An electric kiln heats with coils, like an oven. A gas kiln heats with flame. That one difference changes almost everything about how pottery comes out.
Burners, flue, and the path of the flame
Gas burners at the bottom of my kiln push flame into the firing chamber. The heat rises around the shelves of pots and leaves through a flue and damper. Because the flame moves, the heat is never perfectly even. Pieces near a burner port, behind a tall pot, or high on a shelf each see a slightly different fire.
The slow climb
A glaze firing runs for hours. Early on, the climb is slow so the remaining water and organic material in the clay can burn out without cracking anything. Later the burners turn up and the kiln pushes toward the temperature where clay vitrifies and glaze melts into glass.
Controlling the atmosphere
The real reason to fire with gas is control over the air inside the kiln. By adjusting the burners and the damper, I can give the flame plenty of oxygen or starve it. Starving it is called reduction, and it is where most of the color in my work comes from. I wrote about that in What is reduction firing?
Why it matters when you hold the piece
Gas firing leaves fingerprints. Glaze breaks a little differently on the side that faced the flame. Iron in the clay can bleed through as warm speckles. That is the record of one fire on one day, and it is why no two pieces from my kiln are alike.
You can see what comes out of these firings in the shop.