Engine anode

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Comodave

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Does anyone use any thread lock to hold the anode onto the cap? I am replacing the anodes on my aftercoolers and heat exchangers and 2 of the anodes unscrewed off the caps and stayed inside the exchanger and aftercooler. I had checked that they were tight before I installed them but they still unscrewed from the caps. Now I had to order new gaskets for the heat exchanger and new O rings for the aftercooler, $45 and $85. The worst thing is that I have to remove the aftercooler in order to get the end cap off to get the anode out. Then reassemble it and pressure test it. The remove and reinstall will take at least 2 hours of hard work. So maybe I need to be using a thread locker on the anodes before I install them.
 
I have always used a thread SEALER on the thread between the cap and the anode. Never a locker.
Once I started doing that I no longer had loose connections.
I do the same between the cap and cooler I am trying to protect.

I then always use my Ohmmeter to check that I have made a good connection.

Done this now for over 25 yrs.
 
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Greetings,

Mr. C. Is it at all possible to gently punch the remains of the anode into the mechanism and install a new anode (properly prepared/fastened)? The loose anode remains would simply dissolve over time, would it not?
 
Greetings,

Mr. C. Is it at all possible to gently punch the remains of the anode into the mechanism and install a new anode (properly prepared/fastened)? The loose anode remains would simply dissolve over time, would it not?

I don’t think that the anodes will dissolve quickly since they are not in good contact with the housing. My concern is that the water turbulence will keep the loose anode hitting the cooler and maybe damaging the cooler. The aftercooler in question is brand new and cost over $4K so I don’t want it damaged. Maybe I am overthinking this but it really irritates me that the anodes are coming loose so easily.
 
I don't use anything - but I'm considering it.

When we took our heat exchanger apart to clean it, we found the remains of three of them in there. So that tells me that your theory about them not disintegrating due to not making good contact is probably correct.

Given we found that many, my guess is that they were unlikely to cause any damage in the exchanger - However, I'd rather not take the chance of them somehow fouling something up.

A couple of drops of Threadlocker blue might fix the problem, and if that doesn't work, the red might do the trick, although getting the old one to come out after might be an issue. But I suppose the careful use of a Dremel would do the trick.
 
Dave... what brand anodes are you using? I have had best results with Performance Metals.,steel rod in center of rod reduces breakage. It can still unscrew though.

I have used a small amount if Loctite w no issue. If the rod stays in place & stuck in the housing I have had success grinding the OD threads off an old cap and screwing it back onto the stuck rod... carefully. Once attached continue to turn cap CW / tighten and it breaks the rod free. Extraction with a pair of pliers / visegrips.
I sometimes either relieve / grind a slight ring on the rod close to the cap where the clearance between rod & engine block is tight to reduce probability of sticking in the block.
I have also used nail polish to paint a ring around that same area and it seems to help.
I wish eng mfg would machine more relief just beyond the cap threads so the Rods don't get stuck. The corrosion products take up more space than the alum / zinc alloy and us what causes them to stick.
The other trick I have thought about but haven't tried is to start removal by tightening the cap into the engine.,if you can get even a small - 1/16 turn it may be enough to break the rod free of the engine without breaking the thread / cap threads free.
Then unscrew the cap and hope the rod comes with it.
I just don't remember to try it as an experiment... until I have just a cap in my hand.
BTW.... I agree with your theory that anode Rods stop sacrificial erosion when no longer connected electrically to the housing.
 
I don't recall ever having an issue with the anode coming loose from the plug but I have rung off more than 1 pencil zinc by overtightning the replacement zinc in the plug itself. If If I have a 50% success rate removing a depleted anode from a plug so I can reuse the plug and just add a pencil, I'm happy. I have a toolbox full of plugs with the zinc still in the threads that I foolishly think I'm going to remove by dropping in acid or drilling and using an easy out ,but realistically, I'll just chunk them in the trash one day, I'm sure.
 
If your anodes are mostly unused when you pull and inspect them, you might try reducing the anode diameter. In several applications, I have switched from a 3/4" anode to a 1/2" anode. I then use a 3/4" to 1/2" bronze bushings to reduce the hole size. When removing the anode, I instead remove the bronze bushing, and then replace the anode.

Obviously doing this will sacrifice the anode faster. So I use the longest anode that will fit the application and replace them on a shorter interval. Additionally, because there's an additional threaded surface, I use an ohm meter to verify the conductivity between the anode plug and the housing, through the bushing.

Have had great success with the above and never a stuck anode.

Ted
 
I don't recall ever having an issue with the anode coming loose from the plug but I have rung off more than 1 pencil zinc by overtightning the replacement zinc in the plug itself. If If I have a 50% success rate removing a depleted anode from a plug so I can reuse the plug and just add a pencil, I'm happy. I have a toolbox full of plugs with the zinc still in the threads that I foolishly think I'm going to remove by dropping in acid or drilling and using an easy out ,but realistically, I'll just chunk them in the trash one day, I'm sure.

You can heat the plugs with a torch. The zinc will melt right out.
 
I am using magnesium not zinc since we are in freshwater. The anodes didn’t break off they just unscrewed. That is why I am considering a thread locker but I wasn’t sure if it would still conduct properly. Sounds like it will. One of the anodes is in the bottom of the aftercooler and it is just barely reachable so I can’t even work on it in that location. The second one that cam loose was in the second worse location, i have to reach it and work by feel because it isn’t visable. Of course the 2 that came loose are in the 2 worst locations…
 
I had luck using a wet/ dry shop-vac with a small attachment and sucked out sludge and broken anodes. Maybe worth a try?
 
There isn’t enough room to get a shop vac hose in by the anode. It is in a horrible location.
 
Anode removal

I had the same problem. Anode is left sitting in the cooler. Easy solution. Get an old anode holder and grind or file the exterior threads off. It’s then easy to thread this modified holder onto the anode and pull it out. ?
 
You pretty much can't insulate the anode from the cap with thread locker, sealant, or teflon tape. It is an easy experiment to prove.

Someone should make anodes with left hand threads. The problem occurs only if the anode sticks a bit in the hole, then you are unscrewing the RH thread cap and the RH thread anode simultaneously. I am using Performance aluminum anodes, they are very close to the size of the hole they go in, if they swell at all they stick, do not turn, and unscrew as you describe. Adding to the problem is they are a rough die casting and often not concentric with the threads. I solved this by chucking them all in a lathe fixture and truing them up, also taking the diameter down a little bit.

Another solution would be a small slide hammer, just a tube with internal threads the size of the anode, a sliding weight and a stop. It usually doesn't take much at all to get them out, but they are very difficult to get a handle on.
 
I seem to have a lot of anode and service regularly so gunk on anodes that have not depleted much that interferes with thread is common. I am always nervous about using any sealant or thread lock on anode to plug or plug to cooler to ensure I have a good electrical contact. Pulling anodes out that look like new is my worst nightmare.

So I often end up with just the plug in my hand and anode thread looking at me out of hole. I solved it by grinding a plug until all the thread was gone and it was a loose fit in the housing thread. I then screw that onto the anode and using vice grips or multis turn in direction to tighten and screw the anode out with gunk trimmed to threaded hole size. Haven't had a failure over a lot of years.

Just a a zero cost bush fix.
 
I seem to have a lot of anode and service regularly so gunk on anodes that have not depleted much that interferes with thread is common. I am always nervous about using any sealant or thread lock on anode to plug or plug to cooler to ensure I have a good electrical contact. Pulling anodes out that look like new is my worst nightmare.

So I often end up with just the plug in my hand and anode thread looking at me out of hole. I solved it by grinding a plug until all the thread was gone and it was a loose fit in the housing thread. I then screw that onto the anode and using vice grips or multis turn in direction to tighten and screw the anode out with gunk trimmed to threaded hole size. Haven't had a failure over a lot of years.

Just a a zero cost bush fix.

I like this idea. I will try it and see if I can get the anode screwed into the ground down plug.
 
Can I just say I believe you are over analyzing this... The anode will sink it should not interfere with the aftercooler - put in a new one and let it go. This works for me.


I dont mean to question your concern - I know lots of people that worry about all kinds of stuff that does not seem to bother me.
 
Well since I just spent over $4K on this aftercooler I don’t want to take any chances with it. And besides I like to have things just right on my boat.
 
I was surprised on my first heat exchanger anode change by not finding one in the plug! PO was good with maintenance and had spares onboard. Screwed the plug back in, got a spare anode, and when I took the plug out again, there was a half-eaten anode on it. It was like a magic trick. The threads on the anode were partially shot and I don't know how it rethreaded and held during the second pull.

I solved the thread erosion problem with a little silicon o-ring. The threads still get full contact with no thread lock and the compression on the o-ring keeps it sealed and secure. I've used the same o-ring over several times, which is crazy because I bought a pack of 100 for $6 that I keep with the spare anodes.
 
I had the same problem. Anode is left sitting in the cooler. Easy solution. Get an old anode holder and grind or file the exterior threads off. It’s then easy to thread this modified holder onto the anode and pull it out. ?

Ok, well I owe you a dinner. It worked like magic and saved me at least 3 hours of hard work pulling the aftercooler. If you are ever near mid Michigan let me know and dinner will be on me. Thanks.
 
I am going to grind the threads on an old cap as that sounds good, but what I have been doing lately is putting thread locker on the face of the cap, not the threads. The threads give good electrical contact and the zinc comes out. I also keep a log and as long as the zincs are well deteriorated and shrunken they will come out easily. The trouble comes when the zinc is swollen.
 
Use a very small amount of blue Loctite on the anode and it will remain with the cap. Contrary to common belief, using a thread sealant or tape on the cap will not degrade the connection between the cap and the Hx. Steve D’Antonio has written several articles supporting this. If you don’t believe it just use you ohmmeter.
 

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