if I have to mix, I slap on a dab of pipe dope and cross my fingers. Not exactly textbook, but hey, it’s held up so far...
Yeah, I’ve gone the “hope for the best” route more than once. Did a bathroom reno last year—ended up with a Frankenstein of brass and stainless under the sink. Used Teflon tape and checked for leaks every day for a week. No issues yet, but I still get nervous when I see that green corrosion starting. Stainless is great, but man, those fittings add up fast.
Mixing metals under the sink always makes me a little uneasy too, but sometimes you just gotta work with what you’ve got. I get the appeal of stainless—super durable—but my wallet usually steers me toward brass or even plastic if it’s not under a ton of pressure. Anyone here actually had a mixed-metal setup fail, or is the corrosion mostly just cosmetic? I keep hearing horror stories but haven’t seen a real disaster yet...
I’ve mixed metals under my kitchen sink more times than I’d like to admit, mostly out of laziness or because the hardware store was out of what I needed. Never had a catastrophic leak—just some crusty green stuff on the fittings after a while. Honestly, it’s uglier than it is dangerous in my experience, unless you’re dealing with really old pipes or super hard water.
Mixing metals isn’t the end of the world, but I’ve learned to avoid it when possible, especially in rentals. That “crusty green stuff” you mentioned—
—is usually galvanic corrosion. It’s slow, but over years it can eat through fittings, especially if you’ve got tenants who don’t report leaks right away. Here’s what I do now:just some crusty green stuff on the fittings after a while
1. Stick to one metal type per run if I can.
2. If I have to mix, use dielectric unions between copper and steel.
3. Check for leaks every few months, especially in older units.
It’s not always pretty, but it saves headaches down the line. Hard water definitely speeds things up, too.
Yeah, that green buildup is classic galvanic corrosion—seen it plenty, especially where someone’s swapped a valve or fitting and mixed metals without thinking. Dielectric unions help, but honestly, I’ve seen even those fail if the water’s really aggressive or the install’s sloppy. Hard water’s brutal for this stuff, you’re right. One trick I picked up: if you’re forced to mix, at least keep the runs short and joints accessible. Makes it way easier to catch problems before they turn into a mess.