Pencil Anode Does Not Screw in All the Way

[Squanderbucks]

As several people said every time a NPT fitting is changed out each one will fit slightly differently. If something has been taken in an out a few times you will notice the timing of the hexes are different for the same fitting.

It’s an old wives tale that keeps being passed on in the marine industry. Sealants do not cause a problem with conductivity. Prove it yourself easily. Put Teflon tape or thread sealant on a fitting and screw it in. Then take your multimeter and check continuity between the base of the part and the block or whatever.

Every master mechanic I have worked with uses something. I like Rector Seal yellow or Black. The are recommended by the professionals at the number one Cummins experts in marine applications and they have a set of articles on this matter and maybe a video - they have so many.

How many times have you seen “sealed” tight fittings get a green ring on them over time. You may not see the leak but it IS weeping and the salt buildup is the proof.

Use sealer. Like so many things we are told they are passed down from engineers that never work on something they just design it and Theoretically they are correct. If all are stuff was made to NASA specifications. All we get is Chinese tolerances.
There is enough metal cut thru your sealer to allow continuity.

[chris95040]

Originally Posted by Squanderbucks

Like so many things we are told they are passed down from engineers that never work on something they just design it

You had me til here bud. You have no idea what engineers do nor how they do it.

[Tumblewoods]

I had a similar problem but discovered that the old anode has broken off and was preventing the new one going in far enough.
Perhaps check again by poking something up to clean the area ?

[Mike Banks]

those brass bungs are on a tapered thread mostly. Check using a micrometer the diameter at the hex drive end as compared to the one at the tip.

[FPNC]

What is shown in your photo is completely normal as it is a taper BSP thread. Apply only a little bit of silicone to the threads if required to stop any leaking. Do not use teflon tape. Beta anode bronze caps use BSP thread not NPT. Use only a BSP threaded bronze anode cap.

[RaymondR]

Unlike NPT, BSP threads are not designed to seal at the thread roots and will leak without thread sealant. Pre teflon tape and paste plumbers used to wind a hemp thread into the thread roots to get BSP pipe threads to seal.

[upstateny]

After talking to Beta Marine I decided to try this high heat thread sealant I found in an Auto Parts store.

After applying this permatex high heat thread sealant and being just a tad more aggressive on the tightening no more drip leaks. Also the ohm meter register ZERO ohms. Its all good.

A number of you said you had a Beta Marine and have to reduce the length of the zinc. I found that the length was not the issue. There is more than enough room for the zinc pencil that I purchased from Beta Marine. I think what may be happening to folks that do not remove the end cap from the heat exchanger is the old brittle zinc anode breaks off and does not leave enough space for the new anode. In my cases I had to remove the heat exchanger cap to scrape out the old zinc anode.

Note removing the end cap of the heat exchanger did not leak any engine antifreeze coolant. Only 1/8 of cup of raw sea water leaked out.