Violin Forum/Message Board

[MANFIO]

I think if you follow the above method you will be able to get good results, with some experience and testing in wood samples. Some of the techniques are (the aplication of the thinned varnished, the ground, and the colour very near the wood) quite effective. I'll be quite happy if you get good results, believe me.
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www.manfio.com

http://www.flickr.com/photos/7875988@N02/with/464604020/

[JWH]

The more I think about it, Manfio, I amazed you can get so much golden glow beneath your varnish, when by what you describe, the betumen must be the main provider. You don't add color like a yellow alizarin to the ground varnish with tripoli. The Doratura Cremonese has some golden appearance, I guess, but if equal results occur with the colorless Vernice Liquida then it has to be the bitument, right?

http://www.flickr.com/photos/7875988@N02/465252293/

Also, I wondering if the sodium nitrite can be eliminated. Isn't it just for hurrying up the suntanning process?
I got to thinking about chemical reactions and wondered if there may be any chance that disassociated hydrogen protons in water, and I am talking about long term wood moisture at any percentage level, may form weak nitrous or nitric acids in the wood over time. Water as we know it is H2O but not all H2O are bonded molecules. Certain proportions of disassociated H2O occur leaving positive hydrogen proton ions and negative hydroxide ions in solution. It is this proportion of H-OH ions in numbers to one another that determine acidity and alkalinity in water. The free floating hydrogen protons are looking to link up with negative ions like NO2 which creates acids of nitrogen. We all know what concentrated nitric acid does to wood but I would love to know from a true chemist what the level of chemical activity toward this acid prodution is, and whether it could pose a long term problem.
If sodium nitrite is just a tanning enhancer, Manfio, I don't see why more time in the sun without it is any problem. What are your thoughts on that?

[MANFIO]

Hi! The look you have seen on those pics is the final result of the whole process I described above, each part of the process is important to the final result, I think, detail is everything in violin making.

To get that result we must start with a relatevely dark wood, cinamon/golden colour. Yes, we can use just sun light (or an UV box) to get a good colour (sun light and high humidity is even better), but I find the results I've got with 4% sodium nitrite/sun/tea/amonia fumes are good.

The sodium nitrite plus some hours in the sun produces a good result in a short time, I think (take care with the top, it can get blotched). You can get a good colour in 2 days in that way, it would take 6 months (and some rain and bird craps...) to get it naturally under the sun, and I have a waiting list of anxious violists...

Yes, the colour of the betumen is quite good indeed, the alizarin makes it warmer. I think a good colour must not look like orange, red or brown, it may be a mixture of all that and change depending on the light (cool or hot lights, direct sun, outdoors, indoors, etc.).

I have no chemistry knowledge... scientists are of little help in violin making, I think, they don't see sound, look and style as we makers and musicians see it.
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www.manfio.com

http://www.flickr.com/photos/7875988@N02/with/464604020/

[JWH]

Manfio:

I reread all of the information you provided and believe I understand everything, but if you can bear to answer one more question?
You outline the process quite clearly in the first message by going from tanning and fumigation directly to the application of pumice/varnish ground and then in a subsequent message you state:

"The diluted oil varnish coats will seal the wood a bit, the same with the acqua di colla (weak glue/alum size) and the pumice/varnish paste. When I apply the first coloured varnish there is no penetration of the varnish in the wood."

This seems to read like a three step process before the color coat rather than two; diluted oil varnish coats (preseal?), glue/alum size and pumice/varnish paste. What I took you to mean was that you prepare all wood tanning procedures and then directly apply the pumice/paste after which a glue sizing occurs, then one coat of colored varnish and two coats of Rosso clear?

I beg of you not to laugh. My head gets pretty thick sometimes and I don't want to make a mistake.

[jessupe goldastini]

jwh.....

ulf.stalmach@arcor.de

dwfolkman@comcast.com

these are two of my friends....

they are both phd. chemist's specilaizing in macro molecular chemistry, particularly related to finish {coatings} application and wood science

they are both perhaps the tops in their respected fields....

ulf is german, so you must either speak german well, or keep the "slang" to a minimum....

in your mail header write......{refered to you by jesse"floormasters" goldstein}

if you ask specific questions, they very well may be able to answer them...

they are two of the best in world...

[JWH]

Interesting jessupe, thanks. I'll be straight with my english. It 's worth a chancey try I reckon.