Creaking Bulkheads, Questionable Mast Step on CD 28. Uh-Oh!

[calderp]

I've got a CD 28 which I've done extensive refits on and, of course, I'm still running into issues. The current one has to do with the mast step. First off, my bulkheads make a lot of noise when I'm sailing, creaks and pops, but they don't seem to be moving, maybe working 1/8-1/4". There are no signs of hull deformation or sagging of the cabintop and the deck around the mast feels solid.

Question one: Cape Dory owners, do your bulkheads make a lot of noise? I can't figure out if this is a major issue or just a minor result of CD not actually anchoring the bulkheads to the hull.

The second issue is the mast step. These CD28's have a rather large H-shaped construction of mild steel square tube which is glassed into the deck and has the mast sitting on top. The legs on the H, running across the beam fore and aft of the mast sit directly above the interior doorframes, which are the compression posts on the boat. When I drilled holes for my mast wiring I found that the top of the main member is quite solid but the bottom is completely rusted out, presumably from water sitting in there. I can't tell what shape the sides are in and I haven't investigated the 'legs' of the H. Clearly, this is an issue. Still, if the top and sides of the square tube are intact it ought to still be serving it's purpose. The main issue then becomes the 'legs' of the H - if the main member under the mast is no longer connected to the 'legs' then it's not going to be properly spreading the load to the bulkheads. I need to fix this, but I'm wondering if I can get away with an easier fix than opening the deck and replacing everything.

Questions:

Has anyone done this job of replacing the mast support? Was it difficult? In an ideal world it seems I could just cut the top off the fiberglass covering the mast step and then pop the whole thing out. Of course working on boats is rarely an ideal world. Photos would be excellent if anyone has done this!

What about simply reinforcing the bulkheads from inside the boat by running a pair of laminated hardwood stringers across the tops of the doorframes to connect each pair of compression posts. This way even if the connection between the mast step and legs of the H was rusted out there would still be beam-oriented reinforcement to keep the cabintop from sagging.

I might add that I have sailed in fairly heavy weather, up to 40+ kts of wind and fairly large seas. As usual there was a lot of noise from the bulkheads but didn't seem to be any long-term effects.

[Brian2]

Hello,

I also have a CD 28, and have noticed the bulkheads move while motoring in no wind with large swells with short swells on top due to leftover swells combined with current chop slamming us. Not pleasant.
But, the bulkheads were fine. I haven't noticed excessive creaking, but boats creak, so I haven't been concerned.
I'm no expert here at all, but removing the top will be a big job. Doubtful it will just pop off, but maybe. All in all, I would keep an eye on it, but I wouldn't do anything unless you notice deck compression, or other physical issues.
I think our CD28 has a small "beam" flush with the cabintop gong across the door frames between the posts, both fore and aft.

Others may have better advice and opinions.

Brian

[Shinok]

Is there compression at the cabintop around the mast step? If you spill a little water on it, does it pool around the mast step?

[John Ring]

Does the rig hold its tension? Or does the rig go soft after a while & need to be tightened?

My old CD28 took & held lots of tension, as did my older CD25; as they were designed to do. There was always some creaking, and gel cracks around the mast step 'cause the gel coat was too thick & brittle. There was a little movement in that area as the boat distributed the rigging load, but the structure was fine. My CD36 also creeks & pops a bit down below when sailing or rolling at a rough mooring, but the CD36 is keel stepped. I think all boats creak & pop to some extent if the rig is properly tensioned. See Ivar Dedekham's booklet on rig tuning if you're not familiar.

I've never seen bulkheads loose or moving, that would have me concerned, especially on the deck stepped boats.

John
CD36 Tiara

[fenixrises]

Hi all,

You might check out what I did on my CD28 FeNIX.

http://www.sbastro.com/FeNIX/Projects/P ... temsFS.htm

Take care,
Fred

[Brian2]

One thing I didn't think of...it probably is/could be the boat flexing around the bulkheads, not vice versa. Fiberglass (like most materials) will flex in a sea.