Hi. I'm new here. Glad to be a part of the site. I just tried this method on my Combiner Wars Powerglide which had a factory stress mark on the wing joint. Rather than a hair dryer, I used boiling water as it was more precise. I just boiled the kettle and ran a stream of water from the spout. Holding the stress mark under the stream seemed to make a huge difference. While the stress mark is not perfect it is 80% improved.