Tips for removing engine zincs?

[RobS]

So the question is will a sealant applied to the threads of the zinc cap prevent the conductivity between the zinc cap and the cooler. I think we'd all agree that vinyl electric tape is an excellent insulator. So having all the components here at my desk I did this:

Ohms with "bare" threads

nothing on threads.jpg

One wrap of electric tape on thread. After a couple turns I removed so you can clearly see the tape was going in between the male and female threads, not being "pushed aside"

confirmed tape within threads.jpg

Same Ohm reading with "taped threads"

electric tape on threads.jpg

So if the interference fit "metal to metal contact" of the tapered threads is not effected by vinyl electric tape I surely wouldn't worry about pipe dope getting in the way of a good connection..

resdue left in voids.jpg

[Pitou]

Good post Rob.

I switched up a couple of years ago from using Rector Seal to a bottle of white liquid PTFE plastic thread sealant. Much thicker and no mess.

[Tree]

Obviously the effective diameter of the thread is contacting there where as the major and minor diameters will have a coating of whatever sealant could be used. Thankfully all my threads are good as the damaged thread was the zinc thread as I wound the nut out - with zinc being a soft material it's no wonder the thread would be torn off. It's possible the zincs were never installed with anything on them and any galvanic corrosion has caused the threads to be tighter than normal but like I say, these are coming out every three months as I've machined a load of zincs up ready to replace. Sometimes being a precision engineer with a factory full of machines has its perks!