Purifying Shellac (Full Version)

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constructordeguitarras -> Purifying Shellac (May 21 2014 4:29:08)

I like to use exotic and colorful button shellacs, but I have had problems with them due to the high wax content. Golpeadores don't stick well to shellac with wax in it.

I have found it very hard to remove enough of the wax by filtration, without it taking a very long time with very expensive scientific filter papers. So I tried extraction using a separatory funnel. I dissolved the shellac in alcohol (ethanol) and tried to extract it with naphtha. Unfortunately I got only one layer, but I was able to get two layers by adding a very small amount of water. However there was always an emulsion between the layers that partially separated only after a long time, such as overnight.

I recently filtered a shellac solution three times through plugs of cheese cloth, and still noticed a fine cloud of gray wax particles settling near the bottom of the bottle. Since the wax was settling out, it occurred to me that centrifugation would be a good way to remove it. I doubted that I could afford a centrifuge, but i looked on Ebay and saw that some were available from China for around $100, so I decided to give it a try. (One vendor stated that they were for sale only to qualified people due to FDA regulations. The War On Drugs, restricting a simple machine that spins things around. But I had no trouble with another vendor.)

My machine holds six tubes that hold 20 mL each. (Here it is on top of my clothes dryer, beside my new Aprilaire dehumidifier. The long metal box is what I use for soaking guitar sides in hot water before bending, or for cooking baby alligators.) I filled the tubes and spun the solution for 30 minutes. The ugly gray wax formed pellets at the bottoms of the tubes, leaving nice clear shellac solution above that I was able to decant without disturbing the wax. In fact, the wax was a bit hard to clean off. The dewaxed shellac solution had a more brilliant color than I had seen before and gave faster build in French polishing.

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estebanana -> RE: Purifying Shellac (May 21 2014 9:16:52)

Fascinating, and how to season a baby alligator?

So the refractive index of the shellac became better?



Tom Blackshear -> RE: Purifying Shellac (May 21 2014 13:27:57)

Have I missed something here or is it that you just let the wax sink to the bottom and pour off the purer top shellac.



constructordeguitarras -> RE: Purifying Shellac (May 21 2014 14:23:39)

quote:

Have I missed something here or is it that you just let the wax sink to the bottom and pour off the purer top shellac.


Hi, Tom.

Before I got the centrifuge, I tried that and it didn't work effectively. What I did is put the shellac solution containing suspended wax in centrifuge tubes and spin it in the centrifuge at 4000 rpm for 30 minutes. This made the wax all stick to the bottom of the tubes in a neat little pellet. Then I was able to easily pour off the shellac solution, leaving the wax behind.

Of course, if the Federal government gets its way, I'll have to tie a string to the bottle of shellac and swing it around instead, so that I won't have any equipment that could possibly be used in the manufacture of anything illegal--although most likely breathing will soon be illegal.



constructordeguitarras -> RE: Purifying Shellac (May 21 2014 14:46:24)

Stephen--

I'm not sure how opaque suspended material affects the refractive index of a solution.

I would think that if boiling, a little thyme, lemon, and salt and pepper would do nicely for a baby alligator.[:D]



Tom Blackshear -> RE: Purifying Shellac (May 21 2014 15:10:30)

Ethan, I just order de-waxed from a good source and grind it up in a 12 dollar coffee grinder and then soak it in 190 proof Ever-clear and its ready to go the next day.....And if I want color I use a product called TransTint medium brown #6004 and slightly add a little honey amber #6001 and if it is too yellow, then I add a slight bit of black to cut the yellow, and it comes out a nice tan color.

And if all else fails, call Eugene Clark in Tacoma and get his opinion.



keith -> RE: Purifying Shellac (May 21 2014 15:58:16)

ethan, i suspect the n.s.a. has already read this thread and has informed someone in the justice dept.

it looks like your ph.d. in chemistry is paying off.

i know places like rockler sell shellac flakes in a color similar to what you posted but they state wax has to be removed. there is a place that sells de-waxed flakes. below is a link.

http://www.shellacshack.com/

they are located just down the road from you...ok, maybe a little further but in oregon.



constructordeguitarras -> RE: Purifying Shellac (May 21 2014 16:08:03)

Thanks Tom and Keith. I was aware of that place, but they have the same stuff. I guess Tom's approach might be easier, but maybe I am a purist.

Keith, I assume you mean that my PhD in chemistry is paying off in that I haven't been SWAT teamed already because the NSA thinks I'm qualified to own a centrifuge and a separator funnel, or a filtration funnel.



keith -> RE: Purifying Shellac (May 21 2014 18:31:42)

ethan, a ph.d. in chemistry most likely would raise alarms with the feds--who knows, maybe eric holder is on the phone to his boys planning a raid. i meant few people who have beakers, a centrafuge, etc. and the knowledge on how to use them.



constructordeguitarras -> RE: Purifying Shellac (May 21 2014 18:51:31)

Seriously, Keith, they have done more outrageous things. Even killed entirely innocent people who were asleep in their beds because they thought they might have illegal drugs.



Jim Frieson -> RE: Purifying Shellac (May 28 2014 6:07:40)

If you want clear dewaxed it can be bought like that .
High quality lacs such as Kusmi special etc will result in clear transparent toppings , ordinary orange flake will never be transparent even after settling .
How to avoid filtering , straining , grinding and trying to remove wax with mineral spirits, and all that jazz :
Make it up a few weeks before needing it . Make sure the container is full to prevent condensation and water absorbtion. Leave it in a warm place like up high on a kitchen shelf . All the wax will settle , you are left with toppings , cant them off and throw the rest away or varnish drawer bottoms with it .
You can pour more alcohol on the remaining wax and get some more toppings that way if desired . I use potable 99% anhydrous ethyl , not cheap , so it is a question of expense comparison lac/spirits .
In order to save a bit on spirits , make the lac up a bit thick , and allow for more time , but the thicker it is the slower and less effectively it settles .
I estimate I have been through about 100 kgs of lac in my polishing life - it sure is easier to just let the stuff settle .



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