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Staining revisited


catnip

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I don't have any potassium carbonate and BSC chemicals only sells it in bulk: a minimum of 5 Kg bag.  I was looking at my laundry supplies and found Borax and  Nellies Soda which is too soapy.  The pH of Sodium Bicarbonate is lower (weaker base) so I applied it twice and experimented  with and without tannin followed by my own "Tru-oil" varnish recipe of (35:10:55  :: varnish: Linseed oil: turpentine).  I am also brewing some "grey wash" following Jezzupe's recipe but it will take a week or so to prepare.  My violins have been out in the sun for several days ( weather permitting) and here is a comparison with my test strip.  You can also see the tight grain lines of the spruce are just barely visible in the white even after being out in the sun.

IMG_1082a.thumb.jpg.d61f632be96fcd505c03731bcddc2844.jpg

 

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37 minutes ago, catnip said:

I don't have any potassium carbonate and BSC chemicals only sells it in bulk: a minimum of 5 Kg bag.  I was looking at my laundry supplies and found Borax and  Nellies Soda which is too soapy.  The pH of Sodium Bicarbonate is lower (weaker base) so I applied it twice and experimented  with and without tannin followed by my own "Tru-oil" varnish recipe of (35:10:55  :: varnish: Linseed oil: turpentine).  I am also brewing some "grey wash" following Jezzupe's recipe but it will take a week or so to prepare.  My violins have been out in the sun for several days ( weather permitting) and here is a comparison with my test strip.  You can also see the tight grain lines of the spruce are just barely visible in the white even after being out in the sun.

IMG_1082a.thumb.jpg.d61f632be96fcd505c03731bcddc2844.jpg

 

FYI you can use it sooner than a week, you can expedite it a little by leaving it in the sun with no lid,helps condense it.

make sure you test it after you have gray washed it as much as you want with one coat of your intended varnish,it is not to be judged alone really.

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Thanks, I am going to see if I can get Arm & Hammer Soda.  I have Nellie's Washing Soda which lists the following ingredients:  Soda Ash, Linear alcohol ethoxylate, sodium chloride, sodium metasilicate, sodium carbonate.  It feels a bit soapy.  I found that I can turn sodium bicarbonate into sodium carbonate just by heating it a 300 F  for about 45 minutes.440547431_IMG_10851.thumb.JPG.88893e116aee088f9f1b20732d2f40bf.JPG

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4 hours ago, catnip said:

I don't have any potassium carbonate and BSC chemicals only sells it in bulk: a minimum of 5 Kg bag.  I was looking at my laundry supplies and found Borax and  Nellies Soda which is too soapy.  The pH of Sodium Bicarbonate is lower (weaker base) so I applied it twice and experimented  with and without tannin followed by my own "Tru-oil" varnish recipe of (35:10:55  :: varnish: Linseed oil: turpentine).  I am also brewing some "grey wash" following Jezzupe's recipe but it will take a week or so to prepare.  My violins have been out in the sun for several days ( weather permitting) and here is a comparison with my test strip.  You can also see the tight grain lines of the spruce are just barely visible in the white even after being out in the sun.

IMG_1082a.thumb.jpg.d61f632be96fcd505c03731bcddc2844.jpg

 

You can put sodium bicarbonate in a frying pan and heat it.  It will dance around as CO2 is driven off.  When the activity stops,  if you taste it,  you will find it far more alkyline.  It is now just the carbonate.

Yes, catnip,  I just saw your posting....   sorry for the duplicate

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Keep in mind that in addition to maybe being strong acids or alkalies (destructive to wood), some salt compounds are highly hygroscopic. Potassium carbonate, for instance will absorb moisture from the air when the humidity level of the air is above 43%, and continue doing so until there is enough water for it to dissolve. Treating a fiddle in such a way that it gains more water weight than it would if  left untreated is not something I would want  to do. Sounds like a great way to make a fiddle temperamental and unstable. :o

Here is a chart with some of the salts which can be used in the form of a saturated salt solution to regulate humidity in an enclosed space. When the humidity in a chamber is above the number listed for the chemical,  they will absorb moisture. Below, they will release it.

http://bio.groups.et.byu.net/EquilibriumSS.phtml

By the way, I don't recommend using these exposed saturated salt solutions to try to regulate the humidity in an instrument storage environment. Museums have already tried it in various display case situations, and have run into issues.

 

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1 hour ago, David Burgess said:

Keep in mind that in addition to maybe being strong acids or alkalies (destructive to wood), some salt compounds are highly hygroscopic. Potassium carbonate, for instance will absorb moisture from the air when the humidity level of the air is above 43%, and continue doing so until there is enough water for it to dissolve. Treating a fiddle in such a way that it gains more water weight than it would if  left untreated is not something I would want  to do. Sounds like a great way to make a fiddle temperamental and unstable. :o

Here is a chart with some of the salts which can be used in the form of a saturated salt solution to regulate humidity in an enclosed space. When the humidity in a chamber is above the number listed for the chemical,  they will absorb moisture. Below, they will release it.

http://bio.groups.et.byu.net/EquilibriumSS.phtml

By the way, I don't recommend using these exposed saturated salt solutions to try to regulate the humidity in an instrument storage environment. Museums have already tried it in various display case situations, and have run into issues.

 

Well said David.  Ideally the first wood treatment while being benign to the wood will provide adequate and controllable color, seal the fibers from absorbing color, enhance the optical properties of the wood, and make it hydrophobic without weight gain.

on we go,

Joe

 

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54 minutes ago, joerobson said:

Well said David.  Ideally the first wood treatment while being benign to the wood will provide adequate and controllable color, seal the fibers from absorbing color, enhance the optical properties of the wood, and make it hydrophobic without weight gain.

on we go,

Joe

 

Bingo!! :D

Although it should be established what benign means for wood, perhaps from the acoustic point of view controlled destruction of some wood components could be considered benign.;)

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I haven't used it at all until this test, so you'll have to ask Mike Molnar about it. He's a careful researcher, and so I'm sure he has his reasons. It's a very mild solution, and I would guess that the hygroscopic carbonate reacts thoroughly with compounds in the wood such that the salt in question is no longer present in its original form to soak up water. I saw it in his bench thread and thought it would be fun to play around with. On my instruments I used Joe's ground system.

 

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6 hours ago, JacksonMaberry said:

I haven't used it at all until this test, so you'll have to ask Mike Molnar about it. He's a careful researcher, and so I'm sure he has his reasons. It's a very mild solution, and I would guess that the hygroscopic carbonate reacts thoroughly with compounds in the wood such that the salt in question is no longer present in its original form to soak up water. I saw it in his bench thread and thought it would be fun to play around with. On my instruments I used Joe's ground system.

 

I avoid carbonates for the reason that they are hygroscopic.  Burgess is correct as usual.

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27 minutes ago, Michael_Molnar said:

I avoid carbonates for the reason that they are hygroscopic.  Burgess is correct as usual.

Sorry Michael, I clearly misread your posts in your bench thread. My mistake. This is the post that confused me, where you mention potassium hydroxide and potassium carbonate as being important to the results. 

 

 

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I don’t get the point about this hygroscopic discussion. KOH is comparable to K2CO3 regarding water uptake, solubility is similar regarding weight.  Over the time a portion of KOH is reacting to K2CO3 and water. I usually need about 0,15 grams of K2CO3 to color my top plate. In the worst case this would lead to a water uptake of about 0,14 grams. Does that really matter?

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1 hour ago, Michael Szyper said:

I don’t get the point about this hygroscopic discussion. KOH is comparable to K2CO3 regarding water uptake, solubility is similar regarding weight.  Over the time a portion of KOH is reacting to K2CO3 and water. I usually need about 0,15 grams of K2CO3 to color my top plate. In the worst case this would lead to a water uptake of about 0,14 grams. Does that really matter?

Totally agree ,the amount of water uptake in the quantity used would be negligable . Not all carbonates are hygroscopic  in fact most are insoluble in water ,many used chalk ,calcium carbonate.

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3 minutes ago, fiddlecollector said:

Totally agree ,the amount of water uptake in the quantity used would be negligable .

Yes I hate to say it, but are we to start worrying about the glue next? Speaking of, many historic and modern instruments use gelatin as a sealer.  I would remind us that unless we're talking about unsealed interiors that most of these absorptive grounds will be sealed over thus dramatically reducing any  vapor uptake. 

I think of non film building grounds as 2 part systems that work with the first film building varnish layer, or 1+1=1 coat.

I am aware of all the pros and cons of non or hydrophobic materials, I am aware of Davids knife handle test and I respect both Joe and Davids opinions and advice, but I still like sugar and don't seem to have problems with the "wet blanket" effect or water absorption in general and admittedly do not have the time to be constantly weighing instruments or have a scale that would be accurate enough to measure such tiny differences.

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Although I only took first year chemistry I agree with both Michael and Fiddlecollector's analysis of absortion.  In fact I weigh my violins prior to any finishing treatment so that I can record any weight gain from not only ground-sealer treatment but also the final weight gain after a complete varnishing system.  The one shown above had a weight (mass) of 310.3 gm and is currently weighing at 311.4 gm just from being in the sun because of the recent increase in humidity.  

“When you can measure what you are speaking about, and express it in numbers, you know something about it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts advanced to the stage of science.”   ― Lord Kelvin

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I agree that we are exaggerating destructive hygroscopic effects for milligrams of residue. Yes, carbonates vary in chemical activity. Some are harmless. But some hygroscopic activity can vary the color of an organic ground if not properly protected, thus making it fugitive. 
I do like wood ash water, but it’s composition is a huge variable and not a control in experiments. 
Forgive me for not saying more because I am in the midst of experiments. 
Stay Tuned.

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You could also say that wood is 40-60 % hygroscopic as thats its cellulose content and cellulose is hygroscopic.   You could say that hygroscopic substances self regulate their water content , and so if no extremes of humidity or temperature are  present  then the wood or whatever hygroscopic substance is put on it are  pretty stable.

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3 hours ago, Michael_Molnar said:

I agree that we are exaggerating destructive hygroscopic effects for milligrams of residue. Yes, carbonates vary in chemical activity. Some are harmless. But some hygroscopic activity can vary the color of an organic ground if not properly protected, thus making it fugitive. 
I do like wood ash water, but it’s composition is a huge variable and not a control in experiments. 
Forgive me for not saying more because I am in the midst of experiments. 
Stay Tuned.

Understood, thanks for your research. Looking forward to reading your paper. 

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6 hours ago, fiddlecollector said:

You could also say that wood is 40-60 % hygroscopic as thats its cellulose content and cellulose is hygroscopic. 

Yes, but moisture content of plain wood responds to relative humidity of the air in a fairly linear manner. Some of the salts do not. They will just sit there until a certain humidity threshold is reached, and then they absorb water like a mo-fo and liquefy.

I am not very hot on instruments which sound good at 40%, and go all to hell at 50 or 60 percent.

 

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