By Tammy York
Park signs must endure a lot. Being exposed year round to the elements, park signs need to be able to withstand temperatures from freezing cold to scorching hot. The colors on the signs must be resistant to damaging ultraviolet rays. Plus, the signs have to be resilient to spray paint and permanent marker graffiti as well as gouges and engraving.
Unfortunately, wood signs can be an easy target for vandals to shoot, mar or decorate with spray paint or permanent marker. The porosity of wood that makes it great for accepting stains or paint is also the downfall of wood signs.
Paint and marker graffiti soaks into the wood and can only be removed by either sanding it away or repainting the sign—both options involve time and money. A wood sign that has been target practice for vandals is often too damaged to repair or begins to quickly rot due to the splintering of the wood, which exposes it to the elements.
Metal signs, on the other hand, can be bent, causing the paint to chip. The bent portion exposes the metal to the elements, allowing for oxidation to begin.
While "doing more with less" is the current catchphrase, many park managers have already been doing just that for years by seeking long-term cost-effective solutions, even if the initial costs are slightly higher.
The Town of Mount Pleasant, N.Y., is currently switching from wood signs to recycled plastic signs. The wood signs required sanding and repainting every few years and were fracturing at the bolt holes, creating a safety hazard as well as damaging the structural integrity of the wood.
"We have updated a little over 50 percent of our signs to the routed recycled plastic signs. Right now, we are saving about 40 man-hours per year just in sign maintenance," said Steve Mott, superintendent for the Town of Mount Pleasant, which has more than 300 acres of park land. "Once all of the signs are plastic, we expect to see a savings of at least 80 man-hours per year. We have literally no maintenance on the recycled plastic signs."
Todd Younkin, deputy director, Preservation Parks of Delaware County, Ohio, which covers just over 1,000 acres of land and sees an estimated 300,000 visitors per year, has also employed recycled plastic signs. "The recycled plastic signs are consistent, durable, and blend in well with the environment," Younkin said. "In the last 10 years, we have yet to replace one sign due to vandalism. With a painted wood sign, we needed to replace or repaint the wood every few years."
Recycled plastic signs are created from high density polyethylene (HDPE). High-performing HDPE is created with no fillers from a single stream of recycled plastic, such as finely milled post-consumer recycled products including milk containers. Since milk containers are colorless, to get a uniform color the pigments and UV stabilizers are added during the melting process. UV stabilizers protect the finished HDPE from fading or chalking.
The non-porous HDPE boards are smooth and have a water absorption rate of less than 1 percent. Commercial-grade HDPE does not hold dirt, mildew, mold, paint or marker ink. The material is exceedingly dense and does not mar easily, making it difficult for engravers to quickly make their mark. "When people realize the durability and that it is not easy to write on with a marker or gouge, then that acts as a deterrent," Younkin said.
A lot of the tools of vandalism don't work on recycled plastic signs. "The paint and marker ink stays on top and you can just hose it off. If the graffiti was on brick or wood, it would sink in and be hard to remove," said Doug Foley, director of Parks and Recreation for the City of Manchester, Iowa, which covers 72 acres of park land. "In one case, a group of vandals tried to write words in permanent marker on the signs, but we wiped off the marks with a soapy rag. If that was on a wood sign, we would have most likely needed to paint over or sand off the vandalized areas."