Colophony Varnish Chipping

[Shunyata]

I have generally followed the Hargrave recipe, except that I cook the Colophony for 50+ hours prior to making the varnish.

This makes a wonderful varnish except that is it very prone to chipping if you knock the body with the bow, on a hard part of the instrument case, etc.

Are there any ingredient or processing steps to mitigate this.  If so, can these actions be applied to varnish I have already made?

[Jim Bress]

Are you cooking all the rosin for color, and using the cooked rosin to make the varnish? I make the varnish without precooking the rosin, then add cooked rosin for color and adjust viscosity with additional linseed oil. I’m not getting chippy results. 

[Claudio Rampini]

What proportion oil/colophony are you using in your varnish? Also, the way you prepare the wood before the varnish is very important, a hide glue ground makes the varnish layer chipping. But adding a bit of linseed oil should improve the varnish. Don't use siccatives because they make the varnish fragile sometimes, the problem with the colophony is mainly to raise its melting point, the oil remains siccative anyway.

If you would post some photos of your varnish, it could help to understand the problem.

[ernym]

42 minutes ago, Jim Bress said:

Are you cooking all the rosin for color, and using the cooked rosin to make the varnish? I make the varnish without precooking the rosin, then add cooked rosin for color and adjust viscosity with additional linseed oil. I’m not getting chippy results. 

Interesting Jim, so you make a varnish, then add cooked dark rosin and linseed to the cooked varnish and cook again to blend? Or do you blend two cooked varnishes together? 

[ernym]

25 minutes ago, Claudio Rampini said:

What proportion oil/colophony are you using in your varnish? Also, the way you prepare the wood before the varnish is very important, a hide glue ground makes the varnish layer chipping. But adding a bit of linseed oil should improve the varnish. Don't use siccatives because they make the varnish fragile sometimes, the problem with the colophony is mainly to raise its melting point, the oil remains siccative anyway.

If you would post some photos of your varnish, it could help to understand the problem.

Claudio,  Do you use a different ground on spruce? and maple? What are you using?

[MikeC]

Isn't that what Roger Hargrave does,  from the bass blog.  Use the highly cooked rosin as a colorant?   Or am I remembering it wrong?  

[Claudio Rampini]

40 minutes ago, ernym said:

Claudio,  Do you use a different ground on spruce? and maple? What are you using?

I'm using the same ground both on the spruce and the maple, I don't have any problem with the hide glue ground with my oil varnish, but I had problems using the Lapo Casini varnish and the spirit varnishes in general. Now I'm using the 1:20 hide glue + water + 5% alum. But in these days I'm trying again the casein with just a bit of calcium oxide added.

[Jim Bress]

50 minutes ago, ernym said:

Interesting Jim, so you make a varnish, then add cooked dark rosin and linseed to the cooked varnish and cook again to blend? Or do you blend two cooked varnishes together? 

 

29 minutes ago, MikeC said:

Isn't that what Roger Hargrave does,  from the bass blog.  Use the highly cooked rosin as a colorant?   Or am I remembering it wrong?  

Yes, this is how Roger does it in the bass blog, same recipe. The order of operations is somewhat flexible. Joe Thrift does it a little bit different from Roger (who taught Joe the recipe long before the bass blog), and I do it a bit different from Joe. It might be chemistry, but it's also a lot like cooking.

I cook down the rosin first for color. Then remelt the cooked rosin in linseed oil while I'm making the varnish. When the varnish has finished cooking I combine the two while the varnish is cooling enough to add the mastic. If I later decide the varnish needs more color I will reheat the varnish and add more color. You just have to keep an eye on the temperature so that you don't burn off the mastic.

[ernym]

49 minutes ago, Jim Bress said:

 

Yes, this is how Roger does it in the bass blog, same recipe. The order of operations is somewhat flexible. Joe Thrift does it a little bit different from Roger (who taught Joe the recipe long before the bass blog), and I do it a bit different from Joe. It might be chemistry, but it's also a lot like cooking.

I cook down the rosin first for color. Then remelt the cooked rosin in linseed oil while I'm making the varnish. When the varnish has finished cooking I combine the two while the varnish is cooling enough to add the mastic. If I later decide the varnish needs more color I will reheat the varnish and add more color. You just have to keep an eye on the temperature so that you don't burn off the mastic.

Interesting still why not just cook the colored rosin without adding a less colored varnish, is it too strong of a color? So the combined dark rosin and linseed is just melted, then combined with a lighter cooked varnish? I can see why there would be no/less chipping due to controling the oil ratio. Interesting recipe, Thanks.

[ernym]

1 hour ago, Claudio Rampini said:

I'm using the same ground both on the spruce and the maple, I don't have any problem with the hide glue ground with my oil varnish, but I had problems using the Lapo Casini varnish and the spirit varnishes in general. Now I'm using the 1:20 hide glue + water + 5% alum. But in these days I'm trying again the casein with just a bit of calcium oxide added.

Thanks Claudio!

[David Burgess]

28 minutes ago, ernym said:

Interesting still why not just cook the colored rosin without adding a less colored varnish, is it too strong of a color? So the combined dark rosin and linseed is just melted, then combined with a lighter cooked varnish? I

I think this is done as a final adjustment of color intensity, since it's very difficult (though not impossible) to cook rosin to the same color intensity every time.

[Sean Couch]

4 hours ago, Shunyata said:

I have generally followed the Hargrave recipe, except that I cook the Colophony for 50+ hours prior to making the varnish.

This makes a wonderful varnish except that is it very prone to chipping if you knock the body with the bow, on a hard part of the instrument case, etc.

Are there any ingredient or processing steps to mitigate this.  If so, can these actions be applied to varnish I have already made?

I have the same issue with my varnish. It is my first time making varnish and the instructions I followed were similar to the Hargrave method (I think). I cooked my colophony for 168 hours at 350F and that resulted in about a 24% reduction in weight. I then took 100g of the cooked rosin, 100 grams of washed linseed oil, and 10g of mastic to a pot. I slowly brought it up to 350F and cooked it for 2 hours.

My ground was a casein/ammonia wash followed by a mastic refractive ground. The recipes for both were from Davide Sora. The color of the varnish was not very dark so I added Joha colorant at 7%. The first coat of varnish had no colorant. That was followed by 6 coats of colored varnish. About 11.3g of casein, refractive ground, and varnish was added to the violin.

I get the same chipping as you describe  I swear sometimes if I look at it wrong, a chip will pop off. I even had it chip from where my fingers pushed against the belly when adjusting the bridge. It is not fun, maybe I should have trimmed my nails back to the quick.

The chips look to be the total thickness of the varnish at about 0.1 mm thick. If it is not the varnish, then the only thing I can think of is that I didn’t remove enough of the refractive ground with alcohol before varnishing. Before varnishing the violin it got 24 hours of UV and 48 hours of 50% RH room air.

[David Stiles]

24 minutes ago, Sean Couch said:

I then took 100g of the cooked rosin, 100 grams of washed linseed oil, and 10g of mastic to a pot. I slowly brought it up to 350F and cooked it for 2 hours.

My understanding is that Mastic can't be heated to such a high temperature.  It is added at the end of the process, after rosin & oil are cooked, and cooled to a lower temperature.   I add mastic at 120degC

[David Stiles]

30 minutes ago, Sean Couch said:

My ground was a casein/ammonia wash followed by a mastic refractive ground. The recipes for both were from Davide Sora. The color of the varnish was not very dark so I added Joha colorant at 7%. The first coat of varnish had no colorant. That was followed by 6 coats of colored varnish. About 11.3g of casein, refractive ground, and varnish was added to the violin.

I had some weird chipping on one violin & it seemed to to me be varnish not adhering properly to the casein ground.  I think I put the casein on too thick.  I had no Mastic Refractive ground in this instance.  

[ernym]

14 minutes ago, David Stiles said:

I had some weird chipping on one violin & it seemed to to me be varnish not adhering properly to the casein ground.  I think I put the casein on too thick. 

This was my first thought too. I use gelatine and 4-5% alum to lightly size, not seal the spruce. I don't normally size maple. A light sizing will still allow color or other ground componets to absorb evenly without blotching.

[Davide Sora]

Just now, David Stiles said:

I had some weird chipping on one violin & it seemed to to me be varnish not adhering properly to the casein ground.  I think I put the casein on too thick.  I had no Mastic Refractive ground in this instance.  

It could be "over-sizing". Protein sizes are tricky to control and sealing too much prevents the varnish from adhering and makes chipping easier. This applies to both alcohol and oil varnishes. Even an excessive thickness of refractive ground made of mastic or colophony can have the same effect because these resins alone are chippy. Another thing that comes to mind regarding the varnish itself chipping is the resin cooking done without a lid and therefore with a notable reduction in volume and loss of all the plasticizing substances. Cooking with the lid on the volume reduction is less and less plasticizing substances are lost, obtaining a resin that is less fragile, but also softer and more heat-sensitive.

Then, I got the idea that the old varnishes (Stradivari, Del Gesù, and so on) were chippy in nature, so maybe it's not so bad. If I remember correctly, it was Melvin Goldsmith who wanted his varnish to be chippy, and he used a varnish with little oil and a lot of resin to emulate the natural wear and tear of old varnishes over time.

So what's the problem?

[Sean Couch]

For the varnish, I followed the link below for the recipe and process. I have no issue with adding the mastic at a lower temperature of that is needed. Here is the link: https://www.ruschil.com/blog/making-violin-varnish

Ahhh, I thought I was putting the casein on sparingly, but I will do some experiments before the next violin. I applied it with a cheap foam bush with most of the excess squeezed out. I did two coats. I’ll try one coat and move on from there. It could very well be an issue with the varnish not adhering to the ground and not something inherently wrong with the varnish.

[Sean Couch]

17 minutes ago, Davide Sora said:

It could be "over-sizing". Protein sizes are tricky to control and sealing too much prevents the varnish from adhering and makes chipping easier. This applies to both alcohol and oil varnishes. Even an excessive thickness of refractive ground made of mastic or colophony can have the same effect because these resins alone are chippy. Another thing that comes to mind regarding the varnish itself chipping is the resin cooking done without a lid and therefore with a notable reduction in volume and loss of all the plasticizing substances. Cooking with the lid on the volume reduction is less and less plasticizing substances are lost, obtaining a resin that is less fragile, but also softer and more heat-sensitive.

Then, I got the idea that the old varnishes (Stradivari, Del Gesù, and so on) were chippy in nature, so maybe it's not so bad. If I remember correctly, it was Melvin Goldsmith who wanted his varnish to be chippy, and he used a varnish with little oil and a lot of resin to emulate the natural wear and tear of old varnishes over time.

So what's the problem?

Right on, it has some antiquing going on now. I tried to repair the chips, but probably did more bad than good. Plus I managed to let my violin fall off my workshop chair onto the floor…not much damage, just more character, I reckon. lol.

I will definitely experiment more with the protein size and refractive ground processes before the next violin. This current violin #1 I am not too concerned about its appearance. I’m sure it will get pretty beat up from me learning how to play it, but my heart did skip a few beats when I heard it hit the floor. But hey, it gave me more practice resetting a fallen sound post (strings and tail piece were off during the fall).  

[Mike_Danielson]

Here is my surmise:  the rosin has not completely reacted with the oil--you need higher temperatures.  Thus, there is still some rosin-character to the varnish.

Here is what I do:  put the rosin and oil into a pot and bring the pot to 300 degree C.  Cook it until you get the right color.  This should take less than 2 hours.  Do not precook the rosin--let us make this simple.  You will find that you can get the "right color" doing this.

I think Hargrave's recipe needs higher temperatures and does not need to precook the rosin.  Just try my idea and see what happens, and report back.  And my varnish does not chip.

[JacksonMaberry]

More often than not, the cause of a friable varnish (which, it should be noted, is highly desired by some professional makers, especially those who antique) results from a lean ratio of oil to resin. For example, 1:1 is near the edge for a varnish which will not chip too much. Some prefer 2:1 resin to oil or even leaner. 

However, as some have noted above there can be other factors. Insufficient combination of oil and resin is a common one. Excess mineral content (for example calcium hydroxide/oxide when using limed rosin), or as Sora mentions insufficient plasticiser (whether innate or added, viz. Mastic, Canada balsam, larch turpentine).

Adhesion is another major concern which has been discussed, and I think that as usual Davide Sora hits the point most clearly - while some grounds/sealers/sizes are more likely to decrease oil varnish adhesion, all of them may have an effect if the ground/sealer/size is permitted to build a film.

In my experience both in making and in varnish research over the last decade, allowing the ground/sealer/size to build a film is neither necessary nor desirable for its overall optical and mechanical effects. Its twofold role is, in my view, to provide an optical "wetting" effect through a minimal (sub 10 micron) penetration of a material with high refractive index (RI) matching to the wood itself, and to prevent the incursion of colored/pigmented varnish into exposed vessels, especially in the endgrain regions. 

For this reason, it appears to me at least that with ground/sealer/size, less is more. Mixing media, such as using both proteinaceous and resinous/Oleoresinous sizes is not only unnecessary, but complicates the passage of light through the total system of finishing materials into the wood and back out to the eye. So, for my taste at least, a ground/sealer/size which is as alike to the film-building coatings in material content is preferred. This, in combination with sealing but not building a film with the ground/sealer/size makes for excellent adhesion, as well. 

As always, the caveat - this is my own opinion only, which I've arrived at through a lot of time and expense, and it works for me but may not be appropriate for your personal aesthetic aims. 

[Shunyata]

16 hours ago, Davide Sora said:

t could be "over-sizing". Protein sizes are tricky to control and sealing too much prevents the varnish from adhering and makes chipping easier.

I think this is exactly my problem.  I allowed the casein sealer to develop a clear film, and then the mastic refractive ground to also develop a clear film.

Next time around I will follow the less-is-more idea.

[JacksonMaberry]

7 minutes ago, Shunyata said:

I think this is exactly my problem.  I allowed the casein sealer to develop a clear film, and then the mastic refractive ground to also develop a clear film.

Next time around I will follow the less-is-more idea.

I have no doubt you'll be very happy with the results. Please keep us in the loop, and continue to enjoy the thrill of the chase. Cheers!

[bardia parmid]

On ۱۴۰۳/۸/۲۲ at 01:20, Davide Sora said:

ممکن است "بیش از اندازه" باشد. کنترل اندازه های پروتئین دشوار است و آب بندی بیش از حد از چسبیدن لاک جلوگیری می کند و خرد شدن را آسان تر می کند. این برای هر دو لاک الکل و روغن صدق می کند. حتی ضخامت بیش از حد زمین انکساری ساخته شده از ماستیک یا کلفونی نیز می تواند همین اثر را داشته باشد زیرا این رزین ها به تنهایی براده دار هستند. نکته دیگری که در مورد خرد شدن خود لاک به ذهن متبادر می شود، پخت رزینی است که بدون درب انجام می شود و در نتیجه با کاهش قابل توجه حجم و از دست دادن تمام مواد پلاستیک کننده انجام می شود. پخت و پز با درب کاهش حجم کمتر می شود و مواد نرم کننده کمتری از دست می روند و رزینی به دست می آید که کمتر شکننده است، اما نرم تر و حساس تر به حرارت است.

سپس به این فکر افتادم که لاک‌های قدیمی (Stradivari، Del Gesù و غیره) ماهیت تراشه‌ای دارند، پس شاید آنقدرها هم بد نباشد. اگر درست یادم باشد، ملوین گلداسمیت بود که می‌خواست لاکش تراش خورده باشد و از لاکی با روغن کم و رزین زیاد استفاده کرد تا ساییدگی طبیعی لاک‌های قدیمی را در طول زمان تقلید کند.

پس مشکل چیست؟

..I made a lot of rectangular pieces of exactly the same thickness and tuned them to specific frequencies. I noticed that when I hit the center of the board, I hear the same frequency, but when I move away from the center, the frequency of the piece changes. In fact, we hear the frequency of other modes of the piece. 

The question is.. How is it possible to have a fixed note and a fixed frequency in the imaginary diagonal bands of Wikdorczyk??? 

The second problem is that I made some pieces according to the imaginary diagonal bands of Wikdorczyk and tuned them based on the same frequencies of Wikdorczyk. Interestingly, the thickness of those pieces was much greater than what we see on the violin board. 

These things have caused many questions in my mind as to how such a thing as Wikdorczyk stated in his book is true. 

 If I could find a scientific and logical answer to these two cases, I would follow Wigdorczyk's method, but I have realized that his theories are in complete contradiction and contradiction with the scientific problems of physics. And it is absolutely impossible to implement his theories.

[bardia parmid]

On ۱۴۰۳/۸/۲۲ at 01:20, Davide Sora said:

ممکن است "بیش از اندازه" باشد. کنترل اندازه های پروتئین دشوار است و آب بندی بیش از حد از چسبیدن لاک جلوگیری می کند و خرد شدن را آسان تر می کند. این برای هر دو لاک الکل و روغن صدق می کند. حتی ضخامت بیش از حد زمین انکساری ساخته شده از ماستیک یا کلفونی نیز می تواند همین اثر را داشته باشد زیرا این رزین ها به تنهایی براده دار هستند. نکته دیگری که در مورد خرد شدن خود لاک به ذهن متبادر می شود، پخت رزینی است که بدون درب انجام می شود و در نتیجه با کاهش قابل توجه حجم و از دست دادن تمام مواد پلاستیک کننده انجام می شود. پخت و پز با درب کاهش حجم کمتر می شود و مواد نرم کننده کمتری از دست می روند و رزینی به دست می آید که کمتر شکننده است، اما نرم تر و حساس تر به حرارت است.

سپس به این فکر افتادم که لاک‌های قدیمی (Stradivari، Del Gesù و غیره) ماهیت تراشه‌ای دارند، پس شاید آنقدرها هم بد نباشد. اگر درست یادم باشد، ملوین گلداسمیت بود که می‌خواست لاکش تراش خورده باشد و از لاکی با روغن کم و رزین زیاد استفاده کرد تا ساییدگی طبیعی لاک‌های قدیمی را در طول زمان تقلید کند.

پس مشکل چیست؟

..Materials about Wikdorczyk's book. And his theories 

 

I made many rectangular sticks exactly the same thickness 

I tuned each one to a specific frequency. I noticed that when I hit the center of the board, I hear the same frequency, but when I move away from the center, the frequency of the piece changes. In fact, we hear the frequencies of the modes and other states of the piece. 

 

The question is here.. How is it possible to have a fixed note and a fixed frequency in Wikdorczyk's imaginary diagonal strips??? 

 

  The second problem is that I made several pieces according to Wikdorczyk's imaginary diagonal strips and tuned them based on the same frequencies of Wikdorczyk. Interestingly, the thickness of those pieces was much greater than what we see on the violin's fretboard. 

 

These things have caused many questions to arise in my mind as to how such a thing as Wikdorczyk stated in his book is true???!!!!

 

 If I could find a scientific and logical answer to just these two cases, I would follow Wigdorczyk's method, but I have realized that his theories are in stark contradiction and contradiction with the scientific problems of physics. And it is not possible to implement his theories at all.

[JacksonMaberry]

Sir, this is a varnish topic.