broken anode problem

[ted4200]

I have a Bukh DV36 3 cyl raw water cooled engine, at my last anode change I was supplied with a new anode which turned out to be too long. The anode subsequently broke up when I screwed it in, the pieces have now partially plugged the cooling section of the exhaust manifold. Through the anode plug hole I could feel the broken bits and was able to remove some of them but i fear that the majority remain. I have tried freshwater flushing (in both directions) to no avail. Vinegar soaks ( 3 over 3 nights) did not help.
I had read that RYDLYME will dissolve zinc anodes. Has anyone tried this? or any other suggestions Apart from removing the exhaust manifold I can see no other way forward.

[RaymondR]

Just about any acid will react with and dissolve zinc it's very chemically active however finding one which will not harm other stuff in the engine is the key to the problem. I'd probably go with a weak hydrochloric, the dilute one they sell for cleaning, after removing any temperature sensors, anodes etc and plugging the holes. In making this suggestion I am assuming that because your engine is raw water cooled there are no alloys and only cast iron exposed in the cooling circuit.

[Panacea2183]

Barnacle Buster will do it but it takes some time.
Muriatic acid does a good job, make sure it is all copper/nickel NO iron
I use muriatic acid to clean out the old zinks from the plugs so I can reuse,it's cheaper to buy the pencils and reuse the plugs

[a64pilot]

Have you tried running it with the pieces in? If there is no cooling issue, they will of course go away all on their own.
But muratic acid, pool acid or concrete cleaner will make very short work of zinc, but I'd try running to see if you have a problem, sometimes the cure is worse than the disease.

[exMaggieDrum]

You didn't say what you used to remove as much as you can. The pieces can get lodged in places that are hard to get to, or even see. I have used the little mirrors to look for them and used dental picks to get some stuff out that my little forceps could not. You can get bent forceps (surgical types but you can get surplus or from tool supplies) to get to them too.

I would agree that if it isn't causing a cooling problem after you got most of it out you might try just running it normally and let it dissolve that way. I can't speak to the acids and such. Good luck. It is a common problem, not only from what you did, but more often waiting too long to replace the zincs and having them break off when they get thin.

[ted4200]

Thank you all for your suggestions, in the end we took off the exhaust manifold and also flushed with muiriatic acid. Problem solved