Backstay Chain Plate CD25

Sea Owl · Post by **Sea Owl** » Feb 6th, '10, 15:34

Quick question for the board. My backstay chain plate (photo below) needs replaced. It appears to be a single piece of metal below the deck - does it extend into the transom and I just can't see it?

A single plate will be easier to replace (obviously!) than one extending into the transom....

Thanks to all!

<a href="http://s437.photobucket.com/albums/qq94 ... to0054.jpg" target="_blank"><img src="http://i437.photobucket.com/albums/qq94 ... to0054.jpg" border="0" alt="Backstay Chainplate"></a>

tartansailor · Post by **tartansailor** » Feb 6th, '10, 19:29

No way would I put a single plate under a deck for a back stay .
The stresses are just too great.
My CD-25 has drilled and tapped approx 2feet of rebar embedded in the transom in the shape of an inverted "V" which would be a major job indeed to replace.
If it were my boat I would split the back stay and fasten SS plates outside the transom.

Dick

Sea Owl · Post by **Sea Owl** » Feb 6th, '10, 19:41

Dick;

Good idea.

Anybody out there done that on a CD-25? What I am wondering is how that could be done easily. Chain plates I don't have trouble with, but the 'stay structure' - is it better to have two short stays meeting and going to a longer single back stay, one wire going from chain plate to chain plate with the back stay attached in the middle, or run to complete back stays from the top of the mast?

The latter seems like it would be difficult to adjust as I think about it....

GLutzow · Post by **GLutzow** » Feb 6th, '10, 23:57

I have been considering changing over to external chainplates on my CD25 if I keep it. It will not only give a slightly larger platform for the shrouds/stays but will be easier to inspect and maintain. Just a thought.

Annie Ward · Post by **Annie Ward** » Feb 7th, '10, 04:08

Sea Owl,

We are having the exact same problem on our CD25. Something back there on the inside of the transom had rusted so badly it split the fiberglass and popped through and fell into our hands in small pieces. We still aren't exactly sure what it should look like, except for the photos we've seen on this site, which don't really seem to correspond with what we saw on ours but, frankly, by the time it disintegrated, it probably was nothing like it's original form anyway. We are pretty sure we can't replicate the same thing so we are probably going external, too.

Our previous boat, a 41' Islander Freeport, had a split backstay configured with two short stays attached to a single stay coming from the mast and that's also how we'll do it on this one.

Good luck. Post pics of your progress and result if you can.

fenixrises · Post by **fenixrises** » Feb 7th, '10, 08:39

Hi all,

Your backstay re-inforcement probably looked something like this.

The "thing" as it has become known to Cape Dorians. It is the backing for the backstay deck mounted padeye. The plate is approx. 4" X 8" X 3/8" thick. The bars are re-bar welded to the plate. The "V" towards the camera lay against the transom and had a fiberglass bond over each leg to the inside surface of the transom. The single rod was welded to the apex of the "V". It is shorter now because I cut a piece off during the process of removal. I also cut a piece of the plate off to make a through hull removal tool. As you can see the plate was not quite centered in the boat, as the holes for the through bolts from the padeye are biased towards one side.

On my 28 there was a cutout in the aft face of cockpit footwell for the engine instruments. Through this access I was able to remove the "Thing", just.

Schaefer makes a number of different chainplates, all nicely polished and predrilled. Depending on access to the area on a 25 the installation process would be simple. They can be found here:
http://schaeferhardware.com//SearchResu ... goryID=227

Either a single backstay chainplate or a backstay bridle with two smaller chainplates should work just fine.

Take care,
Fred

Kilgore · Post by **Kilgore** » Feb 7th, '10, 08:58

Thanks for the link Fred.
My port side chain backing plates need attention. I've got to inspect the back and forestays plates.

drysuit2 · Post by **drysuit2** » Feb 7th, '10, 10:00

Please keep us posted on this one. When ever I do my chain plate inspections on Segue. [which Iâ€™m certain is not often enough] I see the same thing. { I have NO rust yet, that I can see anyway} But, while the forestay has an external chain plate that spreads the loads. The back stay and shrouds just seem to just be held on by bolts, and an aluminum backing plate.

Segue is getting to that age where I should be replacing all the standing riggingâ€¦ but I am just not ready for all that work yet. [and I certainly donâ€™t have the cash to pay someone else at this point]

http://farm5.static.flickr.com/4010/433 ... 766f_o.jpg

<a href="http://www.flickr.com/photos/drysuit2/4337005075/" title="CD Chainplate by drysuit2, on Flickr"><img src="http://farm5.static.flickr.com/4010/433 ... 766f_o.jpg" width="592" height="660" alt="CD Chainplate" /></a>

Thanks

Kilgore · Post by **Kilgore** » Feb 7th, '10, 12:12

tartansailor wrote:No way would I put a single plate under a deck for a back stay .
The stresses are just too great.
My CD-25 has drilled and tapped approx 2feet of rebar embedded in the transom in the shape of an inverted "V" which would be a major job indeed to replace.
If it were my boat I would split the back stay and fasten SS plates outside the transom.

Dick

So you'd prefer to redesign the stock setup as well as changing the plates to SS?

seajunkie · Post by **seajunkie** » Feb 7th, '10, 12:26

Your backstay re-inforcement probably looked something like this.

Now I'm really confused. I don't understand where this deep three dimensional design fits into my two dimensional transom. Short of the picture being being an optical allusion, I don't really see where this would fit.

The description states 4 X 8 X 3/8", it seems like it would need another dimension.

tartansailor · Post by **tartansailor** » Feb 8th, '10, 19:09

So you'd prefer to redesign the stock setup as well as changing the plates to SS?

Just try to fabricate and install an original replacement!

Duncan · Post by **Duncan** » Feb 8th, '10, 22:30

seajunkie wrote: I don't understand where this deep three dimensional design fits into my two dimensional transom.

Two legs form a "V" running down the transom, from the rear of the backing plate under the deck. So far, so good, right?

The third leg angles out from where the other two join at the bottom, to attach to the forward end of the backing plate.

Just like in Fred's photo, sort of like a three-sided pyramid, but upside down.

From what I can see, there's no sign of this structure in Sea Owl's photo, which looks like a simple backing plate under the deck.

I think a regular strap chainplate on the outside of the transom would do the job in a simpler, more effective way.

DaveCD28 · Post by **DaveCD28** » Feb 9th, '10, 08:44

I think the pyramidal "Thing" might be a CD 27/28 thing. May not be on a 25. I went through this on my CD28 recently. If you look at my profile here (http://www.cruisersforum.com/forums/mem ... ms551.html) there are photos which you can see some of the work involved in changing to external chainplates. I used a single backstay to an external chainplate. The hardest part was dealing with installing the new fiberglass since I reinforced the hull and transom with 4 to 5 layers of woven roving at Fred's (fenixrises) suggestion.

On a CD28 I think the factory stern chainplate setup, if it's in good shape, is superior to just bolting on a stern chainplate without reinforcement since the transom on the CD 28 is thinner than you'd expect, and the factory setup basically bolts the hull and the deck together, both needing to break before it would tear out. The reinforced external setup seems to be the best, however. The shrouds would have been fine as the hull is pretty thick in the area where they are, but I reinforced these areas anyways.

Must be okay since I just got done sailing this past weekend in a constant 28kts gusting to 36kts and she held up great. Why I was stupid enough to go out in those conditions is for another thread....

mgphl52 · Post by **mgphl52** » Feb 9th, '10, 09:41

gmppz28 wrote:Must be okay since I just got done sailing this past weekend in a constant 28kts gusting to 36kts and she held up great. Why I was stupid enough to go out in those conditions is for another thread....

That's very easy to answer: Because we CAN! With the right amount of cloth up, I'm sure you had a great sail!!!

-michael

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