Getting the Heat Right: The Reality of IR Lamp Arrays for Rocket Fairings
When you’re doing Non-Destructive Testing (NDT) on a rocket fairing, you’ve got a massive surface area that needs to hit a very specific temperature. If you miss a spot, you might miss a bonding defect. That’s a problem you don’t want. We use short-wave infrared (IR) lamp arrays to get the job done, but it’s not as simple as just turning on some lights. The real headache? Cold spots.
The “Striping” Struggle
If you just line up lamps in a row, you get these annoying stripes of heat and cold. It looks like a zebra pattern on your thermal map. To fix this, we don’t just line them up—we overlap them. We spend a lot of time figuring out the exact wattage and length so the heat “cones” bleed into each other. We play around with the angle of incidence until those gaps disappear. It takes some math, but it’s the only way to get a smooth, even soak across the whole part.
Power and Punch
We stick with high-wattage quartz halogen tubes. They’re fast. When you’re working with aerospace composites, you need that heat to ramp up quickly and penetrate deep into the material without just scorching the surface. But you can’t just blast the whole thing at once. We wire the lamps into zoned controllers. This is a lifesaver because it lets you tweak the heat in one specific section without messing with the rest of the fairing.
The Hardware Trade-offs
To get the most out of every lamp, we use heavy-duty reflectors. They basically push all that IR energy forward so you get a wider footprint. One thing to watch out for: the power draw is huge. If you’ve got a massive bank of 2kW tubes, you’re pulling a ton of current. If your electrical panels aren’t spec’d for that initial surge, you’re going to be tripping breakers all day. It’s a frustrating way to spend an afternoon.
Keeping it Running
We build the arrays in modular frames. Why? Because tubes burn out. It happens. With a modular setup, you can swap a dead tube in a few minutes and get back to work instead of tearing down the entire rig. We also use reinforced connectors because these things get moved around and take a beating. Just a heads-up: these tubes get incredibly hot. If your housing cooling system isn’t sized right, you’ll actually warp the support frames. And that’s a mess nobody wants to clean up.