Embedded Chain plate maint/replacement - SailNet Community
 81Likes
Reply
 
LinkBack Thread Tools
post #1 of 185 Old 10-16-2013 Thread Starter
Senior Member
 
chucklesR's Avatar
 
Join Date: Sep 2007
Location: Pasadena Md - Magothy side
Posts: 5,979
Thanks: 10
Thanked 31 Times in 31 Posts
Rep Power: 10
     
Embedded Chain plate maint/replacement

I promised in this thread to start a new thread on the steps going forward.
Chain plate or impact.
This is my attempt at doing so.

Last night I pulled the joinery off and took a look at what I'd be needing to do to replace the chain plates.
Just a reminder - 1987 Irwin 38 CC MkII, chain plates embedded in the fiberglass, the tab with the pin hole (for the shroud) goes through a 2 inch thick toe/cap rail.
Here's the overall view:


The issue that spring boarded this:


That area from the outside on a FLIR image

That area from the inside on a FLIR

That area eyeball view, obvious long term water leak (previous owner).


Okay, here's the big one. That area - no wood or joinery over it. Raw hull.


What you are seeing is two of the three chain plates (the forward one is on the other side of the bulkhead). The chain plates have two horizontal 'tabs' - like an inverted orthodox cross. I do not know how they are joined, no bolts are obvious so I assume a weld.
The obvious dirt is from long standing wet/rot over the years. I had no leaks at all until I removed the jelly fish/snot over the chain plate covers while doing the teak rails. It is all obviously years old.
Between the two horizontal tabs of the plates are some obviously well caulked screw pointy ends - they are what is holding the 2 inch thick, 3 inch wide rub rail on.

There is a heavy glass strip at the bottom of the plates, this folds horizontal over where the coring obviously starts (as well as the gel coat).
At the top there is a gel coat cover strip, up under that looks like this.


Those screws are bunged toe rail/cap rail, stanchion bases etc, going through the bases, teak, and folded 'shoebox' lips of the deck/hull.

Here's the underside showing a plate -



That's enough for now.
Delta-T and leospellmans like this.

Lessons learned are opportunities earned.
chucklesR is offline  
Quote Quick Reply Share with Facebook
The Following User Says Thank You to chucklesR For This Useful Post:
leospellmans (12-18-2013)
Sponsored Links
Advertisement
 
post #2 of 185 Old 10-16-2013
Just another Moderator
 
Faster's Avatar
 
Join Date: Sep 2005
Location: New Westminster, BC
Posts: 16,534
Thanks: 104
Thanked 312 Times in 300 Posts
Rep Power: 10
     
Re: Embedded Chain plate maint/replacement

This is going to be some job.. I expect you'll need to get to the opposite side as well at some point?

Once you get the glass off the inside I suppose you're hoping to pull the chainplates out from inside? or are you going to have to cut them out?

I expect you'll find the external crazing is from corrosion swelling on the plates.

Ron

1984 Fast/Nicholson 345 "FastForward"

".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)
Faster is offline  
Quote Quick Reply Share with Facebook
post #3 of 185 Old 10-16-2013
Senior Member
 
davidpm's Avatar
 
Join Date: Oct 2007
Location: Madison
Posts: 3,998
Thanks: 250
Thanked 62 Times in 53 Posts
Rep Power: 8
 
Re: Embedded Chain plate maint/replacement

I'm confused, how are the chain plates fastened?
They can't just be glassed to the hull and that is all, can it?

Is their any chance that they keep going down and attach to something below the seat. I can't tell from the picture if they stop or keep going.

I notice that they are in the middle of a span not at a bulkhead.
That means that the compression force has to be handled by the deck, yes?

Is that a nut at the bottom end of the forward chain plate?

Nice pictures, thanks for that!!!

The lesson from the Icarus story is not about human failing.
It is a lesson about the limitations of wax as an adhesive.
If you have an engineering problem solve it.
davidpm is offline  
Quote Quick Reply Share with Facebook
post #4 of 185 Old 10-16-2013
Senior Member
 
deltaten's Avatar
 
Join Date: Oct 2012
Location: Lancaster Co. PA/ North East, MD
Posts: 778
Thanks: 7
Thanked 19 Times in 19 Posts
Rep Power: 3
 
Send a message via Yahoo to deltaten
Re: Embedded Chain plate maint/replacement

Oh, Man! Looks like a nasty bit of work ahead!? Appears to be a glassed -in arrangement to me.
Best of luck to ya

S/V Chrysalis
'80 Watkins 27
North East, MD
deltaten is offline  
Quote Quick Reply Share with Facebook
post #5 of 185 Old 10-16-2013
Jnoiur Mebemr
 
StormBay's Avatar
 
Join Date: Sep 2010
Location: Bahamas
Posts: 180
Thanks: 1
Thanked 10 Times in 9 Posts
Rep Power: 5
 
Re: Embedded Chain plate maint/replacement

I see two, how is access to the forward most plates (forward lowers I'm assuming)

Quote:
Originally Posted by davidpm View Post
I'm confused, how are the chain plates fastened?
They can't just be glassed to the hull and that is all, can it?
These Irwin's have chainplates that are yes, simply glassed in. Its not that uncommon. Their are quite a few different boat builders that fastened chainplates this way on at least some of there models. Allied Luders 33, Hans Christian 33, Endurance 35 are just a few that come to mind.

Yu & Frank

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
StormBay is offline  
Quote Quick Reply Share with Facebook
post #6 of 185 Old 10-16-2013
Senior Member
 
Maine Sail's Avatar
 
Join Date: Jan 2003
Location: Maine Coast
Posts: 5,877
Thanks: 20
Thanked 218 Times in 166 Posts
Rep Power: 16
       
Re: Embedded Chain plate maint/replacement

Quote:
Originally Posted by chucklesR View Post

There is a heavy glass strip at the bottom of the plates, this folds horizontal over where the coring obviously starts (as well as the gel coat).
At the top there is a gel coat cover strip, up under that looks like this.


Those screws are bunged toe rail/cap rail, stanchion bases etc, going through the bases, teak, and folded 'shoebox' lips of the deck/hull.
Chuck,

While you're in there you may want to add some through bolts to the hull/deck joint as opposed to just screw & glue....
oysterman23 likes this.

______
-Maine Sail / CS-36T


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.




Images In Posts Property of Compass Marine Inc.


Maine Sail is offline  
Quote Quick Reply Share with Facebook
post #7 of 185 Old 10-16-2013
Chastened
 
BubbleheadMd's Avatar
 
Join Date: Nov 2009
Location: Edgewater/Annapolis
Posts: 3,354
Thanks: 2
Thanked 80 Times in 75 Posts
Rep Power: 6
 
Send a message via Yahoo to BubbleheadMd
Re: Embedded Chain plate maint/replacement

Quote:
Originally Posted by StormBay View Post
I see two, how is access to the forward most plates (forward lowers I'm assuming)


These Irwin's have chainplates that are yes, simply glassed in. Its not that uncommon. Their are quite a few different boat builders that fastened chainplates this way on at least some of there models. Allied Luders 33, Hans Christian 33, Endurance 35 are just a few that come to mind.
For the life of me, I cannot understand why a person would replicate this method instead of simply bolting them to the hull with suitable reinforcement.
mitiempo likes this.

S/V Old Shoes
1973 Pearson 30 #255
BubbleheadMd is offline  
Quote Quick Reply Share with Facebook
post #8 of 185 Old 10-16-2013 Thread Starter
Senior Member
 
chucklesR's Avatar
 
Join Date: Sep 2007
Location: Pasadena Md - Magothy side
Posts: 5,979
Thanks: 10
Thanked 31 Times in 31 Posts
Rep Power: 10
     
Re: Embedded Chain plate maint/replacement

David,

The nut at the bottom of the forward (actually the center) plate is used to fasten a ground wire, it goes from there to the keel.

The plates stop at the heavy glass strip, they do not go anywhere else.

I'm not an engineer, I don't know where the compression is going - I thought it was to the keel, the mast is deck stepped with a post directly under the mast that transfers the compression to at 3/4 plate 2 inches above the (encapsulated) keel.


Maine Sail, you betcha - some of those screws have got to be replaced by bolts, probably all of them that are for stanchions and jib tracks - if I can get to the bottoms.


I have to get tarps, plastic, vacuums, tyvek suits and all that. Then it's off to fiberglass dust hades for a couple weeks.

I'll shoot some pics on the way.

Lessons learned are opportunities earned.
chucklesR is offline  
Quote Quick Reply Share with Facebook
The Following User Says Thank You to chucklesR For This Useful Post:
Alden68 (04-27-2014)
post #9 of 185 Old 10-16-2013
Senior Member
 
overbored's Avatar
 
Join Date: Oct 2010
Location: Dana Point, Ca
Posts: 1,192
Thanks: 1
Thanked 62 Times in 62 Posts
Rep Power: 5
 
Re: Embedded Chain plate maint/replacement

not sure what you worried about where the compression is going. the mast is in compression to the keel. the chainplates are in tension. fiberglass is very strong in tension. get a Fein saw for cutting away the glass. very little dust and the best tool for fiberglass work. worth the money.
FEIN Multimaster Oscillating Multi-Tool Kit-FMM 250 Start Q at The Home Depot
Faster, mitiempo and StormBay like this.

"FULL TILT II" 2011 BENETEAU FIRST 30
"FULL TILT" SOVEREL 33
"GOLD RUSH" PRINDLE 16

Last edited by overbored; 10-16-2013 at 01:51 PM.
overbored is offline  
Quote Quick Reply Share with Facebook
post #10 of 185 Old 10-16-2013
Senior Member
 
davidpm's Avatar
 
Join Date: Oct 2007
Location: Madison
Posts: 3,998
Thanks: 250
Thanked 62 Times in 53 Posts
Rep Power: 8
 
Re: Embedded Chain plate maint/replacement

Quote:
Originally Posted by overbored View Post
not sure what you worried about where the compression is going. the mast is in compression to the keel. the chainplates are in tension. fiberglass is very strong in tension. get a Fein saw for cutting away the glass. very little dust and the best tool for fiberglass work. worth the money.
FEIN Multimaster Oscillating Multi-Tool Kit-FMM 250 Start Q at The Home Depot
It is obviously OK as it has lasted a long time on a lot of different boats. I'm just trying to understand the loads.
The mast is pushing down that makes sense.
The chain-plates are pulling up.
Some portion of the load however is attempting to make the boat narrower.
I see a lot of boats that have the chain plates connected to a bulkhead.
The bulkhead is tabbed into the hull distributing the load.
The bulkhead often has a small beam that goes across the whole boat again distributing the load.

In this case the load attempting to make the boat narrower has to be taken by the deck.

I'm not saying it is a problem unless of course you had a soft deck.

I guess I find it hard to believe that a bandage of glass over the chain-plate on the hull is all their is to it.
Is it possible they are relying in part on 5200?
Does polyester resin stick that well to SS?

Did they do some tricks like put some holes in the stainless so the resin would form keys?

What I'm saying is that a SS bar bolted to a bulkhead makes sense to me. It is obviously strong.

This kind of construction has stood the test of time so must be pretty good, I'm just trying to understand it.

The lesson from the Icarus story is not about human failing.
It is a lesson about the limitations of wax as an adhesive.
If you have an engineering problem solve it.
davidpm is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Chain Plate Replacement casey1999 Gear & Maintenance 35 05-21-2013 11:53 PM
chain plate reinforcement UseDaGreyMatter MacGregor 1 12-30-2010 11:05 PM
Chain plate help atlanticcruiser Gear & Maintenance 15 12-20-2010 12:46 PM
Chain Plate (Not) davidpm Gear & Maintenance 2 04-14-2009 06:52 AM
Chain Plate Replacement jsutor Gear & Maintenance 1 04-30-2005 03:40 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome