I had a similar experience a few years back when I sealed some basement windows with polyurethane. At first, it seemed perfect—flexible, watertight, the whole deal. But after about two winters, I noticed tiny cracks forming, especially in spots exposed to direct sunlight and temperature swings. Switched to a higher-quality brand (can't recall the exact name now), and it's held up way better. So yeah, quality definitely matters, but even then, polyurethane might not be the forever solution depending on your climate...
"polyurethane might not be the forever solution depending on your climate..."
Yeah, that's exactly what I've found too. Polyurethane seems great at first, but have you considered silicone-based sealants instead? I've had better luck with them, especially in areas with big temperature swings. Not saying they're perfect either (nothing ever is, right?), but they seem to handle sunlight and weather changes a bit better. Curious if anyone else has tried silicone and noticed a difference...
Polyurethane seems great at first, but have you considered silicone-based sealants instead? I've had better luck with them, especially in areas with big temperature swings.
I've messed around with silicone too, and yeah, it does seem to hold up better in sunlight. But honestly, nothing I've tried lasts forever... every few years I'm back out there scraping and resealing. Maybe it's just part of the homeowner curse, lol.
Yeah, silicone's definitely been my go-to lately. I remember when I first bought my place, I thought polyurethane was the miracle fix—until winter hit and it cracked like crazy. Silicone holds up better, but you're right, nothing's permanent. Seems like every spring I'm out there again, scraping off old sealant and wondering if there's some secret trick I'm missing... guess it's just part of the deal with older homes.
I've been there—scraping silicone every spring gets old fast. One thing that's helped me is making sure the surface is bone-dry and clean before applying new sealant. Also, using a good-quality caulk smoothing tool instead of just my finger made a noticeable difference in how long it lasts. Still not permanent, but at least buys me an extra season or two before I'm back at it again... Older homes definitely keep us busy, don't they?
"Still not permanent, but at least buys me an extra season or two before I'm back at it again..."
Yeah, silicone can be a bit of a band-aid fix in my experience. I spent years doing the same routine—scraping, cleaning, reapplying—and eventually got fed up enough to try something different. Switched over to using a paintable polyurethane sealant instead, and it's been holding up noticeably better. The key is prepping thoroughly (like you mentioned) but also priming the wood first. A quick coat of primer after sanding and cleaning helps the sealant adhere way better. Then I follow up with exterior-grade paint once it's cured. It's a bit more work upfront, but honestly saves me from repeating the same job every spring.
Older houses are definitely a labor of love...or maybe just stubbornness on my part. Either way, might be worth giving polyurethane a shot if you're tired of silicone letting you down every year.
I went down a similar road myself a few years back, and honestly, I think polyurethane is decent but not quite the magic bullet some folks make it out to be. For me, the biggest issue wasn't adhesion—it was flexibility. Polyurethane sealants are definitely tougher and stick better, especially if you prep right, prime, and paint afterward like you said. But in my experience, older window frames tend to move around a lot with temperature shifts and humidity changes. Polyurethane can handle some of that movement, sure, but eventually cracks still formed again after about three or four seasons.
What finally worked best for me was actually switching to a hybrid sealant—something like those modified polymer (MS polymer) sealants that combine silicone's flexibility with polyurethane's durability. They're paintable too, which helps blend things seamlessly. When I redid my south-facing windows (the worst offenders), I stripped everything down completely and primed carefully before applying the MS polymer sealant. It's been almost five years now without any noticeable cracking or separation, even through harsh winters and hot summers.
Of course, older homes are notoriously unpredictable...what works perfectly on mine might not hold up as well on yours. It seems every house has its quirks and personality. Still, if you're open to experimenting again next time you're faced with this chore, maybe give hybrid sealants a look. They're not exactly cheap, but considering how much time I've saved avoiding annual repairs, I'd say it's worth it in the long run.
Either way, glad you've found something that's at least improving your situation for now. Window maintenance is definitely one of those thankless DIY jobs that makes you question your sanity every spring...
Yeah, hybrid sealants are underrated for sure. I stubbornly stuck with polyurethane way longer than I should've...finally switched to MS polymer last summer, and it's been night-and-day better. Wish I'd listened sooner, would've saved some headaches (and weekends).
MS polymer definitely has its perks, but I wouldn't completely write off polyurethane yet. I've found that proper prep and application make a huge difference—like sanding thoroughly, using a good primer, and applying thin, even layers. Yeah, it's more finicky, but when done right, polyurethane can still hold its own, especially in harsher climates. Maybe it's just me being stubborn, but I've had some solid results sticking with it...though I admit, the ease of hybrids is tempting.
Haha, I hear ya—polyurethane can definitely be the diva of sealants. I've had my fair share of battles with it, sanding till my arms felt like noodles and still ending up with a few questionable spots. But you're right, when you nail the prep, it does hold up surprisingly well. Still, gotta admit, hybrids are pretty tempting for those of us who prefer spending weekends relaxing rather than wrestling window frames...