They have a fairly long shelf life in dry form. Cool and dry is best. Once mixed, esterfication starts and continues until the finish won't get hard any more. This usually takes 6 to 12 months (again depending upon storage conditions).

If you have some doubts, the way to test is to mix up a small batch and run a test on scrap.

It may have clumped up, in which case smash up or run through an old coffee grinder to help it dissolve.

Thank you for replying so fast. What do I mix it with? I remember some type of alcohol. Will rubbing alcohol work? I know it's a type for finishing wood but for what application? Sorry, old age is getting the better of me and I can't remember anything about shellac or seedlac.

Hi Marvin,

Seedlac eh? Seedlac is the most unrefined form of shellac. It containing all the processing impurities, including bug parts and most importantly, wax. This and buttonlac are the two most durable forms of shellac and a topcoat is not recommended. They've historically been used for french polishing and for finishing stringed instruments. Pls remember to strain the impurities and stir the seedlac to fully blend the wax into the solution.

Most shellac flakes (there are yet a number of grades) are sold decanted, meaning they're dewaxed. You can safely put just about any topcoat you wish over dewaxed shellac except waterbourne poly. Alcohol-based finishes will raise the grain so be sure to lightly sand between coats.

Now for the alcohol. Isopropyl alcohol will work, but not very well. Drugstore bought rubbing alcohol contains too much water (among other things ) for it to be used successfully with shellac. You'll want to use denatured alcohol as the main carrier for shellac. However, if you're in a pinch, ammonia can be used to dissolve the flakes, although I can't condone its use because of the inherent health risks.

Most woodworkers use shellac as a sanding sealer, or conditioner prior to staining. It helps to minimize blotching that can come from staining. A spit coat is all that's really needed - usually no more than a 1/2 lb cut.

Before I get any more long winded than I already have, I'll direct you to a friend's website, Jeff Jewitt. He's one of two people that are considered the top finishing gurus in the US. I get all my shellac from him btw.

http://homesteadfinishing.com/htdocs/articles.htm

Don't hesitate to email me if you have any more questions.

best of luck

Rubbing alcohol will NOT work. You need ethanol, commonly sold as "shellac thinner." Don't mix the shellac until you're ready to use it, and try to mix only what you will use within a few months. Mixing it can be a little tricky too. Look around the Web for detailed instructions, it's more than we can really go into here. Once mixed it is the easiest stuff in the world to use.

To expand on the above, I use denatured alcohol.

I don't get real particular with the mix. I grab a glass jar with a treated lid (pickle jars are good). I put in flakes to the 1/3 line. Then I add alcohol to the 2/3 line. The last third is head space. Shake and shake again when you walk past the jar. This gives somewhere around a 3 pound cut.

Do filter to get out dirt and bug parts.

Also Polyurethane will have poor adhesion over waxed shellac.

Jeff Jewitt's article is a good read. Another is below.

Here is a link that might be useful: Flexner on shellac

Thank you all for your help. The links are truly informative. zennmaster, I took you up on your offer and sent an email to you. I have a few more questions I hope you have time to answer.