Fixing the Cold Spot Problem in Glass Tunnel Kilns
If you’ve ever run a long glass tunnel kiln, you know the nightmare of cold spots. It’s frustrating. You’re trying to maintain a perfect temperature, but standard short-wave lamps just aren’t long enough. They leave these annoying gaps in your heating zone that can mess up your entire batch. We figured out a way around this by building custom infrared emitters that stretch over 2 meters. The trick to long tubes Building a tube this long isn’t as simple as just adding more glass. If you don’t get the wattage and voltage exactly right, the filament will either sag or just burn out right in the middle. We design these to sit end-to-end. No gaps. No modular breaks. Just a solid wall of heat. We also tweak the electrical load so you don’t get those weird temperature dips caused by voltage drops. It just stays hot, consistently, from one end to the other. Why we use gold Here is the thing about standard quartz tubes: they waste a lot of energy. A lot of that heat just floats away via convection or heats up the kiln’s frame instead of your glass. So, we coat the quartz in gold. It sounds fancy, but it’s practical. The gold reflects the infrared radiation straight forward, pushing the heat exactly where it needs to go. It’s way more efficient. Now, there is a catch. These tubes cost more and they’re a bit temperamental. You have to be careful when you’re installing them because one bad scratch on that gold coating can create a hot spot. Handle them with care. Making it actually fit When you’re dealing with projects this size, you have to think about how the materials breathe. A 2-meter tube actually grows as it heats up. If you bolt it down too tight, the glass will simply snap. It’s a loud, expensive mistake. That’s why we design our mounting brackets to let the tubes expand and contract. We’ll give you the exact specs for the expansion gaps so you can wire everything up knowing the system won’t tear itself apart during a heat cycle.