Peter,

I misunderstood your question.  If you want to mount your chainplates by thru bolting on the outside of the cabin wall; then, structurally that should be sound.  Be careful not to create an edge with the new chainplates and thru bolts that will snag sails and sheets.  You might need to bevel the edges of the chainplates to fair them.  &, of course you will have to fill in the OEM holes thru the cabin roof.  As you can see from the photos, my repair method made use of the OEM cabin roof holes, doesn’t leave anything outside the cabin walls to foul sails or sheets, is very strong, and easily inspected.

Roger Pihlaja
S/V Dynamic Equilibrium
1978. Sanford, MI

Sent from my iPhone

> On Aug 3, 2024, at 6:17 PM, ROGER PIHLAJA <roger_pihlaja at msn.com> wrote:
> 
> Peter,
> 
> The outer cabin wall is much stronger vs the inner cabin wall.  Also, if you look at the pictures I sent you, the OEM slots for the inner chainplates in the cabin roof line up with the outer cabin wall much better vs the inner cabin wall.  Thru bolting the chainplates thru the outer cabin wall will load the thru bolts in nearly pure shear, which is the strongest load path for the bolts.  Mine have lasted 36 seasons without leaking.  Besides, on the side of the cabin roof, it’s not like these thru bolts are below the waterline.
> 
> Roger Pihlaja
> S/V Dynamic Equilibrium
> 1978. Sanford, MI
> 
> Sent from my iPhone
> 
>> On Aug 3, 2024, at 5:27 PM, Peter Nyberg <peter at sunnybeeches.com> wrote:
>> 
>> Roger (or anyone else with an opinion),
>> 
>> Can you think of a downside to mounting the new chainplate to the outside of the cabin wall rather than inside?  The existing holes would have to be filled in, but once you’ve done that, there would be fewer holes in the boat.
>> 
>> Thanks,
>> 
>> --Peter
>> 
>> 
>>>> On Aug 3, 2024, at 4:13 PM, ROGER PIHLAJA <roger_pihlaja at msn.com> wrote:
>>> 
>>> Hi Todd,
>>> 
>>> The attached file has 3 annotated pictures.  They illustrate my lower chainplate repair.  The pictures are of the front port side lower chainplate.  But, all 4 lower chainplates are similar.  Note that I used snap-in plastic caps for the interior.  If I had it to do over again, I would have used the 4-1/2" Beckson deck inspection plates that I recomended in my recent posts on this subject.  Unfortunately, I didn't take any photos of the project in progress.  Hopefully, these images of the finished project will make things clearer for you.  Keep in mind you are looking at the current state of the chainplate repair originally done in 1988.  So, these chainplates have ~36 seasons of sailing on them.  I think they've held up pretty well, certainly better than the OEM chainplates.
>>> 
>>> Roger Pihlaja
>>> S/V Dynamic Equilibrium
>>> 1978  Sanford, MI
>>> 
>>