[C320-list] Marelon seacock problem

[Catalina]

Great info Scott!  
When we had a handle break apart for the head intake thru Hull, it let in a good spray that we stopped with a couple wraps of rescue tape till we hauled out for the season a week later.
Possible that there was additional damage to the valve in our case that I didn't notice.
Cheers!Jeff
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Scott Thompson <surprise at thompson87.com> Date: 5/21/17  6:33 PM  (GMT-05:00) To: C320-List at Catalina320.com Subject: Re: [C320-list] Marelon seacock problem 
Thanks to all who provided useful advice on fixing this problem. I 
ordered Forespar part no. 932143 and a "Seabung" from Fisheries Supply. 
(Actually I ordered a set of two Seabungs. I do not believe you can buy 
them individually. The larger one might be useful for pulling the speed 
transducer if your plug is missing.) Fisheries Supply had good pricing 
on the seacock and delivered within 3 days. Pricing and delivery from 
West Marine were much worse.

I also received instruction on doing an in-the-water repair from 
Forespar tech support. I followed those instructions except used the 
smaller size Seabung instead of using the little Forespar plug, which 
would have required a dive under the boat, which I did not want to do 
this early in the season. The Seabung worked great. It's a bit expensive 
but a lot cheaper than a diver or haulout. I tied a light line to the 
top of it and secured the other end to the grab bar in front of the head 
sink. With modest tension the leakage was reduced to a trickle while I 
prepared the new seacock for installation. The bilge pump only ran twice 
during the entire operation.

BTW, partially disassembling a Forespar seacock by removing the four 
large screws voids the warranty, but is the method that their tech 
support suggested to do the repair. Without disassembly you would have 
to unseal the base from the interior of the hull and unscrew it from the 
thruhull fitting in order to replace the seacock. Now that could break 
the seal around the thru hull, and there was no way I was going to take 
that approach without a haulout.

After bringing the old parts home I took apart the old seacock. It's 
clear that my worst fear about failure of the handle was not justified: 
The ball valve in the interior of this seacock is completely captive 
within the body, and cannot be removed without first removing the four 
large screws holding the assembly together and then removing one or both 
of the interior seals. (But DO NOT remove those screws without plugging 
the thruhull first!) Removing the handle will NOT cause a significant 
failure or leak. I did not find washers or O-rings behind the handle 
(contrary to info from Jeff Hare, who must be thinking of a different 
seacock design). The handle appears to be held in place only by a 1/4 
inch self tapping screw. I'm sure the leak in my seacock was caused by 
wear and tear on the seals, and not by a loose handle. The worn seals 
may cause a drip, but they aren't going to fail catastrophically.

Scott Thompson

On 5/13/2017 4:40 PM, Scott Thompson wrote:
> I noticed a small leak that seems to be coming from the handle of a seacock when it is open. When I try to tighten the screw through the handle it just spins. Advice welcome!
>
> Scott Thompson
> Surprise #653(1999)
>
>