It is easy to adjust the temperature on a Top Flight model aircraft heat sealing iron. I suspect the other brand irons can be adjusted too, if needed.
When I got mine, it heated to about 198 degrees C (according to my innexpensive infrared thermometer – an oven meat thermometer works just as well). It was not hot hot enough to seal TPU fabric, a light stick, but not a full seal.
To adjust the thermostat, loosen the screw and remove the black plastic knob. Reaching down into the hollow brass stem with a fine jewelers screwdriver, turn the little screw counter clockwise to increase the heat. Try it in 1/8 turn increments, it doesn’t take much. My guess is that many of these will heat up just fine, and mine was just set too low at the factory. But it is easy to change. I really like the 165 watt heat source, and the added thermal mass these irons have. It greatly speeds up heat sealing larger seams!
