Author Topic: External Round Chainplates Design  (Read 2803 times)

Soggy Geek

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Re: External Round Chainplates Design
« Reply #15 on: May 15, 2019, 05:19:31 PM »
Pictures of the Soggy Paws job here:

http://svsoggypaws.com/csy/rig.htm#Chainplates
Soggy Paws the CSY has been sold but not forgotten!
http://svsoggypaws.com/CSY/

Soggy Geek

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Re: External Round Chainplates Design
« Reply #16 on: May 15, 2019, 05:25:14 PM »
And Beaujolais helpful detailed writeup is here:

http://svsoggypaws.com/csy/beaujolaischainplates.htm
Soggy Paws the CSY has been sold but not forgotten!
http://svsoggypaws.com/CSY/

Ron Sheridan

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Re: External Round Chainplates Design, Original drawing
« Reply #17 on: August 26, 2019, 01:25:04 PM »
Hello gang,
Have been off this site for years but checking back in saw some discussion on the Round Chain Plate design I had come up with in the latter 90's.  My design, was a take off of a design by Tillerson Pearson and Steve Dashew for the manufacture 54'-62' Deerfoot Yachts. You can see their design (10 bolts) in the Dashew's Cruising Encyclopedia page 582. For manufacturing it made a lot of sense, as you could make All chain plates the same and just rotate the tang in the direction needed.  Installation was easy, just drill and insert the center bolt first, the rotate the tang in the direction of the rigging wire, or attach it.  Drill the remaining holes, insert bolts and so on. Easy.  CSY used 3/8" tang material (304 SS) welded to a 1/4" triangular backing plate, with 6 bolts.  I used 1/2" (316 grade SS) (no welds needed and 8  "Counter Sunk" headed bolts also 316 grade.  Plated cut on a C&C machine, but later ones were made at a machine shop locally for other owners and looked perfect as well. Note, countersinking the heads, offered crevice corrosion protection.  Many Hex Head bolts used on CSY's failed, heads snapping off because water/moisture could gain access under the head and over time, crevice corrosion cause the stainless to fail.
Here's a few photos from 2000/2001.
 Note, back in the day, I payed about $300/Plate for material, cutting, final polishing(I did it up to 600 grit).  the bolts alone back then were $9.69 each plus Aircraft 316 Nylock nuts and 1/2" large flat washers for the interior.  I ordered 100 as my Pilothouse was a ketch requiring more plates/bolts.
Important I feel is that, without the ability for heavier material used and double width tangs (4" double vs 2" single) and 1/2 thick material vs 3/8's as well as 8 bolts rather than 6, the plates should last 1/2 century! I feel reason this method makes Chain Plates totally trustworthy for many decades....many.
The limit here on 'file size' prohibits me from including a the diagram which is 178 ks' vs 158 allowed, so I'll post a few of these on my blog site for those interested.https://memoryrose.blogspot.com/search/label/Chain%20Plates
Hope this helps anyone engaged in this project.

Ron Sheridan

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Re: External Round Chainplates Design
« Reply #18 on: August 26, 2019, 01:29:47 PM »
...click any photo for a slightly larger version if needed.

Peter Roach

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Re: External Round Chainplates Design
« Reply #19 on: October 19, 2019, 09:44:36 PM »
I redid mine with external chain plates that are straight. I will take a picture and post.

Apparently, the chain plates were designed for the yard manager for CSY back in the day when he built his own boat. They still had the design. I know of one other that has done these style chain plates. I upgraded to 1/2".

When I pulled the chain plates they were in GREAT conditions. Mine did not have the weld across the bottom of the tang (1980 boat) Apparently that caused a lot of the problems.

To get the nuts off - get a micro torch and heat them up until you see the adhesive sizzle. Even though the bolts are behind the rub rail you will mess up the paint on the side (a little). Not an easy job but worth it!
I tried having a bad day once but I did not like it

albore

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Re: External Round Chainplates Design
« Reply #20 on: November 05, 2019, 07:59:07 AM »
Does anyone know what angles the external round chainplates should be bent to for a CSY 44 WO?
Mellivora is not concerned