Plastic And Plastic Chrome Repair
Besides making gauges look concours correct, AutoInstruments also restores plastic pieces. The supply of NOS instrument bezels, armrest bases, and dash knobs for some models has long-since dried up, and the cores aren't looking too good either these days. The company can repair cracked and broken plastic pieces and rechrome them the same way the factory originally did it, before being detailed with the proper trim colors.
First, the part is stripped and cracks are repaired. Then the part is vacuum metalized. The plastic chrome AutoInstruments applies is real metal, not a shiny plastic coating. "It will conduct an electric current," Gentry tells us. This process is comprised of vaporizing an aluminum bar in a vacuum chamber and covering the entire piece in an equal thickness of aluminum. Once done, the part is hand-masked to cover the chrome areas that will remain visible after painting is completed, and then the part is painted.
Tach Compatibility
AutoInstruments has found that since original tachs were designed to work with vintage points ignition systems, most won't work with modern electronic ignitions. They don't use the same kind of tachometer signal as factory points-type ignition systems, be it a factory setup like an HEI retrofitted into an older car, or an aftermarket upgrade such as a Pertronix or MSD. One of the services AutoInstruments offers is a tach conversion to remedy this problem. Besides updating factory tachs, the company can also convert vintage aftermarket and OE accessory tachs to be used with either type of ignition system. To do this, the company builds a new more modern tach inside the factory housing, and the cost is $275.

Once the gauges are refaced...

Once the gauges are refaced and reassembled, each is calibrated and tuned to read accurately. Autoinstruments built its own tach-calibration machine. To calibrate each tach, the movement and meter are balanced, and the resistance on the circuit board is adjusted.

With the new drive installed,...

With the new drive installed, the speedometer is then calibrated. First the hairspring pressure is adjusted until the needle just sets to zero. Next, the magnet on the speedometer drive is magnetized on a magnetizing rig to fully energize it; then the speedometer is set up on a calibration machine (which has its own built in speedometer) using a speedo cable. With the machine turned on, the cable starts spinning.

The onboard speedo reading...

The onboard speedo reading is dialed back to a value such as 60 mph using a knob, but the speedo that is being calibrated will probably read a substantially higher speed, so a demagnetizer is used to slowly remove magnetism from it until it matches the machine's speedometer reading.
Each fuel, volt, and oil gauge is calibrated using another inhouse machine that can be set for a specific resistance value. Said value is applied to the gauge, and the needle of the gauge is reinstalled to match the position of the needle on the machine's gauge.

We wouldn't have believed...

We wouldn't have believed these were the same gauges we sent in if we hadn't watched the restoration from start to finish. These are rebuilt, updated, and accurate. Turnaround time on a set of gauges varies by season. From September through December, it's about four weeks. January through August is a busier season, so it takes about six weeks.

Lenses are buffed and polished...

Lenses are buffed and polished to remove fine scratches and imperfections, then finished by hand with a special rubbing compound.