[C320-list] Water leak onto failed fridge compressor - not what you might expect

[Bruce Heyman]

Hi Doug,
Like so many things with boats there are just a long series of tradeoffs
with often no 100% solutions.   While we currently live and sail our 320 in
Southern California that screen is certainly not needed.  However, having
learned to sail in the Chesapeake I remember how mud daubers (SP?) hornets
(?) would build their mud nest anywhere they could find a dry spot.  A
frequent found dry spot would be inside a hose and my guess is that is why
they put the screen on the vent for the holding tank and for the drain for
the propane tank.
Bummer that you lost a cold unit!
Bruce
Somerset San Pedro, CA

-----Original Message-----
From: C320-list <c320-list-bounces at lists.catalina320.com> On Behalf Of Doug
Treff
Sent: Thursday, May 20, 2021 11:23 AM
To: C320-List at Catalina320.com
Subject: [C320-list] Water leak onto failed fridge compressor - not what you
might expect

This is cross-posted from my message on the Facebook C320 group. If you'd
like to see the pictures, hop over there and have a look at my post dated
today.

After 24 years, the OEM refrigerator compressor on my C320 failed. I thought
it had just died of old age, natural causes. Until recently, when I removed
it to make way for a replacement unit. When I really dug into the repair,
found that the entire thing was suffering from rust and corrosion. It became
clear that a water leak of some kind was happening. So I immediately assumed
that the propane tub above it was somehow responsible. That would turn out
to be true, though the actual issue was far from simple.

It turns out that Catalina has a thing for screened vent fittings which was
the undoing of my refrigerator.

I'll explain... The first thing I suspected was that the propane tub was in
need of rebedding in the deck. After careful examination, it was clear to me
that the tub itself is not leaking around its flange. So my next test was to
see if the drain hose at the bottom was dripping water. I put some water in
the propane tub to wash out the accumulated dirt and test the drain hose for
leaks. I was surprised to discover that the drain hose was clogged. I tried
to blast it clear with the pressurized water, but it wouldn't drain.

But still not a drop of water leaking out of any of the drain hose fittings
above where the fridge compressor lived. While I had my arm in there feeling
around the hose fitting, a drop of water landed on my arm in a different
location. Meanwhile, another drop of water formed on the wires that run up
to the propane solenoid, which is located inside the tub. The wires pass
through the fiberglass through a rubber grommet (circled in red in the
photo) and when I sprayed water in there, I also was trying to wash down
everything, so I had water everywhere, including around the top of the
compartment. It turns out that the rubber grommet around the solenoid wires
was leaking.

But how could that leaky rubber grommet which was located in a place where
water runoff shouldn't collect, be the cause of so much damage? Then it hit
me. With the drain hose clogged, water was slowly accumulating in the tub,
filling it up, and then when the level of the water reached the grommet, it
would start a steady drip into the area below. It doesn't even take that
much water to fill it up with a propane tank in there, because the tank
displaces most of the volume of the space.

So I traced the drain hose and located the through-hull drain fitting at the
back of the sugar scoop transom on the port side. What I discovered was that
this is the same type of fitting that they used on the holding tank vent,
complete with a screen. Of course, the reason the tub wouldn't drain was
that over the years, dirt had accumulated in the propane tub and washed down
the drain, slowly clogging the through-hull until it would no longer pass
any water.

So there you have it. A fitting that is meant to be a drain line to pass
accumulated rainwater had a screen on it... Poor design choices by Catalina
caused the refrigerator to die a watery death. In the attached photo, you
can see a sampling of the muck that I scraped out of the through-hull. In my
opinion, this fitting should only be used as an air vent, and not one that
will also have water draining through. Especially if that water could have
dirt and debris mixed in.

I had cautioned in an earlier post that I thought the propane tub was the
culprit, but I figured a follow-up would be useful since the actual
diagnosis turned out to be different than I expected.

The moral of the story - Check for proper drainage of your propane locker.
If the fitting is clogged, it can be cleaned out, but since I had to remove
it, and the original fitting wasn't in great shape anyway, it is being
replaced with a mushroom-style through-hull that does not have a screen. I
will also be replacing the rubber grommet with a new one.

Not only is a clogged drain a safety issue because any leaked propane
doesn't have an escape path, but the resulting collection of water can cause
other damage as well once the tub fills up.
--
Doug Treff
doug at treff.us