Sunday, December 6, 2009

19_Fresco experiments

Experiments that I have tried:

I tried painting on Portland cement, with just pigment mixed in distilled water (no binders or glue added to the colors). I thought the Portland cement might work like fresco, and bind the pigment to its surface when it dried. So I poured some into a plastic lid, waited a while for it to dry semi-matte, and painted into moist cement, with a Chinese brush:

When I was painting in fresco, from the model at The Drawing Studio in Tucson, someone asked me if I was painting on cement. I thought that was a sharp observation, since I suspected that cement had some lime in it, and thus might be an odd variation on fresco. However, apparently Portland cement has calcium sulfate in it, allying more closely with plaster of Paris than the calcium carbonate of fresco lime.

Still, I wondered if Portland cement might be a cheap and faster alternative to fresco lime, and had to experiment. The cement hardened up pretty quickly, like plaster of Paris, and thus did not allow much more than 5 minutes for painting into it wet. This brief "window of working time" would keep the artist from painting any meticulous scenes:

Weeks later I rubbed the painting with water, to see how well the pigment set into the Portland cement. Some strokes held up, but others smeared. Perhaps the applied pigment was too thick, or I did not grind it fine enough into water. However, I suspect that the pigment would never penetrate well enough into the Portland cement to make a reliable painting.

Perhaps a thinner paint would work better, such as the same pigment ground in nothing more than water, but sprayed on with an airbrush. If one were to spray over a stencil onto wet cement, he could finish quickly, and thus the color would become one with the cement before it set. If these sprayed colors were more brilliant, then buon Portland cement artworks might be the stencil counterpart to graffiti fresco masterpieces:

I applied some Portland cement onto a larger, dry Hardibacker cement board. The cement set faster, and cracked quickly:

Weeks later I rubbed water into this painting as well. The earlier blue strokes seemed to stay put, but the "Later" red strokes smeared a bit. Painting into wet Portland cement was pretty much a failure:

  • In "The Artist's Handbook," author Ray Smith mentions another painting method using raw pigment in water, in which the surface itself is the binder, like with fresco -- Keim painting.

Ed scraped his fresco painting off with a razor, so I thought I would try that as well:

Later, one might spray down the reclaimed white surface with distilled water, and trowel another coat of wet fresco plaster on top, to paint all over again:

I stored some leftover fresco lime/sand plaster in an airtight container, and put plastic wrap over the top. Weeks later it was still wet. I wonder how long I can store premixed lime/sand plaster before it "expires" (perhaps by carbonating from the air).

I thought I was cheating when I mixed some lime putty and sand up the previous day in Tucson, and troweled the plaster onto a cement square the next day in Phoenix. Then I read that this was the preferred technique, so that "the lime can adopt itself to the sand and gain plasticity." Thus, with confidence, I prepared some fresco plaster a few days before delivering it to an artist in Corrales, and also prepared the plaster the night before we were going to do a graffiti fresco.

I am thinking now that I should mix up all the plaster that I need at the beginning of the week, cover it with plastic and store it in an airtight container. Then, whenever inspiration finds me that week (or the next), I can just dole out some fresco plaster and experiment on smaller square panels:

Experiments I have not tried yet:

I know that our fresco plaster is really too wet to trowel. Therefore I bought some nylon mesh (in front of storage tub), and thought about using it to squeeze excess water from the lime putty. I have not tried this yet:

Before tortilla factories, chemists, and Home Depot, artists probably had to burn their own limestone to create quicklime to slake. I bought some crushed limestone, in a small bag sold as "whiting," at Marjon Ceramics in Tucson. I wanted to cook some in the kiln, to see if we could create our own quicklime. I have not done this yet:

Since Michelangelo painted the fresco in the Sistine Chapel, artists have found all kinds of new ways to cheat. Today we might use opaque projectors to help quickly trace an image to the wet fresco surface; or perhaps small digital LED pocket projectors to outline a jpeg onto the wall.

When I had the drawing on the cover of my book scanned and enlarged to 2 feet at Reproductions in Tucson, I realized that the copy might serve as a cartoon for tranfering to a fresco painting. So Gonzalo slipped a piece of cardboard underneath it, and rolled the pounce wheel over it, perforating the contours. I have not painted the fresco yet:

Drawing by Krrrl:

Download electronic version of book for free on Lulu

Stranger things can happen, once the ball gets rolling. Jorge is halfway through realizing the same drawing in welded iron, in front of a 6 foot photocopy, at the Sculpture Resource Center:

Someone told me about Milestone, a blend of acrylic and Portland cement, which might have advantages as the first scratchcoat for fresco, by sealing the rigid support and/or sticking to non-porous surfaces (after adding extra "bonder").

We have not yet prepared a proper fresco with the 5 coats -- scratchcoat, rough coat, browncoat, ( sinope?), and intonaco -- to keep the painting from cracking. Diego Rivera's assistants, Stephen Pope Dimitroff and Lucienne Bloch, recommended putting regular cement into the scratchcoat. So the newer Milestone might well be a decent substitute.

Update, April 6, 2010: 

The "Poly Fresco" Technique

Susan Kelk Cervantes, the director of Precita Eyes Muralists, prepared a wet buon fresco surface and painted into it with acrylic paint, initiating a new "poly fresco" approach. Her 2004 mural "Community Wisdom" on the Leonard R Flynn Elementary School in San Francisco was painted with this technique.  She declares that the fresco surface "is the most beautiful surface I have ever painted on," on page 149 of the book "Street Art San Francisco."  Apparently the artist can continue painting on the fresco after it has dried, and the surface will still absorb the acrylic paints nicely.

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