Jump to content
Maestronet Forums

Ground color ?


AndreaA
 Share

Recommended Posts

According to Brandmair and Greiner's book (which they are careful to say is ongoing research) Strad's varnish is composed of 4 layers.

1/a protein size

2/a stain layer of as yet unspecified ingredients but visible under UV light

3/ a layer of colourless lean spruce of larch resin oil varnish

4/ a layer of similar varnish but with colour and some low pigment content.

Old Cremonese instruments show a big variation of ground/wood colours. Some seem very deliberately gold, others look very dark cinnamon but some can look white and fresh as if they were made last week...the biggest variation is in the work of del Gesu where in some cases the wood looks new or the very opposite.....Old Brescian instruments normally have quite brown wood but I have seen English viols of the same age that ( if genuine) look like new wood.

Link to comment
Share on other sites

I believe that "colored" shellacs are simply less refined than the blond.

I too like the gold-ish or amber-ish tint of blond shellac, but have moved to amber or garnet when I want more ground color to start with.

In order not to contact the wood itself - they can go on after a thin blond coat.

The blonde shellacs are made from bleached shellac. The darker stuff is it's natural state, and usually contain more natural waxes as well.

Link to comment
Share on other sites

According to Brandmair and Greiner's book (which they are careful to say is ongoing research) Strad's varnish is composed of 4 layers.

1/a protein size

2/a stain layer of as yet unspecified ingredients but visible under UV light

3/ a layer of colourless lean spruce of larch resin oil varnish

4/ a layer of similar varnish but with colour and some low pigment content.

Old Cremonese instruments show a big variation of ground/wood colours. Some seem very deliberately gold, others look very dark cinnamon but some can look white and fresh as if they were made last week...the biggest variation is in the work of del Gesu where in some cases the wood looks new or the very opposite.....Old Brescian instruments normally have quite brown wood but I have seen English viols of the same age that ( if genuine) look like new wood.

Hi Melving,

Most things never seen are almost always in plain sight. Sacconi left enough specific information so that even the uninitiated (but open) minded person could grasp the essentials of how to identify old Cremonese and other northern Italian instruments, by the way their varnishes reacts to light and shadow. The latest book on that subject clearly illustrates one thing. - Each instrument and its varnish is a universe within itself.

Your latest varnish is more beautiful than before.

Jmann

Link to comment
Share on other sites

According to Brandmair and Greiner's book (which they are careful to say is ongoing research) Strad's varnish is composed of 4 layers.

1/a protein size

2/a stain layer of as yet unspecified ingredients but visible under UV light

3/ a layer of colourless lean spruce of larch resin oil varnish

4/ a layer of similar varnish but with colour and some low pigment content.

Old Cremonese instruments show a big variation of ground/wood colours. Some seem very deliberately gold, others look very dark cinnamon but some can look white and fresh as if they were made last week...the biggest variation is in the work of del Gesu where in some cases the wood looks new or the very opposite.....Old Brescian instruments normally have quite brown wood but I have seen English viols of the same age that ( if genuine) look like new wood.

Melvin beat me to posting this. Yesterday, we had two power failures due to storms, and I have been incommunicado.

Thanks, Melvin.

Mike

Link to comment
Share on other sites

So the protein layer would be something like a thin wash of hide glue? or maybe even casein glue? Did they say what colorant material was detected? Would it have been something like a dye? Or a particulate like finely ground earth pigments, umber, sienna, cinnabar things like that?

Link to comment
Share on other sites

Yes Don Noon is doing a baking process. Not as simple as microwaving though. I played one of his violins. The violin had excellent qualities. I will be very interested to see his refinement of the baking approach down the line.

I too will be interested to see how the modified processing wood works out.

The appearance, too, can be a benefit, I think. For figured maple, it seems very difficult to get new wood dark, without "burning" the figure with color put into the wood, or obsuring the figure with color put on top. If the wood itself is uniformly darkened, with suntanning or thermal treatment, the figure shows up nicely.

Link to comment
Share on other sites

Has anybody ever tried this on a plate that had been arched but not yet hollowed. I know Don is using microwaved wood but that might get some different results. I know it looks stupid, but at least it would not leave any trace detectable by microscopy or MS or X-ray spectroscopy, and it would give some brown-amber colour... :)

Hi Robert:

Bamboo fly rod makers have the same concerns for materials as violin makers. Many swear by flame treatment of the finished rod blank, others think it a terrible idea. there is much of interest in the linked reference on heat treatment of bamboo, and an interesting table that indicates the similarity between bamboo and spruce. well worth the 20 minutes to read.

http://www.powerfibers.com/BAMBOO_IN_THE_LABORATORY.pdf

Link to comment
Share on other sites

Hi Robert:

Bamboo fly rod makers have the same concerns for materials as violin makers. Many swear by flame treatment of the finished rod blank, others think it a terrible idea. there is much of interest in the linked reference on heat treatment of bamboo, and an interesting table that indicates the similarity between bamboo and spruce. well worth the 20 minutes to read.

http://www.powerfibers.com/BAMBOO_IN_THE_LABORATORY.pdf

thanks for the link Roger. I will read it carefully. I am not a violin maker and have no previous experience in woodworking, but I always try to go to the simplest explanation (it did help me a lot in my job) and at the moment the the simplest explanation for a golden ground harder than the resin, water proof and invisible to mass spec, X-ray spec and miscroscopy is the wood itself :)

Link to comment
Share on other sites

I hadn't seen that bamboo heat treatment paper previously; there's a lot of good work in there. The properties most desirable for violins may be somewhat different than that for rod makers. Modulus and breaking strength are most important in the rods, while the acoustic parameters for plates are very sensitive to density. So what might be "overcooked" for a rod might be good for violin wood (acoustically only). The temperature range and effects noted in the paper appear similar to my experience, but the times have to be longer and heating rates much slower for violin wood due to the thickness involved.

Link to comment
Share on other sites

Hi Robert:

Bamboo fly rod makers have the same concerns for materials as violin makers. Many swear by flame treatment of the finished rod blank, others think it a terrible idea. there is much of interest in the linked reference on heat treatment of bamboo, and an interesting table that indicates the similarity between bamboo and spruce. well worth the 20 minutes to read.

http://www.powerfibers.com/BAMBOO_IN_THE_LABORATORY.pdf

Roger, be careful, the two applications (bamboo flyrod and violin) are quite different. Also, bamboo is a grass, whereas spruce is not.

Link to comment
Share on other sites

Roger, be careful, the two applications (bamboo flyrod and violin) are quite different. Also, bamboo is a grass, whereas spruce is not.

Of course they are different, I can actually operate a bamboo fly rod at a very high level :D . The point is that Robertdo asked about the use of flame treatment as a ground colorant. Many bamboo fly rod makers do this in the belief that, for them, a stiffer rod results as well as providing a very desirable coloration to the rod blank. The article makes it clear to those makers that there is more to heat treatment increasing modulus of elasticity than treating the surface fibers alone. The rod makers and violin makers are both rightly concerned with modulus of elasticity and density. The rod maker is generally trying to create a critically damped structure. The violin maker is also concerned with damping but is not seeking critical damping of the violin body. The similarity of spruce and bamboo in the table is apparent for the constituent breakdown as shown.....whether they are the important constituents or as finely defined as necessary for a violin maker is a different issue. Spruce has a modulus of elasticity approximately twice that of bamboo. As you say, different materials for different applications...............

Link to comment
Share on other sites

With the violin, tone is paramount. Michael Darnton taught me so (he may not know he has, but he did). And while I understand this may seem obvious, in some ways it really isn't, as is evident by the many paths a maker will wander.

I once thought of heat treating spruce for a violin top, because I am familiar with the same for the making of bamboo flyrods and longbows. And I am also familiar with what it does for performance of either, but the idea for a violin top was quickly abandoned because of the certain affect on tone. In short, it wasn't traditional (in other words, it was a path other than the one I knew I needed to follow). However, the making of a traditional Japanese Yumi bow also involves treatment of the bamboo, for coloration (an intense, gold coloration no less), but with long and carefully-controlled exposure to the sun, as opposed to brief exposure to a far more intense heat. And while this may have other possibilities for the maker, again bamboo is a grass whereas spruce is not.

Actually, when it comes to the ground coat and coloration, I find this to be the most interesting article of all...http://www.alfstudios.com/news/articles/preparingground.html

Link to comment
Share on other sites

In old time they took attention to making specific activities following the seasons time or choosing some months of the year in order to make other operations. for example some grass was collected in may because richer juice or in june because poor of juice. Various precautions were took growing trees to their collection and their conservation. I'd suggest to read Griselini dizionario delle arti e dei mestieri vol 2 pag 239 "boscaiolo" woodman http://books.google.it/books?id=CWE4AAAAMAAJ&printsec=frontcover&dq=editions:sODAVPyoMhwC&hl=it&ei=dItXTunfLaLj4QSRu92JDA&sa=X&oi=book_result&ct=result&resnum=7&ved=0CE4Q6AEwBjgK#v=onepage&q&f=false and pagg. 265 "how hardening wood"

Also Griselini dizionario delle arti e dei mestieri vol 8 http://books.google.it/books?id=qWM4AAAAMAAJ&printsec=frontcover&dq=editions:UOM39015065885660&lr=&hl=sv#v=onepage&q&f=false Chapter "legnaiuolo" pag.180 and chapter "Mercante di legnami" pag 316

I'm sorry but they are in old Italian and my poor english don't allow me to try a traslation...

G.

Link to comment
Share on other sites

Returning to the topic title, I got a few manuscript sheet from a local (Bologna) old art supplier, he said me that their old chemist, Mario, made varnish for Pollastri member who give him the sheet. One of these sheet state: Vernice ad olio A. Pollastri, follow the recipe Ambra gialla 2, olio di lino 3, essenza di trementina. Description on making... and how to use list first point is one layer of "terra oriana" boiled in water or urine (Bixa orellana) on bare wood...

Terra oriana litterally oriana earth.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...