Learning the hard way at Ace Hardware last Tuesday after a loose pipe flooded my basement

The guy at the checkout told me to use Teflon tape AND pipe dope together on that brass fitting, and after watching the water pour in from a gap I thought was sealed, I've never skipped both since - anyone else get burned by bad plumbing advice from a store clerk?

3 comments

3 Comments

jasonallen1mo ago

Are you sure that guy was wrong though? I've done it both ways for years and never had a leak. Teflon tape on the threads by itself is usually fine for straight water lines, but on a brass fitting with a loose gap it sounds like the fitting itself was the problem, not the tape or dope. Pipe dope on top of tape can actually make it harder to get a good seal because it lubricates too much and lets the fitting spin past where it should stop. I've seen guys at Ace give solid advice, but you gotta check the fitting is tight enough first before blaming their method.

the_lisa1mo ago

I think you're a bit off on the pipe dope making things too slippery thing. Actually, dope and tape together work better because the tape fills the thread gaps while the dope acts as a sealant and lubricant at the same time. The real trick is you gotta wrap the tape going the same direction as the threads tighten, three or four layers, then put a thin coat of dope on top. That guy at Ace was right about the method, but if the pipe was loose in the first place no amount of tape or dope is gonna fix a gap that big as others said.

the_jana1mo ago

That Teflon tape trick is brutal when you think you’ve got it right and then hear that drip start. I had a similar flood last spring from a loose valve I didn’t tighten enough and it’s a sick feeling watching the water rise.