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Julian Cossmann Cooke

Spirit Varnish for the Convinced and the Curious

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5 hours ago, Andreas Preuss said:

Does anyone here know of an earlier recipe?

Salmon's Polygraphice has quite a few - it dates to 1672 or thereabouts. 

I believe that he had a tendancy to repeat the work of others without properly attributing, so there's a good chance the numerous recipes he provides (example yellow and red varnishes below) are potentially much earlier and in common circulation by this time.
 

Polygraphice.thumb.jpg.3c5e1811b899e2f88ffc50b4f1b16942.jpg

 

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7 minutes ago, notsodeepblue said:

Salmon's Polygraphice has quite a few - it dates to 1672 or thereabouts. 

I believe that he had a tendancy to repeat the work of others without properly attributing, so there's a good chance the numerous recipes he provides (example yellow and red varnishes below) are potentially much earlier and in common circulation by this time.
 

Polygraphice.thumb.jpg.3c5e1811b899e2f88ffc50b4f1b16942.jpg

 

Thanks for this information! That's quite interesting. 

in those days it was quite common to copy recipes from other sources without quoting the source.  

I was cross reading with my book. 

It seems that early spirit varnish recipes were often based on sandarack (recipe XI) as one of the main components. However I would be curious to know what is 'gum anime'?

Do you have the front page of the book?

 

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7 hours ago, Andreas Preuss said:

Earliest spirit varnish recipe I found in my library is Werckschul 1696. It is interesting that the author (who apparently is not the one who made the varnish formula) identifies the recipe as from a famous maker in the city H.

What comes first to mind is Joachim Tielke in Hamburg. 

The recipe describes the procedure. The varnish is made in three different vessels. In  the first vessel the clear varnish consisting of gummi lacca (maybe shellack) and sandarack is dissolved in alcohol.

In a second jar dragon blood and the roots of red berries( in the German text: rother beern Wurtzel) is mixed with alcohol.

in a third jar the yellow color is blended with colophany aloe and Orleans.

When the ingredients are entirely dissolved and colors completely extracted they are filtered and poured together. The mixed varnish has to stand for another week that remaining impurities go to the bottom. The dirt free varnish is carefully poured in another vessel and then ready to use. 

What I find interesting is that colors and the clear varnish are dissolved separately. Maybe when the colors and the cleR varnish are blended not all color is used taking just as much as to achieve the right color either more red or more yellow. 

Does anyone here know of an earlier recipe?

image.jpeg

Karl Roy attributes a virtually identical recipe to Johann Georg Lochner Nürnberg 1738, the main difference being the use of curcuma and gamboge in the third jar.  Roy also suggests that the red berry root is probably madder.  The Violin; Its History and Making, Karl Roy 2006, p. 605

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5 hours ago, Andreas Preuss said:

However I would be curious to know what is 'gum anime'?

It is a secretion from the hymenaea courbaril,  aka West Indian locust tree. 

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Shellac. I once had the idea of trying the 'sediment' left after allowing the wax to settle out. Of course shellac normally has a wax content of around 5%. My sediment was obviously at the extreme, gave a rather waxy soft looking finish. Soft it was too, no surprise. It wasn't a serious attempt, just brushed on to an off cut. 

 It did occur to me that it could become another variable in a spirit varnish recipe i.e. increase the wax content from it's more usual 5% to 10 or even 20%. 

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On 9/27/2019 at 8:01 AM, notsodeepblue said:

Salmon's Polygraphice has quite a few - it dates to 1672 or thereabouts. 

I believe that he had a tendancy to repeat the work of others without properly attributing, so there's a good chance the numerous recipes he provides (example yellow and red varnishes below) are potentially much earlier and in common circulation by this time.
 

Polygraphice.thumb.jpg.3c5e1811b899e2f88ffc50b4f1b16942.jpg

 

I had to go look for that.  That's a big book with a lot of interesting things in it.   

This may be a slightly different edition.

https://archive.org/details/polygraphiceor00salm/page/872

 

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Another thing to keep in mind is that colorants like saffron and turmeric and not very color fast. I've experimented with both and even tough they give an intense, transparent yellow color, both can fade to a mere wisp of their former color in a few  months of normal light exposure.

 

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On 9/27/2019 at 6:13 PM, Michael.N. said:

Shellac. I once had the idea of trying the 'sediment' left after allowing the wax to settle out. Of course shellac normally has a wax content of around 5%. My sediment was obviously at the extreme, gave a rather waxy soft looking finish. Soft it was too, no surprise. It wasn't a serious attempt, just brushed on to an off cut. 

 It did occur to me that it could become another variable in a spirit varnish recipe i.e. increase the wax content from it's more usual 5% to 10 or even 20%. 

I have had a similar thought in the wake of reducing button lac in alcohol with a little heat.  The result looks very promising on maple.  I did not proceed with testing for appearance on spruce because of the waxiness.  Both on the wood and in the jar.  I was concerned about adherence issues as further layers of material were applied.  But I haven't tested that either.

Whatever the original wax content, the lac could be dewaxed much in the way that propolis can.  Since dewaxed shellac doesn't seem to pose adherence issues, maybe it's a matter of getting lac's wax content down low enough. 

Great!  Another research question to be pursued: how much wax remains in dewaxed shellac?  And of course, the answer will vary depending on the source of the dewaxed shellac.  Unless da dewaxer is one's self.  "How much wax could da dewaxer dewax if da dewaxer could de-wax?"

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I use dewaxed shellac (ruby). I'm sure a chemist would be able to find some rest of wax in it, but I never considered micro amounts to be an issue. Wouldn't that be a philosophical question only? :)

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I've dissolved shellac in 91%? isopropyl, and the blonde shellac is more like brown.  But as it settles in the jar, wax comes out as a very thin layer on the bottom.  At least I think it's wax.  So maybe what kind of alcohol you use makes a difference.

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18 minutes ago, Ken_N said:

I've dissolved shellac in 91%? isopropyl, and the blonde shellac is more like brown.  But as it settles in the jar, wax comes out as a very thin layer on the bottom.  At least I think it's wax.  So maybe what kind of alcohol you use makes a difference.

The amount of wax that will precipitate from an alcohol-shellac solution increases with percentage of alcohol.  To remove the wax that remains in solution requires filtration.  I use 95% ever-clear.  I don't remember the percentage that is expected to remain in solution (small amount) with 95% alcohol, but I was satisfied with pouring off the clear solution on top after giving the wax and other insolubles time to settle to the bottom of the jar. 

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20 hours ago, Julian Cossmann Cooke said:

I have had a similar thought in the wake of reducing button lac in alcohol with a little heat.  The result looks very promising on maple.  I did not proceed with testing for appearance on spruce because of the waxiness.  Both on the wood and in the jar.  I was concerned about adherence issues as further layers of material were applied.  But I haven't tested that either.

Whatever the original wax content, the lac could be dewaxed much in the way that propolis can.  Since dewaxed shellac doesn't seem to pose adherence issues, maybe it's a matter of getting lac's wax content down low enough. 

Great!  Another research question to be pursued: how much wax remains in dewaxed shellac?  And of course, the answer will vary depending on the source of the dewaxed shellac.  Unless da dewaxer is one's self.  "How much wax could da dewaxer dewax if da dewaxer could de-wax?"

My guess (and it is a guess) is that if you allowed the shellac to sit for a couple of months and then carefully decanted the remaining wax content would be under 1% - given 5% content for the original. Then again why would you want to dewax (save for ground coats)?  Given that a common complaint is that shellac is too hard (at least with some violin makers) it may be advantageous to increase the wax content a little. In general woodworking folk use dewaxed shellac usually because they are overcoating with a different type of finish and they fear adherence issues. Shellac is noted for how well it adheres to anything though. I doubt that waxy shellac on top of dewaxed shellac is going to be much of a problem. The question might be how waxy can one go. No doubt a lot of testing, trial and error is needed. 

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14 hours ago, Ken_N said:

I've dissolved shellac in 91%? isopropyl, and the blonde shellac is more like brown.  But as it settles in the jar, wax comes out as a very thin layer on the bottom.  At least I think it's wax.  So maybe what kind of alcohol you use makes a difference.

I've used Isopropyl and shellac a LOT and have never seen that happen. It's always been the same clarity as you would get with ethanol. I use 98% Isopropyl though. Then again all the blonde type shellacs I've bought have been processed dewaxed types, the lightest being platina. The only light coloured waxy shellac that I've come across is the button stuff that shellac.net sells (not the usual button lac). That's pretty unusual stuff because in 40 years I've never seen it sold in the UK. 

Another alcohol source is bioethanol. Here in the UK you can buy it relatively cheap for use in bio ethanol fires. It's ethanol with a denaturant added. No purple dye though. 

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It is perfectly clear, and I like the way it works.   Am I the only one who likes to rub it in with my fingers until it doesn't feel sticky anymore?  You can feel the substance in it even though it looks like colored water.  Very cool. 

I was looking at the jar, and it just seemed browner than the shellac in the can used to be.  It seems like the small amount I mixed up with Borax water was more brown when I tried it.  But I used a piece of rough wood.  I could have at least took a plane to it.  It doesn't dry nearly as fast either.

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There is lot of BS floating around internet about shellac so I used to experiment with iti in tha past to find out truth.

I bought several batches of waxed shellac and the most waxy batch was orange flake shellac where I estimate there was at least 15% of wax (by volume) - I put it out in the freezing night and the wax created flakes after that I strained through coffee filter and left it outside covered topreven evaporation. I got perfectly clear solution with no more wax settling on the bottom of the jar. The dewaxed shellac flakes that I buy (from local artist store, no name brand) are after dissolving clear as glass with no impurities to talk about (other than my falling hairs) so if you want dewaxed there is no reason to dewax yourself. I had no problem with oil varnish adhering to slightly waxy shellac seal coat. The shellac has somewhat waxy feel but adhesion was OK. no peeling to this day (20+years). Contrary to internet tales I managed to french polish over polyurethane lacquer or acrylic which many say is impossible...

The best alcohol for shellac is, IMHO, anhydrous bioethanol (I checked MSDS with producer of my brand and it is 99.7%+ ethanol with few drops of denaturants added, no stinking stuff, no color) and it is CHEAP . I've had shellac varnish go bad before (when I used either HW store alcohol or 95% alcohol from pharmacy, either pure or with kind with added "benzin" = naphtha or white spirits in US, I think). Ever since I started using anhydrous alcohol I commonly have bottle of shellac for French polishing that is 3-4 years old that works just like on day one.

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If you wanted shellac for a top coat, would the wax be advantageous?  Would it help resist, or hide scratching?  Would it give a warm sheen, and not a bright shine?  I just wonder.  

How about if you mix in oil, like on a French polish; but more of it?  

It does seem like a varnish high in oil is more scratch resistant; but they all seem to scratch, don't they? I have gotten other texture additions with oil too.  It's fine with me, if it stays stable.

Of course to get rid of scratches is why they French polish them from time to time, or at least used to, anyway, isn't it?

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I don't think that there's much doubt that a high wax content results in a softer appearance. My little experiment certainly did that although it was a bit of an extreme. Very hard finishes resist scratching but when they do scratch it tends to really show, just the nature of hard brittle finishes. 

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5 hours ago, Ken_N said:

If you wanted shellac for a top coat, would the wax be advantageous?  Would it help resist, or hide scratching?  Would it give a warm sheen, and not a bright shine?  I just wonder.  

How about if you mix in oil, like on a French polish; but more of it?  

It does seem like a varnish high in oil is more scratch resistant; but they all seem to scratch, don't they? I have gotten other texture additions with oil too.  It's fine with me, if it stays stable.

Of course to get rid of scratches is why they French polish them from time to time, or at least used to, anyway, isn't it?

Shellac is not as hard as many folks think, perhaps harder than some softer resins or harder than soft oil varnish but I definitely have seen oil varnishes that were noticeably harder than straight dewaxed shellac (mostly amber or copal stuff, my old copal/dammar oil varnish is just about as hard as french polished shellac) and if you compare it to common nitrocellulose lacquer, that is completely different league, much harder than shellac. From my use of waxed shellac I consider the sheen "waxy" or softer than dewaxed that can be mirror like but it takes fingerprints like crazy so it will not stay so shiny unless you clean it all the time. I've used linseed oil, olive oil and now I prefer pure mineral oil and don't see any difference in appearance or properties of shellac, the oil doesn't mix with the shellac and gets to the surface during curing and doesn't seem to stay in the shellac layer in amount that would really alter the result. The difference is mostly in how slippery the surface  feels during french polishing. I found linseed least slippery and mineral most slippery and the mineral doesn't become gummy or rancid if left on the surface for longer time - I left the latest two mandolins right after application on my bench for almost two months this summer while working on other things and when I got back to it I simply wiped the surfaces and finished the polishing. Mineral oil is also safe option for purity linseed, walnut or olive oil can contain various stuff.

Amount of oil during french polishing with shellac seems to affect final surface texture. If you use just tiny amount the surface will be smoother, if you use lot of oil your pad will leave more "strokes" and the final surface will have texture of smooth polished leather (unless you use abrasives or final alcohol polishing to smooth it out)

I haven't used much brushed shellac, mostly for sealer or as base followed by french polish.

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i have only read select tidbits, bu this is what I will add...

 wax free shellac makes a great base, and may be laid up with several coats, and then a waxed shellac may be used on top. IF one is to use a shellac base as the only and primary varnish, the advantage of using a waxed version as a top coat is that with rapid /heat, dry cloth buffing, the wax act as a polish/self healing additive that allows for 'buffing it up'

If one wants to increase the abrasion and chip resistance of shellac,a"hard shellac' can be made by adding some sodium hydroxide and or Drano crystals 

The role of a "sealer" and the role of a 'top coat" are quite different. regardless of what may be said of shellac, related to it's topcoat properties, from my both 'personal'and professional testing in the use of wood flooring {the most punishing} there is nothing that beats shellacs performance as a sealer. It's resistance to uv breakdown is really the key

The problem with adding color to shellac and expecting to use it as a colorant, is that even if you you use lightfast colorants,  color suspension in the alcohol vehicle settling after oxygen crosslinking is not the same as a mordant fixative, and so over a short period of time unexpected unpredictable changes can occur depending on exposure conditions and the type and method of coloration.

Of course the real benefit of using a wax free shellac as the sealer is that it can have any varnish applied to the top of it and makes and excellent base to then use an oil ontop.

the added benefit of using a dissimilar base and or not all oil, is that the first shellac coats will act as a barrier and or "floor" that will not allow the turp based oil to pass through it into the cells below.,If we use all oil, often time we get transdermal outgassing that leads to bubbles and troubles

One should never use wax based shellac as a sealer for anything other than more waxed shellac, oil products should not be applied on top, they may look good and stick for a few years, but over time the wax will cause the topcoats to fail, many times the wax makes it impossible to get the oil to look right as it can fisheye as the oil product looses surface tension as it tries to stick to wax and can not, often seen while observing it dry.

 

 

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17 hours ago, jezzupe said:

wax free shellac makes a great base, and may be laid up with several coats, and then a waxed shellac may be used on top. IF one is to use a shellac base as the only and primary varnish, the advantage of using a waxed version as a top coat is that with rapid /heat, dry cloth buffing, the wax act as a polish/self healing additive that allows for 'buffing it up'

You can buff dewaxed shellac similarly if you do it soon after application and some of the oil is still on the surface. I often do it with bare hand and it makes it shine like crazy (not something traditional violin maker want to see, though). But be prepared for blisters if you try it :-) works on dry surfaces as well but you have to start slower and wait for perspiration to lubricate your hands. (wouldn't recomment to folks with ageressive sweat, my sweat seems to be completely benign to finishes and strings)

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17 hours ago, HoGo said:

You can buff dewaxed shellac similarly if you do it soon after application and some of the oil is still on the surface. I often do it with bare hand and it makes it shine like crazy (not something traditional violin maker want to see, though). But be prepared for blisters if you try it :-) works on dry surfaces as well but you have to start slower and wait for perspiration to lubricate your hands. (wouldn't recomment to folks with ageressive sweat, my sweat seems to be completely benign to finishes and strings)

Well, first, I;m not sure what you mean by "oil"there is no oil is shellac, unless you are talking about a French polish, I assume. But at any rate shellac has a melting point of about 180 degrees, this is fairly low, and is a heat that can be generated by rubbing generating heat friction, so with waxed or dewaxed it can be buffed out. But one must be aware that with no lubricatnt, one can generate the heat with a dry cloth that can damage a finish if too aggressive.

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5 hours ago, jezzupe said:

Well, first, I;m not sure what you mean by "oil"there is no oil is shellac, unless you are talking about a French polish, I assume. But at any rate shellac has a melting point of about 180 degrees, this is fairly low, and is a heat that can be generated by rubbing generating heat friction, so with waxed or dewaxed it can be buffed out. But one must be aware that with no lubricatnt, one can generate the heat with a dry cloth that can damage a finish if too aggressive.

Yes I mostly do French polish, but I also brush shellac into less accessible areas near heel of neck, under fingerboard and such, between the FP sessions.

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On October 9, 31 Heisei at 12:53 PM, jezzupe said:

If one wants to increase the abrasion and chip resistance of shellac,a"hard shellac' can be made by adding some sodium hydroxide and or Drano crystals 

Nothing better than hearing a comment based on long and pure experience. Thanks Jezzupe.

i find the idea of adding inorganic materials to any varnish quite interesting. But as far as I know, sodium hydroxyde is a very aggressive substance (at least when it comes in contact with water) and I was wondering how this would affect any colorant in such a varnish. In the end this depends most likely on the amount added to the shellac alcohol solution. If I may ask what is your recommended amount?

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Do a search on shellac and sodium hydroxide. Doesn't seem to be a simple matter of just adding a scoopful of the stuff. 

Chemmy seemed to really know his stuff when it came to shellac. 

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