Replacing Chain Plates

[Noreastern]

If there is no obvious crevice corrosion on a chain plate that is almost fifty years old should it be replaced anyway? If so is there a favorite company that people here know of to make new ones?

Second issue is how to seal the deck area where the chain plate goes thru the deck? My usual way of picking out the balsa core taping the hole on the lower skin and filling with epoxy will not work. I am afraid goo will drip into the channel that the chain plates bolt into making it imposable to reinsert the chain plate.

Appreciate any thoughts.

[Stumble]

Noreastern,

Crevice corrosion can not always be seen. The on lye ay to know is either dye test or x-ray it. And it takes a competent technician to really know what they are looking at, until you have done a good number your eyes may fool you.

At 50 years I would probably replace them anyway due to work hardening even if corrosion isn't a specific concern.

My recommendation is to switch to titanium, and there are a couple of companies that make them. Figure an extra 25% compared to electropolished chainplates! but they can be stronger and immune to future corrosion.

[boatpoker]

Thicken the epoxy with cabosil to the consistency of peanut butter and it will not drip or run.

[Cheechako]

If they are 50 old and no issues I say keep 'em. They must be something good! I would intensely clean them, Have them Dye penetrant inspected if not too much money, and maybe have them polished or electropolised... again if not too much $.
If none of the above.... buy a good loupe and intensely look at all the area where they passed thru the deck at least.

[mitiempo]

Originally Posted by Noreastern

Second issue is how to seal the deck area where the chain plate goes thru the deck? My usual way of picking out the balsa core taping the hole on the lower skin and filling with epoxy will not work. I am afraid goo will drip into the channel that the chain plates bolt into making it imposable to reinsert the chain plate.

Appreciate any thoughts.

After the balsa is removed and the hole is ready for the thickened epoxy either install a replica of the chainplate made from plastic or a well waxed chainplate in the hole. This will not stick to the epoxy and can be removed easily. I would use the plastic option.

[zboss]

Having just gone through this I say "yes". Forget the dye penetration test and all that. Just replace them. In the grand scheme of boat things they are not that expensive.

On the other hand... and complementary to what Cheechako was hinting at... you are taking tested metal and replacing it with untested metal. So, don't take it right off shore right?

Even new metal can have manufacturing defects, you as the installer could make mistakes, etc...

[Rhapsody-NS27]

I would say replace them. I've seen info from people with 30 yr old boats who remove their chainplates and some of them, while they look ok, would break in their hands.

Replacement will give you peace of mind and no doubt about age and condition.

[a64pilot]

If I went through all the trouble to pull them, new ones are going back in, assuming I had the funds of course

[mitiempo]

I agree - replace them. I did the same with my chainplates and replaced them, using the old ones as backing plates for the new ones as the old backing plates were thin and a bit distorted.

[Cheechako]

When Filling in the balsa core with epoxy etc... I would leave some room for caulking between the glass and the chain plate. Too tight a fit could mean a leak...

[fryewe]

The chainplate in the photo appears to be cracked just to the right of the second hole from the bottom.

Garhauer can replicate your plates with electropolished SS at a good price.

[mitiempo]

Originally Posted by Cheechako

When Filling in the balsa core with epoxy etc... I would leave some room for caulking between the glass and the chain plate. Too tight a fit could mean a leak...

You can wrap plastic tape around whatever you use to preserve the chainplate size hole.

[bobconnie]

Any real Job Shop Machine Shop can make these chain plates for ya ! they are pretty simple !!After this many years why take a chance?? My daddy always said, don't be penny wise and dollar foolish !! New ones should be fairly cheap to have made !! If I had a choice of going cruiseing with 50 yr old ones and new ones, I would have no trouble getting new ones!! They are the heart of your rigging!! Fix now and forget about them for at least another 25 years at least !!

[Noreastern]

Thanks All! I am going for replacing them. will check out Garhauer as well as some local machine/metal shops.

Like idea of using old ones to block goo from filling channels after waxing them.

Thanks for all the responses.

[Cheechako]

A couple thoughts regarding new plates:
*Make sure your vendor includes deburring the holes well, edges of the plates need to be smoothly rounded (break sharp edges)
*This needs to be done properly so as not to embed metal debris into the metal... debris left over from working on plain steel will embed in the SS and rust starts quickly.
*If they are Electro Polished after fabrication this will help to eliminate this by eating away the steel embedded in the surface.
*Proper wheel polishing can make them not only look good,, but highly polished SS is much less prone to Inter Granular Corrosion.
*Plates made from sheared plate rather than flat bar may be more prone to breaking/cracking than old ones made from bar. The whole edge of sheared plate has been "broken" creating a multitude of stress risers. material must be removed from these.
So bottom line, if going new get them done properly.. otherwise you could be getting worse ones than your old ones!