Cockpit Thru Hulls in Transom for MK II

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pkeyser's picture
pkeyser
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Cockpit Thru Hulls in Transom for MK II

One of my two transom thru hull fittings broke. I decided to replace both. I will share some details.

I am 6' tall, 200 lbs. The starboard helm seat locker was tight but manageable to descend into. The port locker contains the exhaust hose and was more difficult to access. Maybe a few beers would have helped.  

The Starboard thru hull attaches to a 1" hose. The port thru hull attaches to a 3/4" hose. Catalina cut  1.3" holes in the transom for both. Our boat had two fittings that were the same on externally, but accomodated different hose sizes internally. I could not find direct replacements for the thru hull fittings so ended up with two different sizes. The starboard side used a 1" Perko part (#0328DP6) and the port side used a 3/4" Perko thru hull. The 3/4" thru hull is a bit undersized for the transom hole- but is the same size as the original fitting. The gap on new (and the original) can be filled with caulk.

A 1" Perko thru hull could be used on the port side, but it would require a short piece of 1" hose and 3/4" - to - one inch adapter. This would create a better looking transom appearance with both sides showing the same size fittings.

The starboard thru hull drains both cockpit scuppers. The port thru hull drains just the propane locker- which is probably why a smaller hose was used.

 

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

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alfricke
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Thank you for your post....the same thru hull broke on Jubilee, took a while to track down the source of sea water in the bilge! I wonder if Catalina has realized that these cheap thru hulls are vulnerable to stuff shifting around in the aft lockers?

Al Fricke
S/V Jubilee San Francisco Bay
Catalina 36' MkII  #1867
Universal 35-B

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pkeyser
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Al-
I have one more thru hull on my list to repair- my AC cooling water discharge- though probably 10 inches above the water line,  it clearly has taken a beating from the sun and is cracking. The engine exhaust thru hull appears to be Nylon, but because of it's location, not exposed to much UV and looks good. My anchor locker drain, and both transom drain thru hulls were all in bad shape and replaced. I have no idea why any manufacturer would use Nylon or any other UV sensitive material for these products but many do...cheaper than stainless or bronze, but can place the boat at risk.

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

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HowLin
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Posts: 355

Replaced last year - seems these were poor quality and not very UV resistant...

---- Howard & Linda Matwick ----

--- S/V "Silhouette" - Nanaimo, BC ----

--- 1999  C36 MkII  #1776 M35BC ---

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