Scupper leaks at the cockpit drains

[queens cove sailor]

I am a 1988 CP16/III owner, a new member of this group, and learned about cockpit scupper leaks after searching this web site. I have caulked the annular gap around the tube where it enters the cockpit fuel tank compartment, under the aft bench, using an elastic sealer.  I have been plagued with rain leaks and want to make sure I understand the construction details.  I am writing this to ask other owners who have had a similar problem to let me know if my understanding of the construction and leakage mode is correct. 

By feel from the deck access plate it appears to me that the scupper tube is solidly bonded (glassed?) to the transom but extends through the inner liner into the fuel tank compartment.  If this is true then the sea water (outside) leaks can only occur when water comes through this tube into the inner hull liner and then leaks around the opening where this tube, coming from the transom, passes through.  By this mode no sea water can go directly into the bilge but first has to enter the cockpit and then flow through this annular gap and into the bilge.  This assumes that the tubes and the outside surface of the transom are essentially integral.

On my boat there was a significant gap all around the tube on the inside of the boat.  It does not appear that this gap was ever caulked, leading me to believe that the clearance was intentional to allow the inner (cockpit) and outer (hull) FG shells to move differentially without developing any stresses.  This is why I used an elastomer sealing caulk rather than the 5200 that others used.

Since I get rainwater below, particularly during the deluges we have in Florida, and I have sealed all deck, porthole, chain plate, hawse pipe, access plates, etc. leaks (or , at least I believe I have, and have observed no visible interior leaks any more) I believe the water running down the cockpit sole builds up to the point where the tubes run full, back up, and water flows into the bilge by going through this gap, even though most of the water flows out the tubes.

The most severe rainwater accumulation occurs during the hot summer months, which is our rainy season, when my boat sits unused at my dock most of the time.  Therefore, leakage of sea water at the transom side could not be involved since the scuppers are well out of the water at that time.

Today I have sealed that gap and hope that this will end the seepage of water that has been driving me bananas.  I did not take off the flange on the outside of the transom. 

Please let me know, other owners who have had this problem, if my understanding is correct and if your fixes allowed you can separate out rainwater entrance from sailing leaks.  Thanks.

[Gil Weiss]

I had similar issues with my 1990 CP16. Rain water DID LEAK in thru the joint between the scupper tubes and inner hull in the gas compartment- lazerette they call it. These areas should be sealed up. There is much info on this site from me and others regarding this and related leakage problem. My round access hatches also leaked so I replaced and resealed them. I also had a few hull joint leaks - minor- and I removed the rub rail and resealed the joint where needed.

All three of these issues are common problems dealing with age and the original sealant drying out. Once I figured out where the problems were, the fixes were easy. Every few years you need to reseal the scuppers. I use 3M 5200 for these tasks. Screws and bolts loosen up, bedding compound drys out, etc. All part of boat ownership.


Regards, Gil

[queens cove sailor]

Thanks, Gil:
It was your post about leaks that inspired me to remove my fuel tank and look at the gap around the sucpper tubes.  Although I have had many boats, of all sizes, in my long sailing life I have never seen the same type of contruction for the scupper drain and would have not had the idea to look there had it not been for your explanations.  My boat is in good shape and I had checked all of the other potential leak zones, only one of which required recaulking (the chain plates) plus a leak from the deck access plates which had the O-rings improperly placed and of the wrong size, but I did not solve the scupper drain leak until I made the site search and found your descriptions.  Other than what I had done, and replacing an inappropriate anchor warp fitting, I did not see any leaks but was still accumulating small amounts of rainwater before this last fix.  I believe that the boat is now dry but we are now in the dry season here and hose simulations can't compare to the afternoon deluges we get in the summer.

However, I did not remove the outside flange and recaulk since, although I could not see the contruction details, it seemed to me that the tube was integral with the transom and, if so , would not need to be caulked, other than for cosmetic reasons.  Did you find that to be the case or did you also see a gap from the outide?  If it ain't broke I don't want to fix it!

Charlie

[Gil Weiss]

I removed those flappers and rings on the outside of the transom to find gaps that needed cleaning out of the old dried cailk and resealing. If you want to replace the plastic rings and rubber flappers Boaters world sells them. Not hard to do as long as the boat is out of the water.

Good luck, Gil

[multimedia_smith]

I wound up fiberglassing both ends of the tubes inside the boat... where they come in from the stern and then again where they enter the cockpit... NOT a fun place to work.  I also replaced the 6" inspection hatches which I found on special for just a few bucks more than gaskets alone.  (the gaskets are placed with the "v" facing up.
Good luck.
Dale

[idouglas]

When I replaced the 6" inspection hatches I put in larger rectangular access hatches and now have a place to stow my bumpers and dock lines.  Sure increases cockpit storage space and makes access to the aft hold incredibly easy  Check them out at:

http://com-pacowners.com/gallery2/thumbnails.php?album=lastupby&uid=709

idouglas

[Rick Klages]

Makes me want to build in a couple of beer coolers!  Drain lines into the cockpit sole..... Hmmmmm!

[idouglas]

Why didn't I think of that?

idouglas

[Rick Klages]

Not too late!

[bbradbury]

Dale,
I have the same agravating leak problem with my scuppers and plan on trying the same repair you completed.  Did you just use resin and hardener, or did you add a filler to the mix?  I have never worked with this stuff before so if you have any suggestions it would be appreciated.  I think I'll try using a dremel tool to smooth down the areas before I apply anything.

Bruce
CP16/2

[multimedia_smith]

Hi,
Since the area is hard to get to... to say the least... I didn't want to use a dremmel or other power tool to rough the area... instead, I used a round "rat tail" file by hand.  I cut fiberglass into two inch squares and mixed up resin and hardner... the epoxy kind bonds fine to our hulls.  I then pre-wet the glass and with rubber gloves, put it in place around the tubes.  The problem came when I wanted to add additional layers of glass.  Since it had hardened, the small pieces that stuck out were really sharp.  I used rough sandpaper by hand and again filed the area and repeated the proceedure.  I was able to do much of the work through the round access ports although I did do some by sliding down the quarterberth (arms out front before you enter).  Be sure to put some newspaper down below the tubes before you start glassing.  I did both ends of the tubes (transom and cockpit) and it is still holding.  (like my breath regarding this area)  Went out Sunday with winds from 16 - 20 and pretty lumpy conditions and came back dry except for some spray drips that had come into the cabin over the rooftop.  GREAT day out... I didn't want to come in...
Good Luck
Dale

[bbradbury]

Dale,
Thanks for info.  My boat is currently sitting in my boathouse in Maine (I'm in Texas) so I'm just making my plans in advance.....like loosing a few more pounds off my butt so that I can squirrel up those quarter berths easier than the last time I was in there.  I will take many pictures when I do this job and post them on the site.  Seems like there are always plenty of inquiries on how to fix these darn leaks.  Last year I replaced the 6" inspection covers as I knew they were part of the problem but the tell-all is always feeling the dampness around those tubes...never alot of water but just annoying.  Always had to leave a small hand towel in the bilge under the tubes to keep the boat real dry.
Enjoy your sailing, wish I was out there myself.

Bruce
CP16/2

[multimedia_smith]

A good method for pinpointing the source of leaks... (I read about it here on the forum or the Yahoo forum... either way, I can't take credit for it) is to start with some paper towels.  You then mark stripes in different colors with WATER based colored markers... since we have a child, we have these on hand.  Anyway, you can then place the bits of striped towel around suspect areas... I put some around each end of the scupper tubes and also under the round access holes on the rear section of the cockpit seats.  I also masking taped strips under the rudder, outboard motor mount, and swim ladder bolts.  That's when I isolated the water source as both the scupper tubes AND the access lids... I replaced the access ports rather than attempting to replace just the gaskets.  Then I fiberglassed both ends of the tubes.  Before trying the marker-towell method, I tried another suggested method of marking areas with chalk and looking for runs in the chalklines.  Prior to this, I fixed leaks around the chainplates (at the hull/deck seam under the rubrail where the edge had been filed flush for the chainplate) and also recaulking the portholes and finally replacing the anchor chain hauspipe with a watertight plastic fitting.  I don't know if we can ever get completely bone dry, but I'm pretty close...  Oh, another thing I did was to fiberglass the rear edge of the cabin floor (behind the portapotty) so that any water that splashes or sprays or spills in won't go into the bilge but will stay in the cabin for easy clean up.
Best of Luck... I would LOVE to sail in Maine during the summers.
Dale

[bbradbury]

Dale,
Good suggestion on finding the leaks but I'm pretty sure my only problem are those scupper tubes.  Interesting thought on fibreglassing behind the porta-potti ( I have the long foam insert).  Did you build something like a stringer to put between the bunks or just glass a rise behind the potti?  Question: Do all 16's have a small hole in the bilge stringer.  Mine has a hole that allows any water accumulation to run forward from the rear bilge into the forward cabin.  I've thought about sealing it...what are your thoughts?
If your ever in the Bangor/Bar Harbor area and want to sail on our lake contact me.  First Mate and I stay May~Oct, after that it's a little to cold for her bones.  I single hand most of the time so an " extra hand" would be a luxury.
Bruce

[multimedia_smith]

I cut a few inches off of the foam so I could push the portapotti toward the stern just enough to clear the companionway vertically... forgive the pun, but it is now flush with the opening and you don't step on it as you enter the cabin... I cut the foam into a couple of blocks and stuck them into the space between the floor and the underside of the bunks at the back corners and that provided enough backing to hold the fiberglass in place.  Here's a pic of the job... (note the pvc pipe holder for paper towels and toilet paper out of the way but handy to reach.

http://com-pacowners.com/gallery2/displayimage.php?album=49&pos=14

be sure to click on the image to get it larger...

Best Regards

Dale