Those “miracle” sprays really do get hyped up, but I’ve yet to see one hold up through a full freeze-thaw cycle, especially on exposed metal. Even the ones that claim to be flexible seem to get brittle or start flaking once we hit January. I’ve tried a few brands over the years—some on gutters, some on flashing—and honestly, the only time I got halfway decent results was when I used a self-etching primer first. Even then, it was more “less bad” than actually good.
Prepping the metal makes a difference, but it’s not a silver bullet. I’ve always cleaned the surface thoroughly, sometimes even roughed it up with a scotch pad, then wiped it down with acetone. Primer helps with adhesion, but if there’s any moisture left or the temps drop too soon after application, you’re back to square one. The real kicker is that most of those sprays aren’t rated for the kind of temperature swings we get here—one day it’s 40°F, next day it’s single digits.
One thing I’ve noticed: the thicker you apply those coatings, the more likely they are to crack. Thin coats seem to flex a bit better, but then you’re reapplying every year anyway. I’ve started leaning toward mechanical fixes—like replacing sections or using proper flashing tape—over relying on any spray-on solution. It’s more work upfront, but less hassle long-term.
Funny enough, I had a tenant try one of those “as seen on TV” sprays on a rusty stair rail last fall. Looked great for about two months, then started bubbling and peeling off in sheets once the snow hit. Ended up having to strip it all off and repaint in spring.
If you’re dealing with exposed metal in our climate, I’d say don’t skip the primer, but also don’t expect miracles from any spray can. Sometimes old-school methods just hold up better when winter rolls around.
I get where you’re coming from, but I’ve actually had a bit more luck with the spray-on stuff—at least for short-term fixes.
That’s been my experience too, but on a few rental properties, a good primer plus two light coats of Rust-Oleum held up surprisingly well for a winter or two. Not perfect, but it bought me time until I could do a proper repair in spring. I wouldn’t trust it for anything structural or long-term, but for patching up minor rust spots or seams in a pinch, it’s saved me from bigger headaches. Still, nothing really beats replacing the bad sections when you can swing it.“the only time I got halfway decent results was when I used a self-etching primer first. Even then, it was more ‘less bad’ than actually good.”
- Always wondered if the spray-on stuff would hold up in our damp climate—seems like it’s a gamble.
- For me, the real pain is finding the balance between cheap fixes and not having to redo it every year.
- Anyone tried using those rubberized coatings instead of primer + paint? Wondering if that’s worth the extra cost or just hype...
Rubberized coatings are kind of a mixed bag in my experience. I used one on a shed roof last fall—figured it’d be a good test before trying it on the house. Prep took longer than I expected (cleaning, drying, taping off edges), but application was pretty straightforward. It’s held up through a pretty wet winter so far, no peeling or leaks, but I’m still watching for any bubbling. Price-wise, it was more than primer + paint, but I’m hoping the extra layer means less touch-up next year. If you go that route, just make sure everything’s bone dry before you start... learned that the hard way.
Interesting to hear you had decent luck with the rubberized stuff—I've seen mixed results too, especially on older roofs with a lot of movement. Prep is a pain, yeah, and if there's even a hint of moisture trapped underneath, bubbling seems almost guaranteed after a season or two. One thing I've always wondered: did you look into any of the newer eco-friendly coatings? Some of those claim better flexibility and UV resistance without the VOCs, though the price tags can be pretty wild. I tried a “green” elastomeric on my workshop roof, mostly for the energy savings, and it’s held up surprisingly well through hail and a brutal summer. Makes me wonder if the added up-front cost is worth it in terms of lifespan and less frequent re-coating.
Did you notice any difference in the shed’s temperature or energy use after coating it? For me, the white finish made a bigger difference than I expected—curious if anyone else has seen that kind of payoff, or if it’s just marketing hype.
