Thread: French polishing questions

Originally Posted by woodPixel

I used to do a bit of cross stitch (it was a phase)

Hey, it's all cool - no judgments here. Thanks for the info.

Originally Posted by surfdabbler

Hey, it's all cool - no judgments here. Thanks for the info.

I became fascinated with fabrics, manufactory and textiles for a bit (especially the machinery and mechanisms). I enjoyed studying how Persian carpets are made (they use a CARTOON for the pattern). This then lead to surface embellishment and thence cross-stitch.

It was all very nerdy. I did dinosaurs, video game montages (like early 8-bit cassette games and arcade games) and tech inspired work (8086 intel CPU circuits and logic diagrams).

The kids absolutely loved them.

Originally Posted by ubeaut

No offence taken Ian. However we're talking White Shellac (dewaxed) here and there is a reason why it is premixed. White shellac has to be kept at a constant 8C or below in its raw state. That's why we won't supply it raw to distributors or customers.

So I should be storing my dewaxed super blonde shellac flakes in the fridge? Or is white shellac different to blonde?

Originally Posted by jack620

So I should be storing my dewaxed super blonde shellac flakes in the fridge? Or is white shellac different to blonde?

Have to refer that one to Neil, Jack. I do know blonde shellac has a much shorter shelf-life than orange flakes. I've kept orange flakes for several years without problems (in a plastic bag inside an air-tight tin). However, there is definitely a limit, a couple of weeks ago I pulled out some flakes that have been around for about 10 years & made up a ~2lb cut. About 1/3rd of the shellac dissolved after several days, which I think Neil will tell me is a very good indication that my flakes are cactus (unless there is some secret way of reviving them!).

It seems counter-intuitive that "dry" flakes kept in an airtight container could undergo chemical change (though maybe it wasn't quite as air tight as I thought). I don't understand the chemisrty of it, but all the books say it does deteriorate, & the bottle of glug still sitting on the end of my bench seems to indicate they are right! ..

WP, the sort of linen my better half uses for cross-stitch & needlework is much too open-weave to make wrappers for polishing rubbers - maybe you were using a much denser weave? You can probably buy suitable stuff if you go to one of the big chains that sell fabric, fashions come & go & at the time I was talking about, the more open style was in fashion. I've got some cotton cloth atm - some bits of (new) reject shirts that the women in LOML's club re-purposed to make stuff for a charity. It's pretty good stuff & wears well & I got enough of the scraps to keep me in rubbers for a few more years. But next time I have to tag along when the other half goes to 'Spotlight', I'll have a good scratch around & see what they've got....
Cheers,

Originally Posted by jack620

Originally Posted by ubeaut

No offence taken Ian. However we're talking White Shellac (dewaxed) here and there is a reason why it is premixed. White shellac has to be kept at a constant 8C or below in its raw state. That's why we won't supply it raw to distributors or customers.



So I should be storing my dewaxed super blonde shellac flakes in the fridge? Or is white shellac different to blonde?

White shellac is different to almost all others. It is either a powder or fine granules. When the white shellac (waxy and dewaxed) get heat effected, it can lose a fair amount of its goodness. The powder can block, and, in that case it needs to be literally ground back down to a powder before it can be used or it won't disolve. Even if not blocked the liquid needs to be strained and if there is more than a tablespoon spoon of solids in a gallon (imperial 4.5lt, US 3.8lt give or take a little in both) of shellac, it has lost an good amount of its guts.

We had some heat effected stuff once, a few years ago and in a 25kg bag of shellac which is added to 80 liters of Ethanol we were losing around 1kg of solids which definitely isn't good.

Anyway... back to jack620's question above.

Flake shellac, waxy or dewaxed, super blond or golden, ruby or garnet do not need refrigeration. Neither does button shellac. However by the same token, I wouldn't be leaving any of those out in the sun for days on end or storing it in a shed that gets to 40C+ on a regular basis. Keep it all in a cool place away from direct heat and sunlight.

WARNING - do not store any shellac in tin containers weather solid or in liquid form. Unless you want it to go black.

We had a 25 litre cube of golden shellac go as black as the ace of spades in a couple of weeks because a nut and bolt had found their way into the drum. The shellac was useless and so was the nut and bolt which were thick with rust.

For what it's worth. We have a 20ft refrigerated shipping container in which we store all our shellac and other products. unit can go down to 3c but mostly set to turn on at 13c and cool down to 6c. Brilliant on a stinkin' hot day.

Cheers

Originally Posted by ubeaut

Keep it all in a cool place away from direct heat and sunlight.

Thanks. That's what I've been doing.

Anyone got a favourite source for darker shellac flakes? Or should I just add a drop of alcohol stain to the orange flakes that I can get easily?

You might find this video interesting, it explains how pumice works when used to fill the grain. How to fill the grain using pumice powder before French polish your guitar. - YouTube

Originally Posted by surfdabbler

Anyone got a favourite source for darker shellac flakes? Or should I just add a drop of alcohol stain to the orange flakes that I can get easily?

I've never tried colouring shellac, SD, I think that's another question for Neil to address...

I presume you want the colour in the finish rather than in the wood (otherwise you'd just pre-stain the wood)? The old bloke who I worked with a bit used to use button lac to give things an 'old' look. It's a bit more faffing about than using fresh orange flakes, takes longer to dissolve & is full of extraneous stuff so has to be strained before you can use it. Personally, I don't like the finish it gives, it looks a bit "muddy" to me, but obviously there are those as does like it...

Cheers,

In this video at around the 42 minute mark it talks about adding colour to shellac Finishing Seminar with Peter Gedrys - YouTube

Originally Posted by IanW

I presume you want the colour in the finish rather than in the wood (otherwise you'd just pre-stain the wood)?

Normally I would absolutely stain the wood, and I generally don't like coloured finishes. The colour sitting on top doesn't look the same, and if the finish is not consistent thickness, then the colour is not consistent. I guess I'm just a little scared about staining the wood, as it's an antique, and I don't like the idea of doing something that's not reversible. I'll experiment with scraps first and see how it goes.

I hear you bro. - staining is definitely not my bag! I have a big handicap to start with (I'm colour-blind), but even when I conscript the acutely-colour-sighted (= any of the females in your life) to help, I'm never happy with the result. Stains just kill the wood to my eye, which is far more attuned to texture & depth & shades than actual colour. I know experts can do an amazing job of blending repairs & making them look the part, but most still stand out to me because of subtle changes of texture or depth.

So I can fully appreciate your wanting to be ultra careful & not do anything that can't be reversed; that would be my approach too. My preferred way with a repair on an old piece is to carefully match both wood & finish and let time blend in the new work. If the entire section, or the whole piece needs re-finishing, often as not the repair will disappear almost completely after a few months. However, there are exceptions, unfortunately, where the new wood just doesn't play ball when you apply the finish & decides to go a completely different shade from the wood around it! I've had that happen more than once!

So yes indeed, if it's a valuable piece & you want to preserve your reputation, prepare several test pieces and try various treatments until you are satisfied you have it nailed...
Cheers,

Niels post about the White shellac is great . I never knew that . I knew it went off. Ive had such stuff not dissolving . Didnt consider re grinding it though . I just though White was Blonde as well and called them both Blonde. Or I also knew white as Bleached shellac to but I just called it Blonde.


Any way with White or Blonde I like adding some flake or Button if I want (1) a richer colour and (2) for a better working light coloured shellac . I believe just White or Blonde by itself doesnt work as well under the rubber on the job when a lot of bodying is required. It seems a little easier to frizzle up a bit more easy when your bodying . I do use it straight as well on jobs and its good though .
A bit of flake or button added seems to strengthen it up a bit and not change the colour on the job to much.

With woods like Mahogany or Walnut that doesnt matter much and I use a much stronger mix on the flake or button side . !00 % Flake or button on some Mahogany jobs. If I was polishing Rock Maple from the US I would have the no 2 mix. light as possible or slightly warmed up. Otherwise the orange of the flake or button throws the Maple colour . Same when polishing light white pines . Yellow or orange pine from strong Flake or one of the Button types of shellac looks awful.

As for colouring shellac . That's usually for matching or fine adjusting already stained in the right direction boards . Or shifting whole pieces warmer or colder. Or touching out repairs like patches or filler where its used quite strong . oxides mixed with spirit colours then applied.

And I read before about cutting back between coats . I have always used an Oil and turps mix . The pro polishers used it . When your doing a lot of cutting back its faster and keeps the paper free from clogging . One piece of folded paper lasts a long time .
For flat finishing, paper cuts things flatter . Steel wool doesn't .

Flake Button or Blonde can be had here.
Graeme Brown Antiques

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Here's some Mahogany I polished some time back.
The shellac in the tub is all Flake or Button . This was bodying up and filling grain with pumice.
Three of those leaves on the right are replacements. New Fiji plantation Mahogany matched to solid Cuban Mahogany table from the 1860s roughly . light as a feather compared to the old ones. The match was perfect though . Some of that Fiji stuff is very good.

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Below is staining the three new leaves to match the old. The Old is second in from the right. And one new leaf is remaining to be treated with Potassium dichromate, as the two on the left have just been . The stuff is legendary in Mahogany or Red Cedar work but very toxic apparently. I'm not saying use the stuff.
Its just Me showing off. If I'm going to show a bit of that job I will show the best bits as well .

The staining on jobs like this could be attempted with out of the can stuff, then shellac with spirit colours mixed in could be used to fine tune . It wouldn't have been anywhere near as good.
When I was doing this if I found the leaves were going to Red then I could adjust to the brown side with shellac mixed with Black and green added, used on the rubber. This will swing the colour as the polish is nearing completion . It still needs clear body's on top though to seal it in . The trick is always staying just under the lighter side when colouring and fine tuning as it goes when the colour job is critical . Like when you have a nutty decorator telling you the Exact colour she wants and its a only thousandth off .
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While I'm at it . Here's a job I made and keeping the light pine look was uppermost . It was bleached after finishing the build first. And Blonde was used. I do use straight blonde with no probs but a bit of the more orange shellacs can be used in the mix and with a careful eye kept on the colour they don't show if thin enough. Just straight blonde could be to cold and the slightest warmth to it looks good.

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Rob

@Rob, Nice work!

I called five professional paint stores, and quite a few cleaning products distributors. None of them had ever heard of industrial methylated spirits, and just had the normal 95% stuff. I've just ordered some online from Sydney, so it should be here in a couple of days. I'll be interested to see whether it makes much difference from 95% in terms of drying times.