Mike Molnar's Bench

[Michael_Molnar]

Jim,

I started writing a year ago. I hope the VSA is a good place to publish it. Thanks.

[Jim Bress]

45 minutes ago, Michael_Molnar said:

Jim,

I started writing a year ago. I hope the VSA is a good place to publish it. Thanks.

I think so.  If you need a proof reader say the word.

[Guy Booth]

On 7/18/2019 at 1:57 PM, Michael_Molnar said:

Here's an example using cover slides to make a wedge for studying dichromatic varnish. BTW, this sample is not mulled very well so it is not very transparent nor is it dichromatic.  But I happen to have this photo on hand.

That’s a brilliant idea! Silly question, but do you notice any differences between looking at the wood beneath the sample, and the wood when actually varnished? 
 

[Michael_Molnar]

2 hours ago, Guy Booth said:

That’s a brilliant idea! Silly question, but do you notice any differences between looking at the wood beneath the sample, and the wood when actually varnished? 
 

Yes. The background is important. Try it.

[Michael_Molnar]

FWIW, I find that Zout stain remover works nicely to remove varnish from my clothes. Spray it on the varnish spot. Rub it in. Let it sit for at least 10 minutes. Then wash.

[Michael_Molnar]

I purchased some hardwood ash from a woman in New Hampshire. I put 2 lbs in a 2 quart Mason jar and filled it with filtered water removing any chlorine or other chemicals. I let it stand for about 2 weeks with an occasional shaking. No boiling. I then filtered the liquid through a coffee filter and got what you see in this photo. I quickly dipped one end of scrap maple in the real wood ash solution and the other end in my synthetic version. I feel that there is no significant difference. The real wood ash solution is on the left in the photos. 

This proves to my satisfaction that this is a chemical reaction involving the high pH components, namely KOH and K2CO3. So, I do not do any UV tanning.

BTW, any difference is due to odd wood figure in this trash maple.

[MikeC]

Alkaline substances can have a tendency to go a greenish gray,  a baking soda solution will produce a similar darkening.   So are you not concerned with long term effects of a strong alkali on the wood?   Would that be less damaging than an acid over time?  

[Michael_Molnar]

12 hours ago, MikeC said:

Alkaline substances can have a tendency to go a greenish gray,  a baking soda solution will produce a similar darkening.   So are you not concerned with long term effects of a strong alkali on the wood?   Would that be less damaging than an acid over time?  

All alkaline substances are not equal. Sodium hydroxide for example will destroy wood over time. I like potassium carbonate because it is not destructive and historically relevant. So is calcium hydroxide but less important because it is less soluble. As for any grey green color, that would look great under a yellow ground and increase contrast. IIRC, ammonium hydroxide and ammonia fuming gave me grey green. In any case, it doesn't matter for me.

[Ken_N]

Hey Michael,

I made up some wood ash water a week ago.  I just used the ashes from my grill,  Cowboy Charcoal.  I filled a quart jar a little more than 1/2 full of ashes, and added water from the tap on the side of the house; not through the softener.  Shook it up, and after it settled I boiled it in a pan for a few minutes.  Then I poured it into a smaller jar.  I have a white settlement on the bottom just like your chemical one.  The water is clear like your chemical one.  The bottom of the pan turned black.  Weird. I guess it was an aluminum pan.  I don't even think about chemistry, let alone KNOW any chemistry.

I tried it on some scrap, and it darkened it somewhat in the sun.  So I put it on my guitar, and it didn't seem to do anything.  The European Sycamore was already in the Lightbox for a week with NO RESULTS at all.  Yes, it was not quite white, but you could tell that only if you held a white piece next to it.  I figured that it was just a lost cause, it was never going to color up.

I wiped some on, and left it on the deck, or in the Lightbox. After a week, and several applications, it is now very different.  I like the result.   I don't think it does much of anything without the light.  Maybe it is a weaker solution?  Maybe chemically different?

 

 

[Michael Szyper]

On 8/7/2019 at 1:31 AM, Michael_Molnar said:

I purchased some hardwood ash from a woman in New Hampshire. I put 2 lbs in a 2 quart Mason jar and filled it with filtered water removing any chlorine or other chemicals. I let it stand for about 2 weeks with an occasional shaking. No boiling. I then filtered the liquid through a coffee filter and got what you see in this photo. I quickly dipped one end of scrap maple in the real wood ash solution and the other end in my synthetic version. I feel that there is no significant difference. The real wood ash solution is on the left in the photos. 

This proves to my satisfaction that this is a chemical reaction involving the high pH components, namely KOH and K2CO3. So, I do not do any UV tanning.

BTW, any difference is due to odd wood figure in this trash maple.

Very nice color Michael, seems to be the perfect counterpart for any golden colored stain.

[Michael_Molnar]

On 8/8/2019 at 11:25 AM, Ken_N said:

Hey Michael,

I made up some wood ash water a week ago.  I just used the ashes from my grill,  Cowboy Charcoal.  I filled a quart jar a little more than 1/2 full of ashes, and added water from the tap on the side of the house; not through the softener.  Shook it up, and after it settled I boiled it in a pan for a few minutes.  Then I poured it into a smaller jar.  I have a white settlement on the bottom just like your chemical one.  The water is clear like your chemical one.  The bottom of the pan turned black.  Weird. I guess it was an aluminum pan.  I don't even think about chemistry, let alone KNOW any chemistry.

I tried it on some scrap, and it darkened it somewhat in the sun.  So I put it on my guitar, and it didn't seem to do anything.  The European Sycamore was already in the Lightbox for a week with NO RESULTS at all.  Yes, it was not quite white, but you could tell that only if you held a white piece next to it.  I figured that it was just a lost cause, it was never going to color up.

I wiped some on, and left it on the deck, or in the Lightbox. After a week, and several applications, it is now very different.  I like the result.   I don't think it does much of anything without the light.  Maybe it is a weaker solution?  Maybe chemically different?

 

 

Hi Ken,

I think that the pan is steel which will turn black with wood ash liqueur as I call it. Aluminum gets white.

The white residue is lime, namely calcium carbonate and calcium hydroxide. The former is almost insoluble while the latter is partly soluble. Some trees have more calcium than others. So, the residue amount will vary.

The likely reason your sycamore does not darken is due to the lack of natural tannin. Light (UV) or bases react with tannin turning it dark. Next time, I suggest that you apply a dilute solution of tannic acid or something rich with tannin and let it dry. Then apply UV or still better the wood ash liqueur. Too much tannin can look ugly, so be careful.

Hope that helps.

[Michael_Molnar]

15 hours ago, Michael Szyper said:

Very nice color Michael, seems to be the perfect counterpart for any golden colored stain.

Hi Michael,

As I told Ken (above), tannins are the reason wood becomes darker when reacting to high pH bases. I have experimented with several different sources of tannin. I like the reddish hue of quebracho which is used to tan leather. Some tannins are dirty and need filtering or they leave an ugly blotchy or dusty appearance. Pure tannic acid is clean and so is quebracho.

BTW, tannic "acid" is not an acid but a phenol that behaves like an acid. That tidbit is from my vast warehouse of worthless knowledge. 

[LiamBlack]

Great photos! I like. Thank you for making these shots!

Edited December 6, 2019 by LiamBlack

[Urban Luthier]

On 8/6/2019 at 7:31 PM, Michael_Molnar said:

KOH and K2CO3. So, I do not do any UV tanning.

 

Hi Michael,

Sorry for the very naive question but is this K2CO3 the same stuff we use to precipitate lake pigments? i.e. potassium carbonate?

any adverse affects of applying such an alkaline substance on wood?

interesting stuff, I enjoy your bench thread very much. 

Thanks

Chris

[Urban Luthier]

6 minutes ago, Urban Luthier said:

any adverse affects of applying such an alkaline substance on wood?

a quick search here may have answered my question 

 

[Michael_Molnar]

All alkalis are not created equal. Sodium hydroxide (lye) is one of the most potent. There is a story that a luthier used this to darken his wood and later found his violins decomposing irreversibly. Potassium hydroxide is less reactive, but it is still pretty potent. Potassium carbonate is less reactive and is a standard stain for woodworkers. This alkali makes tannins dark which enhances the wood figure. I notice many makers here on MN adding tannin to their wood, but not applying any alkaline solution. The tannin will not turn dark until it is oxidized by an alkaline solution such as potassium carbonate. 

I like wood ash liquor as I call it. This was the main source of alkaline solutions in earlier times. BTW, calcium hydroxide (lime) is also very good, but less reactive than potassium carbonate. It is another component of wood ash. So, wood ash contains the alkalis  I like. It makes historical chemistry sense too.

Let me add this. I never nuke the wood with high concentrations of alkali. Excess alkalis will remain to degrade the wood fibers over time. Alkaline wood ash is pretty benign unless it is distilled to concentrate the alkalis. I guess any alkali could destroy wood over time if a saturated solution is used. I suspect that the fellow who used lye made it very concentrated, but I would still stay away from that alkali. 

Applying a weak acid such as vinegar (acetic acid) diluted in water can be insurance to neutralize any alkali still lurking in the wood.  I think it's unnecessary if you did not nuke the wood. Just don't overdo it with acid and wind up back at square one. 

[Peter K-G]

And it's possible to go really dark. The dark piece is a test how far I could go with tannins in tea, UV (Sun) and high ph casein/lime. The other piece is the same ground on white wood. The biggest problem is spruce and end grains, they go black. 

[Michael_Molnar]

Nice color, Peter.

[Michael_Molnar]

I measured the radii of some Pfeil gouges and stamped the radius on each handle. No more guesswork.

 

[Peter K-G]

2 hours ago, Michael_Molnar said:

Nice color, Peter.

Thanks Michael,

I'm sure you have looked at my progress as I have looked at yours.

I'm at the stage where I'm taking a step back and looking at the beauty of the wood -> I hate "less is more" , but sometimes it is, because wood is the winner in all cases.

 

[Michael_Molnar]

We had a family event in New York City, so we made a stop at the Met to see  Stradivari 's 1711 "The Antonius".

[Ken_N]

Michael, have you noticed that either the UV tanning, or the wood ash water will give a hardening of the surface?   I cut the rabbits for the edge work and binding on the guitar last week, and it seemed like the outside surface was harder than underneath.  Like TiN coating on an end mill.

I took some pictures at the Henry Ford last year, and then found that they have GREAT photos of ALL of them online.  It would be a very cool thing to have a real instrument to copy.  Photos are one thing, but up close and personal is another.

[Jim Bress]

Thanks for the pics. Mike.  I really like the front pic. showing the c-bout arching in the reflections with part of the reflection passing through the f-hole.

[Michael_Molnar]

6 hours ago, Ken_N said:

Michael, have you noticed that either the UV tanning, or the wood ash water will give a hardening of the surface?   I cut the rabbits for the edge work and binding on the guitar last week, and it seemed like the outside surface was harder than underneath.  Like TiN coating on an end mill.

I took some pictures at the Henry Ford last year, and then found that they have GREAT photos of ALL of them online.  It would be a very cool thing to have a real instrument to copy.  Photos are one thing, but up close and personal is another.

I have suspected that some treatments harden wood, but this was anecdotal on my part. Someone needs to verify it and determine what are its effects, if any. 

Thanks for the heads up about the Henry Ford.

6 hours ago, Jim Bress said:

Thanks for the pics. Mike.  I really like the front pic. showing the c-bout arching in the reflections with part of the reflection passing through the f-hole.

That photo was my primary goal. Recently, I have focused on the f-hole hollows that so many makers don't mention. The hollows became the 600 lb gorilla in the room for me. Note that they are not the shape of curtate cycloids nor tangential kissing circles. The hollows are scooped out indents that this violin manifests so well.

[Jim Bress]

3 hours ago, Michael_Molnar said:

I have suspected that some treatments harden wood, but this was anecdotal on my part. Someone needs to verify it and determine what are its effects, if any. 

Thanks for the heads up about the Henry Ford.

That photo was my primary goal. Recently, I have focused on the f-hole hollows that so many makers don't mention. The hollows became the 600 lb gorilla in the room for me. Note that they are not the shape of curtate cycloids nor tangential kissing circles. The hollows are scooped out indents that this violin manifests so well.

Also wrapping around the top of the f-hole to create the eye brow ridge.  Something I hadn't noticed until pointed out to me in the Smithsonian and was able to brush my finger across the ridge of a Stradivari and the exaggerated eye brow ridge on a Vuillaume Strad copy.  It becomes apparent in many photograph reflections once you start looking for it.

https://www.thehenryford.org/collections-and-research/digital-collections/artifact/200698#slide=gs-227291

 

Violin, _The Rougemont,_ by Antonio Stradivari, 1703 - The Henry Ford.html