The Rainbow Recreation Center in Oakland, CA, serves the East Oakland community with recreational activities for all ages. In March, the 40-year-old center began an extensive renovation project to replace most of the facility and add new features, which was recently completed.

To accent the main facade on International Boulevard, a local artist was commissioned by the City of Oakland's Public Art Program to craft a tile mural that was both colorful and reminiscent of the surrounding community. Johanna Poethig, a visual, public and performance artist who has been actively creating public art works, murals, paintings, sculptures and multimedia installations for more than 30 years, has worked on many similar public art projects throughout California, and designed this particular mosaic utilizing glass tiles from Artaic in Boston, MA.

“This glass mosaic titled, ‘Rainbow Power,’ was designed to integrate with the architecture of the building, which includes an archway, and rainbow reflections using refractive and reflective material in the windows and skylights,” said Poethig. “A rainbow landscape inspired by the surface of bubbles creates a colorful backdrop for figures. The figures are based on photographs of youth from the Rainbow Recreation Center that are connected through their gestures.

“Art and science come together as the gestural figures refract light that passes through them,” the designer went on to explain. “Reflection, refraction and diffraction are all boundary behaviors of waves associated with the bending of the path of a wave. This is what creates rainbows. The color wavelengths connect the figures in a metaphor for the sharing of our ideas, our culture and our friendship.”

The 13- x 65-foot mural, which took several months to design and fabricate, was constructed using mosaic tiles because of their durability. “I have done a number of public art works with Artaic, as well as ceramic and mosaic tile,” said Poethig. “Cities and arts agencies like this material as it’s easy to maintain and doesn’t fade with time.”

Although the design process took several months, the installation was completed in only three weeks by a talented duo of installers, Gabriel Cortez and Jose Calderon, from Heritage Tile & Marble in Columbus, OH. “Because of the tedious work, we wanted to use just a small crew to keep the quality consistent,” said Martin Brookes, president of Heritage Tile & Marble in Mill Valley, CA, who worked on a previous mosaic project with Poethig. “Gabriel is a master tile setter with years of experience and a Ceramic Tile Education Foundation Certified Tile Installer [CTI] and ACT-certified installer. His knowledge and attention to detail is second to none.”

The installation was completed using a range of products from Laticrete in Bethany, CT. “We worked with Laticrete to come up with an installation process to give superior performance and longevity,” said Brookes. “They had just released their Hydro Ban Quick Cure, which was perfect for waterproofing, especially during the wet season because it needs moisture to cure out. Then, we went with the high-performing 254 Platinum thinset, followed by Permacolor grout and Latasil silicone caulk at the expansion joints.”

Since the mosaic was installed outdoors, there were some temperature-related issues, according to Poethig and Brookes. “The most challenging aspect to the install is knowing when and for how long you can adjust the mosaic when installed on the wall. There is a limited time to do this before the thinset grabs and you risk losing bond if you try to adjust once the open time has expired,” Brookes explained. “The mosaic is also face-mounted with plastic. This can create problems if the mosaic is exposed to heat and the thinset is curing out; the vapors will get trapped behind the face-mounted plastic and create blisters pulling the mosaic off the substrate. It’s therefore important to cut slits in the face-mounted plastic to relieve the build-up of vapors and limit the blistering. If this is not carried out, a loss of bond will occur, creating hours and hours of piecing in the 1/4- x 1/4-inch mosaic back into the mural.”

Since the glass tiles are so small and required exact measurements, Poethig had to make some onsite adjustments during the installation. “With this mural, it was very important that it went up correctly according to the image to show the way the tiles act like pixels to create the image,” she said.

Since the project’s completion a couple of months ago, the mural has received favorable feedback, from visitors and community members alike. “People love it,” said Poethig.