My big mistake with the heat gun on quarter panels

I was working on a 2017 Civic's rear quarter panel, trying to soften the filler before sanding. I had the heat gun on high and was moving it in circles like I always did. The painter came over, pointed at a faint ripple I hadn't seen, and said, 'You're cooking the metal, not warming the mud.' He showed me to keep it on low, hold it about a foot back, and just warm a small spot until it was hot to the touch, not scorching. That ripple was from the metal expanding under the filler. Anyone else have a simple trick for getting filler to release without messing up the panel?

2 comments

2 Comments

chen.jade2d ago

My first heat gun job looked like a baked potato, and @shane_perry29 is right about that low setting.

shane_perry292d ago

Oh man, that's a classic lesson. Honestly, I've seen guys warp thin door skins the same way. Tbh, the low setting is everything. I'll even use my hand as a gauge, like if I can't hold it near the spot for a second, it's too hot. Just warm it enough so the filler gets a little waxy, then hit it with the sander. That ripple is a killer.