HeatX zinc hole plugged by?

[Porchhound]

1986 C34 M25: When I removed the pencil zinc cap, no water drained out of the HX, and no zinc was left attached to the cap. Further inspection revealed it is plugged by what I assume is some part of the zinc. I can carefully drill this out of the way but now I have a problem with loose zinc in the HX. unfortunately the zinc is on the opposite end of the HX opening. Anyone know any spells or incantations that will solve this issue, or do I remove the HX? It was cleaned out about 40hrs ago by a PO. He was very conscientious so I doubt he jammed an oversized zinc into the exchanger...?

[Ron Hill]

Porch : I'm sure that the hole is clogged with sediment and old Zn pieces.  I'd probe with a screwdriver or a wooden dowel (straight up about an inch to 1 1/2") and that'll open it up.  Don't go higher or you could screw things up!!

Another option is to remove that HX and take it to a radiator shop and have it boiled /cleaned out.  I'm sure that it hasn't been cleaned since 1986!!


A thought

[Porchhound]

Thanks, Ron. The P-PO did a lot of work on her and his maintenance log indicates he cleaned the Hx along with other work like replacing head gasket, new zinc. That was only 40 hours ago, but over three years. The PO just let the boat sit in the marina, running about ten hrs per year. I'll follow your advice. I think I read the zinc length for that 2 inch HX should be 3/4 inch. There was no restriction of water flow obvious during the 30 min sea trial or the 8 hr run to the new marina, temps were holding too.

[Porchhound]

Okay...there was corrosion plugging the hole. New zinc in. Thanks again.

[KWKloeber]

What do you mean "other end"?  Both ends should be checked to make sure they're free of debris.  I used to get grass collecting on the intake end of the tubes (never had a strainer installed on my 84.)

You run a wire through each tube to assure that none are blocked.

You probably found out that right above the anode hole is air, no tubes - you just hit against the other side of the outside shell of the Hx.  If the bolt for the end cap interferes with the full length anode just get a shorter bolt (3/8" NC thread) or trim that one shorter.

You might bond the Hx to a good ground to help prevent galvanic corrosion.

[Porchhound]

What I meant was the Hx body only opens up on one end. It's the original from 1986. I'll pull off that end and clean it while I'm in that location and already bent one way and twisted the other! I can only imagine how much easier this would have been fifty years ago.

[KWKloeber]

Ohhhh Mea Culpa, mine has caps on both ends. Two caps probably cost another $1.25 back in the 80s.

[Porchhound]

It is odd the design started with only one.

[Ron Hill]

Porch : If there was that much corrosion - just take off that HX and take it to a radiator shop and get it cleaned out.
Look on line and get 2 new end caps w/gaskets and you'll have a "new" Hx.!!

A few thoughts