Stop the Peeling: How Medium-Wave IR Actually Fixes Aluminum Coatings
There is nothing more frustrating than finishing a part only to have the paint peel right off. It usually happens because the heat is all over the place—some spots are barely warm, while others are practically scorching. That’s where medium-wave infrared (MWIR) comes in. Most people try short-wave lamps, but those often “skin over” the top layer too fast. It’s like searing a steak on the outside while the middle is still raw. Medium-wave is different. It actually sinks into the coating. Getting the heat where it matters The magic here is how the energy hits the paint. Instead of just bouncing off the surface, the heat migrates through the paint film and right down into the aluminum. When the heat is steady across the whole part, the solvents evaporate slowly and naturally. You don’t end up with those tiny, invisible gas bubbles—micro-voids, if you want to be technical—that act like little wedges, pushing the paint away from the metal. Dialing in the settings You can’t just plug these in and hope for the best. You have to look at your conveyor speed and how heavy your parts are. If your wattage is too high for how fast the line is moving, you’ll burn the surface. Too low? The paint never fully bonds. It’s a balancing act. You want a stable output and a reflector that spreads the heat evenly so you don’t get those annoying “hot spots.” The trade-offs Now, keep in mind that these high-output lamps put a lot of heat into your oven. You’ve got to make sure your exhaust is actually pulling those solvent fumes away. And don’t forget the cooldown. You need a cooling zone that brings the part down to a temperature where you can actually touch it, but not so fast that you shock the metal. If you rush the cooling or leave too much residual heat, the coating can soften right after it cures. And that’s how you end up ruining a perfectly good finish at the very last second.