Mixing copper and galvanized is one of those things you only mess up once—my uncle’s old solar loop basically turned into a science experiment after a year. The corrosion was wild. I always stick with copper for anything exposed to the collector, just to be safe. For inside runs, I’ve seen PEX used, but I’m a little wary. Some brands say they’re rated for high temps, but I’ve heard stories about it getting brittle or even warping if the system overheats. Maybe it’s fine if you’ve got good temp controls and pressure relief, but I’d rather not risk it.
As for those clamp-on mounts, our inspector wouldn’t even look at them—said wind uplift was too much of a gamble. Ended up using lag bolts and just being extra careful with the flashing. Haven’t found a kit that lines up with rafters perfectly either... always seems like there’s some drilling or bracket-bending involved.
Honestly, every install I’ve seen has been at least a little Frankenstein’d together. Guess that’s half the fun (or headache) of DIY solar hot water.
I get the hesitation with PEX, but honestly, I’ve had decent luck with it on my last setup.
That’s true, but if you use the oxygen-barrier type and keep a mixing valve in play, it holds up better than folks expect. My budget didn’t stretch to all-copper inside, so PEX was kind of a no-brainer. Haven’t seen any warping yet—though I do check for leaks every few months just in case.“Some brands say they’re rated for high temps, but I’ve heard stories about it getting brittle or even warping if the system overheats.”
As for mounting, yeah... lining up with rafters is always a puzzle. I ended up making my own brackets out of some scrap angle iron and just painted them to match. Not pretty, but it’s solid and saved me a chunk of change.
“My budget didn’t stretch to all-copper inside, so PEX was kind of a no-brainer. Haven’t seen any warping yet—though I do check for leaks every few months just in case.”
That’s a smart move, honestly. Copper is great, but the price these days is just wild. I’ve run PEX in two different solar setups now—one with the oxygen barrier and one without—and as long as you keep an eye on temps and use a decent mixing valve, it’s held up fine. The leak checks are key, though. I’ve seen folks skip that step and regret it later.
Making your own brackets out of angle iron is exactly the kind of practical solution these projects need. Not everything has to look perfect behind the scenes if it does the job and saves you cash. I’ve done similar with some leftover unistrut—paint covers a multitude of sins.
Mounting always ends up being more fiddly than expected, but sounds like you found a solid workaround. If it’s sturdy and safe, that’s what matters most.
Can’t argue with the PEX route these days—copper’s basically liquid gold now. I’ve seen PEX hold up just fine in solar hot water, as long as you’re not running it right up to the collector where things get toasty. Mixing valves are your best friend here, unless you like surprise sauna showers. And yeah, angle iron and unistrut… I swear half my garage is just “future mounting hardware.” If it works and doesn’t rattle, you nailed it.
I get the appeal of PEX—price and ease are hard to beat—but I’ve seen it get brittle over time if it’s anywhere near sustained high temps. Even with mixing valves, you’re still rolling the dice if your collector ever spikes. Personally, I’d still run copper for that last stretch, even if it stings the wallet. Sometimes peace of mind is worth a few extra bucks and a little sweat.