Making shellac

[Wally Crawford]

Shellac is my go to finish on my film finished bowls. Up until now, I have been buying the Zinzer stuff, but am trying to transition to making my own to save money. I have tried to make 2# (2oz. flakes to 8 oz. alcohol) and 3# (3 oz. flakes to 8oz. alcohol), but, after three days and dozen of shakings on the jars, I still have a lot of undissolved flakes on the bottom of the jar. I am using 99% pure isopropyl alcohol as a solvent.

Having run into this problem first with the 2#, I ground the flakes into fine powder before I mixed the 3# cut. Same results.

Any advise? I feel I am doing something wrong, but I don't know what.

 

[Jim Reynolds]

I referred to my copy of Bob Flexner's Understanding Wood Finishing from 2005. On page 127 he recommends using denatured alcohol (ethanol) because: "

• It is inexpensive.
• It is not harmful unless you drink it or breathe excessive amounts.
• It evaporates a little more slowly than methanol, giving you more time to brush the shellac.

"

Perhaps trying denatured alcohol is your next experimental step. A local, to me, retailer is selling a gallon of denatured alcohol for $15ish. Flexner also says that ethanol, methanol and isopropanol all dissolve shellac flakes. He describes a procedure on page 129 where in step 4 he strains the dissolved shellac solution through a filter to "remove impurities".

I have no personal experience with this procedure. Wishing you the best of luck.

 

[John K Jordan]

Check the MSDS for ingredients of denatured. A few years back I checked and it looked like besides the traditional bitterant some suppliers were "watering it down" with higher percentages of other things such as methanol. (Methanol is a known serious health hazard, even the vapors.)

If only making a little, is it worth using pure ethanol or would that me it cost too much? I buy Madagascar and Tahitian vanilla beans and make extract from the cheapest 180 proof ethanol I can find - it's cost effective for vanilla (and I get to control the concentration and quality), but I have no clue about shellac.

Are you starting with good quality shellac flakes? I skimmed this article:

Mixing Fresh Shellac from Flakes - Sokolowski Studios

Mixing fresh shellac from flakes can give you piece-of-mind knowing the liquid shellac will be fresh and will reduce frustration in finishing

sokolowskistudios.com

Looks like some useful information. I saw this:
"Button lac contains wax, and for that reason, I don’t recommend using it unless ...".

JKJ

 

[Kevin Jenness]

I made my first batch of shellac recently using 4oz of "Platina" flakes from Shellac Shack in 16oz. of 99% isopropyl alcohol. I broke up the flakes by pounding them with a mallet in a plastic bag, stirred them half a dozen times and had only a few undissolved dregs after 24 hours. Maybe you had some old flakes? Or out of spec alcohol with water in it?

 

[Matthew Dudak]

I don't normally weigh my shellac, I put flakes in a jar, then just pour in enough to cover the flakes. I think this works out to somewhere between a 1-2 pound cut. Works pretty well for me.

Are your flakes dewaxed shellac? Would that make any difference?

 

[Richard Coers]

Old flakes can be hard to dissolve. Some will say there is no shelf life, but the conditions of storage greatly influence the shelf life. Humidity is especially bad!