Anode / Drain Plug Torque Spec?

[Mike Lewis]

Originally Posted by float5

I would prefer the tape because the other stuff can get into the tank. And I would think that the tape is easier to deal with even though it takes a little trouble.

Well, I tried the tape and screwed up. So I'll try the paste. I've used the paste before on other plumbing joints without problems.

That's assuming, of course, that it is the anode that is leaking. I'll make sure of this before I remove the anode again.

[float5]

Originally Posted by Mike Lewis

Well, I tried the tape and screwed up. So I'll try the paste. I've used the paste before on other plumbing joints without problems.

That's assuming, of course, that it is the anode that is leaking. I'll make sure of this before I remove the anode again.

Yes, the tape is a little bit of a bother but paste is going to be messy, messy! . Tell us how it goes.

[Brian B-P]

Although thread seal paste can contaminate the water if it applied improperly, extra bits of PTFE thread seal tape often have the same problem. The end turn of thread should not be covered in tape, to keep bits from being ripped off as the thread tightens and ending up loose in the pipe. Since the PTFE is not toxic this isn't usually a big deal for water, but any particle is a potential problem in hydraulic power and lubrication systems, so this caution is a normal part of pipefitting instructions. Sealant which is sometimes factory-applied to pipe threads on fittings is normally only in the middle turns of the thread, not the whole length; the same is true of thread-locking adhesives.

Also, thread sealants (other than tape) come in two varieties: traditional solvent-based paste or "dope" which is usually brushed on, and anaerobic-curing materials similar to thread-locking adhesive (such as those from Loctite) which are squeezed from a tube. I haven't used either for pipe threads except where a fitting has the anaerobic type pre-applied - I just use PTFE tape.

[rbryan4]

I don't quite understand how the ptfe tape can be messed up. As long as you wrap it in the opposite direction of how the threads will turn, and don't apply too much, it's a cinch.

[Iowa Dave]

I did not notice any comments as to how many wraps of tape were being made. Personally I use four wraps stating about two threads back. I clean the threads of the anode and the water heater with the tip of my pocket knife so no old tape remains. I pull on the tape pretty good so the threads are apparent through the tape. I've never torqued it with the wrench, just snug her up.
Dave

[rbryan4]

Pretty much what I do Dave. Maybe 3 wraps and pulling tight as I wrap. You're not trying to make the threads thicker, just provide a good seal.

[Great Eggstrications]

One nice thing about using the tape is that it's real easy to clean out any extraneous left-over pieces of tape from the female threads before reinstalling the anode. Just stick your wet pinkie in and any pieces of tape tend to stick to it and can be extracted easily. It would be a pain to have to clean hardened paste goop out of the threads every time.

On a related note, I recall seeing something somewhere about not gooping / taping the entire set of threads, the theory being that you want some metal-to-metal contact to provide a conductive path between the anode and the tank. I leave the innermost 1/4 or so of the threads bare for this, although I would have to guess that in the course of tightening the anode there would be sufficient metal-to-metal contact through the goop or tape to serve as a conductor. Any thoughts?

[rbryan4]

Originally Posted by Great Eggstrications

On a related note, I recall seeing something somewhere about not gooping / taping the entire set of threads, the theory being that you want some metal-to-metal contact to provide a conductive path between the anode and the tank. I leave the innermost 1/4 or so of the threads bare for this, although I would have to guess that in the course of tightening the anode there would be sufficient metal-to-metal contact through the goop or tape to serve as a conductor. Any thoughts?

I don't think it would be a problem unless you used a bunch of teflon tape - so much that threading the anode back in would be very difficult. As the anode gets screwed in, the tape is partially cut away on the threads, and conductivity isn't an issue.

Bit of trivia:
Speaking of sacrificial anodes, I didn't know this but they are even used to protect the hulls of ships. Makes sense.

[Great Eggstrications]

And people with small recreational boats use sacrificial anodes to preserve propellers, rudders, and trim tabs.

[cpaharley2008]

I believe that is where they originated from, the ship building industry when they switched from wooden ships. Now it is used everywhere, even in pipelines or anyplace 2 different metals are used.

[Iowa Dave]

There's an anode on one of my outboard motors. We used to change the anodes on the high rate sand filters at the municipal pools each spring. Anodes are pretty common including home water heaters.
Dave

[rbryan4]

Originally Posted by cpaharley2008

I believe that is where they originated from, the ship building industry when they switched from wooden ships. Now it is used everywhere, even in pipelines or anyplace 2 different metals are used.

Or I suppose, anywhere water creates a corrosive effect on a ferrous metal.

[Brian B-P]

The way tapered pipe threads are supposed to work, when they are tight the inside and outside threads jam directly into each other (so there is conductivity between them); the sealant (whether tape, dope, or polymer sealant) is primarily there to fill the imperfections. The tape is also a lubricant, and the sealant is also an adhesive to reduce loosening under vibration, but none of them are supposed to keep metal from hitting metal. When the joint is disassembled, there should always be bare metal area visible on the threads.

There are even tapered pipe threads that fit better and seal without any added sealant (NPTF or dryseal)... but regular NPT threads don't fit well enough for that.