- I’ve noticed the same thing—those “lifetime” sealants sound great, but I’ve had them yellow or even crack in spots where there’s a lot of sun.
- For exterior windows, I usually stick to a high-quality silicone, even if it means redoing it every few years. It just seems less prone to discoloring.
- Curious if anyone’s found a hybrid that actually stays clear over time? Or is sticking with tried-and-true silicone still the way to go?
- Totally agree with this:
“those ‘lifetime’ sealants sound great, but I’ve had them yellow or even crack in spots where there’s a lot of sun.”
- In my experience, even the hybrids (like those polyurethane-silicone blends) make big promises but still tend to haze or peel after a couple summers, especially on south-facing windows.
- High-quality silicone does hold up best against UV, but it’s a pain to remove when you need to reapply. Still, I’d rather deal with that than ugly yellow lines all over my trim.
- Polyurethane is tougher but almost always yellows, and it’s not as flexible once cured.
- Haven’t found any “clear forever” product yet… seems like a tradeoff between appearance and durability. If anyone’s had luck with a hybrid that actually stays clear, I’d be interested too, but for now I’m sticking with silicone and just planning to redo it every 4-5 years.
Yeah, I hear you on the “lifetime” claims—my last go-round with a so-called forever sealant ended up with the stuff looking like old banana peels after two summers. South-facing windows are just relentless; feels like you could fry an egg on the trim some days.
I’ve tried those hybrids too, thinking I’d finally found the magic bullet, but nope. They went cloudy and started peeling up in spots where the rain hits hardest. Honestly, I’d almost rather deal with scraping off stubborn silicone every few years than have my window frames looking like they belong in a smoker’s lounge.
It’s a pain, but I guess redoing it every 4-5 years is just part of keeping the place from turning into a water park. At least silicone keeps things watertight and doesn’t yellow as fast. If anyone ever invents a totally clear, UV-proof, easy-to-remove caulk, I’ll be first in line... but until then, looks like we’re all in the same boat.
Yeah, those “lifetime” labels are pretty misleading in real-world conditions. I’ve yet to see any sealant truly stand up to full southern sun and constant weather swings. Silicone is still my go-to, even though it’s a pain to remove—at least it doesn’t chalk up or get brittle as fast. I’ve tried the so-called “UV-stable” acrylics, but honestly, they just don’t hold up. Maybe in a milder climate, but not here. At this point, I’d rather plan for a re-do every few years than chase a miracle product that doesn’t exist.
That’s a fair take. I’ve also found the “lifetime” claims don’t really match up with the reality of southern exposure—UV just eats away at most things over time. Silicone’s durability is hard to beat, even if it’s a hassle to scrape off later. I do think prepping the surface and making sure there’s no leftover old caulk can buy you a bit more time between re-dos, but yeah, nothing’s truly permanent. At least with silicone, you’re getting a few solid years before it starts to degrade.
Yeah, those “lifetime” labels are mostly wishful thinking, especially if your windows face south. I’ve seen even the pricier silicones start to chalk and peel after a few years in full sun. Prepping is huge—if there’s any old caulk or dust left, it just won’t bond right. I’ve had decent luck with high-grade polyurethane sealants too. They’re a pain to tool and can yellow, but sometimes they outlast silicone in rough spots. Still, nothing’s truly set-and-forget... just part of the homeownership game, I guess.
I get where you’re coming from, but I’m not totally sold on polyurethane over silicone, at least for windows. I did a ton of research before tackling mine last fall (1950s ranch, faces dead south), and the consensus seemed to lean toward high-grade silicone specifically for UV resistance. The stuff I used—GE Supreme, I think—still looks brand new after one brutal summer. Prepping is definitely key, but if you really dig out the old caulk and go slow, silicone can hold up. Polyurethane’s just too messy for my taste, and that yellowing drives me nuts...
Polyurethane’s just too messy for my taste, and that yellowing drives me nuts...
I had the same concern about yellowing. Tried polyurethane on a basement window as a test, and it looked rough after one year—definitely not worth the cleanup either. Silicone seems like the smarter choice for sun exposure, especially if you’re dealing with old wood frames. Your point about prep is spot on. If you really take time to scrape out the old stuff, silicone holds up well. I’m sticking with it for now.
Silicone seems like the smarter choice for sun exposure, especially if you’re dealing with old wood frames. Your point about prep is spot on. If you really take time to scrape out the old stuff, silicone holds up well.
I get where you're coming from with silicone—it’s definitely cleaner than polyurethane and doesn’t have that weird yellow tint after a year or two. I used it around the kitchen window, south-facing, lots of sunlight. Prep made all the difference. First time I rushed it, didn’t bother getting every bit of the crumbly old caulk out, and had leaks back by spring.
Second go-round, I spent a Saturday scraping everything down to bare wood, vacuumed out the dust, even wiped it with rubbing alcohol (probably overkill). The silicone stuck way better after that. No leaks so far, even after a couple hard rainstorms.
One thing—some brands of silicone attract dirt and end up looking grimy after a while. Not a dealbreaker but worth mentioning if aesthetics matter to you. Polyurethane might last longer in spots that don’t get much sun, but for me, I’ll stick with silicone as long as I can keep up with the prep work.
You nailed it with the prep—scraping, vacuuming, even the alcohol wipe-down. That’s really what makes or breaks a seal job. I see a lot of folks slap on new caulk right over the old crusty stuff and then wonder why they’re back out there with a tube six months later. Been there, done that... learned the hard way.
Silicone’s my go-to for sun-exposed frames too, especially on older wood that likes to flex and move around with the weather. It’s flexible, holds up in UV, and like you said, doesn’t get that weird yellow vibe like poly does. Only real downside is, if you ever want to paint over it—good luck. Paint hates pure silicone. For painted trim, I’ll sometimes use a paintable hybrid (like those “siliconized acrylics”), but they don’t last quite as long in direct sun.
About the dirt thing: yeah, some silicones are like magnets for dust and pollen. The clear ones seem to show it more than the white or almond colors. If you’re picky about looks, maybe stick to colored silicone or at least be ready for an occasional scrub.
One little trick I picked up: after laying down the bead, I dip my finger in soapy water before smoothing it out. Keeps it from sticking everywhere and gives you a nice clean line without pulling at your hair (or cursing at your window). Just don’t over-tool it—too much fussing can break the seal with the frame.
Haven’t had much luck with polyurethane outside unless I’m dealing with masonry or places that never see sun. It turns into this brittle mess where I live (hot summers/cold winters). Maybe it’s better in milder climates? But for old windows and shifting wood, silicone wins for me... as long as you’re not trying to paint over it later.
Curious if anyone’s tried those newer “hybrid” sealants for this kind of thing? I keep seeing them at the hardware store but haven’t been brave enough to swap out my trusty tube of silicone yet...