Companionway Hatch Cover Rotting

[tedseward]

This is heads up to a problem I had no idea could occur. I have hull #375 from 2006. Over the last several years I noted rain water had gotten into the deck storage locker (wine cellar) in the galley. I assumed my aftermarket companionway doors were leaking during heavy rain. This summer I was on a cruise with heavy rains and noted lots of water on the ladder and deck under the hatch cover, apparently due to overflow from the sliding hatch rail grooves. I called a local yard company to do repairs which I assumed must be a failing gasket around the sliding hatch cover. Turns out the drains on each side of the deck behind the traveler had become plugged from the inside....no way to tell from the outside. The area under the hatch cover had become a swimming pool with the only exit for rain water being the hatch grooves and into the interior. Worse yet, this had been going on for long enough that the rails under the hatch cover that the screws go through had infiltrated with water causing the coring to rot and much of the fiberglass to fail. The estimate to repair is a big number and I am looking to get other estimates. May just try to dry out and fill with epoxy since it is not visible or structural to hull.
So beyond ugly history, the only intent of this note is to advise all 350 owners to pay attention to those tiny drains and make sure they stay unplugged.

[Triumph]

I had the same issue. I removed the big cover, got all the rotten wood out along the edges where it was exposed, put it back, caulked it and have had no problems.

Triumph

[Mark Sutherland]

Thanks for this heads up. Anything that threatens the deck core scares me. Can anyone share some details on how to remove the sliding cover and where the drain holes are located for inspection and cleaning? Thanks!

[Triumph]

The drain hole are on the side of the hatch area near the traveler. Spray a pressure hose up in these holes and see if you get a bunch of black debris. This would be a sign that you need to pull the hatch cover and clean out the deadwood. The sliding hatch comes off when you remove this large cover piece. Yes, it is under the traveler but it will come off.

The deadwood is along the edge of the hatch cover. I think it was used to lay up the fiberglass. It does not really serve a purpose. You can scrape it all away, clean it all up and put the hatch cover back. Then caulk it.

The in no way affects the core of the deck of the boat. It's just a trim piece sitting atop the boat. No worries there.

Triumph

[cuthbert]

I checked this on my boat for the first time after seeing this thread and although both drains are free flowing the starboard side drain did have some small dark debris. In summary.... if the drain is not blocked, no problem? I read this that there is some small piece of wood that was used as an initial framing piece that serves no purpose and is decaying this is a non issue?

Or should this be a dismantle and remove the offending part?


Anybody got some pictures?

[pieterv]

I will have to check this out on my boat now too.... #36
If somebody has some pictures that would be great.
Thanks , Pieter

[tedseward]

Unfortunately I didn't take pictures and won't see my boat again probably until the spring. The hatch covering that is held in by multiple screws has two ribs on the bottom side, through which the screws go. They are wood strakes fiberglassed in and covered with gel coat. In my case the water flood had forced water into the fiberglass ribs through the screw holes and caused the wood inside to rot which ultimately caused the fiberglass to fail such that you could see the inside of the ribs. It was still wet inside the ribs when the contractor took the cover off.
I don't think you will have this issue if your drains are clear and flowing because the water will not build up inside...which was my problem. Just keep the drains clear.

[SeaBreeze78]

Today I removed the cover over the main sliding hatch. I am going to refer to it as the “Turtle Hatch”. Although I did not have any issues with clogged drains or water backing up. I could tell it was only a matter of time. There was practically no caulking left in the seams around the hatch. Any water on deck was bound to run down inside where there was said to be raw open wood ready to soak it up.

This project kept me up the night prior. But it has turned out to be non event so far. I would suggest all C350 owners to do this sooner rather than later. My boat is 17 years old. The calking is gone. Very good design by Catalina, other than not encapsulating the wood stringers.

The sliding hatch rest on slick HDP, so it slides pretty good. At the far end are two rubber bumpers to stop the forward movement. I bought bumpers today as close as I could find ($1.29). Mine are just old and not very pliable at this stage.

Contrary to what has been said in the forum previously, the wood on each side is an integral part of the Turtle hatch. My wood was not originally totally encapsulated. I doubt yours is either. On the port side there was lots more bedding compound applied about mid hatch. Apparently a puddle of water would get trapped between the bedding and the wood.The wood sat on top of that and soaked up water for years. That section is the worst of the rotten wood.

I dug out the rotten wood and am letting the stringer dry. Plans are to paint the wood with 50/50 mineral spirits and polyurethane. After it soaks up as much as possible, I will paint it with 100% polyurethane to seal it. I will clean any old caulking, replace the turtle hatch and then recaulk it.

The other option is to cut out the rotten wood entirely and either rebuild something similar or just leave it cut out. I am not that good at rebuilding. I could fill any empty voids with epoxy and micro balloons. I will see.

Anyways, I suggest everyone either recaulk the hatch today or remove, clean, reinstall and caulk it sooner rather than later.

[SeaBreeze78]

Rotten wood close up.

[cuthbert]

Many thanks for the pictures. although my 2003 has good caulking I am adding this to the winter list.

I had a generic caulking question for all who have tackled the hatch cover. What is the preferred caulking to use?

[KenKrawford]

Silicone used to be my preferred caulk/sealant but if you ever have to go back and work on that area again, it's difficult and tedious to remove all of it. I've now use butyl tape whenever possible. It remains flexible, isn't too difficult to clean off and provides a decent seal. I believe that's what Catalina used to bed our ports, hatches, etc.

[cuthbert]

Here is another variation.....Today I took the "turtle hatch" cover off, with good caulking and mild southern california weather the past 10 years I thought I had dodged this bullet.....not so.
The coachroof and the wooden rails etc underneath the cover were all good and well constructed/encapsulated with no exposed wood and no signs of any damage. However, The turtle hatch itself had been screwed down poorly as it had no sealant on the majority of the screws, there was caulk around the screwholes on the coachroof to ensure that the tip of the long screws passing into the coachroof was sealed but any water that got around the screwhead passed into the turtle hatch and sat there rotting. Since the dodger covers some of this it was not a problem on every screwhole, but there are 4 bad points. I cleaned it up in the 4 areas with a wire brush, took a hairdryer to it until the wood could no longer be compressed with a fingernail and painted it with primer.

rot.jpg (87.02 KiB) Viewed 2845 times

I have got a tarp on the hatch so I have a few days before the next rain to get this resolved. So I may fill it with wood putty and give it another coat before reassembling.

I don't like this type of job and approached it with trepidation, but my advice to anyone on the fence would be to back out a single screw half a dozen turns and if there is no sealant on the screw ....you need to take the cover off, it takes about an hour to take it off and clean everything to get a good look at what is going on.

Many thanks for the heads up on this one. I would never have checked this otherwise, sorry it has to be at the cost of an expensive repair for the OP.