The Headache of Cold Spots (and How We Fix Them)
If you’ve ever run a long glass tunnel kiln, you know the struggle. Most infrared lamps stop at about a meter. That sounds fine until you actually line them up. You end up with these annoying “cold spots” at every single joint where one lamp ends and the next begins. It’s a nightmare for consistency. We decided to stop messing around with short lamps. Instead, we build custom infrared units that stretch past 2 meters. The goal is simple: one long, steady wall of heat that doesn’t dip or drop while your glass moves down the line.
The Math Behind the Heat
You can’t just stretch a piece of quartz and call it a day. If you make a lamp longer, the electrical resistance climbs. If you aren’t careful, your voltage drops and the ends of the lamp stay lukewarm while the middle is scorching. To fix this, we get picky about the internal tungsten filament. We usually bump up the voltage configurations to keep the heat density high from end to end. Just a heads-up: make sure your power supply can actually handle the amperage these long units pull. If you starve them of power, they’ll burn out way faster than they should.
Built for the Long Haul
We use high-purity quartz to keep the filaments safe, and depending on what kind of glass you’re working with, we can add specific coatings to tweak the heat spectrum. The connections are where a lot of people get burned—literally. We use industrial terminals that can take a beating in high-heat environments. Because these units are designed to sit side-by-side without those gaps you find in 1-meter setups, you finally get that smooth, unbroken heat flow.
The Reality Check
Here is the honest part: long lamps are fragile. A 2-meter tube is much easier to snap during installation than a short one. It’s stressful. To keep things from going south, we use reinforced mounting brackets. This stops the kiln conveyor’s vibration from shaking the quartz until it cracks. And don’t forget your airflow. A continuous 2-meter heat source puts a massive load on your ventilation. If your cooling fans aren’t strong enough to pull the ambient heat out of the tunnel, you’ll end up melting your own lamp sockets. Not a great look.