Bulkhead/interior unit creak/squeek with hull flex

[Rich Stidger]

I have a problem. My h40.5 is 15 years old and for the last couple of years (I'm not exactly sure when it started) I get a creaking/squeaking sound when the boat is rocking in a moderate sea. Sleeping is almost out of the question in the aft cabin. The creaking seems to be coming from the aft bulkhead or the shelves, or the hanging lockers in the aft cabin. Even the bulkhead between the aft cabin and he engine seems to creak. But mostly the noise seems to come from the aft bulkhead. If I put my fingers bridging the bulkhead and the overhead fiberglass trim I can feel some movement between them at the same time as hearing the creaking noise. There are no visible fasteners to tighten.

There doesn't seem to be any creaking that originates in any place forward of the aft cabin.

I am at a loss to figure out how or what to tighten to eliminate this noise.

Has anyone else experienced this problem and know how to solve it?

 

[Rick D]

I get some minor creaking from what I assume is the aft bulkhead. But, it doesn't sound a fraction of what you are experiencing.
I have always assumed the bulkhead was adhered to the hull/deck with 5200. But I have zero to support that assumption. No fasteners and the bulkhead fits in the molded recesses, so that's where the assumption came from.
I wonder if so if you could tape off and add an adhesive caulk around the molding? You could also perhaps experiment for location by buying some wooden wedges and placing them in the area where the sound seems to be most prevalent to isolate the location?
Just thinkin'...

 

[Rich Stidger]

Rick,

I have thought about trying some wedges to see if I can stop the creaking. I'll try that when I am on-board next. Regarding any adhesive caulk- I am reluctant to just apply caulk without knowing that it will correct the problem. If the caulk did not stop the creaking, I may need to remove it in order to perform the final fix- whatever that might be, and that could be a bigger problem.

My visual observation of any of the structural bulkheads is that they are tabbed to the fiberglass hull. The panels that are visible in the aft cabin are (I think) screwed to the primary structural bulkheads via stringers- but I am guessing to some extent here. For instance, I would expect that the bed platform is screwed to stringers that are glassed to the hull- I should try to confirm that fact.

The bottom line is that I really don't know how everything is connected. Nor do I know what parts are moving against what other parts to cause the creaking from the flexing. The only time I can troubleshoot this issue is when the boat is rocking in the waves at anchor without the noise of the auxiliary.

I think your idea of wedges might be the best next step since it is something that I can try with minimal effort and would give an immediate answer of either helping or having no effect.

I was just hoping that other h40.5 owners might have solved this problem and have a best case solution.

I also get creaking from the bulkhead by the rear engine compartment cover. It's not the cover rubbing because I have removed it and still have the noise. If I press on the mirror edge trim the creaking does not change. In the case of that bulkhead, the fiberglass ceiling is caulked to the wood panel to which the mirror is attached, yet I still get creaking from that area. As yet I haven't detected the source of motion between two pieces of the interior assembly that might suggest the source.