Paul Grzybowski, a junior materials science major from Appling, and Tommy Keen, a sophomore aerospace engineering major from Peachtree City, Ga., were injured when they tried to mix aluminum powder with rust powder, officials said.
Such a mixture might produce thermite, a combustible compound, said Kati Smallwood, who was Grzybowski's chemistry teacher at Greenbrier High School.
"It's not something we would ever work with in a high school chemistry lab, so I'm not real knowledgeable about it," Smallwood said. "I just remember him (Grzybowski) talking about it when he came back into town."
Grzybowski visited his former high school, where he was an honors graduate and AP Scholar, during his winter break from Georgia Tech.
"He came back to let us know how his science classes in high school got him excited about science classes in college," Smallwood said. "A lot of students wouldn't think to do that: Come back to the teachers and say, 'You really got me into this and I appreciate it.'
"He was very thoughtful, and really into science and learning."
Grzybowski ran for Greenbrier's cross country team and held a black belt in Chun Kuk Do, an American martial art founded by Chuck Norris, according to a newsletter from the Army and Air Force Exchange Service Retired Employees Association.
The newsletter also noted that Grzybowski played trombone in the Greenbrier High School Jazz Band.
Smallwood's husband, Tom, once served as Grzybowski's band director at Greenbrier. He is now principal of Grovetown Middle School.
"Paul was a great kid and a great musician," Tom Smallwood said. "He got along with everybody, but he wasn't laid back. He was very excitable, but in a good way. He was just an all-around great kid when he was in my band."
A phone message left at the Appling home of Grzybowski's parents was not immediately returned.
Grzybowski and Keen were taken to Grady Memorial Hospital in Atlanta for treatment of burns to their upper bodies.
A Grady spokeswoman said Wednesday that it is against hospital policy to release the condition of patients to the media, but the Associated Press previously reported that both men were in critical condition.
"It's really sad this has happened," Kati Smallwood said. "I hope he's OK."