Collaborative Concrete Art Gardens
We’re standing in the garden at the back of Visitation Elementary School on the Southside of Chicago. I worked here for several months over two summers. I worked on it with the school kids in small groups during a 6-week summer session. Though for me, a six-week program means three months on and off because I get involved in making the best piece that I can. In each of these summers, I also had two assistants working with me.
The first summer we made the Visitation bench, the St. Martin statue, a number of other benches, and decorated a few planters. The next summer we decorated the planters in the front of the building.
These planters weren’t part of the original plan. They were dropped off through a program of the Chicago Botanical Gardens. They were quite unsightly, big heavy things. The good news is that they led us to figure out something to do with them. We experimented with them the first year and then made them the focus of our project the second year.
I get some great community interaction. People see this guy working out here with a car that’s full of stuff, a guy who looks like he’s a homeless guy. We first worked back in the garden so people saw us from a distance. When I built St. Martin de Pores, I was right out by this sidewalk and had more interactions with the people who pass by and who live across the street. The following year being out on Garfield Boulevard, we were more visible and interacted with a wider audience.back to top
Ceramics, Landscape, Concrete, Landscape
My concrete sculpting is an offshoot of my early beginnings in ceramics. I was making largish clay sculptures and I had a storage problem so I began putting the art in the gardens around campus.
I am now a gardening zealot; I believe in the power of landscaping, in how landscaping and art can transform an area. I believe in landscaping with evergreens and with grasses: these are things with all year interest.
The beauty part of this artwork is that it coincides with my interest in year round landscaping as I’m often doing foliage forms, concrete plants—an ever green contribution to the landscape.
At Lake View High School, the kids and I made a prairie on the wall that hides the school dumpsters. We began by sculpting prairie plants in relief (flat on the back) out of clay. Imagine a room full of kids—each one making a plant part—flowers, leaves, stems. Then the kids would bring their leaves up to the front table and combine them with other parts.
We prepared each of these accumulated designs to make a plaster mold. This means there can be no undercuts. All the edges must be straight down or on an outward sloping angle. We get rid of undercuts by filling in undercut edges with additional clay.
We then poured plaster over the clay pieces to make big plaster press molds. The first coat of plaster should be a little soupy to be sure to get the detail. Additional coats of plaster can have more body. Try to smooth out the back of the mold so that you have a level surface to sit firmly on the table. This is important so the mold doesn’t crack or break when pressing clay into it. After the plaster sets up, pull out and discard the original collaborative clay design. (You can recycle and reuse this clay for further models, but it’s not a good idea to use it for fired ceramics because embedded plaster bits can cause clay to shatter when fired.)
We pounded and pressed slabs of damp clay into the finished molds. After the clay stiffens a bit (from air and from moisture being absorbed into the dry plaster), pull the pieces out of the mold. The beauty of this is you can make many pieces from a single mold.
After the clay pieces are taken out of the press molds, the students can work on the pieces—refining the details and adding texture. Many of the undercuts that were taken away in preparation for the plaster press mold can be added back by hand sculpting.
Concrete Multiples from Molds
You can also make concrete multiples from molds. The design is made in clay. To cast in concrete, you make a latex mold. I use the kind of latex that you paint on in layers.
I make a clay model. I don’t use a releasant. I paint several layers of latex onto the damp clay model to make a strong mold. After the first couple of coats of latex, I add loose weave burlap into one of the layers, usually the third or fourth layer. I buy my latex from a statuary company in Chicago, but one could also buy gallons of latex from an art supply store. The latex mold should be at least 1/4 inch thick all over. That’s at least 5 or 6 coats. It will still be flexible. That’s what allows the mold to come off the rigid cast concrete.
Some of the very detailed plant forms on my sculptures come from molds, such as the little fern peeking through the letters on the Visitation bench. The advantage of having these molds is that I can cast only a part of them; I can also layer up various pieces. I also make use of scraps and broken parts.
I have done lots of cast concrete with volunteers. In the Lighthouse Project, I made with Mirtes Zwierzynski last year, blind people participated in sculpting the forms. When doing community projects, kids and other volunteers love to paint on the many coats of latex.
After you’ve completed coating the clay with latex, you need to make a “mother mold” to hold the form rigid when you pour the concrete into the pliable latex mold. You do this by blobbing plaster over the back of the completed latex mold. In the early days, I used to add burlap layers to the plaster, but now, I often don’t bother to do that. It’s a good idea to have the mold flat on the back so that it’s easier to vibrate the mold once the concrete is in it.
When the plaster is set, you flip the whole thing over and pull the clay out. It’s ready to use.
You can use a mold many, many times. I ran into somebody who used to have a business, collecting African masks and then making molds and casts from them. He said he pulled out molds from 20 years ago and they were still good.
I made furniture for the Suite Home Chicago installation out of fiberglass. I was able to use my molds to cast in fiberglass. Because the fiberglass set up so quickly, things would be ready to take out in only 15 or 20 minutes.
The winter is a time is a downtime for me so that’s when I do clay things and make molds out of them. Usually, I know longer work with fired clay—I cast the final pieces in concrete, but I still begin with clay to make the model.
I have a collection of 50 or so molds. They’re expensive in materials and it takes time to make them so I carry them over from piece to piece. Often I make new pieces in the winter. I don’t have a use in mind when I make them.
If I’m planning to apply the finished molded piece to a concrete form such as a bench or planter, I don’t use metal mesh in the concrete pour. Even if it’s one of my individual plants that is 1 1/2 to 2 inches thick, I don’t use internal wire mesh. I don’t use it in stepping-stones either because they sit solidly on the ground. For me, if the cement is thick enough or if the casting will be applied to something, it’s not necessary to have internal structural metal.
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Direct Sculpting in Concrete
You can also apply cement and sculpt directly with a trowel on the statue or bench. First paint the surface with a bonding agent such as Quikcrete Bonding Agent. I “scrub in” the first coat, then I’m able to trowel on and build up the surface. Layer on the concrete, making sure to apply enough pressure to compress all air pockets. Concrete and gravity only allow one to build up about 1/2” at a time. When you’ve achieved your desired thickness, you can start carving. If you haven’t achieved your desired thickness, score the surface, let the concrete set up for at least a couple of hours, and repeat the process until you have gotten to the depth/thickness you require.
Kids could do this layering process and carve directly on a piece, but I would have to be watching them like crazy. I just don’t think that a lot of kids have the sensibility needed to technically make sure that the cement is attaching well.
I’m more comfortable having the kids direct sculpt their components separately and then attach the hardened pieces to the final form.Typically, one uses trowels to work with cement. For big groups of kids, I use plastic putty knives. We work at tables. Each kid has a putty knife in each hand. Rubber gloves are nice. After three or four days of doing cement work with bare hands, you can end up with little holes in your fingers! The first rule is compacting, compressing this blob of concrete, and getting the air out of it. Then you shape it into its basic form and then you do the details. When having kids make pieces in concrete to add to sculptures, we work on scraps of upside down carpet. It gives us a texture on the back that promotes better adhesion onto the final piece.
All of these leaves were sculpted by kids and then added to the final piece. Each leaf has a slightly varied vein structure and texture—like nature. I think this adds a charm to artwork, to see that plant and realize that each person made a different leaf. It’s a success-oriented activity for the kids. It’s exciting for them to be molding concrete—using putty knives, shaping the form. They make a leaf; they make another; they get quicker and better. It’s a feel-good activity.
This was a first attempt at layering lots of little stuff. A teenage girl selected pieces made by the younger kids and just had a great time putting this together.
Sculpting rocks out of concrete is a great introduction to the medium for young kids. They made the rocks that were later installed with the lambs and snake as a first concrete experience. I do this in elementary schools from the youngest kids to the oldest. With the youngest, I might just stay at the “rock stage,” but that’s okay because they totally enjoy making rocks at that age.
There is something about working in concrete that is not as intimidating to the kids as working in clay. It simplifies things for them. They’re working in an unfamiliar material and they know that it’s permanent.
There’s no time for messing around. They have to finish it in 20 minutes or it will set up. It gives an immediacy and focus to their work.
Pieces are attached to the finished form using Custom Flexbond, a flexible bonding mortar. Things adhere best if there is a texture on the back. Scratch a thin layer of the bonding mortar into the underlying form, then “butter” the piece to be attached, and press it onto the form until the mortar barely oozes out at the edges. Clean up the edges.
Putting a flat surface onto a rounded surface is not a problem. I build up the concrete to get rid of gaps. I fill the voids between the leaves as I build it up. After bonding mortar sets up, we come back and add more concrete if necessary. It’s very important not to have gaps or fissures in which water can collect. I use the Custom brand of bonding mortar because I find that it allows me to build up the mortar to fill voids more than most other thinsets.
When there are really big gaps to fill(1/2” or more), I use the same fiberglass reinforced acrylic modified mix that I use for direct sculpting. (See below.) This enables me to sculpt the concrete and blend the surfaces together.
You wouldn’t think that it would work to add fresh concrete to hardened concrete to fill voids and match surfaces, but the latex and fibers make it work. These ingredients prevent shrinking and cracking. I’ve done this for years and have not had such problems. The assembly is done by me or with kids who are older and more skilled.
Here, my assistant, Cara Kuball, did a nice job creating “rock mosaic flowers” in the gaps amongst the leaves.
I begin with a big, deep hole in the ground for a foundation. I go as deep as I can. (42” is the standard for getting below the frostline in Chicago.) If you are trying to keep a piece completely steady to prevent cracking, you have to have a deep solid foundation so it won’t heave around from frost. On the log benches, I have no foundation at all. It’s fine for them to “float” with the winter.
I put rebar (structural steel) and cement into the hole. The rebar sticks out and becomes the structure of the above-ground concrete. I attach stucco mesh (a steel mesh designed to hold concrete to a wall) troughs and cylinders around the rebar. I fill these “tubes” of stucco mesh with concrete and then gradually add to it. Some people attach and form stucco mesh onto their rebar and then only layer the concrete on the surface, but I like to create a solid form. I think it holds up better.
I have a basic idea of my design as I begin constructing, but then it evolves as we work. It’s important to design in a way that water sheds off the work, rather than pools and then potentially chips areas away when it freezes and expands. Good joining techniques are also important.When building a project use quality materials—plenty of metal, plenty of latex. I have projects that are over ten years old and are all in good shape—no sign of cracking.
An alternate way to construct is to build solid with concrete block. After creating a foundation with rebar protruding from the ground, build a solid structure with mortar and cement block. Thread the cement blocks onto the protruding rebar and then fill the holes in the blocks with concrete mix. Actually, you can also add rubble—broken bricks, cement blocks, large rocks, and broken bottles…but not things that will deteriorate such as wood. It’s a great way for a community to clean up a vacant lot.
I paint the surface of the pieces with an outdoor masonry paint. For my work, I begin by painting the whole thing a dark “greenblack” with a concrete stain or watery paint. (Lately I’ve been using Behr Concrete Stain.) I mix black and green together. I thin it down a little so it soaks into the cement. I cover the whole surface—staining into every crevice.
The painting is so quick and easy. It comes out really great. You drybrush over the dried dark color. It usually takes more coats of colors. I usually dry brush on one color and think it looks great, but when it dries the piece still looks too dark over all. So then I very lightly drybrush on another color as a highlight and sometimes create instant aging. This drybrush technique emphasizes the texture of the surface, enhancing a sense of depth by leaving the grooves dark.
The colors on my pieces are holding up really well. When one thinks of painted concrete —like something you’d see in somebody’s yard—you think chipping paint. I don’t know if that stuff is oil-based paint or what. I’m using masonry paint that is a plastic polymer. I also apply it very thinly as a stain and as drybrush so I haven’t had any flaking. Over time, the paint can fade, but that can add to the effect or easily be touched up to the original brightness.
I’d like to close with reminding people of the advantage of working in relief sculpture. It’s a very easy segue into artmaking for volunteers.
Relief sculpture is easier than drawing, less intimidating. You can have a basic outline and push in a few lines, create a few layers of depth, and suddenly you have something with a presence—that’s real. People feel success immediately.
The drawing may be primitive and crude, but by the time it goes through that process of becoming