Shellac not dissolving - what's going on?

[Doug Miller]

Somebody check my math here, too, please... So I'm trying to mix up a small amount of shellac in a 1-pound cut -- i.e. 16 ounces (by weight) of shellac per 128 ounces (by volume) of alcohol, right? The ratio 16:128 is the same as 1:8, so this should be equivalent to one ounce (by weight) of shellac flakes in 8 ounces (by volume) of alcohol.

Which I stirred up just before going to bed on *Sunday* night.

Forty-three hours later, despite frequent agitation of the container, only about half of the flakes are actually dissolved. What's going on here? Old shellac? This stuff isn't especially fresh, but it's been stored in a sealed zip-lock bag, at room temperature, away from light, moisture, and heat.

[tiredofspam]

Hi Doug,

So you are correct.

I use a coffee grinder on my flakes.

Since you are already past that.. try heating the jar up with some hot water around it, or stick it in the car during the day. The heat from the sun maybe enough to dissolve the flakes. (I got that from someone else and have successfully used it myself)

It's like hot water dissolves sugar better than cold for tea.

I have used flakes that are years old. But that said I have on occasion just struck out and gone what the hey.

ounces (by volume) of

equivalent to one ounce

about half of the flakes

especially fresh, but

light, moisture, and

[Larry Blanchard]

How strong is the alcohol? Has it been exposed to air and absorbed water? How big are the shellac flakes? Are they blond, garnet, etc.? Are they dewaxed?

I've had the best luck using 97% alcohol from a chemical supply house and breaking up the flakes with a mortar and pestle. Dewaxed blonde seems to dissolve the quickest and garnet flakes with wax the slowest.

Heat helps a lot. If you have a way to keep a container of water at a steady warmth, put the shellac container in the hot water.

[Doug Miller]

tiredofspam wrote in news:ksKdnYyhcbq_C1PSnZ2dnUVZ_s- [e-mail]:

I've heard that tip before -- and remembered it about ten hours after dumping in the alcohol. :-(

Thanks -- I tried that already. Didn't help. :-(

I think that's where I am now. Our local Ace Hardware carries Bulls-Eye shellac in quarts, and they open at 8 tomorrow morning.

[Doug Miller]

Larry Blanchard wrote in news:jqm5f3$d4f$ [e-mail]:

Pure denatured alcohol from the Borg.

Tightly closed steel gallon can.

Blond dewaxed flakes from Woodcraft. Probably 1/8" to 3/8" across.

I've used a coffee grinder before, but inexplicably forgot to do that.

Tried that already -- I needed to heat up some hide glue yesterday morning anyway, so I warmed up the pot early, put some water in it, and let the shellac mixture warm up to glue- pot temperature (about 140 F). This had no apparent effect on the solubility of the flakes.

[Larry Jaques]

+1 on the heat idea. Loosen the jar lid, set in a bowl of hot water. Shake every few minutes until it dissolves. It can be 10 or more times quicker than the cold method.

Denatured alcohol dissolves the fastest and evaporates the fastest. And the thinner the flake, the quicker it dissolves. Crush buttons with pliers for quicker dissolution.

-- Silence is more musical than any song. -- Christina Rossetti

[clare]

Keep a lid on the shellac when you warm it up, or it will boil all the hooch off.

[Larry Blanchard]

Doug, if you haven't tried it before, get the SealCoat. It's a 2 pound cut and dewaxed - much more moisture resistant than BullsEye.

[Larry Blanchard]

One of the things that bugs me about alcohol from Home Depot and Lowes is that they don't list the alcohol percent on the can and no one at the stores has any idea. I know it's not 100%, that's darn near impossible and very expensive.

I do know that the 97% stuff from a supply place dissolved flakes a lot quicker, so I'd assume 80%-90% for the Borg stuff. Although I did find an MSDS on their stuff that claimed 45%-50% each for ethanol and methanol.

[Lew Hodgett]

--------------------------------------- SFWIW, 200 proof = 100%.

Booze is seldom listed above 190 proof or 95%.

Alcohol left open to the atmosphere will suck moisture out of the air, thus reducing it's proof.

Lew

[Dr. Deb]

Doug, all the advice was great - however, it could be that your "de-waxed" isn't as de-waxed as it should be. I bought a couple of pounds of super blond de-waxed flakes from a very reputable dealer. Every batch I have brewed up (using 190-200 proof alcohol) has had a large sediment lump in the bottom of the jar, making it look like only half the shellac was dissolved. Truth be told, it was wax and residue. Just pour off and use what you have.

But as Lew said, next time get the "good" alcohol from someone other than a Big Box store.

Deb

[Swingman]

99% Isopropyl, at just about any drug store, is about as good as it gets for cutting shellac without an excise tax. A bit pricey (IIRC, Amazon has it for around $9/32oz or $50/case of 12/160z), but for spraying on on hot humid days it is insurance for a good job.

I spray a lot of shellac in my shop and I typically use 99% Isopropyl on hot humid days to cut 3# to 1 1/2# for spraying as it mitigates blushing with high humidity.