Dissolved HX Zinc

[Kevin Henderson]

Lots of stuff happening over the past few days.
I have been meaning to inspect my HX Zinc and finally got a chance to take a look at it today.  After finding the correct 11/16 socket to back the zinc out I removed the plug and to my astonishment found that the zinc had been completely dissolved. 
Now... the question is what do I do from here.  I am not certain when the last time the zinc had been replaced and when I checked up into the HX it looked as though the dissolved zinc remnants were inside the HX.  Can I "dig" out the remains of the old zinc?  What about whats left inside the plug?  Is my HX shot?  do I need to remove and clean??  Lots of pondering but in the meantime I'm getting a couple new zincs to be ready.
TYIA for all the help and wisdom 

[Ken Juul]

Search for Heat exchanger, there are a bunch of posts with pictures.  Saves retyping.  The only way to be sure of it's condition is to remove and inspect it.....but it is probably ok because the pieces inside will give some protection.  If you don't want to remove it, just remove the end cap, clean it out, and replace the end cap using a new gasket and o ring.  Be careful, not all replacement zincs will fit.  I always have a spare zinc cut to the correct length, before I change the zinc I buy a new one, use the spare (a template would work also) to cut it to the correct length.  Ron's pencil method also works just as well.

[Stu Jackson]

Kevin, Ken's right.  But my experience, most likely included in one or more of your search for heat exchangers, indicates that it's easier to take the HX out to get rid of those messy pieces.  You'll also learn more about it and be able to check if the inlet port is beginning to start to build up with dropped out salt.  Don't forget to either capture or replace the antifreeze when you do so.  First time I took mine off I shook it and it sounded like a mariachi band.  You can also check to see if there's any rubbing from the mounting bracket unless yours is a welded on bracket.  If yours is hung on the back of the engine with hose clamps (BIG ones) then check for chafing and insulate with a bicycle inner tube.

[Ron Hill]

Kevin : From the number of recent posts, I'll guess that you are a new owner of your C34.

The best advice I can give you (considering the age of the boat) is to remove the HX and really have a look inside.  Then you can find out the size (1/4"/3/8" diameter?) of the Zn you need, condition of the inside (may need cleaning out) and determine the length of the Zn you need to cut off - if necessary.  You can look at the web site info and also get some new gaskets from Sem-Dure.

You"ll be able to clean up your HX and give it a new coat of paint (metallic bronze). 

Another tip is if there are any hoses on that engine that are the color of the engine
-- change them!! 

[Kevin Henderson]

Thanks for all the advice everyone.
I may try my hand at removing the HX to perform the inspection and cleanout.  I have ordered correct size zincs from Catalina Direct and should have them soon. (I ordered 2 zincs so that I can use one to shop for a generic replacement to save $$ in the future).
However, If I remove the end cap to clean and inspect, do I need a new gasket and O ring?  where can I get those and is it absolutely necessary.  I would like to find a local resource for such an item.  Would a good Chandlery have them or can I cut a gasket out myself?

Once again.. any ideas please.

[Stu Jackson]

You could make your own gasket, but try SENDURE.  Do a search, the #s been posted many times.  http://c34.org/bbs/index.php/topic,3744.0.html see reply #1

[Mike and Joanne Stimmler]

Kevin,
In San Diego, a good source for boat engine parts is "Marine Exchange" on Shelter Island Drive right next to the Red Sail Restaurant.
There is also an authorized Univerasl parts dealer on Rosecrans right next to the big West Marine callad A to Z Marine.

Hope that helps,
Mike

[Ron Hill]

Kevin : You can make your own gaskets, but WHY when you can call Glen Mar Marine (800) 282-0123 and buy a kit for a few $$  !?!
By all means, YES change the gaskets and inspect your old end caps for cracks!! If cracked change them out.

[Indian Falls]

Good Idea to pull the HX for close inspection and removal of the chunks of old anode.

About the pieces doing their job floating around inside... the anode must have an electrical connection to the metal you are trying to protect.  Otherwise they will not corrode or protect anything.  I would get the pieces out to keep them from lodging in the tubular parts of the HX. 

[Kevin Henderson]

An update to my HX Zinc:
Please bear in mind that I am a newbie and that while I'm pretty handy I have never previously considered myself much of a  "wrench monkey".  That being said I am finding I am really enjoying "mucking around" the systems on my boat and gradually building my confidence and skills.... All with the help of the sage advice found here in the forum.
1.  I have discovered A to Z Marine here in San Diego and they carry HX gaskets, zinc's and o rings. And for a reasonable price.
(as a side note I picked up a couple of replacement impellers as well for the water pump.... next task)
2.  I had two plans for replacing the dissolved zinc.  My first plan was to remove the HX and clean out thouroughly as recommended with the Limeaway and completely clean, paint and replace.  I wanted to make absolutely certain I had the correct size zincs and gaskets before committing myself to removal.  After verifying, I proceeded to remove the raw water hoses and had little trouble in doing so.  However, when I got to the coolant intake hose I found it to be impossible (for me) to remove.  (As a note... all my hoses are pretty new and supple... I'm still just a little timid to be ripping too hard to remove something that is already working fine.)  I struggled with this hose for awhile but decided to revert to plan B.  I reinstalled the raw water hoses, started the engine and checked for leaks.  None found.
3.  Plan B - Reading Ken Juuls response to my original question, I decided to remove the end cap on the side where the zinc had dissolved.  reading previous horror stories I prepared myself for the worse and upon removal I used my trusty IPhone and shot a video closeup inspection of the inside of the HX.  Upon review I discovered the interior to contain what looked like my old dissolved zinc.... and nothing more.  The coolant tubes look to be in satisfactory condition but still need to be cleaned.  I dug out the old zinc, cleaned the threads, and then removed the old gasket . cleaned and replaced with new.  I replaced end cap and zinc and... after trimming down the length of the zinc I started the engine and ran for almost an hour.  I checked and double checked for leaks and found none.  My engine temperature never went above 175 degrees.
My plan is still to remove the HX to clean and service but for now I consider it a great victory to at least have a fresh zinc in place,  no leaks and a temperature that seems reasonable.
I may actually get the hang of this after all 

[Stu Jackson]

Please bear in mind that I am a newbie and that while I'm pretty handy I have never previously considered myself much of a  "wrench monkey".  That being said I am finding I am really enjoying "mucking around" the systems on my boat and gradually building my confidence and skills....

I struggled with this hose for awhile but decided to revert to plan B.  I reinstalled the raw water hoses, started the engine and checked for leaks.  None found.

... after trimming down the length of the zinc I started the engine and ran for almost an hour.  I checked and double checked for leaks and found none.  My engine temperature never went above 175 degrees.

My plan is still to remove the HX to clean and service but for now I consider it a great victory to at least have a fresh zinc in place,  no leaks and a temperature that seems reasonable...I may actually get the hang of this after all...

We've ALL been there.  We weren't born being diesel mechanics. 

Hose struggles:  every time you remove a clamped hose, put Lanacote on the port and you'll never have to hassle with removing the hose.

Unless you've run the engine under load, not at the dock, you won't know.  Good for leak checks, though.

Little victories are nice.  Add 'em all up and you'll get there.