Rudder Leaking?

6 posts / 0 new
Last post
canadacatman2016
Offline
Joined: 4/2/16
Posts: 9
Rudder Leaking?

We have a 1984 C36 Mk1 Tall Rig and I have made really important upgrades and had 3 seasons of great sailing in her.
Each fall when she is hauled I've noticed a rusty water track down the rudder from the top of the rudder in the lower bushing region.
We always have a few inches of water in the bilge which slowly returns every few days or so - nothing major but it's always puzzled me and concerned me a little.  I've sealed the mast track and boot  really well, put food dye in the water tanks to see if there's a leak from those or supply hoses. The water pump rarely runs to repressurize since I replaced a perforated hot water tank  I've checked the prop shaft stuffing box, but still can't find the source of the bilge water.
I've checked the small separate rudder bilge at the inside of the transom under the aft berth and the water seems stagnant . I've vacuumed out the water with a shop vac and I never see it refill evn after 15 minutes of watching it, yet I'm suspicious the rudder shaft is leaking somehow. The only other possibility would be the bronze skeg that supports the cutlass bearing. There are small hairline cracks at the place where it enters the hull yet the skeg seems solid with no movement at all. I realise with 6-7 tons of boat pressing down on the water it would easily enable water to get in the smallest crack or defect so 5 gallons of water would not take long to accumulate. We sail in the the Great Lakes in fresh water so unfortuantely I can't do the salt water taste test.
Has anyone got an opinion as to which seems the most likley cause of the leak? The cracks at the skeg  will be repaired before launch but I don't know if replacing the rudder stuffing box packing is an easy in or out of water fix, or do I need to have the boat raised in the lift slings high enough to remove the complete rudder assembly so I can service both top and bottom bushing/stuffing box and packing? I can't seem to find any diagrams or instructions in the Owner's Manual as to what is required. Any help or advice would be much appreciated.
 

KevinLenard's picture
KevinLenard
Offline
Joined: 1/28/15
Posts: 209

Ah, yes, the old slow leak issue...After years of searching for sources, I have this to contribute:

1. Rudder rust streaks/crack -- our '91 has water that seeps down the metal post into the base of the post about 8 inches into the top of the rudder.  It then freezes over winter and causes a small crack in the starboard side of the rudder.  The Catalina sales guy at our club says it is a common issue and not much can be done about it.  Not a really big structural issue.  I've drilled it out to drain it over winter on the hard, then filled it with epoxy, but it re-cracks the next winter.  There is nothing about this issue that results in water in the boat.

2. Cracks around the cutlass skeg -- the skeg is external to the hull and no cracks in the skeg will realistically goe through to the interior.  However, vibration from the shaft will continue to open up those cracks and you should cut out along the cracks, epoxy, possibly glass over and apply waterproof paint and anti-fouling.  The only reason we had those cracks appear was wrapping the jib sheet around the shaft.  No shaft or motor damage seemed to be done (I have found one of the motor mount brackets is broken and need to be replaced or welded), but the cracked skeg required a fix.

3. Mysterious water source/leak -- after a ton of detective work, I identified the most persistent source as both the dripping shaft (stuffing box) packing (needs regular checking and adjusting the nuts around the shaft) and the central water tank.  Turns out that using too much water pressure from the city water supply hose was blowing out the plastic screw-in fitting at the top of the tank.  Had to use heavy duty hot melt glue (yellowish colour) and sealant to address the issue, plus never run full pressure to fill the tank.  I also had a leak at the bottom tank fitting that required cutting away the plywood box at the port side and replacing and sealing the drain fitting attached to the hose running to the water pump.  With these repairs to the tank, the leak into the bilge is now mostly gone, although I have the fridge draining into the bilge since my foot pump failed and I removed it.  One more project to get to...  Each boat is unique, however, and many have chainplate and window gasket issues. 

4. Standing water in depressions -- We also have a circular SS plate over a central hole in the transom under the 'swim platform' that allows a tiny amount of water in from rain.  To address this I crawled in back there and both sealed around the plate, as well as putting expanding foam into the shallow V-shaped depression back there, and also the depression at the base of the tiller shaft in order to keep any water flowing all the way down to the bilge rather than sitting and getting foul/mouldy.  After the foam hardened I had to slide back in with a serrated knife to cut the foam down smooth and paint it with a generous coat of waterproof paint.

Best of luck!

Kevin Lenard
"Firefly"
'91 C-36 Mk. "1.5" Tall Rig, Fin Keel, Hull #1120, Universal M-35 original (not "A" or "B")
CBYC, Scarborough, Lake Ontario, Canada

HCJ's picture
HCJ
Offline
Joined: 5/14/18
Posts: 19

Does the bilge get water in it even on dry days? If you have a week of no rain and the bilge still fills up it must be from the water tanks or a hull leak like a through hull, hose or indeed the rudder post. 
It took me a while to figure out where my mystery leak was. It turned out to be the mast.  It leaks on the inside... No idea how to fix that or even where to start. 

Henk Hiensch
Mar Y Sol
1984 Catalina 36
Hull# 379 Universal M25
Ladysmith, BC

Mother Ocean's picture
Mother Ocean
Offline
Joined: 6/4/15
Posts: 38

The skeg is through bolted from inside the boat. Mine had small cracks around it and slight movement from side to side. The bolts that hold the skeg in place are under the center water tank in the aft birth. I had to cut the tabs on the box around the tank and slide the tank forward enough to get to the bolts to tighten them. Then went to the skeg and ground out a few inches all around it and filled with thickened epoxy. Never had signs of water leaking in though.
 Tim

Tim Askew

 S/V Allure​
1990 Catalina 36 Hull # 1079
Std Rig, Wing Keel, M25XP
​3 Blade Auto Prop
​Elizabeth City, NC
 

Chachere's picture
Chachere
Offline
Joined: 10/27/10
Posts: 825

I would greatly doubt its a leak around the prop strut skeg.   The material where the cracks are is just filler.
Here's a link  to an posting I put up a few years ago that has a bunch of links to that subject: https://www.catalina36.org/comment/56764#comment-56764 
I actually replaced the skeg last winter (nasty job), and with the way the bolts are sealed in I cannot imagine water ever getting through there.  

Good luck ending the leaks -- I've never been able to solve the mystery on our boat.  I've at times wondered if any water could get throught the keel bolts (I've torqued them up to spec once or twice).   I realize the mast may be an entryway....

 

Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY

canadacatman2016
Offline
Joined: 4/2/16
Posts: 9

Thanks to you all for your comments. The water tank was an issue with the top inspection caps when pressure filling for sure but I taped those with sealant tapeto seal them and they're now fine. No water tanks / hoses or fittings are leaking - red food dye test. I agree - I didn't think the cutlass bearing prop shaft skeg was an issue, but it's right under the central water tank which is not easily removable.
I'm sure my prop stuffing box is fine and my keel bolts are tight with no sign of a "catalina smile" the keel / hull joint is fully sealed.
I'm still thinking it's the rudder stuffing box so I'll be checking this when spring comes and repacking it before re-launch. Could be a chain plates - or stanchions but I've looked for signs of weeping and none have showed up. Definietly have a nav station window leaking but not 5 gallons over a week with no rain. Definitely a mystery so I'll keep looking - thanks for all your suggestions.

Log in or register to post comments