Universal M-18 HX - what the...

[Skipper]

I found an earlier post from someone with an M-18 who couldn't figure out how to get the port-side end off of the heat exchanger. Well, that's because you can't. Unless there is some magic incantation that I need.

The left side is totally enclosed (see attached pdf, lower image), and I'm having the age-old issue of jammed zinc anode.

How the heck do I clean out a zinc(s) etc that are stuffed up in there?

I studied Mainsail's HX pictures, but his Westerbeke HX appears to have clean-out caps on both ends.

Thanks

 

[Stu Jackson]

How the heck do I clean out a zinc(s) etc that are stuffed up in there?

What you do is remove the HX from the engine. Your picture is just like my 25: two big hose clamps. Yes, you'll either lose or have to catch the coolant and reuse it. Good time to change that, too.

Since you only have one end of the HX you can inspect, shake the HX - it'll sound like a mariachi band!

While it's out, check the ports for salt buildup.

Buy ne wzincs, and check them at least every three months.

 

[Skipper]

Thanks, Stu.

But I still have the same access issue; can't get to the zincs\debris clogging the zinc hole.

I'm assuming that the core is permanent, which means that shaking it will only make noise. That is, I'd have to smash the rattle to get the beans out.

 

[Stu Jackson]

What you do is shake, shake, shake... and use a small screwdriver and punch it in the zinc hole. This takes time and patience.

I had to do it when we first bought our boat in 1998. Don't forget to take the end cap you do have off, too.

 

[Richard19068]

Pretty much what Stu said.

It also helps a bit if you can be running some water through it while shaking. The running water helps move the bits toward and through the hole. Also, swizzling a very thin stick or piece of wire in the hole helps the bits collect and run out.

If there is a piece of zinc stuck in the hole you just have to push it back in.

You might never get it all out but after you get it as good as you are going to make sure you inspect the zincs frequently enough so they don't break off.

My mechanic suggests cutting off the top inch or so of the zinc to help keep that part from breaking off. Seems a little counter productive to me but he is pretty well respected around here.