Arcosanti - An Urban Laboratory in the Arizona Desert.


December 08. 2014

Cosanti Foundation staff Roger Tomalty is in France to teach a Silt Casting workshop at the Graphics Design Department of the Ecole des Beaux-Arts in Toulouse.

The students are working on a small model of the panels for the Vaults at Arcosanti.

[photos by Aimee Madsen, filmmaker of "Paolo Soleri BEYOND FORM". The film will be shown as part of the silt workshop]

The silt has to be cleaned and sifted.

Paints for the silt.

This workshop was organized by alumnus artist Aurelien Froment, here with Raffael and Stephen, two of the teachers of the Graphics Design Department at the Ecole des Beaux-Arts.

The students are using plaster instead of cement and Filasse from the Agave plant to add more strength to the final piece.

Here is the final piece.

Congratulations, this came out very well!

December 05. 2014

Cosanti Foundation staff Roger Tomalty traveled to Europa to give presentations at the Department of Architecture, University of Strathclyde in Glasgow, Scottland and at the Ecole des Beaux-Arts in Toulouse, France.

[photos by Aimee Madsen, documentary film maker of "Paolo Soleri BEYOND FORM"]

The Ecole des Beaux-Arts in Toulouse, France.

Roger giving a slide presentation.

Part of Rogers presentation in Toulouse was a silt workshop. Here is Roger preparing the silt bed.

Roger and the students.

This report continues on Monday, December 8. 2014.

New directional signage was erected at the visitor's parking entrance. Sign panels were made in concrete using siltcast technique devised by Arcosanti founder Paolo Soleri.

[Photos by Daniel Wagner and Lily Ericsson, text by Tee]

Styrofoam letter patterns were impressed onto the prepared silt bed. Planning intern Lily Ericsson is pushing an arrow pattern onto the silt.

Volunteer Daniel Wagner is carefully pouring slurry cement mix over the designs on silt.

Concrete mix and reinforcement steel are placed in the form.

After the concrete panel is dried enough to be lifted in few days, the silt attached to the concrete is washed away with water.

The raised letter surfaces are sanded and painted.

[We will report on how we erected the signage in place in the next posting.]

This finishes the report about participants in the last 2 workshops who worked on light weight earth cast panels as part of their Phoenix field trips.

[photos by Aimee Madsen, text by Roger Tomalty]

The panel on the left was designed by Paolo and carved by Roger, hence it was actually the last piece that Paolo did before he died in April.

The panel on the right was cast in two segments by the workshop and then installed during their visit to Cosanti."

 - Roger Tomalty

This continues our report about participants in the last 2 workshops who worked on light weight earth cast panels as part of their Phoenix field trips.

[photos by Aimee Madsen, text by Roger Tomalty]

After curing for over a week the panel pieces were carefully lifted from the earth form. 

Earth still adhearing to the concrete was washed away with water.

 - Roger Tomalty

This report continues on 8/12/2013.

"Participants in the last 2 workshops worked on light weight earth cast panels as part of their Phoenix field trips.

Each panel was cast on a curved earth form which was carved and painted with concrete pigment shortly before the concrete was cast.

[photos by Aimee Madsen, text by Roger Tomalty]

The panels, less than one inch thick are experiments in casting very thin, less than 1/2 inch thick, light weight concrete reinforced with glass fiber rather than steel." 

- Roger Tomalty

This report continues on Friday, 8/9/2013

Construction crew is working on a silt-cast panel.

Beginning the painting of the silt with concrete pigments.

[photos and text by Nadia Begin & David Tollas]

Painting near completion.

The finished painted silt cast right before the slurry.

Applying slurry before concrete. More photos of this silt-cast project will be posted soon. 

This completes our reports from 6/26 and 6/27/2012 about work on a silt-cast planter right next to the guestrooms.


As the crew continues, a piece of formwork is used to help shave the concrete into and help form the interior shape of the planter.

Dan Reiff is working on the finishing details of the planters edge.

The construction crew carefully removes the form work and compacted silt from around the planter.

Dan hoses off the silt to reveal the planter and the carved designs.





June 27. 2012

We continue our report from June 25. 2012 about construction of a silt-cast planter.

David Tollas carves the negative image design into the compacted silt.


[photos & text: Jenna Dern]

The construction crew begins mixing concrete.

A stiff concrete mix is shoveled into the carved silt to form the bottom layer. The 5 inch thick base is compacted and rebar is added.

Construction volunteer Elfriede molds and packs the concrete, paying special attention to the planter's carving.

More to come on 6/29/2012.

With so many events to be reported, we are way behind with reports on construction projects.

Here the construction crew digs up silt along the Agua Fria river bed for our siltcast planter.

text & photos: Jenna Dern

After setting up form work, the construction crew spent two days sifting, packing and trimming the silt for the planter.

Construction manager David Tolla gives Jenna a demonstration on carving designs into the packed silt.

More to come on Wednesday, June 27. 2012.