Fixing the “Cold Spot” Problem in Tunnel Kilns
Most infrared lamps stop at about a meter. That’s fine for small jobs, but if you’re running a glass tunnel kiln that needs a steady stream of heat over two meters, you’ve got a problem. Standard bulbs leave gaps. Those little cold spots might not seem like a big deal, but they mess up your thermal profile and ruin the glass. We fix this by building custom quartz halogen emitters that actually fit your space—no gaps, no guesswork. The tricky part about going long You can’t just stretch a lamp and call it a day. If you do, the filament sags or burns out right in the middle. It’s a nightmare. We spend a lot of time balancing the wattage and voltage. We tweak the tungsten filament density so the heat stays steady from one end to the other. If we get the voltage drop wrong, you end up with dim ends and a scorching middle. We calibrate everything so the radiation is identical at the first centimeter and the last. Handling the glass We use high-purity quartz because the halogen cycle gets incredibly hot. But here’s the catch: these long tubes are fragile. To keep them from snapping during installation or when they start to expand from the heat, we use reinforced end-caps and specific connectors. A word of advice on mounting:**be careful.**Since these units are so long, even a tiny bow in your support frame creates a stress point. If the tube isn’t sitting perfectly flat, it’ll crack the second it hits operating temperature. A few things to keep in mind When you go for a continuous layout, you’re cranking up the heat density. It makes curing and heating way faster, but it puts a massive strain on your power supply and cooling fans. You can’t just plug these into a standard circuit and hope for the best. Double-check that your transformers can handle the total wattage of the whole array. Otherwise, you’re just waiting for a breaker to trip or your wiring to overheat.