Kail already immortalized Unitas in bronze in 1973.
But he had to work slyly to get the pictures he needed to create the sculpture because it was a surprise gift from fans.
Kail went as far as asking Unitas to hold a yardstick next to his head for photographs. If Unitas suspected anything, he didn't let on.
"He knows what I'm doing this time," said Kail, who will work mostly from old photographs.
The sculpture will be an action pose, probably Unitas passing a football. His jersey will sport the number 16, which he wore in college, and not the number 19 that many people are familiar with, Kail said.
Unitas may be a football legend, but he's also a great person who has a lot of class.
Unitas never turns down a request for an autograph even though a pinched nerve in his right arm makes it painful for him to even hold a pen, Kail said.
"He really adores all those kids. He's a real gentleman," he said.
Kail's first attempt at sculpture, under the instruction of artist Clyde Roberts at Hagerstown High School, didn't turn out so well.
When Kail put his clay Herculean figure into the 2000-degree oven, it exploded. His work, as well as his classmates' work, was destroyed.
Roberts scolded Kail for causing the blast by failing to work the air bubbles out of the clay.
"He was a remarkable instructor. I give him a lot of credit for the artistic development that I had," said Kail, who graduated from Hagerstown High School in 1955.
After high school, he studied at the Maryland Institute of Art in Baltimore.
An avid football fan, he got to know the Baltimore Colts players, including Unitas, and sculpted small figurines for them. Friends and family helped him paint the tiny statues at the kitchen table of their apartment on Broadway in Hagerstown.
Kail claims his idea was stolen by a company that made a mint off the highly collectible figurines.
Kail later got into graphic design, but sculpture has remained an intense hobby.
He is most known for his sports sculptures. Recently, he has focused on the sport of lacrosse.
Kail has always loved sports, although he was sidelined at age 14 by polio. Doctors told him he would never walk, but he recovered and went on to play high school football with braces on his legs, he said.
Kail credits his parents for giving him the encouragement to succeed. His father, Fred Kail Sr., passed away, but his mother, Marcella Ard, still lives in Hagerstown.
His sister, Eileen Harbaugh, also lives in Hagerstown.