Cooking Colophony Down For Color, Low and Slow?

[jacobsaunders]

Oh I agree entirely about the significance of this and I suspect it may even be the source of the "Hamburg" story, although I was always given to understand that this was 'Joachim Tielke' related. However, I had the information about the Austian governers of 'Northern Italy' from an impecable source. I cannot say more until I have asked, but apparently the Autrians tried systematically to destroy the guild systems of 'Northern Italy'.

Well, I'm afraid that I can't take mysterious “impeccable sources” into consideration that I have no knowledge of or access too.

I am aware of the conspiracy theory, that the change from Spanish sovereignty to Austrian at the beginning of the 18th C. had wide ranging detrimental effects. I fully expect that the opposite was the case however, and that Austrian sovereignty was far more a boost to Italian musical activity. Evidence of this would, for instance, be the “Hof Ehrenkalender” which lists every employee of the royal court in Vienna from 1711 until 1740, which I would be happy to mail to you (379 pages, if I can work out how!). You would see from that how Composers/Musicians from Italy dominated musical life in Vienna, after all, even Vivaldi moved here.

The reason why violin-making business wasn't so good down there in the early 18th. C. will surely be that people like Hans Caspar Reichelt (post #44) were making (oil varnished) violins everywhere else.

[David Burgess]

 

David:  I don't know if you use the same method of cooking that I use, but I have had many samples, both in the dark and in my light box for at least 20 years. (Under UVB) Those in the light box do appear to have become a little more transparent. (I am not entirely sure about this)  However, none of the samples from the dark, or the UVB box, appear to have changed color in any way. They have certainly not faded. The same cannot be said for most of the variety of colors which were added to much the same varnishes. Almost without exception these have faded. (UVB is brutal) Some have disappeared entirely. (Best example being Dragons blood, both in shellac and oil varnish.)  

 

Hi Roger. I didn't mean to say that varnish made with heat-darkened resin fades over time, but that it lightens considerably upon initial drying and curing. I don't know the mechanism behind this, whether some component of the color fades or is chemically altered upon drying, or if it has something to do with the refractive index changing.

 

I mostly mentioned it as a warning to people who try it that the final color of the varnish cannot be determined from the wet varnish, like it can with many other types of varnish.  It needs to be cured (and maybe under sunlight or UV) before they'll know what the color and intensity will be. At least that's been the case with every heat-darkened resin (combined with oil), and every method of making it that I've tried (probably over a hundred different methods, including having nothing but clear glassware in contact with the resin and varnish. Same with stainless steel). Copper-ware can give an interesting greenish tinge.   

[Berl Mendenhall]

I've used an iron pot for cooking varnish for years. I'm not sure what effect it has on the color or darkening of the varnish. Although I'll probably be looking for a nice used stainless steel pot now, just to be sure. I've argued that I thought old varnish makers used cast iron pots to make their varnish in. I don't know what else they could have used, other than ceramic and I'm not really convinced of that. I can tell you that adding rust to the cook will make your varnish darker and a beautiful transparent red brown. Only problem is it doesn't stay that color. It gets darker, "MUCH" darker. I've got a fiddle in my shop now for a bridge that I made in the 1990's and it is way darker that when I made it. Very disappointing. It was a beautiful color when new. I've argued before I didn't think this happened to this degree, but I was wrong. God that's hard to say.

[robertdo]

If I understand what I read, the black iron oxide is formed when oxidation of the rust is stopped. Does it mean that this black colour is due to the varnish part becoming less and less permeable to oxygen/water?

[CarloBartolini]

Stainless steel gives a yellowish tint to the varnish..

[Michael_Molnar]

Stainless steel gives a yellowish tint to the varnish..

Hmm. I am surprised by this. It says that SS is not all that inert.  

[Don Noon]

SS is inerter than many other things, but not really inert.

 

The unfilled rectangles are for the worst case of acidic water, I understand.

 

Maybe I should break out my new platinum varnish pot.

[Carl Stross]

Hmm. I am surprised by this. It says that SS is not all that inert.  

 

It's "stains less" not "stain free".

[DonLeister]

So Berl, have you chosen a temperature to cook your resin at? And what kind of colophony have you got?

[Jose Catoira]

I am just working on a varnish recipe from a colection of trade secrets from the cabinet making and woodworking trades, printed in Madrid in 1806. 

 

There is a greatly detailed chapter on cooking oil varnishes. It seems that it was common knowledge among artisans. The description of the varnish in the book really does match the caracteristics of the Greiner and Bradmair book on Strad's varnish.

 

Maybe he was Spanish too? After all, Amati was Spanish and so was Guarneri... 

 

Anyway, the author recommends using an earthenware pot that has been glazed for cooking the resins and then for making the varnish. He also recommends using a new pot for each cooking as it "glaze degrades with heat and then rosin may get in contact with clay and contaminate".

 

Just did a batch and looks promising, made with Strasbourgh Turpentine. Dries very well, but it is a little light in colour for my taste. Working on the rosin version of the same recipe as I type...

[Berl Mendenhall]

So Berl, have you chosen a temperature to cook your resin at? And what kind of colophony have you got?

Still not for sure, I'm thinking somewhere around 200C, but I have to build a enclosure to keep it away from the buildings. I probably could cook even lower, just turn it on and check it daily. I know Roger advocates higher temps. but that scares the you know what out of me.

Jose, I've heard of the ceramic pot thing before, I just didn't think they could take the heat and cooking oil and resin. Maybe they did use earthenware pots and change each time they made varnish. That might would explain some of the ingredients they find in old varnish.

[Melvin Goldsmith]

Hi Berl,

If it's any use....personally I cook resins more from observation and experience than temperature measurements. I find that resin becomes more likely to burn as it darkens and the volatile fractions evaporate away. I tend to reduce heat as the resin darkens. What we don't want is carbonisation of the resin leading to green or dirty looking colors....so caution and lower temps would be the way to go in my opinion.

Earlier in this thread Roger mentioned something to the effect that that different batches of resin might not behave the same even the same grade from the same supplier. It is always important to keep that in mind. This is why I tend to cook resin cautiously and by observation rather than buy temperature settings. Even stuff that is from the same species and same grade of a given supplier can vary as probably we should expect with a natural product.

[Melvin Goldsmith]

One other thing I'd like to add to this topic is that different species of conifer produce rosins of different character. Rosin/colophany  as we buy it these days is a bastard concoction that comes from multiple tree species generally of non alpine and non European pines with probably little similarity to what was available to the old Cremonese. 

Brandmair and Greiner in their Strad varnish book talk of spruce resin being the main resin component of the varnish. I am not sure if this is a concrete observation or a misuse of terminology but certainly colophony made from alpine spruce is a totally different animal compared to colophany that is generally available. As far as I am aware colophany made from alpine spruce is not commercially available.

[Roger Hargrave]

Hi Berl,

If it's any use....personally I cook resins more from observation and experience than temperature measurements. I find that resin becomes more likely to burn as it darkens and the volatile fractions evaporate away. I tend to reduce heat as the resin darkens. What we don't want is carbonisation of the resin leading to green or dirty looking colors....so caution and lower temps would be the way to go in my opinion.

Earlier in this thread Roger mentioned something to the effect that that different batches of resin might not behave the same even the same grade from the same supplier. It is always important to keep that in mind. This is why I tend to cook resin cautiously and by observation rather than buy temperature settings. Even stuff that is from the same species and same grade of a given supplier can vary as probably we should expect with a natural product.

 

Very true, but I might also add, having cooked in ceramic and stainless steel, stainless steel is undoubtedly better. It is better because any staining is negligible in spite of the truth of Don and Carl's observations. The biggest advantage is in emptying and cleaning the pots. As I pointed out on the bass blog, an asparagus pot is very good. But to be quite honest I'm getting a bit fed up of telling people all this stuff over and over and then having them either asking the same questions, or doing something different and complaining that it doesn't work. Melvin is absolutely right, there are no magic recipes, temperatures or ingredients. Sometimes you just have to listen carefully and then prepare carefully and then work carefully and above all use common sense.    

[Roger Hargrave]

Why should the Austrians have shut anything down??? What makes you think that?

I agree that Markneukirchen and Cremona are different places, but the interesting thing about the Stadt chronic of 1706 is that it shows that a cooked oil varnish was standard across a wide geography at the time, and not a “secret”(that Mr Reichel cooked his own himself quite by the way)

 

 

Well, I'm afraid that I can't take mysterious “impeccable sources” into consideration that I have no knowledge of or access too.

I am aware of the conspiracy theory, that the change from Spanish sovereignty to Austrian at the beginning of the 18th C. had wide ranging detrimental effects. I fully expect that the opposite was the case however, and that Austrian sovereignty was far more a boost to Italian musical activity. Evidence of this would, for instance, be the “Hof Ehrenkalender” which lists every employee of the royal court in Vienna from 1711 until 1740, which I would be happy to mail to you (379 pages, if I can work out how!). You would see from that how Composers/Musicians from Italy dominated musical life in Vienna, after all, even Vivaldi moved here.

The reason why violin-making business wasn't so good down there in the early 18th. C. will surely be that people like Hans Caspar Reichelt (post #44) were making (oil varnished) violins everywhere else.

 

I really don't want to get into this because I want to publish this elsewhere, but affiliated or autonomous, guilds controlled musical instrument makers throughout Europe. Musical instrument guilds were particularly influential in Austria and southern Germany which, as you know, provided Italy with many instrument makers. In the course of time apprentices became journeymen and began their ‘wanderzeit’ when they were obliged by the guild to move away from the town or city where they had received their training taking their charters and tools with them. The fact that several instrument makers of Germanic origin were present in Nicola Amati’s workshop again suggests that structures similar to those in place in the Germanic cultural areas north of the Alps were also established in Cremona.

 

There can be no doubt that in bad times guild discipline was supportive, but in good times it could often be inhibitive, stifling both new ideas and fresh talent. Sadly guild power eventually contributed to the downturn in the Italian economy and perhaps even to the downfall of Cremona’s violin makers. By the mid 17^th century the cities outside the peninsular had learned to copy Italian products and on occasion even restricted their import. Faced with such tactics the Italian guilds proved unwilling to compromise on either their quality or their wages and consequently they gradually lost their lucrative foreign markets. In Cremona, after protracted argument and government pressure, guilds and other commercial restrictions were finally abolished by the Austrian governors between 1771 and 1773. A notary called Bianconi was employed to officially close the guilds and make an inventory of their assets. He began with the guild of woodworkers (one of) the largest. He reported that its members were extremely belligerent towards each other.

[jacobsaunders]

affiliated or autonomous, guilds controlled musical instrument makers throughout Europe. Musical instrument guilds were particularly influential in Austria and southern Germany

There was a “Innung” in Vienna from 1696, the original document of which you can go and visit yourself in the ”Wiener Stadt und Land Archive” HA Akt 3/1696, which was ONLY for the city of Vienna. Otherwise in Austria there was NO OTHER violin maker Innung. So much for controlling everything throughout Europe. What you say might be true of the larger Italian economy, but not for a trade with relativly few individuals making violins.

Pre-1700 ish there was precious little violin making elsewhere, unless you have noticed more than I have, and post-1700ish it rather mushromed everywhere (Holand, England, Bavaria etc.) so as I said before, The reason why violin-making business was poor in  early 18th. C. Italy will have to do with there beeing a lot more competition, not guilds or Austrian soverenity. Just as we have to put up with a tidal wave of chinese stuff, which our fathers didn't.

[Roger Hargrave]

Jacob I was not suggesting any of the things you mention. You must also know this from my previous writings. All I said was that in Cremona the Austrians began a campaign against the guild system; the guild system being a contributory factor in the demise of the Cremonese economy. Of course there were more and more important reasons for this, but it was a factor. I was not saying anything to deride your beloved Austria. Also I think that you are confusing musical instrument making with violin making. Moreover just because their was no specific guild for violin makers (when they later started to appear), does not mean that they were not controlled by guilds (or the equivalent by another name). My simple point was that in Northern Italy whatever guild system there was would probably not have allowed violin makers to cook varnish and if, then certainly not inside the city walls.  

 

As for the Guilds generally they were remarkably international in their influence well before Cremonese violin makers arrived on the scene. Between the 11^th and 16^th centuries guilds developed and flourished with the growth of European towns and cities and the division of labour within them. Somewhat remarkably the structure and organization of guilds was similar and often strongly linked throughout the continent. At this same time merchants and traders working in foreign parts required commercial protection and a powerful pan European system known as ‘The Law Merchant’ arose. ‘The Law Merchant’ was the forerunner of modern commercial law and in Italy especially it was largely administered by the guilds. These factors probably explain why so many instrument makers were able to travel apparently unmolested across Europe’s political borders selling both their labour and their wares.

 

The chief role of guilds was to regulate production and control standards, but often they determined the entire manufacturing process including the purchase of raw materials and marketing strategies. They certainly set down the duties of each master journeymen and apprentices, the lengths of their working day and their wages. They were even employed to collect taxes on behalf of the town city or state. There were guild courts with the power to fine members for poor workmanship unfair trade practices and the like. As you well know in Nurnberg a conflict between the violinmakers Leonhard Maussiell and Leopold Widhalm, led to Widhalm being forced to conduct his business outside the city. Decisions of this nature were a common occurrence in the Austrian Empire, which as you also know, from the first half of the 18^th century also governed Cremona. There were many reasons why such decisions could be taken, including the fact that there were simply too many instrument makers. A serious misdemeanour might even result in banishment. Banishment was an extremely harsh penalty and without the right connections it could eventually mean death. In spite of the apparent international nature of the guild system, a maker’s religion, place of origin, or an apprenticeship in a foreign workshop could still be considered unfavourably. Not surprisingly with so much at stake political power games were rife.

 

The body of craftsmen in a given town usually consisted of a number of family workshops, in the same quarter. The masters of these workshops were often related or strongly acquainted with one another. Extreme hierarchical structures were based upon a master journeyman and apprentice system. The system was regularly exploited by masters setting unreasonably high standards for qualifications. Apprentices often received only food and lodging during their training, while some crafts were so revered that masters took payment from parents for their child’s tuition. In many instances, to become a master it was simply not enough to prove ones technical competence, proof of wealth and status were also required. Nevertheless, although undoubtedly autocratic, guilds often promoted cooperation rather than competition between their members and for those accepting their rules there were many benefits.

 

In ‘Italian’ cities guilds controlled the manufacture of almost everything. There were even guilds covering the production and distribution of foodstuffs. Although no documentary evidence has been found referring to a guild for musical instrument manufacture in Cremona it is virtually inconceivable that such a guild did not exist. The type of product, its high and consistent quality, the materials employed, the strict adhesion to method, the presence of apprentices (in the house of Nicolas Amati), and even the sad decline of the business all suggest the influence of a guild.

 

As was often the case in similar professions Cremona’s violin makers may have been affiliated to a larger related group such as the guild of woodworkers. This was certainly the case with the Cironi family. Ironically although no instruments from the family are known to have survived they are the only Cremonese musical instrument makers for whom guild membership is documented. Giovanni Maria Cironi had been a musician and instrument maker in Pozzaglio before settling in Cremona. He applied for Cremonese citizenship in 1610 declaring that the family had been making viols, citterns, and other musical instruments in the city for several years. He was required to support his application with testimonials confirming his professional skills. The fact that he needed to prove his proficiency, suggests that more was involved than simply demonstrating that he was a good citizen capable of sustaining himself.

 

It is perhaps significant that the Cironi were eventually affiliated to the guild of woodworkers in Cremona. Although the high social status of Cremona’s violin makers would suggest they were a more autonomous group this may not have been the case. Indeed, somewhat later, the violinmakers of Milan were also affiliated to the guild of woodworkers and as we know Cremona fell under the jurisdiction of Milan. In fact there were several subdivisions for musical instruments in Milan, which included violin, harpsichord, organ and plucked instrument. You might recall that in the post above I mentioned that a notary called Bianconi was employed to officially close the guilds and make an inventory of their assets and that he began with the guild of woodworkers (one of) the largest. Also that he reported that its members were extremely belligerent towards each other.

 

There are other examples of guild membership amongst violin makers in Italy. In Piacenza Giovanni Baptista Guadagnini used an additional stamp on his label for the first time. This stamp incorporated his initials G.B.G. surmounted by a cross with the letter P beneath. Piacenza’s chamber of merchants granted this stamp, and in their records Giovanni Baptista is registered as a woodworker. Under normal circumstances, for this to have happened, he must have served an apprenticeship of at least four years. (It might be noted that Antonio Stradivari employed a similar ‘extra’ stamp on his labels. Just a suggestion)

 

In Venice guilds for musical instrument makers were both independent and powerful. In 1744 Sanctus Seraphin made an undertaking to his guild to produce no more violins. It seems likely that this promise was forced upon him by the guild, because he lived on for at least fourteen years and from documents it is clear that he could still sign his name in 1758. Also of interest is the fact Pietro Guarneri of Venice (formally of Cremona) is recorded paying tax via the Venetian guilds at least up to 1753. However, his shop was registered in name of his son Guiseppe. This was probably because Pietro was Cremonese and Guiseppe was born in Venice. And that's my last word on the subject. I have  to make a viola.

[Jacob]

 As far as I am aware colophany made from alpine spruce is not commercially available.

 

Melvin, I thought Burgundy resin was from pica abies?

[jacobsaunders]

I have  to make a viola.

Sounds like a good idea

[CarloBartolini]

Great post Roger, thanks.

 

I've translated the passage on varnish cooking outside of town, please excuse the traduttore tradittore.

 

Firenze Vecchia [Old Florence]  1799 -1869, Giuseppe Conti

 

Exiting a bit the road as the walls where closer to the gates the level was in descent, and continuing through the Porta a Pinti, facing the Vicolo della Mattonaia which placed the Cross in the Village you could glimpse the gracious cottage Ginori with the two small domes with yellow and turquoise scales, and at that point of the wall existed a void  as an arch with a great recess all black, and full of a lustrous and greasy soot. That was the place where the varnishers, the paint makers, and the woodworkers, would go to make varnish, because it was not allowed to be made in the city,  in reason  of the frequent cases of blasts of matracci [matrasses, florence flasks], and which could have been causes of fires.

 

Risalendo un po' la strada poiché quando le mura si avvicinavano alle porte il piano era in discesa, e continuando per la Porta a Pinti, in faccia al Vicolo della Mattonaia che metteva in Borgo la Croce si scorgeva il grazioso villino Ginori con le due cupolette a squamme gialle e turchine, ed in quel punto delle mura esisteva un vuoto ad arco come una gran nicchia tutta nera, e piena d'una fuliggine lustra come unta. Quello era il luogo dove i verniciatori, i mesticatori e i legnaioli, andavano a far le vernici, poiché non era permesso di farle in città, a causa dei frequenti casi in cui scoppiavano i matracci, e che potevano esser causa d'incendi.

[DonLeister]

Here is a link for many unusual evergreen resins, mostly north american. http://www.naturallist.com/pinesap.htm

[Michael_Molnar]

SS is inerter than many other things, but not really inert.

corrosion.jpg

 

The unfilled rectangles are for the worst case of acidic water, I understand.

 

Maybe I should break out my new platinum varnish pot.

Don,

 

What are the open (clear) boxes for SS?

 

BTW, remember in high school chemistry how we would ignite a strip of Mg - the most reactive on your chart?

[Don Noon]

Don,

 

What are the open (clear) boxes for SS?

 

 

 

SS is inerter than many other things, but not really inert.

corrosion.jpg

 

The unfilled rectangles are for the worst case of acidic water, I understand.

 

Maybe I should break out my new platinum varnish pot.

 

Open boxes = unfilled rectangles.

[Michael_Molnar]

I am still learning to read. 

[Bill Yacey]

Over the years I've gathered a considerable amount of white spruce (Picea glauca) which is quite common in our region. This is sap that has bled from broken branches and other wounds on the tree. Campsites and other public areas are good pickings because of people breaking the lower branches off.

 

This sap however is mixed with bits of tree bark, insects and other impurities. I was considering dissolving it in alcohol first so it may be filtered, but I was concerned that it may not dissolve some of the desired resin components.  Perhaps turpentine would be better for this.