E27 Chainplate upgrade. Need Advice

[JacknRose]

Hi All,
I am changing the location of all six chainplates to the outside of the hull and need some advice. The plates I am using have 1/2" clevis pin holes and I and I am pretty sure that the standard, and size of my clevis pins on the end of the turnbuckles, is 3/8" (Not yet confirmed). Without changing the turnbuckles, does anybody know of an adaptor/toggle that will work? Ideas? Thanks guys!

 

[Loren Beach]

Somewhere around the site are some great pics and/or a link to an Ericson 27 (29?) with a great looking set of external polished SS chainplates.
Anyone recall the link??

LB

 

[JacknRose]

Somewhere around the site are some great pics and/or a link to an Ericson 27 (29?) with a great looking set of external polished SS chainplates.
Anyone recall the link??


LB

Hi Loren,
I have read that whole thread and will be following the install that was carried out. I just need the answer to the clevis pin issue. Thanks!

 

[Mark F]

Hi JacknRose,

I think you are right about the existing being 3/8". You should be able to use a bushing with an OD of 1/2" and an ID of 3/8" or maybe drill the turnbuckle toggle to 1/2".

 

[bigd14]

If you go the drill route run the numbers to ensure you have enough strength left over one you remove additional material. I think a bushing would be better.

 

[exoduse35]

Do not drill out the turn buckles... there is not enough material left to be safe! Use a bushing or better get a chain plate that fits. Also consider titanium, It can be custom made for less than stainless and will never need replacement again!!! Edd

 

[Seth]

Why?

Just curious-what is your reason for moving the chainplates outboard?

 

[JacknRose]

Seth. I had my port upper chainplate snap due to corrosion and metal fatigue. I have fitted the new chainplates to the hull sides using the horizontal part of the glassed in chainplate as the backing plate. Now she is as tough as a tank!

Just curious-what is your reason for moving the chainplates outboard?

 

[Seth]

Chainplates

Looks like you did a good job, but I think the right move would have been to replace the chainplate. The rig loads are designed to be transferred to the bulkheads, and the hull layup was not designed to take rigging loads. It does look like you did a good job, but I hope you did some structural calcs first. I'm not saying in any way that this won't work or will fail, but it is not the way the boat was designed to take loads.

Perhaps you beefed up the layup on the inside of the hull (and distributed the extra glass over a wide area), and determined all of the load factors, I hope so.

I don't mean to be negative-the jobs looks very good from your pics, but my feeling is it would be have been easier to replace the chainplate and keep the better sheeting angles available from the inboard chainplates.

Still, looks good and sail safe!

 

[JacknRose]

Seth,
I don't think you know that the original chainplates were glassed into the inside the hull and that they were never tied in to a bulkhead. The loads were never originally transferred to the bulkheads on the 27! My modification hasn't changed anything with the original design apart from shrouds being a little further outboard and the sheeting angles are minimumly effected. The external plates are bolted through the horizontal part of the E design chainplate (Imagine an E turned 90 degrees counterclockwise) and are stronger than the original. Many owners of the 27 have done the same and are very happy with the outcome. Check out other members and pics on the site.

 

[Loren Beach]

Seth,
I don't think you know that the original chainplates were glassed into the inside the hull and that they were never tied in to a bulkhead. The loads were never originally transferred to the bulkheads on the 27! My modification hasn't changed anything with the original design apart from shrouds being a little further outboard and the sheeting angles are minimumly effected. The external plates are bolted through the horizontal part of the E design chainplate (Imagine an E turned 90 degrees counterclockwise) and are stronger than the original. Many owners of the 27 have done the same and are very happy with the outcome. Check out other members and pics on the site.

Aha. I was sort of remembering that the original chainplates were glassed into the hull.
FWIW, that's the system that was used in all the Cascades and quite a few production sail boats in the 60's and 70's.
IIRC, as fin keels became more refined, boats could point a bit higher and it became more advantageous to bring the shroud base inward from the hull.
Also, hulls began to get wider to put more interior inside while also gaining some advantage under the then-popular IOR. Wider hulls meant wider decks and even more reason to being the shroud connection into the deck area.

Anyhooooo, using the glassed-in chainplate for a "backing plate" for the new external plates should be very very strong.

This opinion worth about one cent on Thursdays. YMMV.


Loren

 

[bigd14]

Those look good JacknRose!

Here is a shot of one of my E27's glassed in chainplates. I decided to replace them due to the rust stains and the fact that the core was saturated around all the chainplates. There is a lot of opportunity for crevice corrosion if (when) you get leaks around the chainplates.

After cutting the upright off and prior to installing the exterior chainplate through the strap glassed into the hull. Its very difficult to replace it on the inside due to clearance issues and because several bends would be required. Of course once I cut them off, they looked ok (fresh water boat), so I probably didn't really need to, but peace of mind is worth a lot to me.

I added some monstrous backing plates of G10 glassed into the surrounding hull. Total overkill I am sure.

And here are the chainplates bolted on the outside. I probably only needed 4 bolts! I had the chainplates bent to match the curve of the hull. According to Brion Toss I should have ideally made them a little shorter to eliminate flex and twisting, but it was his opinion that they were definitely strong enough. And they are visible so i can inspect them periodically.