Mike Molnar's Bench

[Don Noon]

Assuming those are all fresh, untreated white wood, I think that's about the best that can be done.  My testing on white wood all looks horrible, and doing something to the wood itself (UV, nitrite, other chemical treatments, thermal processing) has been needed to get visually decent results.  My usual mantra.

[Jim Bress]

3 hours ago, Michael_Molnar said:

I am experimenting with different compositions to understand how to control colors. Any thoughts?

Mike, It might help if you can tell us where these samples fall within your varnish protocol (e.g., ground, ground + first application, etc). General impression from left to right is that 2 and 4 look like washed out versions of 1 and 3, respectively.

[MikeC]

If it's just ground color I like the one on the left...   2nd from the left looks too pink....   the right two don't seem to have as much color might look too white under varnish.   

[Andreas Preuss]

14 hours ago, Michael_Molnar said:

I am experimenting with different compositions to understand how to control colors. Any thoughts?

Those are experiments with plant dye stuff, right?

There is certainly an infinitive number of solutions to match the ground with the varnish. Just from the picture I would go with the second from left. However often old Cremonese instruments (if that is what you are aiming at) have a a rather orange looking color in the ground when seen on pictures. So the sample on the left looks good.

In this respect I have to say that I am more and more convinced that the color and depth of ground on old Italians comes from not treating with any colorants. Since I am steaming my wood I found some very interesting results. Colors can range from yellow brown to reddish brown and sometimes with a hint of green. But all shades are dark enough that no further coloration is needed. 
 

From there the coloration of the varnish becomes a different story as well. Even the best colorant can’t really hide the white wood underneath (at least to my experience). So with the color directly from the wood you work on a darker canvas which makes many things all of a sudden much easier. One of the most obvious things is that the color contrast between varnish and ground becomes less what again IMO is just what is desirable.

[Michael_Molnar]

Wow. These are great posts. I will get back with comments later.

[Don Noon]

On 3/12/2021 at 9:08 PM, Andreas Preuss said:

However often old Cremonese instruments (if that is what you are aiming at) have a a rather orange looking color in the ground when seen on pictures. 

...

In this respect I have to say that I am more and more convinced that the color and depth of ground on old Italians comes from not treating with any colorants. Since I am steaming my wood I found some very interesting results. Colors can range from yellow brown to reddish brown and sometimes with a hint of green. But all shades are dark enough that no further coloration is needed. 

Some things that I think are relevant that I may or may not have mentioned...

I took a sample of my torrefied spruce and a sample of untreated (very white) spruce and put them in the sun for several days.  The fresh spruce darkened and turned orange, and the brownish-tan torrefied spruce lightened and was headed toward orange.  I feel that with further exposure both samples would end up very nearly the same color... orange... or maybe with much more esposure photobleaching would take over.

So although I have not personally examined any orange-tinged Cremonese instruments, I would be suspicious that it might be either a wood conversion effect, or it was polished over with orange shellac.

In any case, we KNOW that old Cremonese wood is quite opaque, meaning the wood has some strong pigmentation that does not exist in fresh wood.  The questions are: what color is it?  and what effect does it have on the appearance?  and does in vary from instrument to instrument?

[Michael_Molnar]

Time for me to jump back in.

The four strips are  2 pairs of identical components as Jim noticed . Each pair has one strip painted with an organic (plant) colorant. This is the darker of the pair. The other is a tempera of the organic colorant. The tempera is made with cheese. The tempera is lighter because less colorant is drawn into maple wood. The orange-side pair is with my standard old favorite colorant. The other includes a strong yellow-side colorant added to the old standard. I feel that Preuss' choice is the one I like best as a Cremonese candidate. But I am not done tweaking this.

As Mike noted, there is no colored varnish, just a protective very lean 4:1 clear varnish. I am focusing just on the ground color.

Now, Noon says a couple of imporant things. Aging is the joker in this card deck. My samples are not several hundred years old, but they were blasted with a lot of UV that fades natural organic colors. I think the experts who work on Cremonese instruments can spot indications of a new, fresh Cremonese ground. So, I depend upon them to steer me to the right color. When I started on this endeavor I thought it was yellow, but now see it is more orange in the flames while light yellow on the surface, but the yellow sometimes has faded leaving more of the orange in place. Colorant in the flames is better protected from oxidation. FWIW, French polishing is not an issue.

Finally, I haven't said anything about this, but I refer to Brandmair's chemical (element) detections. I think I get everything that she reported in B&G because they are in what I use and in large quantities. I don't use anything that contains something she has not detected in important concentrations for Strads. The idea of photobleaching does not add what she has detected. My simple color stain does.

 

[Michael_Molnar]

I’m back at the bench varnishing the Coronaviolin. First, I’m working on adjusting the wood stain. Here are some photos. The lighting is a combination of a 6500K fluorescent overhead and a small ~4700K bench light. Camera is an iPhone 11 Pro. I’m halfway done with staining and burnishing. In a few days I will put on the ground varnish.

[Don Noon]

Looking very good.  Nice, clean corners and purfling, too.

[Urban Luthier]

Really nice work Mike. Love the ground. Both front and back are very fine.

[violins88]

Mike, how about an update? It’s beautiful.

[Ken_N]

Mike,

That is some serious color for "bare" wood.

[Michael_Molnar]

Here is the same stain off steroids, namely toned down (no pun.) Chemically the same but I applied it in many diluted coats to work it into the flames. Potassium caseinate overcoats the stain and contains some talc ground that researchers think is present. Optically, the caseinate wets the stained wood making it "pop". The talc rubble does nothing but fills voids which is one purpose of a ground, namely smooth the surface. On top of this I put on a very thin coat of a clear varnish that has just a hint of green meeting B&G's findings. My green tint might be too insipid. I think it does nothing. 

I took this photo under a hot fluorescent ceiling lamp. The paper is white, so you should adjust your monitor to make it pure white.

 

[Urban Luthier]

Really nice looking Mike.

[Mike Atkins]

1 hour ago, Urban Luthier said:

Really nice looking Mike.

I second that! Looking good!

[Andreas Preuss]

Looks good. 
 

However, I am not sure if Cremonese ground started on white wood. 

[Michael_Molnar]

4 hours ago, Andreas Preuss said:

Looks good. 
 

However, I am not sure if Cremonese ground started on white wood. 

You know, I too am thinking along those lines.

[Don Noon]

On 9/5/2021 at 5:31 AM, Andreas Preuss said:

 I am not sure if Cremonese ground started on white wood. 

I too am not sure what they started with either... but it sure isn't white now.

Let me know when it is determined positively whether it's natural aging or something else.

 

[Michael_Molnar]

I posted this photo on FaceBook of the new Coronaviolin belly. It is Engelman Spruce from Kevin Prestwich log 1601 resawn by me and torrefied by @Don Noon almost two years ago. The photo taken in diffuse sunlight on a white chair makes the plate darker than it is.

So just now I photographed it again on my bench with overhead lights.  Looks like a different plate.

 

The plate weighs a little under 60 g w/o bass bar.

 

[Don Noon]

Should sound and look good.  Right now it looks like an old violin where the varnish has been stripped off cleanly.  The challenge will be to get the untorrefied maple to match.

[Urban Luthier]

nice colour Mike - your don-torrefied spruce reminds me of the nice cinnamon colour spruce turns after a decade or so of oxidization.

[Michael_Molnar]

Here is the Coronaviolin with its ground of protein-stabilized annatto. I am evaluating PR179 and other pigments for final color.

I replaced the top with one made from Prestwich’s Engelmann  spruce torrified by @Don Noon a few years ago. The back is too thick according to body modes. So, my focus is now just on varnish. 

Stay tuned.

 

[scordatura]

Looks like you have done a good job of matching the maple to Don’s top. I have a couple of torrefied tops that I will be having the same challenge to match. Did you play the violin with the old top on? It would be interesting to compare with Don’s top. Can you show more pics?

[Ken_N]

I like the gold/green You got that top. I think that the initial color helped a lot. If the color underneath is darker, you don't get a top color that is too bright, even if it is bright. 

I've thought of pr179 before, but I can only find it in paint. Kremer has pr264, they call it opaque, but Handprint gives it a 3 for transparency, just below the pr179's 4. There is a huge difference between opaque and semi-transparent! They have the same hue angle and about the same value. 

I might try that one out. Something for a Venetian red, but hopefully not so opaque.

My cello has a Euro Sycamore back and sides, and they are  WHITE. I made a guitar with it. It gets barely yellowish white with tannin and lots of uv. Not hardly worth it. Almost zero photsensitivity. The top is Sitka, almost as dark as your torrified top is. I tested some iron oxide on the Sycamore, and it gets around the same color as the top. Great with the light flames too.

Do you know if there would the be any issues with the acetate? I would seal it before finish color. I haven't seen anything about using it as a ground colorant.

Here is the acetate,  just varnish, and varnish over the acetate.

[Michael_Molnar]

@scordatura

The body modes with the first top looked weak. Tone was muffled. The torrefied top improved things. It sounds better across all strings, but the back is evidently too thick. I decided to move on and not try to improve the back.
 

@Ken_N

Kremer 23504 is very fine PR179 . I use it. You must mull it well into the varnish or an oil.

Sorry, I have no experience with guitar acetates.