CD 27 Mast Step Questions - Design & Construction

[TVinYpsi]

CD 27 Owners and other Experts: As you know, the CD 27 has a deck-stepped mast with no obvious compression post below. Please share the knowledge you have regarding this design, and any information that would be useful to us (actual plans & dimensions, for instance) in evaluating the extent to which the cabin roof of our CD 27 may have subsided.
Do any CD 27 owners out there have experience with needing repair in way of the mast step and what was your experience?
A former owner of a CD 27 stated on another forum that there is a steel structural member within the deck that spreads the compression forces between two bulkheads (bulkheads separating the head from the forward and after sections of the boat).
We are reluctant to cut out the headliner of the head space simply to examine the glass from below, but is this the only way to verify everything is still okay?
[The mast was up and the boat was in the water when we bought it, but suffice to say, we had not thought at that time to make measurements because the surveyor indicated his opinion that since the doors closed & opened without difficulty that the desk must not have subsided unacceptably.]
Any and all general info and details would be much appreciated as we continue our refit in Monroe, Michigan of our CD 27.

[fmueller]

Your basic premiss is correct ... there is a mild steel structure embedded in glass under the mast plate in the trunk roof that spreads the mast load to the 4 bulkhead posts. These post are very sturdy lengths of mahogany, and act as "compression" posts for sure. I cut an access panel (about 8"x10") in one part of my headliner over the head so I could easily access the cable gland which allows wires to pass through the cabin trunk to the base of the mast but also to be able to check the integrity of the structure there from time to time. (I'm not on my boat until later this week, but I'll post some pix then). This is not difficult to do. Almost any flat material will suffice to make a cover for the cutout headliner - and then you've got a window to an important structure on your boat. I used a piece of 1/16" glass board and 1 doz stainless sheet metal screws. Just cut the cover material slightly larger than the removed headliner.

What you want to verify is that there has not been water ingress into this area. One thing to consider as a new to you boat owner is to unstep your mast at some point and remove then re seal the mast step plate.

I put a wire barrier strip up here too to give me a ready way for disconnecting the in-mast wiring when periodically the mast comes down (every three to five years).

cheers

[csoule13]

Fred has the bulk of it. You can poke around and find a blog post on, I think, Sail Magazine's site, of Paul Calder doing some work on a CD28 with the mild steel under the mast. Same deal on the 27. On my 27, my survey pointed out that the area around it is some level of wet, likely because of the stupid hole the wires from the mast run through. Yet even in that condition, he saw no structural issues around that area. Additionally, I had the mast pulled to have the boat trucked to me this year. No issues discovered.

Fred, great idea about opening up that area on the liner where the wires come in.

Chris