LaCoe says the crew slowly adds the crushed glass on site according to the sealer producer’s mix design, then monitors the consistency making sure it’s “ a little thinner than latex paint.”
The A-1 Sealcoating crew then applies the sealer using either spray or squeegee though his company generally applies with squeegee.
“That’s what most of our customers want but we’ve tested it with a spray too and it works just fine,” he says.
LaCoe says crushed glass offer advantages to the contractor – it stays in suspension longer so requires less agitation, and he says it gets hotter than sand so sealer sets up faster. He says one disadvantage of crushed glass is its availability. “Using glass isn’t as convenient as sand because you can’t just go to Menard’s or another store and pick up bags of crushed glass,” he says.
LaCoe says he has talked with the Environmental Protection Agency about using crushed glass and he says “the EPA was floored by this. There are no Material Safety Data Sheets (MSDS) for what we’re doing, for example. They’d never even considered it.”
He says the existing MSDS applies to glass crushed to 3/8 inch to ¾ inch size, much larger than the crushed glass A-1 Sealcoating is using. In addition the existing MSDS refers only to washing of the crushed glass.
To try to gauge the impact of replacing sand with crushed glass LaCoe asked his supplier how much silica sand it sells in a typical week. The answer: 18,000 lbs.
“If we replace it with glass it takes 18,000 lbs. of glass a week out of a landfill,” LaCoe says. “That’s a lot of glass that can be taken out of a landfill each year.”