Compression post measurement

[Dove16]

I'm hoping that someone here can give me the measurement for the compression post on an early 70s boat. Mine is in need of replacement and I suspect my existing one may have been cut too short by a previous owner. Thanks!

[JTMeissner]

If you're concerned that the post doesn't reach from roof to keel, perhaps not a big deal.  For my 1976 boat, the post "floated" an inch or so off the concrete. It was bolted through the bulkhead and then up to the roof, transferring the load from the post to the bulkhead.

When I replaced all the interior wood, I did the same.  I just used a post that fit in the slot I cut, from roof to just above keel, put a slight bit of upward pressure to get a tight fit, and bolted through the bulkhead.  YMMV, but so far so good.  I'm not sure how much the hull shape changes when the boat in in the water versus on the trailer/hard, but there is some difference.

-Justin

[Dove16]

Thank you Justin. That complicates things a bit for me. The compression post in my boat is sized about as you described but the bulkhead has rotted. I screwed in a plate across to the good portions of the wood last year so I had something solid to bolt the post to, but the forestay is still slack even when the turnbuckle is fully tightened.

I'm hoping to turn some of those temporary fixes into permanent ones this spring. If the post is the correct height, hopefully this will resolve itself when I replace the bulkhead.

[Chris D]

The compression post in mine is about 28" and had a 1 1/2" thick by 8ish" long block under it that was "epoxied" to the hull. Like Justin's, mine was also through bolted to the bulkhead. The block underneath seemed like it may give it a little extra support.

Chris

[JTMeissner]

I'm with you... I did the same for a few years, patched a board across the bulkhead and post that had good wood for the fasteners.

If the issue is forestay, perhaps the side stays are not tight enough?  They are slightly aft of the mast, so pull towards the stern.  I replaced the turnbuckles, and found that I could not get any of the stays taut; had to go back to the previous ones (could not tighten enough, too long).  It took some time to tune all three to where it was good to go on the trailer... then had to be done again when on the water. 

If not tunable, then a shorter turnbuckle would probably work.  I couldn't guess how significant the stretch in the stays works out over 40 or so years, but I suppose there is some... at some point they should probably get updated as well.

-Justin

[Dove16]

Thanks Chris. That helps give me a good starting point.

I bet you're right on the side stays Justin. The forestay was spliced together by a previous owner so I had a new one swaged using the measurements from another CP-16 they happened to have at the yard, but I didn't think about the side stays being an issue. Clearly learning as I go here. I'll give that a shot after I get the new post in.