Ilia, have you heard of "ashgrove kemilime", chemical hydrated lime? If you go to their website and check the chemical compounds, it seems ok.(ashgrove.com)
I had to pay 50 dollars for a bag of 50 pounds last time, the lime works fine for fresco,(the telephone number I gave you last time), but the price seems a little high, even if you take in consideration the cocts of shipping here in hawaii.
The lime from ashgrove is only 15 bucks for the same quantity. How can you tell the difference? What would be the criterias to differenciate?
I did my own bianco de san giovanni, 8 days stirring and changing water, drying in the sun, crushing the powder. When I apply it to my painting it seems a little weak, how many layers of bianco would you use to come out with a perfect white?
I have access here to the work of Jean Charlot, I can take close ups of his work, all sorts of pictures. Do you think it might be interesting for your site?
Tell me if you need some picture data from him.
Thanks for your your help.
Mathieu

LAST EDITED ON 19-Jan-02 AT 00:33 AM (PST)
 
Hi Mathieu,
just dropping a note. I am teaching workshop this weekend and will be back to reply later the coming week. And please do as much info as you could on Jean Charlot frescoes. Use "Peter Hurd Fresco" as an example for the info needed go to http://www.truefresco.com/history

Your contribution will be placed there with your credits. Thank you in advance. (if you only can get the images -fine - send me your local museum's phone# and I will give them a "shake down")

LAST EDITED ON 01-Feb-02 AT 01:01 PM (PST)
 
>Ilia, have you heard of "ashgrove kemilime",
>chemical hydrated lime?
>The lime from ashgrove is only 15 bucks for the
>same quantity. How can you tell the difference?
>What would be the criterias to differenciate?

I have never used it and can not see anything apart from checking the chemical specifications on both.

The real check is the trying. Nowadays we know way too much about molecules and stuff, so we do get confused and lost in it.

According to researchers, modern techniques of slaking are far more superior to the ones used in the past (kiln temperature control, hydration, etc.) The problem is that production is commercial, oriented for builders and such. The setback for us is that "dry" lime that comes in the bag will result in a "second
generation" lime putty - which may or may not be "puttied" long enough when artist is preparing to paint. Unfortunately for the moment plants do not offer putty resulted from the slaking directly (commercially inefficient), but dry it out and put in bags. So what you get is a "second generation" putty. High calcium lime for fresco has a lot to do with proper interpenetrating of its particles with water. Improper burning (too hot, too cold) of limestone and then insufficient time allowed for slaking of resulted quick lime may cause for lime not to hydrate properly or take a long time to hydrate, hence "aging" is essential. Modern technologies allow to control these processes to high commercial/constuction standards, but do these standards work for fresco painting is anybody's guess. And until there will be funds for testing directed to fresco painting, not just stuccoing and ornamental plastering nobody will be able to say for sure if it will work.

So my advise for use of bagged lime would be mixing it with water into the paste and let it sit in the paste for as long as possible 1-2 years or at least for several months.

On the other hand if we will get too technical we may not see fresco renaissance for another hundred years. And as might as well change the profession.

So how did it work for you? How is your fresco? Can you post some images?

ilia,
i tried the lime, works ok for now, i try to prepare my mix of sand/lime/crushed volcanic rocks a week or two in advance, to get a maximum of plasticity when I use it.
I called the chemist from ashgrove, he told me their lime is fine for fresco, that the quality now is much better than during the renaissance. I don't know what to believe, i just use it, I'll see later.
I'll soon get a digital camera, I'll be able to send pictures from my work+pictures from jean charlot's work.
Do you use only terra verde for undertones? Can you use all sorts of cold color, like the blues, violet?
If only terra verde can be used ,how do you insist between a zone of moderate shade and a zone of very dark shade? Do you double the layer of terra verde?
About the amount of layers you can use for coloring, can you only use 2 layers of ocres? What does happen if you use more? You "plug" your plaster? You loose the luminosity of the plaster?
My paintings are sometimes well balanced in tones and luminous, sometimes "plugged" and stern.
Easy to loose your cold blood using that technique...It is also very satisfying, it has a sort a magy that oil doesn't have.
I should have some picture data next time I talk to you.
Mathieu.