draining water heater

[Brian B-P]

Originally Posted by War Eagle

Has anyone ever run a thread tap into the anode hole to deep clean (get rid of rust) and re-thread the female threads on the water heater? And if so, what size tap does the trick?

I haven't done this, and I wouldn't because it is a tapered thread. I would use a small (toothbrush-sized) brass brush, and might try a round wire brush (such as the battery cable terminal cleaning brush already mentioned) if one of mine was the right size.

Given that the hex size is 1-1/16", the thread is likely 3/4" NPT.

[Vermilye]

Originally Posted by LeonW

My anode is always more than 'finger tight'. When I first got the trailer I had to use an 12” wrench to loosen it. So now I always make sure it is snugged up pretty well.

On a related topic, anodes come in aluminum and magnesium varieties. Any notion on which one is better than the other? I have been told it depends upon the minerals in your water, but with an rv the minerals are different each time you fill the tank

The magnesium offers better tank protection, is more expensive, and will be consumed more quickly. If you have sulphur in your water, it may add an unpleasant taste & smell to your hot water. Suburban suggests switching to the aluminum anode if this is a problem.

I've found it is difficult to get a shop to order the magnesium anode. Evidently, Camco (a general parts supplier) only sells the aluminum version.

[thoer]

The reviews say this Suburban magnesium one is the correct one for 6 gallon water heaters like we have. I'd check the manual first and see if it lists correct model numbers.

[War Eagle]

Originally Posted by Brian B-P

... I wouldn't because it is a tapered thread. ...

Aren't taps tapered, as well, to cut a little deeper with each revolution? Every tap I've ever owned/used has been. One would just need to know when to stop. Or forget it and just use a wire brush....

[Brian B-P]

Originally Posted by War Eagle

Aren't taps tapered, as well, to cut a little deeper with each revolution? Every tap I've ever owned/used has been. One would just need to know when to stop. Or forget it and just use a wire brush....

Taps to make straight threads have the first threads at the end chamfered off, so you can start tapping a hole (each turn cuts progressively deeper), and even to completely tap a through-hole. If you are tapping a blind hole, you also need a bottoming tap, to finish the threads at the bottom. In-between is a plug tap (not as long a chamfered section as a taper tap, but much longer than the 1 or 2 turns of chamfer of a plug tap), and that's what is provided in a basic tap-and-die set.

Since the normal tapered and plug taps are not for pipe threads, they are not shaped correctly: the taper is formed by chamfering off the tops of the threads at the end, not by changing the root diameter of the thread. Even if only run part-way into a hole, they will not form a tapered full-depth thread. There are taps for tapered pipe threads, but they are not the same as chamfered taps for straight threads.

If you really want to clean up existing threads with a tap, the best (safest for the threads) method is to use a chaser... but again chasers will be for straight threads.

So I wrote all of that, then found a nice illustrated explanation:
Hand Taps, the difference between a Taper, Plug and Bottoming tap

[gbaglo]

I pick out fragments of tape with my pocket knife, to the best of my ability.
In year nine, I see no reason to do anything more, and risk screwing up my water heater.

[Anne H]

Originally Posted by Vermilye

If you can't find a shallow 1 1/16" socket, stuffing a bunch of quarters in the socket makes it much easier to start the anode bolt back into the tank...

Thanks for that tip! Getting the anode to thread back in is a huge hassle!

[Vermilye]

Originally Posted by Anne H

Thanks for that tip! Getting the anode to thread back in is a huge hassle!

Your welcome! By the way, the reason for quarters rather than washers is I always keep a roll in both the truck & the trailer (tolls & laundromats), plus unless you buy the expensive stainless versions, washers rust!

[War Eagle]

FWIW, it happens that my wife has a really nice little cordless Dremel Micro with an LED work light built into the tool end. I put a little wire brush tool on it, and it did a great job of cleaning anode threads, both in the water heater and on the anode, of rust, corrosion, teflon tape remnants, etc., and leaving them both buffed and looking new. Super easy to re-wrap with thread tape and reinstall the anode.

[StarvingHyena]

Originally Posted by War Eagle

FWIW, it happens that my wife has a really nice little cordless Dremel Micro with an LED work light built into the tool end. I put a little wire brush tool on it, and it did a great job of cleaning anode threads, both in the water heater and on the anode, of rust, corrosion, teflon tape remnants, etc., and leaving them both buffed and looking new. Super easy to re-wrap with thread tape and reinstall the anode.

What happens to the broken off bits of wire from the spinning brush?

Tom

[War Eagle]

Originally Posted by StarvingHyena

What happens to the broken off bits of wire from the spinning brush? Tom

I used a steel wire brush rather than brass (see photos) so I could sweep with a magnet, gave it another good flush from the back side out using a water heater flush wand (https://www.etrailer.com/Accessories...SABEgKuXPD_BwE ), then stuck my finger in the hole to feel around for any remnants of whatever. I'm pretty confident nothing metallic was left that would rise up to the top of the tank to exit the hot water line and then find its way through the various strainers built into the water faucets.

[AllanEdie]

Regarding using a tap to clean threads, if you choose to do this, you must use a pipe thread tap. Never use any kind of regular thread tap, even if it has the same number of threads per inch and diameter. The pipe taps are tapered exactly the way they should be, the other taps are not tapered appropriately, and will bugger up your threads and prevent ever achieving a thread seal later.