Injection molded parts can last if you pick the right resin and UV stabilizers.
That’s been my experience too. I put in some injection-molded deck balusters a few years back—went with a fiberglass-reinforced polymer, and they’ve held up way better than the old cast iron ones. The metal looked great at first but started rusting around the bolt holes after just one winter. I guess it really does come down to picking the right material for where you live and what you’re building. Sometimes plastic just makes more sense, especially if you don’t want to be out there sanding and repainting every year.
I get the appeal of low-maintenance plastics, especially for outdoor stuff. But I’ve always wondered—how do those injection-molded parts hold up in terms of color fading? I’ve seen some older plastic railings turn a weird yellow or chalky after a few summers. Maybe it’s just the cheaper resins, but I’m a bit skeptical about long-term looks. Anyone actually had theirs out in full sun for, say, 10+ years? Or is it just a matter of time before everything starts looking tired?
Casting Vs Injection Molding—Which Method Works Better?
You’re not wrong to be skeptical. I’ve had injection-molded deck chairs out back for about 12 years now, and honestly, the color’s definitely not what it used to be. They started out a nice deep green, but now they’re more of a faded, almost grayish tone. I think a lot of it comes down to the quality of resin and whether there’s any UV protection mixed in. Cheaper stuff just doesn’t hold up, no matter how you slice it. That said, I’ve seen some higher-end brands that still look pretty sharp after a decade, so it’s not all doom and gloom. But yeah, if you want something that’ll look pristine forever, plastic’s probably not it...
Casting Vs Injection Molding—Which Method Works Better?
That color fade is all too familiar. I’ve got a couple of old molded planters that started out a nice terracotta shade, but now they’re more “mystery beige.” It’s definitely true that not all plastics are created equal, and the UV inhibitors (or lack thereof) make a huge difference. I’ve noticed, too, that some of the higher-end injection-molded stuff holds up better, but even then, you’re fighting a losing battle against the sun if you don’t bring things in during the off-season.
From a sustainability angle, I lean toward casting for certain applications—especially when you’re talking about concrete or recycled materials. Cast concrete benches, for example, might not win any beauty contests after a few years, but they don’t really fade or get brittle the way plastic does. Sure, they’re heavy as heck and not exactly easy to move around, but they’ll outlast most of us.
Injection molding is great for mass production and getting those crisp details, but it’s hard to ignore the environmental footprint if you’re using virgin plastic. Some companies are starting to use more recycled content, which is a step in the right direction. Still, I’d rather see something that can be repaired or at least recycled at end-of-life, instead of just turning into landfill fodder.
Funny enough, I’ve seen some cast aluminum outdoor furniture that’s held up surprisingly well—minimal fading and no rust. Not exactly cheap, though. At the end of the day, I guess it comes down to what you value more: longevity, appearance, or environmental impact. There’s no perfect answer... just trade-offs. And maybe a little bit of wishful thinking that someone will invent a sun-proof plastic someday.
At the end of the day, I guess it comes down to what you value more: longevity, appearance, or environmental impact. There’s no perfect answer... just trade-offs.
Totally get this. I’ve specified cast concrete planters for commercial spaces before, and yeah—they’re not moving anywhere once they’re in place, but they still look decent after years outside. The injection-molded stuff always seems to get that weird chalky finish after a couple summers, no matter what the sales rep promises. If only UV inhibitors actually worked long-term...
