I’m redoing the caulking around my windows - some of which is right on the glass. A heatgun helps remove the old stuff significantly, but I don’t want to crack the glass. Is it safe to use this bugger on low setting next to glass? I can do my best to keep the direct hit from the glass itself, but even then I have concerns.
WAG since it’s not GQ, but I wouldn’t imagine it’d be a problem unless the glass was cold.
It’s not heating per se, but differential heating - if you heat one part of a pane quickly and too much,the differential stress will make the pane crack or even shatter.
I was taught this by old Professor Hardnox, when at about 12 I thought I’d see if I could melt a hole in a (thick) coke bottle with a propane torch. I had a lovely glowing white spot that was about to melt away… when the bottle exploded into a thousand shards, many of them red-hot, and entirely away from me.
One of two or three such incidents that can make me wake up in a cold sweat.
Use low or moderate heat and keep heating the whole area. Generally good advice on several levels for using torches and heat guns.
Thank you! Took your advice and it’s been going well.
Put a few layers of aluminum foil or a piece of sheet metal over the glass. The direct high heat on the glass is what will crack it.
And it’s glazing, not caulk. Please don’t use bathroom caulk!
I’ve done this before (a sheet of masonite works as well), and it works okay. If you’re careful, you can preserve most of the glass. But if you have a lot to do, you’ll probably end up breaking a few panes in the end.
Side note: if these are old windows, take some precautions, because white lead was used in some older glazing compounds. Wear a mask, don’t heat the glazing compound too hot, and clean up thoroughly.