Chainplate question

[Gavinvt]

A recent inspection revealed moisture at a chainplate on my '83 Catalina 25. The bulkhead is dry. I pulled the plate and there was no rust on the plate, hardware or backing plate. All looked good but when I put some polish on it these horizontal lines showed up in the critical area where the plate passes through the deck.

Attached is a photo. Are these serious enough to replace the plate? Simply surface blemishes?

(FYI, once the plate issue is resolved, I plan to clean out the area the chainplate passes through with an allen wrench, epoxy the cavity, and drill out/epoxy/coutersink the chainplate cover holes before re-bedding with boatlife lifecaulk/polysulfide).

Any feedback or advice is welcomed. Thank you!

[Searles]

They might be scratches or more likely stress cracks , get a stress crack or crack test kit,will give you a better idea ,for my,money replace them all ,no more worry for many years ,plus good sales point , 2205 s/s is a good start .⛵️⚓️

[Orion Jim]

I’d be inclined to replace 39 year old chaimplates. Having pulled one and found indications of stress would seal the deal. You can attempt to analyze the flaw or just put that money toward replacement. You can rest assured that chainplate did not have that appearance when installed.

[tkeithlu]

Now that you have them off, do replace them. I'm saying that despite a closer look at your photograph. The lines look a whole bunch more like tool marks than like stress cracks.

[Rumrace]

The metal appears to be stretched. I’d toss them. Having only repaired stanctions and cleat mounts on power boats I’d like to follow your repair on the passthrough. Switching from power this hardware is very alien to us.

[Bowdrie]

Originally Posted by tkeithlu

The lines look a whole bunch more like tool marks than like stress cracks.

Yes, it appears that after the original installation a knife blade/chisel was used to remove cured caulk.
Corrosion doesn't look like that.

[sck5]

Its the labor in getting the chain plates off and back on that is the trouble. No way I want to go through all that and not put new chain plates. Not that expensive. Sleep better

[boatpoker]

Retired Certified Marine Corrosion Tech -
I see no indication of corrosion on that plate.

Can you say specifically what was said about moisture and where/how that was determined ?

[Cheechako]

That looks like scratching to me. You can inspect with a loupe or get a Dye Penetrant inspection kit. Amazon even has them, or have some place do it. You can polish it out if you want.
Chainplate looks pretty good to me.
I would expect to see light rusting where those bends are but I dont even see any of that...

[AKA-None]

To me that doesn’t look like a fracture
But as they are off you could replace them but I don’t see why you must replace them

[tyzardoz]

My first question is where do you sail.

From the info and pic provided I would be inclined to keep them. If you are sailing inland protected waters.. I'd say keep them. Your boat isn't especially heavy in displacement and the rig isn't particularly massive. If you are sailing ocean..I would replace them since they are off already (all of them).

[pesarsten]

I had new ones fabricated by a local shop in 2018. Marine sources were 10 x what I paid.

6 plates 316 ss, 3/8 thick, 1 1/2 wide, and 20 in long about $40 each

Not worth keeping the old ones at that price, check non-marine sources. You can even buy the stock cut to your lengths on line so, some drilling and polishing and your set.

[boatpoker]

Originally Posted by pesarsten

I had new ones fabricated by a local shop in 2018. Marine sources were 10 x what I paid.

6 plates 316 ss, 3/8 thick, 1 1/2 wide, and 20 in long about $40 each

Not worth keeping the old ones at that price, check non-marine sources. You can even buy the stock cut to your lengths on line so, some drilling and polishing and your set.

it's a 25' Catalina !

[ThereAndBack]

The cost of a chainplate like that is small compared to the labor required to remove and re bed a new one. If these things come out once every 20 years or so, I'd replace them on principle.

[pesarsten]

Originally Posted by boatpoker

it's a 25' Catalina !

I know, my boat was substantially larger so he should be able to pay even less, hopefully.