At the same time, he said, their differences allow them to approach each problem from a different perspective. “I find myself feeling out of balance or awkward without him there to bounce things off of,” he said.

The third Hindenburg experiment would theoretically test the notion that the original craft’s fabric had been treated with a thermite-like substance. The crew had mixed about 15 pounds of actual thermite, which is highly explosive, into the fabric.

For this test, no one was allowed near the building. Yellowish brown smoke billowed out and tore at throats and burned eyes. On the monitors, the flames were blindingly bright. White sparks were thrown far and wide. It was all over in moments.

The purpose of the third burn — aside from an excuse to have a truly awesome conflagration — was to suggest what the Hindenburg might have looked like if the chemicals used to coat its skin had actually been thermite instead of a chemical cousin. “The skin of the Hindenburg was not coated in 100 pounds of thermite,” Mr. Hyneman said. Mr. Savage watched the replay again. “Dude, there’s no doubt that does not look like the Hindenburg.”

The sun was setting as they finished the day’s shoot. Mr. Savage’s face was smudged, and both men seemed exhausted. Mr. Hyneman and Mr. Savage set fire to the remaining tub of thermite paint for the cameras, and then the crew packed up.

Earlier in the day, Mr. Hyneman said that he sometimes worried about “glorifying explosions,” which could send the wrong message to young and impressionable viewers. “If I had my druthers, we wouldn’t be blowing stuff up,” he said.

Mr. Savage appeared behind him. “But then we wouldn’t have a show,” he said with a cackle, and darted away.