I forget now what the heat distortion temperature of Airex core is. I used to know off top of my head. I did always know it was lower than a cross linked pvc and slightly lower than SEN core. So when I set about heat bending some Airex window stops on the lander, I was surprised that this was all I could get to bend. It was a 100F day and I set the pieces in dark sand that was reading 155F. I thought just a little extra boost from a hair dryer was all I needed. No way. And this was with using weight.
Some youtube video shows forming in boiling water, clamp and chill with a hose.