|Topic Review (Newest First)|
|12-26-2007 07:44 PM|
|sailaway21||I'm thinking it's moisture damage either within the plywood or the glass as well in the area around the plywood, and that, at a minimum, the full extent iof it must be revealed and repaired properly. It might be that replacement of the plywood would not only be the best way to approach the project as a whole, but the lack of doing so in a previous repair is what has led to the apparent migration of damage.|
|12-26-2007 07:07 PM|
|davidpm||As the pictures show the black is not consistant with the edge of a piece of plywood. It is a layer over a significant part of the hull. My current theory is that the black part is a layer of a prior repair that went wrong. Maybe glass that got too hot. Some kind of patch material improperly applied or cured. I can't imagine what happeded exactly as I have not seen a layer that looks like this before.|
|12-26-2007 04:16 PM|
Like Sailormon6 says, the keel construction is (from the bottom up) lead keel, 5200 sealant/adhesive, fiberglass, plywood and then fiberglass that is visible from the bilge. I have the aforementioned sheet from Catalina that shows the keel stub construction. Let me know if you would like me to email it to you.
From what you are describing, it sounds like the black layer is actually part of the hull layup in places (since you had to grind through it to get through to the bilge), and if that is the case, I agree it sounds like something used in a previous repair.
|12-26-2007 10:24 AM|
|Sailormon6||The bottom of the keel stub of the C27 consists of a plywood board, and the keel is through-bolted to that board. The plywood is encased in fiberglass, but occasionally the seal can get broken, such as in a hard grounding, admitting water, and causing the plywood to deteriorate. The plywood can be replaced, and it can be done by the DIY'er. Catalina used to have an instruction sheet, that shows how to do the job, if in fact it needs to be done. I suggest you contact Catalina, show them your photos and ask their advice.|
|12-26-2007 08:38 AM|
Yes. This location is a few inches forward of the engine water intake. It was covered with the soft black layer and had soft glass underneath so it had to be ground out.
Some of the black layer is hard Some is hard and over solid glass, some is soft over solid glass and some is soft over delaminated glass.
I'm leaning towards the theory that it was repaired more than once. That would explain the normal glass at the deepest layer and the blue glass near the surface. Still donn't know what the black layer is.
Plywood sounds unlikely but maybe if they used a plywood form to cover with glass.
|12-26-2007 07:51 AM|
Does that hole in the second pic open into the bilge?
|12-25-2007 08:20 PM|
This shot is from the starboard stern side. A couple of inches out of frame to the left is the engine saltwater intake. The first shot it at the same elevation (just at the point where the bilge of the boat curves down to the skeg) about 6" to 12" to the right.
I just never expected so many colors and donn't know what they mean. The black spots under the hole are solid so the blackness itself may not be evidence of rot.
|12-25-2007 08:19 PM|
|sailingdog||Hmm... the plywood would be a good candidate for the black stuff...especially if it was rotten.|
|12-25-2007 05:51 PM|
Have you got another pic from further away that puts the position of the ground out spot in perspective? Catalina used plywood in the bottom of the bilge sump in this era C27, but it is hard to tell exactly where the black band is on the keel.
|12-25-2007 04:10 PM|
|Freesail99||The soft caulk like stuff, maybe boatlife. I had it on my boat around the cutlass bearing tube.|
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