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Old 08-02-2019, 09:54 PM   #5
Russell Clifton
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City: La Conner Wa.
Vessel Name: Sea Fever
Vessel Model: Defever 49 RPH
Join Date: Sep 2012
Posts: 877
I started a thread about this last March. Here is what the guru had to say:

Originally Posted by Russell Clifton View Post
Since it is much cheaper to buy just the anode and reuse the brass pipe plug, that is what I have been doing the past few years. But when they are removed from the heat exchanger, it is usually difficult to unscrew the anode from the plug. Sometimes I will need to drill the remaining anode and re-tap the threads. I have had to discard many plugs in the past and I am getting low on them.

So I am wondering if using anti seize on the anode threads would be acceptable. Here is some information I found on the internet:

Graphite is an excellent conductor of electricity and high temperature solid lubricant (up to 900 degrees F). It is therefore widely used in formulations of anti-seize. In assemblies with electrical current running through a fastened joint such as the threads of spark plugs, ground screws, and antennae connections, anti-seize can be used with minimal increase to resistance. Corrosion of a threaded joint increases the electrical resistance. The use of anti-seize on these types of connections will ensure current is transmitted reliably by preventing corrosion.

What is the general consensus on doing this?
Graphite-based anti-seize should not be used in marine application, it is extremely noble, i.e. every other metal, when in contact with it and and electrolyte (seawater) will corrode. If you were going to use an anti-seize I'd use a nickel or copper base. However, I'd run a test, before and after coating the threads and screwing the anode into the plug I'd check the continuity, anything over one ohm is too much, make certain the anti-seize is not increasing resistance. The fact is, I don't believe you need anti-seize per se, you could use a dielectric grease like Teflon Superlube, or a conductant paste like Koper Shield.
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