news from the waterfront by Tim Matson
A RINK MASTER'S PRIMER Part Two
Creating a flooded rink is like building a pond every year. There’s a lot of preliminary site preparation involved, and a delicate balancing act with the weather. It’s important to select or create a stretch of flat terrain; seal the rink with ice, packed snow, or a waterproof liner; and then build up and maintain the ice by flooding, spraying, scraping, and clearing. Snowblowers
and portable pumps help to make it happen, but the primary ingredients are human initiative and labor. It takes at least one true zealot to keep the ice. Not long ago, my town had a skating rink that was a magnet for hockey players and figure skaters and once provided the inspiration for a nostalgic New Yorker magazine cover. Now it’s a snow-covered potato patch. The rink master moved to Alaska, and the skating went with him.
Level ground is essential for good skating-rink construction, particularly if an earth base will be used. Vermont’s Division of Recreation suggests a maximum fall of 1 inch per 100 feet, while conceding that it is possible to make ice on surfaces that decline as much as 18 inches per 100 feet, if the temperature is zero or below. Naturally, the more uneven the surface, the more water required.
You can use a hand level or transit to determine the slope of the land. People who put their first rink on a slope quickly learn that water won’t tilt. Some try to overcome this problem by using a high curb at the low end. Occasionally it works; mostly it doesn’t. Leaks and difficulty in layering ice at the deep end are frequent problems. So leveling the site is a top priority.
Leveling can be done by hand for a small rink, using a shovel and rake; you’ll need a tractor or bulldozer for a larger rink.
Perhaps the greatest obstacle to rink construction is water seepage. Porous soil allows water to drain away, making it difficult to establish a solid base of ice. It’s important to find soil with enough clay content to hold the water while it freezes. An area with a cover of mowed grass holds water better than does raw earth. Clip the grass short and rake it before flooding or spraying; fewer decaying leaves will float up in the ice to ruin the surface.
Keep snow off the rink area during early winter to allow the ground to freeze. Frost to a depth of 3 to 6 inches is essential for a good base. It may help to spray the rink and allow the moisture to seep into the ground and freeze. Some rink builders have had luck with a base of tamped-down snow, using a four-wheeldrive vehicle for packing.
One obvious way to avoid the whole problem of seepage is to use a waterproof liner. The liner may be a permanent cover, such as asphalt, or a temporary one of plastic. The liner can also help overcome problems with slope.
Alleyne Howell takes care of the Vershire, Vermont, skating rink. He says he does it because he loves to skate, and indeed he must, because over the past three years he has faced a combination of natural obstacles and bureaucratic resistance that would have undone a less enthusiastic soul. When the town built a playing field, Howell saw the opportunity to enhance it with a winter skating rink, and in fact a group of local kids had begun to level the ground in preparation for the rink. But the village elders objected, fearing that a skating rink in the middle of town would attract rowdies and vandals.
“First they were nervous about teens using it,” Howell recalls, “and then they feared it wouldn’t be proper on the state-funded playing field. But as it turned out, a skating rink is a legitimate winter use of a playing field.” Howell circulated a petition and won overwhelming support for the rink. “Democracy blew them away,” he says.
But democracy doesn’t blow away snow, so Howell has to use a truck. “The worst part is plowing after a big storm,” he says, explaining that the ice makes steering rather dicey. The advantage is that plowing is usually quick, and he doesn’t have to worry about his truck breaking through and sinking.
“This is a low-tech operation. After the ground is frozen, I pack the first big snowfall with my jeep, running back and forth over it. That’s better than plowing it off because it has a white surface that reflects the sun and stays cold. After Christmas, I spray the rink to get a watertight surface, and then I flood it.”
Howell uses a 3-horsepower portable gas pump to draw water from a nearby stream. He builds up the surface in layers ¼ to ½ inch thick. Total thickness is about 3 to 4 inches. “The rink isn’t perfectly level, so sometimes I’ll get a frozen ripple effect on the downhill end,” Howell says. “Eventually, we’re hoping to build a paved basketball court that will double as a rink in winter.”
While pavement covered with a sealant is unquestionably the ideal base for a flooded rink, plastic sheeting is an effective and economical alternative, especially for a relatively small backyard rink. Tom MacMillan uses plastic for his 56- by 24-foot figure-skating rink in Lebanon, New Hampshire. The plastic prevents seepage and enables him to correct for a slope of 4 inches over the length of the rink. MacMillan uses two sheets of construction-grade plastic overlapping a foot or two, with the uphill sheet on top. The seam is sealed with duct tape.
MacMillan’s rink is surrounded by a curb of 2-by- 4s supported by stakes driven into the ground. He runs the plastic up over the 2-by-4s, then staples strips of cardboard over the plastic to secure the edge. The plastic is good only for one season, but it doesn’t cost much. MacMillan figures he spent only about $35 on materials for his rink last winter, including plastic and lumber. Flooding the rink probably added $35 to his water bill, “but I don’t consider that an exorbitant price to pay for having a rink outside my door,” he says.
Building up the ice in a flooded rink is a fine art. Spraying is the most reliable method for layering ice without creating air pockets and uneven areas. The Vermont Division of Recreation recommends the following procedure:
Start at the end of the rink farthest from the water supply, walking backward to the opposite end. Work across the rink, back and forth, moving fast enough to match water to water; that is, each pass across the rink should overlap the previous pass before the water has frozen. Hold the nozzle of the hose up, rather than parallel or downward. Don’t drag the hose on new ice
or allow it to lie on the ice in one spot too long. Little or no water should be standing on the rink when each layer is finished. Scrape off any bumps and grass blades and fill in any holes before applying another layer. The next layer should be applied when the surface is frozen
but still tacky, like fresh paint. Continue to build up layers until you have 3 or more inches of ice.
The volume of water required to establish a skating surface will vary with the thickness of the ice and the size of the rink. Three inches of water on a rink 100 by 75 feet adds up to approximately 14,000 gallons. That’s enough to overdraw the supply on many private
household water systems, which helps to explain why many flooded rinks are community affairs tended by the local fire department.
Tom MacMillan’s modest backyard rink requires only 2,500 gallons of water and provides a whole winter’s entertainment. After his workday is over, he likes to come home, put on his Walkman, and practice his spins in the light of the Coleman lantern that hangs on a ladder beside the rink. “I don’t have to drive to the nearest indoor rink and pay to get in; I don’t have to listen to music I don’t like; I don’t bump into any crowds,” he says. He also enjoys the safety of ice that won’t break through. He can’t swim.
adapted from Earth Ponds Sourcebook, Second Edition, by Tim Matson
January 6, 2014