Plumbing Question Anyone ?

[ssmith1627]

Still working on this rental house for my inlaws.......started out that I was going to replace a rotten bathroom floor. I'm not sure how it turned into this but I've built 4 new drawers for the kitchen, replaced an 8 foot section of kitchen countertop, worked on two garage doors, had the main service panel replaced (it was a FUSE box, sheesh), and now it looks like I'm going to be painting the whole exterior! lol

I'm putting the sink and drain pipes back in place in the kitchen. They really had a rigged up mess in there -- which is why there was a leak there too. You really shouldn't HAVE to have a bucket under the trap ! lol

I have a 4 inch long glavanized pipe sticking out of the wall as the drain. I'm running plastic pipe down from the two sink strainers, through a trap and then I have to connect to this metal pipe. Is that an issue at all ? The section of tube that connects drain to trap has a "nut" that will screw onto the end of that galvanized pipe. Do I use teflon tape in that situation, a plastic nut on a metal pipe ?

Most of this is straight forward but the waters got a little muddy when it came to those two different types of material. Thanks for any feedback you can offer.

Steve

[Ken Massingale]

Steve,
Firstly, I ain't a plumber, if there's anything I hate more than painting, it's plumbing.
I have the same connection in the kitchen. The plastic drain pipe connector from the sink trap had a 'nylon?' washer in it. I did choose to use teflon tape on the metal pipe, tho it may not have been necessary.
It's 3 years since I made the connection and it's still dry.
Good luck
ken

[ssmith1627]

Thank you for the message !

I don't even have the water back on in the house yet -- because I'm also replacing the shutoff valves for the washer connections -- a whole separate issue ! So I can't REALLY test it but I have poured some water down the drain.

First I had a good bit of a leak there and I tigthened it down more, yes with that nylon washer (gasket?) in place. After that it seemed fine but I did finally get a drip after a few minutes so still not perfect and so not acceptable. I'm gonna try to go back tonight and really scrub those threads clean with a wire brush and then use the teflon tape and see if that gets me where I need to be.

If I had a year to work on this house, I could really get a lot of things fixed ! haha

Steve

[Tequila]

Also not a plumber, but I ALWAYS use teflon tape, because it's fast, cheap, and I hate doing things twice.

[ssmith1627]

Joe, you use it even with "plastic" joints ? I guess that's really my confusion.

I haven't done much plumbing but I have always used it as well where metal joins with metal -- for the most part for me this has been on the "supply" side of things.

Thanks again for the feedback.

Steve

[Tequila]

Joe, you use it even with "plastic" joints ? I guess that's really my confusion.

I haven't done much plumbing but I have always used it as well where metal joins with metal -- for the most part for me this has been on the "supply" side of things.

Thanks again for the feedback.

Steve

I guess I don't use it on plastic to plastic joints, but when either component is metal I do. I probably don't need to in every situation, but as I said, it's cheap and quick.

[ssmith1627]

Thanks again guys. That's exactly what I was looking for -- just a couple people to bounce that stuff off of.

I'll be very happy if I get this reassembled and working properly. My very first attempt at a small plumbing project was humiliating. I spent DAYS trying to put a sink drain back together in a bathroom a few years ago. Clearly didn't know anything and I could not make it work so that it didn't leak. I called a guy out to look at it and he put it together in about 3 minutes with the parts I already had laying there and it worked fine, done. Charged me $20. I was disgusted ! haha But all you can do is learn and go on.

The net sure helps and this board is great.

Steve

[Tom Miller]

I only use teflon tape in situations where the threads themselves are forming the seal. In many plumbing joints, the seal is being formed between two mating surfaces, in which case the threads are only being used to pull these mating surfaces together. There's a small chance that teflon tape could get in the way in these joints, either from accidentally getting between the mating surfaces, or by keeping the threads from snugging up all the way.

Regards,
Tom

[DaveStL]

I only use teflon tape in situations where the threads themselves are forming the seal. In many plumbing joints, the seal is being formed between two mating surfaces, in which case the threads are only being used to pull these mating surfaces together. There's a small chance that teflon tape could get in the way in these joints, either from accidentally getting between the mating surfaces, or by keeping the threads from snugging up all the way.

Regards,
Tom

What he said. Pipe thread is tapered, and it does make the seal-- use dope or tape for that. If you have a flare, or a drain w/ external compression arrangement, the threads pull the mating surfaces together, so you don't want to make the threads falsely tight with tape or have a chance of getting a piece of tape between the surfaces.

BTW, yellow (gas) tape is thicker and doesn't shred like the white stuff. One turn with a little overlap does it. Also, whenever you use tape, make sure you put it on so that it tightens as you screw the joint together. I use it infrequently enough that I have to think it through each time. Dope is messier but requires less thought.

As to the original question in this thread, to transition plastic drain pipe to a cast-iron soil pipe coming out of the wall, I've used "no-hub" connectors that are flexible rubber sleeves with clamps at both ends. I would think you could use that on the galvanized, too. Galvanized tends to be a little rougher than the plastic or chromed drain pipe, and the no-hub should give a better seal. Slide it on the galvanized far enough to get a good clamp but not excessively, as there will be a little more corrosion going on in the area where water lays, and eventually (after years and years) you might have to trim the galvanized back a little and put on another clamp. Code may require use of a no-hub connector that has a metal sleeve on the outside. For a kitchen where you store stuff under the sink, I'd use that anyway.

Dave

[scorrpio]

Some thoughts:
1. Plastic to metal is fine. It is when you join dissimilar metals, you have to be careful. i.e. copper to steel is a no-no. Gotta use a piece of brass between the two.
2. What is the condition of the steel pipe? If the edges are rusted/ uneven, getting a good seal with a nylon gasket is near impossible. Putting tape/whatever under the slip nut will not work.
3. Far as thread sealing, I use a pro tip I read someplace. A couple turns of yellow tape, and then dope on top of it, and the joint is guaranteed leak-proof. That tip is for gas piping, but I never got a drip with water pipes either.

What are your options if the pipe has uneven edges - cleaning the thread will not help. Rather than using a compression joint, I'd screw some sort of fitting onto it, and connect the rest of the trap to that fitting.

[ssmith1627]

Thanks for the information guys. I really do appreciate it.

I got it all put back together on Saturday. We'll see what the result is over time. I will be watching it very closely because I don't have much experience with all this. We're working on the house almost every day so I'll be there to see if any leaks develop. I'm also just 4-5 doors away in case a problem comes up once we have renters back in there.

I had to replace a sink drain in a bathroom, remove and re-install a toilet after rebuilding the flooring in there, install this new sink and supply lines / drain lines in the kitchen and replace a shutoff valve for the washer connections. So now I'm constantly checking each one to make sure everything is in good order. Clearly from reading these messages I still have a lot to learn. I did find a really helpful older guy at Lowes that I've talked to repeatedly in the past week.

My other fear is the work that I'm doing creating another problem somewhere else -- so I'm going to spend a fair amount of time in the crawlspace as well looking for possible problems or leaks that I can see otherwise.

Thanks again.

Steve