buy Bekol which is ethanol denatured with butyl alcohol. The idea is to keep out the gasoline and such. The problem was not this Bekol, I am sure.

Try dissolving in a good quality alcohol to see for a clear and normal solution. Then advertise it, I might take some.

[Michael Richwine]

Do the dry flakes go bad? I recently had some bleached blond flakes and they made a gelatinous mess in alcohol. I buy Bekol which is ethanol denatured with butyl alcohol. The idea is to keep out the gasoline and such. The problem was not this Bekol, I am sure.

Try dissolving in a good quality alcohol to see for a clear and normal solution. Then advertise it, I might take some.

Yes, dry flakes do indeed go bad. It's easy to tell when. They don't dissolve any more, no matter how long you let them soak. Yours sounds typical.

I had some great stuff I bought around 2000, and put away in a cupboard in the garage, in a sealed jar, when I quit restoring furniture. I brought it out again last year and it was no longer any good. "Gelatinous mass" is apropos.

Shellac that's made up can go bad in a few months, depending on temperature and, presumably, humidity. It won't dry hard. I always make up small quantities and don't keep it more than three months. It just works so much better when it's fresh.

Shellac is probably my favorite furniture finish, when applied by French polishing. The most beautiful furniture finishes I have ever seen were French polished with shellac and pumice. The finish, though very thin, had the same depth and luminosity described above, even after 100 years. In my minds eye, it's still breathtaking. You can get a similar look with some modern catalyzed finishes, but they won't last like shellac, and they are much harder to repair.

Based on my tests, freshly made shellac is very water resistant. If it resisted heat and alcohol better, it would be perfect, IMHO. As it is, it would still be my choice on anything I thought would still be around in 300 or 400 years.

As a sealer for violins, or a component of a ground, it certainly wets the wood out well, giving a great look, and it's a great base for any other varnish to adhere to. As mentioned above, it stiffens the wood a bit, too. However, there are other grounds that look as good, and give different tonal effects. I've mentioned before that we routinely fine tune the voices of different instrument lines we make by changing the composition or application of the ground. The changes are very obvious, and repeatable. After 15+years of testing, Anton's gotten so good at it that he can get the effect he wants in just a couple of tries. (The hard part is choosing the sound the market will like best. "Old Italian" isn't always what buyers are looking for at lower price points.)

[jezzupe]

I generally use wax free shellac as a sealer as well, nothing introduces grain celebration on properly prepared wood as shellac, in my opinion. Once in awhile, as on the last one I just finished, I will use a very weak solution of glue and sugar water, this helps to achive a very light "water based finish" look. It has no special{no negative either} effects. It is used purely as a color option for me. The amount of glue must be minimal in order to have the wood remain "free".

[jezzupe]

http://www.ubeaut.com.au/hardshell.htm

here is a cool product.

caustic soda improves hardness and wear dramatically when added to shellac

[Johnmasters]

Yes, dry flakes do indeed go bad. It's easy to tell when. They don't dissolve any more, no matter how long you let them soak. Yours sounds typical.

Many thanks,, I had never had the problem before, I usually buy at a local woodworker's store. I suppose they sell less and less of things like that. Likely very old stock.

http://www.ubeaut.com.au/hardshell.htm

here is a cool product.

caustic soda improves hardness and wear dramatically when added to shellac

You can add weak ammonia water... others use borax water. Lye-water seems extream. Does it stay water-sensitive?

[jezzupe]

Many thanks,, I had never had the problem before, I usually buy at a local woodworker's store. I suppose they sell less and less of things like that. Likely very old stock.

You can add weak ammonia water... others use borax water. Lye-water seems extream. Does it stay water-sensitive?

Shellac has a very unusual dry/curing period where it happens in stages. "hard" shellac imo is much less sensitive than "regular" shellac, shellac for instruments must be 100% wax free imo.

It is easy to influence or change shellacs dry film by modifying it, ie. "spirit" varnish, by adding different resin's... "poly resin compounds" suspended in an alcohol solvent once dry will have different properties depending on what the additives are and what the proportions are. These additions can also dramatically effect the "cure rate"...

Shellac is in a constant state of transformation for up to about 80 years, after that it will have achieved full cure. Depending on what time you were to catch shellac during its life cycle may determine its properties at that given time....shellac analyzed on a instrument that is 5 years old, will yield different characteristics results on the same instrument 50 years later. It is a optimum finish base for many reasons, one of the most important is that it is not effected by uv light degradation like many finishes are. Conifer Saps, Thistle extracts, resinous flower extracts as well as hemp tar all can help influence uv breakdown as well as add other physical properties

[DBurns]

Here is a nice display photo of Shellac.

Nice picture showing all of the different flakes.

[David Burgess]

Do the dry flakes go bad? I recently had some bleached blond flakes and they made a gelatinous mess in alcohol. I buy Bekol which is ethanol denatured with butyl alcohol. The idea is to keep out the gasoline and such. The problem was not this Bekol, I am sure.

Try dissolving in a good quality alcohol to see for a clear and normal solution. Then advertise it, I might take some.

It's quite old, and still dissolves fine in ethyl alcohol. There's no difference from when it was new, as far as I can tell. Perhaps some types of refining processes give the product a short shelf life, and others don't. According to Zinsser, this was their most stable, highest quality product. From what I understand, Zinsser is the source of almost all shellac on the market, and this is purchased, repackaged and re-sold by others.

I'm not interested in selling small quantities.... more trouble than it's worth for me. It doesn't take up very much space compared to other things I have that will probably never be used.

[Don Noon]

caustic soda improves hardness and wear dramatically when added to shellac

Any idea what mix ratios work best, and if potassium hydroxide works as well?

[jezzupe]

Any idea what mix ratios work best, and if potassium hydroxide works as well?

Admittedly I am not a exact ratio kinda guy, heck the only "measuring" tools I use during construction are a neck gauge,compass and straight edge, I don't measure anything. Including finishes. What I am big on are "real world" tests. Generally I am a dash of this dash of that, eye of newt kinda finish maker. Once I get something I think I like, I will apply it to scrap wood, let it dry and then mess with its physical properties to see what it "acts" like under various conditions, I also make "pancakes" on wax paper and glass. Between scratch tests, hot/ cold tests, stretch tests, crumple tests and alike, many things can be learned as far as what any particular finish film will do and how it will react.

Potassium hydroxide I have not messed with, I do feel however it may be usable, they are very similar and used in many of the same products for similar purposes.

I learned the "drano" trick from an old furniture maker long ago. It does dramatically increase scratch resistance.

I like shellac because I like ethanol as a solvent. There are so many things that can be melted into it and its evaporation times are very fast, perhaps too fast for some. But once you are good with it, you can easily have several coats on and be done quickly. Ethonol also is great at sucking the color out of natural plant materials also. Virtually any plant material with natural pigments, once dry, can transfer that color into the ethanol, simply by soaking the dry material in the liquid then straining. That can the be used to mix up shellac and make colored finishes. Also many plants once dry have natural saps, resins and other gooey compounds that can be leeched into the ethanol. There are many plants that I experiment with that I don't even know what the name of them is, but I do know when I've got something that has potential. For example , I live in a marsh land, in the back of my house, for about 3 months, grows a type of weed like flower. It smells like camphor, but I do not think it is, at any rate before it goes to flower there is the period of time where the buds have this very sticky resin, this resin melts well into alcohol, the end result is that this material not only acts as a modifier to the shellac resin, but also seems to add a spike lavender like effect by allowing at little more open time during application{when you need it} but allows for quick normal drying. The resin alone has finish like properties that act as a finish.

So to me there are so many fun things to do with shellac base finishes as far as experimentation goes that to measure would be a killjoy....

I guess if I had to say it, it would be like this.

I use a small plastic folgers coffee container as my finish cup, in that I have about 1 1/2" of fluid, to that I add a few pellets, or a pinch of crystals{depending on what form}, test some out after its dry on wood, too much it drys funny and becomes brittle.

[fiddlecollector]

Any idea what mix ratios work best, and if potassium hydroxide works as well?

Potassium hydroxide will work exactly like sodium hydroxide.The only difference is potassium salts tend to be slightly more soluble and often slightly more expensive.

Never tried whats suggested in this thread it but i would expect the shellac to become water soluble when treated with an alkali.

[Wm. Johnston]

Never tried whats suggested in this thread it but i would expect the shellac to become water soluble when treated with an alkali.

I've made watersoluble shellac by mixing it with borax. This also had the side effect of turning orange and garnet shellac into an ugly red-brown color that I really disliked. I don't remember if I checked if other bases would change the color of shellac in similar ways or if this color would occur if bleached shellac and borax were used.

[cbouts]

Potassium Hydroxide will turn some shellac flakes purply reddish brown depending on the solution amount - and then you end up with a sticky mess that wont ever dry. The adhesion qualities are greatly impacted as well.