Shellac

[berry]

I use shellac as a sealer in finishing. I make it from scratch using 1 oz of flakes to 4 oz of denatured alcohol mixed in a mason jar.

For most projects I use blonde flakes but in my current effort, a cherry wine rack, there was quite a bit of sap wood so I thought I'd darken that portion of the wood with garnet shellac. I used the same formula and did the mixing at the same time. Typically a batch of blonde takes 3-4 days for the flakes to fully dissolve. In this case the garnet formula was fully dissolved in 2 days!

A couple of questions here. Why would the garnet flakes dissolve any quicker? Does anyone have a method to speed the process? I've tried grinding the flakes in a coffee grinder before mixing and I've tried setting the mixture (while in the mason jar) in a crock pot of water with the temp set for low. I purchase my shellac at Rockler, I wondered if any of you have experience getting shellac from Highland or Woodcraft or someone else.

Thanks.

[shaun]

That's a big difference! It's been a very long time since I worked with shellac, but here's my take on it: my first suspicion would be the solvent. Are you using the same brand alcohol, from the same source? You probably know that it is really hard to find denatured alcohol with a high percentage of Ethanol -- it is commonly mixed with other alcohols, which is not reflected on the label (read the MSDS).

[beeg]

My flakes dissolve in a matter of hours. Maybe your blond flakes are older, than the garnet flakes? I bought em here.

http://www.shellacshack.com/

[terrydowning]

Mixing my own shellac is on the list of things to do. No experience, but I will be following this thread.

Thanks for the link Bob.

[shipwright]

Heat and agitation will speed things up. Be very careful with heating of course for obvious reasons but a water bath on an electric stove is safe.

I've never tried it myself but I'll bet that you could speed it up quite a bit by using more alcohol (higher dilution) and then evaporating off the excess after it is all dissolved.

I've had quite a lot of variation in dissolve times myself with no real explanation, but I'm not usually in a hurry so I don't pay a lot of attention.

Paul M

[Ed in Tampa]

Also alcohol exposed to air will absorb water. If you have 100% pure alcohol and open the lid to the air the liquid is no longer 100% pure alcohol. The change isn't much but it could effect dissolve time.
Also where you buy your alcohol could effect dissolve time as well as temp, age of flakes, age of alcohol, size of container (surface areas of flakes exposed) and actual amount of alcohol and flakes ratio.

One thing you mentioned is grinding the flakes, I would be cautious of this since grinding generates heat and heat will effect the flakes.

[trainguytom]

Up to this point, I've always used Zinsser's pre mixed stuff, but have always thought of mixing my own. My question is this: I've always just gotten D-alc from my local big box store-usually Sunnyside brand, and it's fine for brush cleaning & diluting, but if I do decide to mix my own, are there better brands, purer brands, more consistent brands, etc...or are they all pretty much the same?

[kalynzoo]

Great post. I've always purchased canned shellac too, often the can is close to the expiration date when purchased. After hours of loving labor making the wood just right I am fearful of using an outdated sealer.
Making my own product from flakes is worth a try.
My question:
How do you guys store the flakes?
Do the flakes deteriorate when in solid form?
Thanks.

[berry]

Paul - good to know I'm not the only one to see a variation in time it takes to dissolve the flakes.

I use Sunnyside brand denatured alcohol, it's what Menards sells here. (I use their mineral spirits too.) I purchase it in a plastic gallon container. When I get home, I transfer it to a older metal gallon container. I store it in an unheated garage. As I need it I transfer it to a transfer metal quart container that I keep in the shop.

(I re-use the plastic containers for used mineral spirits and alcohol. I can take them to the local hazardous station and leave the container.)

As far as I know, all the alcohol came from the same lot, but I'm not sure and as indicated I handle it a lot.

I know my shellac flakes are pretty old. Rockler sells them in 8 oz batches so for me that could be a year or two. My understanding is, it doesn't matter how old they are. Thanks for the link to shellacshack.com, I'd love to try a new supplier.

I know temp makes a difference, which is why when I make a batch I keep it in the bathroom until it dissolves, its the warmest room in the house. The temp in my house, during the day and evening it 67-68 and at night we set back to 55.

Thanks for all the input.

[greitz]

If you have an ultrasonic cleaner (like jewelers use to clean rings), it will speed up dissolving the shellac flakes quite a bit. As Paul said, agitation helps, so continuous shaking, stirring, or sonication will speed the process.

Gary