I totally hear you on the hidden hardware being the weak link. I’ve tried to save a few bucks with 304 or even galvanized in spots that “shouldn’t matter,” but sure enough, that’s where the trouble started—especially with door hinges and gate latches. What’s worked for me lately is a mix: 316 for anything I touch often, and then those plastic-coated screws for spots I know I’ll never want to mess with again. It’s not perfect, but it’s kept me from having to rip out rusted screws from my deck boards (which is a nightmare). If you’re careful about picking your battles, you can keep it affordable without sacrificing too much on longevity.
That mix-and-match approach definitely makes sense, especially with how salty air finds every little weakness. I’ve seen a lot of folks get tripped up by fasteners under trim or deck boards—out of sight, out of mind, until you try to replace something years later. One thing I’ve started doing is hitting exposed heads with a dab of marine-grade sealant, just as an extra barrier. Not sure it’s a cure-all, but it seems to slow things down. Curious if anyone’s tried those ceramic-coated screws? I hear mixed things about them holding up long-term, especially right on the coast.
I get where you're coming from with the sealant—I've done that on a few spots just to buy some time, especially on exposed deck screws. But honestly, after a couple years, I started noticing that even marine-grade sealant can peel or crack, especially where the sun hits it hard. Once that happens, moisture just sneaks in underneath and you’re back to square one. It’s not a bad short-term fix, but I’m not convinced it holds up for the long haul.
On the ceramic-coated screws, I tried those when I replaced a gate last summer. They went in easy enough and looked decent at first, but after our first round of winter storms, I saw some rust starting to peek through around the heads. Granted, we’re only about three blocks from the water, so conditions are pretty brutal here. Maybe further inland they’d hold up better? For me, stainless steel still seems like the more reliable option, even though it costs more up front. The ones I put in five years ago under my porch are still solid—no rust at all.
One thing I wish I’d done differently is pay more attention to what was going under trim and fascia boards. Like you said, out of sight means you forget about them until it’s too late. When I had to replace some siding last year, every single hidden screw was practically fused in place from corrosion. Ended up snapping half of them off trying to get them out... If I ever do another project near salt air, I'm leaning toward overkill: stainless fasteners everywhere and maybe even a dab of anti-seize on threads for good measure.
Not sure there’s any perfect solution if you’re right on the coast, but for me stainless has been worth the extra cost compared to coatings or sealants. The hassle of replacing rusted-out hardware isn’t something I want to deal with again anytime soon.
If I ever do another project near salt air, I'm leaning toward overkill: stainless fasteners everywhere and maybe even a dab of anti-seize on threads for good measure.
I’ve had similar results—stainless is the only thing that’s lasted more than a few years right on the coast. The anti-seize is a good call, especially for anything you might want to remove later. Have you ever tried using plastic or composite trim boards instead of wood in those spots? I’ve found they help cut down on trapped moisture, but I’m not sure if that’s just luck or if it really makes a difference long term.
Stainless fasteners are definitely worth the extra upfront cost near the ocean—anything else just turns into a rusty mess in no time. I’ve tried galvanized and even coated screws, but they still end up corroding after a few seasons. The anti-seize is a smart move, especially if you ever need to swap out hardware down the line. I learned that the hard way with some deck rail brackets that basically fused together.
On the composite trim boards, I’m a fan, but with a caveat. They do seem to handle moisture better than wood, and I’ve noticed less swelling and rot around fasteners. That said, some of the cheaper brands can get brittle or fade faster than I’d like. If you go that route, it’s worth spending a bit more for the higher-end stuff. Also, I still run a bead of caulk where trim meets siding—salt air finds its way into every crack.
Honestly, it’s a constant battle. I’ve started thinking of it as “managing” rust rather than eliminating it. If there’s a trick to making things last more than a decade out here, I haven’t found it yet...