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!

 

[Michael Ogden]

I use Everclear. Yeah, that nasty liquor store stuff. 180 proof (90%) grain alcohol - AKA ethanol. If you drink at all and are curious how it tastes, you've been warned. Don't ask me how I know that.
I've been using dewaxed shellac flakes - Platina and Super Blond - from The Shellac Shack. [Not necessarily plugging Shellac Shack... just sayin'] My preference is 2-lb cut or less.
I store my shellac flakes in my shop refrigerator.
The flakes are more-or-less fingernail size. I don't break them up, but I'm sure they would dissolve more quickly.
I put weighed flakes in a clean Ball/Mason jar and pour in the measured Everclear.
Seal and shake vigorously for several minutes, then shake vigorously again maybe every 30 minutes until the stickies at the bottom become floaters again.
For me, if I'm pretty diligent, I can have usable shellac in a couple of hours. If not, it's kind of a chore to unstick big clumps of flakes from the bottom of the jar. Lots and lots of shaking.

I don't pretend to be an expert. This method works for me.
Cheers!

 

[Steve Tiedman]

As a side note regarding storage of shellac flakes and moisture, specifically humidity. Polyethylene bags (aka Ziplock, etc) may seem convincingly moisture-tight, but polyethylene sheet plastic does, in fact, allow moisture to pass, albeit very small amounts. This is referred to as the permeance rating, or "perm" rating. From a construction website-
One perm is defined as 1 grain of water passing through one square foot of material in 1 hour with a vapor pressure difference of 1 inch of mercury between the warm and cold side of a material.

Head to the grocery store and look at the garden variety ziplock backs available to you. Regular sandwich bags may have a mil thickness of 1-2, while freezer bags can be up to 4-6 mil. These thicker plastics can have perm rating well under 0.1 perm. But then there is the zipper, which in my mind is the weak point. I did not research the water vapor leakage rate of a ziplock bag zipper, but I doubt it is as low as the plastic itself. Maybe a piece of thick plastic packaging tape folded over the zipper will help?

Which makes me think that for longer term home storage of flakes, rather than twist tie bags or ziplock bags with the air squeezed out by hand, shallac flake should be stored in vacuum/heat sealed bags with as thick of plastic sheet as possible. I don't own one of these food storage systems, so I'm clueless as to the mil spec of the bag stock, but you can pick it up from here if interested. (It must be pretty heavy if they claim to keep frozen steaks and veggies in a fresh state for many months in a freezer. Freezers will pull moisture right through thinner poly plastic- "freezer burn".)

It also makes me think that the in-service container of liquid shellac would benefit from a shot of argon gas (oh, what's that brand of aerosol spray argon for varnish?) to displace moisture-laden air from the can. Probably not a concern for heavy users of shellac, but for casual users trying to get 6 months from a batch, it may help.

 

[Fred Hargis]

We all have different experiences with this, so here's mine: I use DNA, usually the Sunnyside brand, which is labeled as methyl alcohol and ethyl alcohol combined. My flakes (both waxy and dewased) are quite old, some as much as 15 years old. But they alwsys been stored under refrigeration and have held up very well. When I dissolve them, I always mix the amounts of the finished shellac at once, and I always have a small amount (very small) of undissolved flakes in the bottom after mixing, the shellac gets poured through a strainer to remove them. But what I do to help the flakes dissolve is warm the solution up. In the winter this means sitting the jar (I always use canning jars to mix shellac) in a pan of very hot water. In the summer I'll sometimes sit it out in the sun, or inside my car, or even the mailbox to warm it up. I think if you try warming it up a little you'll have much better results, but I'm not sure you will ever get it all to dissolve.

 

[John K Jordan]

It also makes me think that the in-service container of liquid shellac would benefit from a shot of argon gas (oh, what's that brand of aerosol spray argon for varnish?) to displace moisture-laden air from the can

Bloxygen. It's pure argon now after they changed the formula some years ago. Not cheap but doesn't need much for an opened container of finish.

The old formula.




I use argon to displace the air finish containers once opened (and in the large bottles of Parfix 3408 CA before putting the lid back on.) Nitrogen and any inert gas will work. (Even helium, but it's notoriously difficult to contain - helium atoms are so small they will go through glass)

To store shellack flakes in moisture free environment it would need to be sealed in more than plastic bags. Even CA glue suffers from storing in plastic bottles.

Or do this with the bag of shellac (or CA, or anything) to keep moisture out:
Find a well sealed container. Put some indicator desiccant beads (Amazon) in the container. They absorb and hold any moisture. I like the blue ones which turn pink when exhausted. Dry them out in a toaster oven until they turn blue again and reuse indefinitely. Note that the clear desiccant beads are fine if you mix in a few indicator beads for monitoring.

Some people save the little desiccant bags from medicines and such. But how can you know when they need to be "recharged?"

JKJ

 

[Mark Mandell]

2 points;
A. As mentioned, moisture will degrade stored flakes of dewaxed shellac Light is also not friendly to the resin. Best place to store your flakes is in a Ziplock freezer bag in the refrigerator as long as the light goes off when you close the door.
B. I use only 200 proof ethanol (about $40/gal. on the internet. it has no methanol and is made undrinkable with Bitrex which doesn't effect the solvent or the dried film.
C. You can extend the shelf-life of a mix by putting it through a coffee filter. It's a slow process but the shellac comes out crystal clear. The mix ( stor3ed in a dark cabinet, is usually good for 6-7 months before the esterification progresses beyond useful time.
PS Forgot to mention: I use a "chopper-ina-hopper" to pulverize the flakes before mixing. I mix 4 oz. to a pint to make a 2lb cut. Dissolves in about 2 hours.
BTW Shellac is an evaporative finish rather than a polymerizer like oils. It cures by evaporating the solvent so argon is a waste of time and money. Save it for the Waterlox.

 

[Steve Tiedman]

@John K Jordan, when you have a moment, could you show some photos with an outline of your argon delivery system? I've hemmed and hawed over the years of setting up something more cost effective than Bloxygen cans, but haven't done so. The argon bottle, a regulator, dispensor hose... it has all been a bit vague to me how to set something up without doing/buying something unneccesary. I think plenty of folks would appreciate your effort to show it. Thanks!

I haven't thought too much about it in recent years because I've dedicated myself to Tried & True products which have not had issues with product loss in the can. A pint can not only goes a long way, but lasts a long time after opening. But if I ever go back to home brew wiping varnish, I'll need a system (i.e. Bloxygen-like) to prevent product loss.

 

[Don Schwartz]

I use small quantities of weight-measured shellac flakes in Everclear. (I have a spreadsheet with proportions for various mixes.) Mix with a small magnetic stirrer. Heating some helps in my chilly basement, but the alcohol evaporates, so not too much. Works quite quickly and reliably. Filter any bits remaining.

 

[Bob Barth]

I use a coffee grinder on the flakes, and never had a problem.

 

[John K Jordan]

@John K Jordan, when you have a moment, could you show some photos with an outline of your argon delivery system? I've hemmed and hawed over the years of setting up something more cost effective than Bloxygen cans, but haven't done so. The argon bottle, a regulator, dispensor hose... it has all been a bit vague to me how to set something up without doing/buying something unneccesary. I think plenty of folks would appreciate your effort to show it. Thanks!

I haven't thought too much about it in recent years because I've dedicated myself to Tried & True products which have not had issues with product loss in the can. A pint can not only goes a long way, but lasts a long time after opening. But if I ever go back to home brew wiping varnish, I'll need a system (i.e. Bloxygen-like) to prevent product loss.

Steve,

I decided to answer in a different thread. That would make it easier to point to when this comes up again.

Thread 'Preserving finishes by replacing air with inert gas'

Sunday at 1:56 PM

@John K Jordan, when you have a moment, could you show some photos with an outline of your argon delivery system? I've hemmed and hawed over the years of setting up something more cost effective than Bloxygen cans, but haven't done so. The argon bottle, a regulator, dispensor hose... it has all been a bit vague to me how to set something up without doing/buying something unneccesary. I think plenty of folks would appreciate your effort to show it. Thanks!

I haven't thought too much about it in recent years because I've dedicated myself to Tried & True products which have not...

• John K Jordan
• Replies: 10
• Forum: Woodturning Discussion Forum

• 

JKJ

 

[Kent Reisdorph]

I make a 1# cut with DNA, one pint at a time. I pulverize the flakes in a food grinder first. Then I shake the jar every few minutes while I'm doing other things. It will all be dissolved in about an hour.

 

[Bill Hamilton]

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.

i switched to bullseye sanding sealer and that solved my finishing problems

 

[Jay Simmons]

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.

Ethyl alcohol (ethanol) is a much stronger solvent than isopropyl. As recommended by other poster’s suggestions use denatured ethanol as it is less expensive. The Everclear version is not denatured. The producers must pay a beverage tax making it more expensive. Another example of a “sin” tax

 

[Jay Simmons]

i switched to bullseye sanding sealer and that solved my finishing problems

Methanol is highly toxic and has been the denaturing method for many years by adding a small % to ethanol. Seems that the industry has migrated to other hydrocarbons to denature the ethanol. Recommend that you not use methanol. Denatured ethanol works better and is safer