Finally tackled that metal edging thing on my roof

Bubbling usually means trapped moisture or air, but if your patch held up and didn’t leak, you probably got lucky. In my experience, bubbles can sometimes lift the sealant over time, especially if you get a hard freeze or a lot of sun. I’d be more worried about warping thin metal with too much heat than the bubbles themselves. Have you ever tried using a roller or just pressing it down while it’s warm, instead of blasting it with the gun? That’s saved me from making a mess a couple times.

Have you ever tried using a roller or just pressing it down while it’s warm, instead of blasting it with the gun? That’s saved me from making a mess a couple times.

I actually ran into something similar last fall when I was patching a seam on my old galvanized gutters. I used a heat gun to soften up the sealant, but I think I went overboard because the metal warped a bit - nothing dramatic, but enough that the finish looked wavy. In hindsight, I probably should’ve just used a small hand roller like you mentioned. It’s tempting to crank up the heat, especially when you’re in a rush and want everything to set fast, but I learned the hard way that patience pays off.

I’m still not convinced the bubbles are harmless, though. Even if there’s no leak now, I keep worrying about what’ll happen after a couple freeze-thaw cycles. Maybe I’m just paranoid after dealing with water damage before... Anyway, for anyone else doing this on a tight budget, I’d say go easy on the heat and try rolling first. It’s less risky than having to redo the whole patch later.

- Been there with the heat gun - got a little too enthusiastic and ended up with a “custom” ripple effect on my flashing.
- Bubbles make me nervous too. Last winter, one turned into a tiny leak after a cold snap.
- Anyone ever try those self-leveling sealants? Wondering if they’re worth the hype or just another mess waiting to happen...

Anyone ever try those self-leveling sealants? Wondering if they’re worth the hype or just another mess waiting to happen...

Had a go with one of those on my back porch roof last fall. Looked promising at first - poured out like pancake batter, smoothed itself out, all that. But by spring, I noticed it had shrunk a bit and pulled away from the edge, so water found its way in anyway. Maybe I messed up the prep? Still, I’m not convinced they’re a magic fix. Has anyone managed to get a good long-term seal with them, especially in places with big temp swings?

Maybe I messed up the prep? Still, I’m not convinced they’re a magic fix.

I hear you. I tried one on my garage flashing last year - followed the directions, cleaned everything, even used a primer. Looked great at first, but after a cold winter, it cracked and peeled back. Prep helps, but I think temp swings just do a number on these sealants. For me, old-school caulk plus some mesh tape held up better in the long run.