How can I tell if my chain plates need to be replaced?

[unbusted67]

[unbusted67]

They look okay upon first inspection but is there some detail I need to pay attention to? Something specific? It looks a little corroded on the bottom but it doesn't look like the structural integrity has bee compromised.

[Sailmonkey]

Too didn't post any pics of the important part. There the threads pass through the deck devoid of oxygen. That's where they'll fail.

[Sailmonkey]

Stupid autocorrect!!!

[unbusted67]

Too used autocorrect the wrong way!!!

[unbusted67]

Please excuse my weathered fingers it's been a long week. Pics are of opposite sides of chain plate.

[Sailmonkey]

Those don't look too bad. But all it takes is one hairline crack that won't show up to the naked eye. How much are new u-bolts?
Best case scenario, clean them with a wire wheel and inspect them with a magnifying glass and reinstall them.

[Cheechako]

It's pretty hard to tell. You could clean everything off them and take them to a place that does flourescent penetrant inspection. As mentioned, you cant see a crack ready to propagate in the thread valleys.... and it may be hard to determine with FP inspection too. You couls ask them though. If they are available, maybe the cheapest is just new ones. Otherwise, roll the dice...

[sailorchic34]

Being a cheap, er frugal sailor, If they were mine, I'd clean them up rebed and re install them. All the threads look uniform and there is no real signs of crevice corrosion. You can get a dye penetration kit at many auto parts places if your really concerned with cracks.

[gjordan]

Here is another question. Does electro polishing make flaws easier to see, or does it cover up flaws???? Another note, if you clean up the threads with a normal wire wheel(mild steel) you will imbed bits of mild steel into the surface of the stainless and cause later rusting that might not be visible. This is a great question. ____Grant.

[fisherman.ben]

with things that are that important, don't be cheap, and get new ones. if nothing else you'll be buying piece of mind

[sailorchic34]

Hum... I'm more worried that the metals nowadays may not always be up to spec. Gee my chain plate are 42 years old. But they are 3"x 24"x1/2" for a dinky 34' mast.

[unbusted67]

Where the hell does one find chain plates? The Yard that I am working at has a complete wall full of catalogs, many of them rigging, I spent a good hour yesterday not finding what I was looking for. That chain plate in the picture is quite hefty, 18mm.

[robert sailor]

Check with Garhauer Marine

[unbusted67]

Nope nothing at the Garhuer web site. I will give them a call.