Ken Frank has been cut, burned, and poisoned. So far, he hasn't been electrocuted, he says in jest, but is "extremely respectful of electricity."
Like all benders, he doesn't wear gloves so that he can sense the heat in the glass. "My hands don't really burn anymore," he says. And he also abjures safety glasses. He moves with deceptive casualness around his shop, sidling by open flames and dangling wires, neatly filing and snapping off pieces of glass.
The sounds and smells of the Golden Gate workshop suggest a blacksmith forge more than a place where tubes of glass smaller in diameter than your little finger are melted, shaped, pinched, and otherwise coaxed into forms to delight the eye. A block and tackle hangs from a rafter; a drill whines over metal somewhere out of sight.
Frank's piece of the workshop is a corner of about 500 square feet. The apparatus he works around is straight out of an old-time Frankenstein movie.
Live electric leads dangle from an insulated frame overhead. Below this frame, on a massive wooden table, sits a maze of glass tubes connected by bulbous hollow glass valves; these tubes are the manifold of a vacuum pump, which is used to remove the air from neon signs under construction.
Lining the wall of Frank's shop are clear glass globes the size of large grapefruits -- containers for the argon and neon that will be pumped into the bent glass tubing being made into signs. An electrical transformer about as big as a picnic cooler lurks under the table. It pumps out high-energy electricity until Frank removes his foot from the dead man's pedal beside it.
But the most hellacious-looking pieces of the shop setup are the torches used to weld the glass tubing. There are several types of torches. One variety is composed of two semicircular gas jets a few inches across; they spew flames at each other, making a literal "cross-fire." Then there is the ribbon burner, an adjustable horizontal grid of flame a foot or so long on a chest-high stand. Frank will also use the hand welder, a heart-shaped device on a long handle, with an open flame at the top. All the torches run continuously, fed by rubber hoses attached to a gas line.
The flames and the gas roar.
The heating and bending of the glass tube that will become a new neon sign is an extremely tricky business. Apply too much heat from any of the torches, and the glass will become too soft to shape. Apply too little, and the tube will snap. And there are no second chances. The glass will be ruined if it is heated more than once.
But Frank knows all of the tricks. To form a new tail on a letter in a broken sign, he holds the tube over and in the flame, turning it so that the bend is heated evenly on its entire circumference. Then he carries it over to a pattern he's traced on paper and bends it to fit the shape. The paper singes.
Once the glass tube is shaped, the truly hard -- and truly dangerous -- part of neon sign-making begins.
A kinetic dance of molecules creates the glow of a neon sign. For those molecules to perform properly, the tube's atmosphere has to be reduced to a near-vacuum and made almost completely free of debris before neon or argon is introduced. Any stray particles in the tube will flare when the electricity passes through, depositing scorch marks or causing the light to flicker.
Frank gestures for his visitor to take a few steps back, out of harm's way, and begins evacuating the tube with the vacuum manifold. When he's satisfied it has emptied enough, he attaches live wires to the electrodes at the tube's ends, and throws a switch, sending several thousand volts through the inside of the tube.
He waits until the electrodes heat to near-melting; if he waits too long, the tube could implode or the electrodes burn out.
Frank runs the vacuum pump, which evacuates any gas created by any vaporized debris inside the tube. When a scrap of paper he's placed against the tube starts to scorch, Frank kills the juice, and gives the tube five minutes to cool down, during which time he keeps an eye on the interior pressure. The best pressure is determined by the diameter and length of the tube and the strength of the charge that will be applied to it. Now Frank closes the valve to the vacuum pump and opens another to inject a small amount of argon. He also adds a dollop of mercury to give the tube a bluish tint. He seals it with a weld.
In the final step, the electrodes are attached to the transformer again, and the argon/mercury combination gradually wakes up. Frank twists the tube and rotates it to disperse the mercury evenly along its entire length; the tube goes from cloudy white to pale blue as the mercury does its work. Left undisturbed, the reaction could go on 30 years.