Getting Glass Tempering Right Without the Cracks
Working with glass is a bit of a tightrope walk. You need it hot—fast—but if you push too hard or heat it unevenly, you’re just making expensive shards of scrap. That’s why we use twin-tube shortwave infrared (SWIR) lamps. Think of it as packing more punch into every inch. Instead of a single tube struggling to keep up, the twin-tube setup cranks up the heat density, getting your glass to tempering temperature in a matter of seconds. The trick to not breaking things You can’t just blast the lamps at 100% and hope for the best. That’s a recipe for thermal shock. We pair these lamps with SCR power controllers because they let you dial the voltage up and down on a dime. It gives you a “gas pedal” for your heat. You can ramp things up smoothly, letting the glass expand naturally instead of shocking it into a crack. Plus, shortwave radiation actually sinks deeper into the glass. Since the core heats up along with the surface, you don’t get that nasty temperature gap that causes internal stress. The trade-off: Heat vs. Air Here’s the thing: when you put that much wattage in such a small space, things get hot. Really hot. Your reflectors and housing are going to feel the strain. If you don’t get your cooling fans and ventilation dialed in, you’re looking at warped reflectors or filaments that burn out way too soon. It’s a simple balance—more power means you need more airflow. Real-world setup When you’re actually wiring these in on the floor, keep an eye on your power supply. The initial inrush current can be a beast. We use high-grade quartz envelopes because they can take the constant heating and cooling without giving up. These lamps usually slide right into where your old, slow heaters were, but don’t just “set it and forget it.” Check your PID settings. Shortwave IR reacts way faster than old-school elements. If your settings are too aggressive, you’ll overshoot your target temperature and end up scrapping the whole batch. Take a second to tune them, and you’ll be golden.