Replacing Chainplates

[Jim 5757]

I've finally decided it's time to replace the 45 year old chainplates on our Morgan 28OI. These are 1/4 x1_1/2" SS Bar stock, externally mounted with 3 1/2" carriage bolts per. No obvious failure but lots of rust running down the hull over the last few years.
Anyway Morgan had welded bushings at the the clevis end. I believe this is to give the clevis pin more bearing area? Our plan is to use 3/8" bar stock to avoid the expense of welding a bushing. Thoughts anyone?

 

[MitchM]

the bushing adds to strength of the clevis/ plate joint as it provide more bearing surface than just having the clevis or bolt's outer surface bear on the inside surface of the hole in the chainplate . the bushing also aids somewhat in preventing moisture entering the joint surface . (bushing plate design and pin loading is a whole topic on eng-tec and the other professional engineering web sites especially complex where the pin is in double shear . ) rig-rite has a number of stock chain plates for just about any boat ever manufactured. why not call them , give your boat spec and see what they recommend? and ask about the advantage of having the original 1/2 " chainplate w/ bushing replicated, vs. a straight plate 'of the shelf' of upgraded 3/8 " thickness with no bushing ? then proceed accordingly...

 

[Jim 5757]

Thanks for your input Mitch. I spoke to Rig Rite but they did not give me a good feeling about this. I also spoke to Garhauer. they are happy to accommodate my needs at a fair price so I'm sending my original chainplates to them. We will see how it comes out pics to follow...

 

[agprice22]

You could have those bushings welded into the stock bar by ANY local shop. Stainless welding can be done by Mig, Tig, Gas... 10 minute job.

 

[jssailem]

@Jim 5757 You might also check with Schaefer Marine in CT. https://www.schaefermarine.com/
They are equipped to cut your chainplates to match the hole pattern on your current plates.

That is one of the issues in addition to the bushing. Contrary to popular belief, some manufacturers drilled the chainplate holes after the boat was built. They are not all identical premanufactured pieces that go together like Legos.

 

[Jim 5757]

Thanks for your input. Agprice, I did look into having bushings welded in and I agree, it's not really a big deal. However, it's actually allot less expensive to just use 3/8" bar stock, and much easier to polish them after mfg. Since these chainplates are mounted externally, the extra 1/8" thickness won't matter. (also, while my engineering math is quite rusty, I just can't believe that extra 1/8" of bearing surface would even make a difference as far as supporting the clevis pin in shear mode).
jssailem, someone else also suggested Schaefer to me so I checked out their website. They have a nice video, but they never returned my messages (?). Anyway, the nice folks at Garhauer have the parts now... we'll see how they make out.

 

[Jim 5757]

News update: Garhauer has my chainplates and has given me a price: it's 1/3 the price of Rollformers'!!! I'll post pics when I receive them...

 

[Jim 5757]

Okay, chainplates arrived today from Garhauer. Quality is exceptional as is

usual. Here is a pic before and after...
$230 including the shipping...