Shellac compatibility with other finishes, and glues

I've been getting back to some bush 'stick' furniture making after a long hiatus.
At my best, like this (local acacia "sally wattle")
Attachment 457774

For all that the shaped sanded parts bring out wonderful luminous grains it was the pale, unblemished natural skin of the acacia poles that always drew me to it. That and there's lots of acacia's on our block - but what emerges from under the bark can be as luminous as it's grain and I love how it looks in the round, just as it is. Preserving that appearance 'unblemished' has been a continuing aim, not ever fully realised. It seems surprisingly good at taking a mark or stain and keeping it clean seems to end up with rounds of scrubbing or pressure cleaning. Someone long ago suggested shellac as a sealer to help resist marking but I only recently got a 'white de-waxed' shellac as granules after finding regular orange too darkening.

I'd been making a guitar stand and tried out the shellac. I gave it's parts a single coat, with some going back over end grain - with a less than 1/4 recommended strength shellac mix. Yet I do like how it looks, just like that - a hint of emerging gloss and negligible colour change! Out of all the things I've used over the years I think it might look the best. At least for indoors.

But if I want something to have a decent lifespan outdoors - like the piece above - I won't get it with shellac, so, can I marine varnish over a shellac sealer? The usual "sand back to clean wood" advice isn't going to do it; I will light sand, sort of, between of varnish coats but sanding every little undulation just isn't gonna happen. If these finishes are incompatible it would be a good thing to know before I get carried away. And if I have a tenon with shellac on it, will it affect the the strength of a glue bond? I might use PVA, Polyurethane or Epoxy, depending.

I'd been thinking I'd like to wash and seal some of the best of the poles I have as stock - and try a sealer early, when my next poles are washed for drying and storing.

Ken in Drake NSW.

Hello Ken

Best bet would probably be our Hard Shellac which is a premixed, dewaxed, bleached shellac, containing a hardener giving the hardness and almost the same durability as Melamine /Laminex bench tops.

It shouldn't darken the timber any more than wetting it down with water or metho. It will make the internal grain really pop and keep the creamy sections pretty much the same colour, without darkening it. The timber may darken with continual bright light from the sun as it is not UV stabilized, but that could take years.

There should be no need for washing down due to staining.

Probably not a good idea to put anything over shellac or any other finish as mixing and matching can often cause crazing down the track due to different movement of the finished.

The dewaxed white you have is great as a sanding sealer if mixed with around 1 part shellac to 8 parts metho and it is alright to use under the Hard Shellac.

Warning re buying dewaxed white shellac in its powder/granular form.

• The raw product has a short shelf life if not kept refrigerated or is subjected to heat and bright light.
• Mixing with 100% Ethanol (100% IMS (Industrial Methylated Spirits)) is the best.
• If you can't get 100%, 95% will do but if it doesn't say 11% or 95% on the contained don't use it.
• Dewaxed is excellent for sanding sealer as there is no wax meaning almost anything can adhere to it.
• Because it is dewaxed it will not have any elasticity and may craze or crack with time.

U-Beaut Hard Shellac is dewaxed, but has an elasticizer added to it to stop it from the crazing and cracking that the normal dewaxed can have.

It is premixed ready for use and has 18 months shelf life with a best before sticker on the bottle

Hope this is of some help or interest to you.

Cheers - Neil :U
U-Beaut Polishes

PS Sorry for the bit of blatant advertising. :B Nah not really.

Don't anyone bother reporting the blatant advertising. I have the Administrators approval... Hey that's me. https://www.ubeaut.biz/woohoo.gif

Neil,

So your Hard Shellac would be a far better option for the guys using EEE and Shellawax as a finish on small treen and pens?

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So your Hard Shellac would be a far better option for the guys using EEE and Shellawax as a finish on small treen and pens?

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Not really....

Shellawax, Shellawax Glow and Aussie Oil are all Hard Shellac based and if used in multiple coats will be pretty much as tough and in the long term better than ciynoacrylate which can break down over time,

For pens etc and basically anything that isn't purely decorative it is recommended that multiple coats of the above 3 are used, as the first application is basically in the timber (wood) and may be damaged by continual long term use. Second, third and subsequent coats if needed will give a surface coating that will last way longer and be almost impervious to marking.

However some people have acid sweat that may damage the finish and almost any other surface coating on pens and other constantly handled items with regular use. I had a man doing classes with us years ago who we had to put cotton gloves on as he would rust the blades on turning tools within a couple of minutes of touching them. Would also dull most bright surface coatings when touched including polyurethane, nitrocellulose lacquer, and shellac, etc. However we never saw the same short term results on any of the friction polishes and we weren't using the hardened shellac back then.

Shellawax Cream is not recommended for use on pens and constantly handled pieces as it has a much higher wax content making it a little easier to be damaged long term with water, alcohol, heat, etc. However multiple coats will give a better long term result.

Even so I wouldn't use it on pens. But keep it for use on larger items or to mix with Shellawax or Glow to use as an extender for those finishes . Mixing a little with the liquid Shellawaxes will allow them to sit on the surface of the work piece for longer so it can be worked easier as a friction polish instead of soaking in to end grain on larger items like bowls, platters, etc over 100mm dia.

Sorry for the rambling post.

Hope it is of some help.

:U

Thanks ubeaut. It is use as that sanding sealer, diluted down, that interests me most - it's ability to help resist staining from handling, it's ability - or not, it sounds like - to take other kinds of finishes after.

Despite the cautions against, it's very likely I'll try some marine varnish over the top of a few pieces, to see for myself; dealing with that natural surface, and the whole exercise in using the wattles (and sapling eucalypts too) has been about making it up as I go. A big part of what keeps me interested! I think I'll have to try it when some poles are green as well as on existing dried poles - but it is doing it green I'd like to have work, for keeping it clean from the word Go. Dealing with and preserving the best of that natural surface hasn't been nearly as simple as just doing nothing to it!

In the outdoors I'm sort of resigned - marine varnish is as good as I've managed; past a decade exposed but under a verandah roof and looking good is a win. Full outdoors, well, some pieces with nothing but an initial oil last about 6-8 years and get nicely silvered by halfway, (after a not so attractive sooty, mouldy stage), whilst varnish by then is getting a bit flaky as well as starting it's own version of sooty and mouldy - and yes, I know follow up coats are recommended and I haven't, but... hey that's me. And then there is the gate I made, under an eave, with nothing but linseed - but fairly regular linseed - is quite sound, and nearly black, after 10 years. Indoors, well, I'll be trying out more pale shellac.

Quote:

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Originally Posted by ubeaut

Not really....

Shellawax, Shellawax Glow and Aussie Oil are all Hard Shellac based and if used in multiple coats will be pretty much as tough and in the long term better than ciynoacrylate which can break down over time,


Sorry for the rambling post.

Hope it is of some help.

:U

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Neil, Thank you for clearing up some of the misinformation about your products. I've encountered the "acid sweat" issues and the frustrations of trying to explain that there is nothing "wrong" with the products or the application of them. Same goes explaining to wood turners the benefits of good finishing schedules, i.e. multiple coats of a well applied finish over one thickish poorly applied coat slopped on.