Strange fiberglass cavity between bulkheads?

Nov 15, 2015
268
J J/30 Seward, AK
There is a glassed-off section under the cabinets between the two bulkheads on my C30. Anybody have any idea what it is? It's behind the settee back right under the cabinets, probably about 3" thick, and there is about 1/2" gap between it and the hull.

I wanted to drill a hole in the shelf behind the settee but didn't know if this was structural or not. I imagine it is, as the heavy-duty chainplate upgrade the PO installed is bolted to it from the bulkhead.

Peace,
-patrick
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
Photos would help us to know that you are talking about. It would also be helpful to know the year was your C30 built becasue Catalina made significant changes to the fiberglass liners in 1987 when they changed to the Mk II.
 
Jan 18, 2016
782
Catalina 387 Dana Point
A picture would definitely help us know what you're talking about.

Two bulkheads? Where two? My chainplates for the shrouds are held by the bulkhead that is the rear of the head/hanging locker. Fwd/aft lowers are to other pcs.

Picture (stolen from the internet)


The chainplate for the cap shroud is just to the left of that bizzare porthole thing into the head.

So if you have a picture of the strange fiberglass thing it may help us tell you what it is, and/or if it was some POs idea of structural reinforcement.
 
Nov 15, 2015
268
J J/30 Seward, AK
A picture would definitely help us know what you're talking about.

Two bulkheads? Where two? My chainplates for the shrouds are held by the bulkhead that is the rear of the head/hanging locker. Fwd/aft lowers are to other pcs.

Picture (stolen from the internet)


The chainplate for the cap shroud is just to the left of that bizzare porthole thing into the head.

So if you have a picture of the strange fiberglass thing it may help us tell you what it is, and/or if it was some POs idea of structural reinforcement.
It is between the mahogany piece where the aft shrouds connect (I called it a bulkhead because I think technically it is) and the main bulkhead where the middle shrouds connect, behind the settee cushion between the hull and the cabin liner that the settee cushion rests on, precisely where the arrows point. It is hidden so a more detailed photo wouldn't help. I am convinced that it is stock fiberglassing.
 

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Jan 18, 2016
782
Catalina 387 Dana Point
Your's is a MKII right? I'll look at mine next time I'm down at the boat, but I'm pretty sure I've got bare hull both behind the settees and above where I think your boat has enclosed cabinets. (Mine has shelves like the picture shows)

Possibly Catalina put a 'beam' in the liner to help with oilcanning or something. I don't have easy access to a MKII so maybe somebody else with one can chime in.
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
On my 88 C30 there is large opening behind the back cushions with a significant storage area. I think that the back of that storage area is the inside surface of the hull.
 
Jan 18, 2016
782
Catalina 387 Dana Point
It is between the mahogany piece where the aft shrouds connect (I called it a bulkhead because I think technically it is) and the main bulkhead where the middle shrouds connect, behind the settee cushion between the hull and the cabin liner that the settee cushion rests on, precisely where the arrows point. It is hidden so a more detailed photo wouldn't help. I am convinced that it is stock fiberglassing.
Ahhh... It makes so much more sense now since I've looked at my boat. Yup. My boat has them too - under the entire length of the lowest shelf, behind the settee back. It's part of the liner, and I'd guess it's for stiffening the boat at those locations. No reason to be there if they don't serve a structural purpose. On my boat it appears that the liner is affixed to the hull right above this mystery fiberglass thing.
 
Jan 22, 2008
402
Catalina 380 16 Rochester NY
Are these what you're talking about. The fiberglass backing that the cushions rest against? There is nothing behind mine, these holes were either there or were cut by original owner. Boat is a 1977 C-30, so I don't know if that was standard. They are useful for storage.
 

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kbgunn

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Sep 19, 2017
210
2005 Hunter 33 Lake Lewisville, TX
Are these what you're talking about. The fiberglass backing that the cushions rest against? There is nothing behind mine, these holes were either there or were cut by original owner. Boat is a 1977 C-30, so I don't know if that was standard. They are useful for storage.
You're brightwork looks amazing!! Nice work.
 
Jan 18, 2016
782
Catalina 387 Dana Point
Are these what you're talking about. The fiberglass backing that the cushions rest against? There is nothing behind mine, these holes were either there or were cut by original owner. Boat is a 1977 C-30, so I don't know if that was standard. They are useful for storage.
No. Later boats (mine is a 1980) have those storage areas a bit more refined - i.e. the liner was fashioned in such a way to create actual storage locations and the holes to get inside have trim around the lip. The rear is the hull though. What was being discussed is that if you reach into the area behind the settee and then reach UP, you'll notice that what you find is NOT the underside of the lower shelf. There's fiberglass there creating a box shape. I'm guessing it's to give some structural support to the hull at that point - likely to prevent oilcanning.

At least my boat and Patrickidd's boat have this. I'll try to get some sort of a picture next time I'm down at my boat.

Wish my brightwork looked that good.