Sealing with shellac temporarily?

[Skew ChiDAMN!!]

Recently I managed to score a set of four lovely old chairs from kerbside pickup. In all honesty I only picked them up because we've recently moved from a furnished rental to an unfurnished and we needed somewhere to plonk our butts.

On sanding back the first chair I quickly realised they're figured Blackwood (solid and veneer), quite well made and still in excellent condition; it's only the old shellac finish that has deteriorated. I'm now kicking myself for not going back for the remaining two chairs or large dining table that went with them.

Anyways... I finished sanding the first and brushed on several coats of dilute shellac as a temporary protective measure so we can still use it to sit on while I work my way through the rest. I'm hoping to apply the "proper" finish in one batch job so the chairs are 'out of commission' for as short a time as possible.

I intend to give the quickly sealed chairs a quick wipe-down with metho and a light sand before applying the final coats. Am I likely to run into any problems with this approach?

[Xanthorrhoeas]

Very nice finds indeed.

Are you sure that is Blackwood? It certainly looks a possibility but they could also be figured Queensland Maple from the photographs.

Why don't you final finish in shellac too? It does give superb clarity and vibrance to timber. Quick drying so there is less down-time.

However, if you do want another final finish I don't foresee any problems with your approach. Shellac is often used as a sanding sealer before applying other finishes.

[Skew ChiDAMN!!]

I'm fairly certain they're Blackwood. Even the freshly sanded legs and rails have a degree of chatoyance that surprised me. Of course, without having any bark, leaves or flowers attached one can never be sure.

I meant to add that I was planning on finishing in Shellac too, which is why I'd like to do the final coat(s) on all the chairs in one sitting, more or less.

I'm slightly concerned that because the chairs will be in regular use until I get a round tuit, the temporary coat may not really be suitable. I think it will, but I've been blindsided by the obvious before.

[Skew's_Girl]

Another question, WTH am I going to reupholster it with?
I think for art deco [they're art deco... right?] it would be cream fabric in either a short pile or a brocade.
But that's such a pain to keep clean in a house with so much sawdust. I was genuinely surprised how many types of sawdust are a natural dye.

Would a milk chocolate coloured leather work? Black leather with white piping? Worse come to worse I might have seen a dark royal blue brocade picture once.

I have no idea what i'm doing.

[Cliff Rogers]

Cream works but shows the dirt, at darker satin finish vinyl or leather might be better.

[Xanthorrhoeas]

I have shellac sanding sealer finished bare wood and given a coat of hard wax on objects and found it to be very hard wearing. Obviously you would ahve to remove the wax before final polish.

yes, definitley Art Deco.

[Skew ChiDAMN!!]

Thanks. That's what I thought. I won't be waxing, as hopefully the chairs will only be in this state for a month or two. (Life keeps getting in the way.)

With a modicum of luck I can use this sealing coat as a base needing only a light clean up before moving on to the finishing coats.

[Xanthorrhoeas]

I think that will work well. I have seen some deco chairs upholstered in leather and they looked good and very serviceable. Although a lot of deco chairs were originally upholstered in vinyl or maybe its predecessor fabrics I understand the best were also sometimes originally leather upholstered.

[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.

[Skew ChiDAMN!!]

I have seen some deco chairs upholstered in leather and they looked good and very serviceable. Although a lot of deco chairs were originally upholstered in vinyl or maybe its predecessor fabrics I understand the best were also sometimes originally leather upholstered.

Leather is my preference, purely from a serviceability stand-point. After all, these chairs are and will be daily users for, hopefully, a long time.

Now... picking a colour? UhOh...

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.

On the first chair I applied 4 coats of a 15:1 dilution I had to hand for surface penetration/sealing while woodturning. I denibbed then brushed on another coat. So it is a very thin coating overall and I don't expect any problems with imprinting, but I'll keep an eye out.

Hopefully a bit of care in the meantime will minimise chips or discolouration to something easily cleaned up.

[ubeaut]

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.

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.

___________________


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

[Ari2]

Neil,

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

Colin

[ubeaut]

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, but don't tell anyone. Shhhh.

Hope this is of some help.

Sorry to have hijacked the post.

[Pat]

Don't use it to light a fire in your fireplace.

Something you wish to share?

[Xanthorrhoeas]

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

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 ...

David