On the ground near a large grave marker, about ten plastic spray bottles, some filled with water and some filled with a cleaning product called D2, were available for anyone who wanted to try their hand at cleaning the marker for the Rev. Dr. Reginald H. Helffrich, who died in 1906.

More than 50 people gathered around the monument in the cemetery at Ziegels’ Church to learn how to clean the commemorative gravestones.

Brenda Mankos was there to explain the process.

“Bleach can eat through the stone,” explained Mankos, who has become quite an expert in cleaning gravestones.

Mankos has worked on over 100 gravestones, many of them in the Alburtis area.

“My grandmother’s people are buried there,” she said.

The instructional event was sponsored by the Weisenberg Lowhill Historical Society.

“I thought people would be interested in how to clean stones, so I invited her to come here,” Gloria Zimmerman said. “We used to work together.”

Mankos described the process in a few steps.

“I scrape the algae off first, and then I spray the stone with water,” she explained. “Then I spray D2 and scrub with a soft bristled brush.”

“D2 or whatever cleaner you use, should be used last,” Mankos said. “Brushes with soft bristles should be used so as not to scratch the stone.”

As Mankos answered individual questions, Zimmerman wove through the crowd showing photos of newly cleaned stones.

The National Cemetery Administration and conservation groups consider the D2 Biological Solution as a “safe and effective product for cleaning gravestones” since it is pH-neutral and won’t etch or damage marble, granite, limestone, or sandstone.”

D2 kills biological growth and is safe for use on historic stone.

The product continues to lift deep stains for weeks after the initial application.

It targets mold, mildew, algae, moss, and lichen at the root inside the stone’s pores.

Arlington National Cemetery primarily uses D2 Biological Solution to clean headstones.

There are many reasons why you may want to clean your family’s gravestones.

Cleaning can make the names and inscriptions more easily readable.

“Cleaning them is a way to show care or respect for loved ones who have passed,” wrote Binh-An Nguyen, in a blog post titled “Your Collections: Caring for Your Family’s Gravestones.”

She is a student in the Winterthur/University of Delaware Program in Art Conservation.

That kind of reverence resonated with the crowd gathered at the cemetery, just as the sun was setting on a beautiful September evening.