Island Packet Chainplate Replacement

[Eder]

Wow, your boat looks great. Seems like Mack Sails did a pro job for you.

[a64pilot]

Originally Posted by Eder

Wow, your boat looks great. Seems like Mack Sails did a pro job for you.

Most of that video is not my boat, it's an older video of another boat.
However they do sort of all look alike
I'm still about two weeks from being finished I'm afraid

[a64pilot]

I don't know the story but this boat showed up this weekend, I think it a 32' or maybe smaller. If you look at the pic, you see that the chainplate to the upper stay is "missing" however the mast and all other rigging is still there, so it wasn't catastrophic.

[Capnjb]

I just posted this in the IPY owners website. This is a good thread, so I'm
interested in feedback from here as well.

BOLT AND SUSPENDERS (EXTERNAL) CHAINPLATE DESIGN DISCUSSION (the original design by Bob Johnson was dubbed 'Belt and Suspenders')

Several owners have already installed external chainplates, and at least one yard. Here's a link to a discussion on the IPYOA site - https://www.ipyoa.com/forum/26-recom...te-replacement

Owners should not proceed down this path unless:
1. They think external plates look cool on our Traditional Watercraft (I happen to think so)
2. They are not overly concerned how this repair might affect resale value of their already 'vintage' craft.
3. They personally believe the replacement is as strong, or stronger than the original design. Hoping to start this discussion here...
4. They do not wish to completely deconstruct their boat and spend a significant fraction of the boat's value on the current 'industry standard' replacement.
5. Disclaimer: I am not an engineer, but wish to initiate some real conversation about alternatives to replacement.

Here is the concept regarding maintaining structural integrity with an external application:

1. The first throughbolt (BOLT) goes through the horizontal metal bracket sitting just under the deck, the one that the indwelling vertical chainplate piece is welded to. This bracket can be directly inspected once glass around it is removed, just like you can inspect all the other backing plates on your boat. Every picture I have seen in removed plates, these brackets are intact, the failures occur in the weld above (or below) it. An additional plate is added as backing for the BOLT. This should effectively (INPUT HERE WELCOME!) maintain the ORIGINAL strength of this portion of the installation. Again, this bracket is accessible for inspection.

2. The second BOLT goes through the horizontal metal in the next part of the old chainplate. Again, external glass is removed and the metal can be inspected. This is used as a backing plate only, and additional backing plate is added. These two steps already in use by several owners. INPUT HERE PLEASE regarding backing plate size, bonding method (if done) AND POSSIBLY glassing to reinforce to nearby existing 'suspenders' unilateral glass that was part of the original installation. Why remove and replace when you can build on it? Finally, this portion should NOT depend at all on remaining integrity of the original plates. (INPUT?)

3. Third throughbolt below this attaches to a horizontal backing plate and the SUSPENDERS are the unilateral glass used similar to original installation. At least on the IP38 I believe only the small cabinets in main cabin, and cabinet tops (port side main cabin/bulkhead and in front berth) need removal. Liners come out and you are good to go. There should be enough room for the installation.

4. Additional external throughbolts below this can go to backing plate, or additional glassing. This BUILDS on the current hull without having to grind out the old installation. This is where I hope some other ideas can come out and with comments on structural integrity.

This would end in a robust installation well exceeding the attachment points of the original plates. Just doing #1, then applying SUSPENDERS to BOLT #2 outside of the existing internal glass would duplicate the original installation... why is it necessary to remove the metal already there if you are not using it?

OK - looking forward to additional conversation... I believe this concept will put chainplate replacement within the realm of more owners. Notably, one company is already doing 'stubby' chainplates incorporating the 'BOLT' part of this idea.

I wonder if Mr. Johnson would care to comment?interested in feedback here as well. THANX!

[nihikai]

Originally Posted by a64pilot

Been quite a bit of talk about how IPs chainplates are sort of an end of life item for the boats.
My boat becomes a Florida antique this year, she celebrates her 30th this year, so for her birthday I'm having her chainplates replaced.
I thought I'd start this thread with sort of a photo essay to show and try to explain what all is involved and costs etc.
All boats that I have head of go with Garhauer manufactured 316L replacements, and they are good I'm sure and have an expected life limit of about 15 yrs. now of course they may last much longer, but may not too and they would be very, very difficult to inspect, so to be sure your safe, the 15 yr life limit, or recommended replacement interval was established.
I went a slightly different route and had mine made out of 6/4 Titanium, which should have no realistic life limit, not as expensive as I brought it would be.
Anyway a few pictures to try to explain the process.
Attachment 152431Attachment 152432Attachment 152433Attachment 152434

Hi,

Do you know which IP models suffer from this problem?

[JoeRobertJr]

Originally Posted by nihikai

Hi,

Do you know which IP models suffer from this problem?

Hi, Nihikai. to the forum.
I understand that IP switched to the better material in 1998, so earlier models are more likely to have issues.