Shellac Problem

Please watch out how much shellac you brush on - especially if you intend to sit on them in the short term. It dries by evaporation of the alcohol solvent. That can take a while - I have had brushed shellac finishes take the better part of a year before they wouldn't imprint... It's also pretty fragile while it's fresh in terms of chips and discoloration from water drops....

A better solution is to brush 1 thin coat or wipe on a coat and wipe it back off... Let it dry as long as you can and then hope for the best.

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Originally Posted by truckjohn

Please watch out how much shellac you brush on - especially if you intend to sit on them in the short term. It dries by evaporation of the alcohol solvent. That can take a while - I have had brushed shellac finishes take the better part of a year before they wouldn't imprint... It's also pretty fragile while it's fresh in terms of chips and discoloration from water drops....

A better solution is to brush 1 thin coat or wipe on a coat and wipe it back off... Let it dry as long as you can and then hope for the best.

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Sounds more like your shellac was out of date. Probably not the thickness of the shellac but the age or condition of it. In most instances shellac is best mixed and used fresh, within 6 months. Old shellac or heat affected shellac will often not fully cure which would give you the problem of imprinting.

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Skew.
The timber in the back is reminiscent of walnut which was often used in that type of chair and other furniture of the same era. Up until a year ago I had part of my parents walnut bedroom suite that was almost identical to the back of your chair including beautiful chatoyance in the fiddleback.

Cheers - Neil :U

Neil,

Slightly off-topic, but probably not, what can one do with 'out of date' shellac?

Colin

If it's dewaxed shellac you can mix it down with 8 to 10 parts metho and use it as a sanding sealer which will work well for many years as it is mostly pure alcohol. If it's waxy shellac probably the best thing to do is chuck it out.

Although it does come in handy for sealing pitch into pine etc around knots and other points of gummyness, but how often does a person need to do that. Also works better for that purpose if it's fresh.

The problem with shellac is esterfication, which begins once the shellac is mixed with the alcohol. This means that the shellac loses its ability to dry hard over a period of time.

Chuck it out!!! Thoughtfully.....

Disposal

• You can let the alcohol evaporate off and dispose of the hard stuff that's left in the rubbish.
• Buy some Kitty Litter put some into a plastic bag and and pour the shellac in until it's all absorbed. Add more litter if needed. Dispose of in rubbish. Not toxic or hazardous.
• Cheaper way is to buy a bag of spill kit absorbent granules and do the same as above. We always have a number on hand at the factory in case of spills. Way better than kitty litter and a lot cheaper. Try bunnies.

• Pour a bit on your next bonfire to get it started after all it does have a high percentage of ethanol in it so burns well. Don't use it to light a fire in your fireplace.
• Dig a hole in the back yard and bury it. It is all natural product and no reason why it can't be taken back into nature.

You didn't hear the last 2 from me. Oh bugger yes you did,:doh: but don't tell anyone. :shhh:Shhhh.

Hope this is of some help.

Sorry to have hijacked the post.

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Originally Posted by ubeaut;2087566

The problem with shellac is esterfication, which begins once the shellac is mixed with the alcohol. This means that the shellac loses its ability to dry hard over a period of time.

[SIZE=3

Chuck it out!!! [/SIZE]Thoughtfully.....

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Darn, I thought the problem was air. How long would one expect stock solution of button shellac to last before throw out time? I have 5 litres sitting there ...:oo:

David

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Originally Posted by Xanthorrhoeas

Darn, I thought the problem was air. How long would one expect stock solution of button shellac to last before throw out time? I have 5 litres sitting there ...:oo:

David

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If it's any consolation, I feel your pain. I foolishly bought a gallon tin of Zinnser shellac (I didn't know better then!) from Masters. It was the first time I'd used shellac and I was pretty disappointed that it was taking so long to dry. Live and learn and throw money into the bin I suppose.

I have heard the shelf life is 3-6 months from mixing....

I admit mine also came out of the can.. I doubt I helped anything glopping it on thick... It took a year (not figuratively - 12 actual months) to dry all the way so it wouldn't print... It was dry to touch the day I brushed it... But it just stayed soft forever... But since it did dry - it has been fine..