MERRIMAC — There will be three days filled with hot air balloon rides, the annual bonfire and anything on wheels when the annual Old Home Days celebration begins Friday.

While the history of Merrimac Old Home Days remains something of a mystery, the event takes place the second weekend in August each year and features plenty of free activities for families, including Touch-A-Truck and the annual Anything on Wheels Parade.

Karen Pambianchi is the volunteer-run event's co-chair along with Jaclyn Scarsell. Pambianchi said the Old Home Days tradition has been going on for "at least the past 30 years."

"This is only my second year involved with Merrimac Old Home Days," Pambianchi said. "I know it has been going on for at least 30 to 35 years, but I have a feeling it has been going on a lot longer than that."

Pambianchi and Scarsell oversee a crew of about 25 volunteers who put together the summer celebration, with preparations usually starting in early March.

"The basis of Old Home Days is that it is a local, community event and we try to offer as many things for free as we can," Pambianchi said. "We want to bring Merrimac and the surrounding communities and towns together. People can spend time with their neighbors and friends and the rest of the community."

Old Home Days used to be tailored more toward adults, she said.

“It was sort of a block party-style of event about 15 years ago," Pambianchi said. "It would take place on Merrimac Street and they would close off the roads."

Old Home Days eventually moved to Steven's Field to make way for more family-friendly activities such as face painting, movie nights and hot air balloon rides.

"This makes it easier for parking and keeps everyone off the streets and they don't have to close the roads," Pambianchi said.

The fun begins Friday when participants in the parade decorate their wheels at Merrimac Public Library from 10:30 to 11:30 a.m.

"This is just an opportunity for kids to decorate whatever they have got on wheels that's not motorized," Pambianchi said. "It can be a scooter or a skateboard, a bike, anything that they ride and power themselves."

Face painters and balloon artists will show up at Steven’s Field on Friday from 5:30 to 8 p.m., food vendors will also be on the premises, a beer garden will be open for adults, and an outdoor movie will be shown Friday and Saturday evenings.

The Anything on Wheels Parade begins Saturday at 9 a.m. at the Merrimac Light Department, 10 W. Main St. 

Tricycles and pushcarts are also welcome in this parade for young children. The rest of the day will feature plenty of events at Steven's Field, including a craft fair; an appearance by the Lexington Minutemen; the Kids Zone with life-size Jenga; community partner booths; the Santa Committee Duck Drop; Touch-A-Truck; the hot air balloon rides; and performances by the Merrimac Valley Concert Band, Cats n' Jammers Music Studio, The Annual, Doctor Brewster and Southbound Outlaws. 

Children dressed as superheroes can take part in the Kids Fun Run at Steven’s Field, which kicks off at 7 p.m., followed by a showing of "Incredibles 2" from 8 to 10 p.m.

The highlight of Old Home Days is the annual bonfire overseen by the Merrimac Fire Department. The bonfire is from 8:15 to 10 p.m. on Saturday.

"I would say the bonfire is a good, two, three stories tall," Pambianchi said.

The weekend concludes Sunday with the Old Home Days Softball Tournament at Steven's Field from 8 a.m. to 3 p.m. 

A full schedule of events can be found at www.merrimacohd.com.

Police Chief Eric Shears said his department is ready for "an incredible event."

"I expect it will be a fantastic weekend for the town of Merrimac," he said. "There are a lot of great events planned."

Staff writer Jim Sullivan can be reached via email at jsullivan@newburyportnews.com or by phone at 978-961-3145. Follow him on Twitter @ndnsully.

Pambianchi and Scarsell oversee a crew of about 25 volunteers who put together the summer celebration, with preparations usually starting in early March.