# How do you know your shellac has gone bad.



## PASs (Dec 1, 2009)

I use the Zissner sealcoat type shellac.
I buy the gallon can.
I pour about a pint in a flip-top glass jar where it sits with an acid brush and piece of rag in it until I want to wipe it on to finish a project.
On most of my projects where I use the shellac is is just a sealer. I put it on, let it set for a few seconds and wipe the excess off while it's still wet.
Then I polish it with the Beall Buff ensuring any excess shellac is polished off in the first stage.
If the shellac in the jar gets a little thick I cut it with denatured alcohol.

So, I will I know when the shellac isn't doing what I want it to do, to seal the wood grain prior to polishing.
It takes me about two years to use up a gallon (so far.)

Appreciate any info, and would appreciate even more if you can identify your sources.
Personal experience is good too.

Thanks,
Pete


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## shampeon (Jun 3, 2012)

When I've had bad shellac it just takes forever to dry. If you put on a coat and it's still gummy 10 minutes later, it's time to toss it (or just use it to seal the end-grain of rough lumber). 2 years might be pushing it, though the Zinnser SealCoat seems to last longer than their heavier-cut shellac.

I buy the quart cans of SealCoat or mix mine from flakes so I don't have to worry about using up the full gallon.


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## wapakfred (Jul 29, 2011)

That's the thing, the drying really slows down. If I question whether shellac is good, I'll put a drop on a piece of glass (or non pourous surface, so none of it gets absorbed) and see if it sets up in 20 minutes or so.


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## PASs (Dec 1, 2009)

Soooo, if the shellac is bad even thinning it with alcohol won't speed up the drying?
For me that would mean a sticky texture to the wood.
Then I'm fine (for now.)
Thanks for the feedback…now gotta go shellac some coin displays.


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## woodchuckerNJ (Dec 4, 2013)

Why do you wipe off the excess?
Thin it for a sealer and let it dry.
As far as when it goes bad, like everyone says. It should dry in 10 minutes, 20 at most.

I thin seal coat, I don't use it straight. I always build slowly.


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## wapakfred (Jul 29, 2011)

If it's bad, it's not a solvable problem…it's only use is to start a fire.


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## NiteWalker (May 7, 2011)

When shellac goes bad it won't dry.

The zinsser shellac and sealcoat (dewaxed shellac; I love that stuff) have a shelf life of 3 years from the date of manufacture. Don't store it in a hot environment; it decreases the shelf life. Using sealcoat, you shouldn't need to thin it since it's a 2lb cut, but if desired 50/50 with dna works fine.

Since sealcoat isn't available locally for me any more, I had to buy a 2 gallon pack from homedepot. When it gets here I stir it and transfer it into quart plastic jars and only bring one down to the shop at a time; the rest are stored in the pantry in the house.

Re: application; I spray it and sometimes wipe it on. If you have to wipe excess off, you're applying it incorrectly. Shellac doesn't like to be applied thickly.


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## PASs (Dec 1, 2009)

woodchuckerNJ,
I wipe the excess off because most of my projects are polished with the Beall System.


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## JoeLyddon (Apr 22, 2007)

I just put it on, thin coats, when dry (20 min or so), light scuff with 330 grit, and keep going until I like how it built up… Finish with a light scuff 400+ grit.

Yep, if it doesn't dry, it's over & out.


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## NiteWalker (May 7, 2011)

Joe, that's the same process I use for applying sealcoat, though I don't hit it with 400 if a waterborne clear coat is going over it.


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## JoeLyddon (Apr 22, 2007)

The ONLY thing I usually put over shellac is wax… nothing more…
Shellac is a rugged hard finish that holds up good… IMHO.

I love Shellac…


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## NiteWalker (May 7, 2011)

Joe, while I agree shellac is a hard finish, it's not very rugged to anything exposed to moisture or even sunlight.

I love it too, but for different reasons (fast drying, great sealing properties, works great as a toner, etc.).


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## Kentuk55 (Sep 21, 2010)

Interesting questions, and lotsa good answers. I'm learning as well.


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## wormil (Nov 19, 2011)

I use Zinsser and have never had a can go bad to the point where I stopped using it. The can I'm using now is several years old at least and still dries just fine, I added a little fresh DNA to it.


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## Allen78 (Feb 5, 2015)

I sprayed an old can of Zinsser Bulls Eye Shellac Sealer & Finish on some small ornaments. The product is two or three years old, stored in the garage, (Indiana). Didn't dry well on the ornaments. After 6 hours, I stacked them up and had to use a knife to gently pry them apart from one another. I'm thinking this is too old to use now; glad to hear that so many have good luck with shellac, but I'm giving up on this can.


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