Why Your IR Lamps Are Probably Ruining Your Glass
If you’ve ever pulled a batch of glass out of the oven only to find the edges are under-stressed and the center is totally over-baked, you know the frustration. It’s a nightmare. Most of the time, the culprit isn’t your process—it’s your lamps. Here’s the thing: Cheap lamps are all over the place. One might be pushing 110% power while the one right next to it is lagging at 90%. When you’ve got that kind of mismatch, you get hot spots. Those temperature swings create internal stress, and that’s exactly why your glass cracks. The secret is in the consistency. To get a stable batch, you need lamps that actually behave. We focus heavily on the spectral distribution—basically, making sure the infrared light is hitting the glass the same way across every single tube. When every square inch of the surface feels the same heat, the guesswork vanishes. You don’t have to “hope” your soak times are right. They just are. But look, this kind of precision isn’t free. Getting this level of uniformity takes high-purity quartz and filaments wound with extreme care. And you can’t just slap these into a dying power supply and expect magic. If your transformers are drifting, even the best lamp in the world will fluctuate. You’ve got to make sure your controller’s output and the lamp’s voltage are a perfect match. I see engineers try to “fix” bad lamps by just leaving the glass in the oven longer. Don’t do that. It just burns through electricity and risks overheating the whole piece. If you switch to lamps with a tight ±5% wattage tolerance, you can actually tighten your process window and get things moving faster. One last tip for the install… Check your reflectors. A high-end lamp is basically useless if your reflectors are pitted or crooked. Make sure everything is seated firmly in the sockets so you don’t deal with arcing. And if you’re packing a lot of wattage into a small space, double-check your cooling fans. If they aren’t spec’d for the heat, your sockets will burn out, and you’re right back where you started.