chainplate followup

[niftynickers]

Last spring I replaced the chainplates on our 1982 Crealock 37.Upon removal we thoroughly inspected the old plates including a dye test.The old plates looked and tested fine,no cracks and no corrosion.Since I had no further use for them I gave the old plates to my friend who is a metal shop instructor at a vocational high school
Yesterday my friend called me to tell me that he had attempted to cut one of the old chainplates with a hydraulic shear for a project. The metal crumbled like an old cookie rather that shear.He tried again with another plate and that too crumbled.
We can only think that 20 plus years of weathering and stress has led to some molecular or crystalline changes in the metal.
The lesson being that even though the plates may appear sound and strong the prudent thing to do is replace over time.Lesson learned.

Dianne and Chuck Burke S/V NiftyNickers C37 #139

[jrd22]

I'm guessing that your post has caused a lot of Crealock owners to go change their shorts.
Pictures could cause heart attacks.

Good post, important stuff.

[SlowButSteady]

Yikes!!

[steneck]

That is a sobering observation. However, does your friend have experience using his hydraulic shear on stainless steel of that gauge? I'm wondering if this may be a property of the massive stainless.

Flip side of this is whether we have examples of apparently flawless PSC chainplates failing as a result of suspected change in metallergy?

Bob Steneck
PSC 34' Alaria
Christmas Cove, Maine

[orientalnc2010]

If this post is two days old, that would make it posted on April 1..... something about that date.

[niftynickers]

The date is purely incidental I would not joke about something this serious.The facts are just as I wrote them.Secondly my friend has been in the business of metal working and welding for over 30 years he has worked with plenty of SS i varying grades and hardnesses.He felt so strongly about this metal failure that he called me immediately to warn me about my headstay and backstay which were not replaced.They will be replaced within the month.You can take this info for what it is worth,I simply felt that I had to inform others with similar boats about what I felt was important info.

Dianne and Chuck Burke S/V NiftyNickers C37 #139

[eherlihy]

Pics would be awesome - in a horrifying kind of way...

[jrd22]

A shear is a shear, that wouldn't have anything to do with the SS crumbling. Might be a good idea to pass this experience on to the C37 owners group if there is one. I would want to know if I had one.

[MC1]

Originally Posted by jrd22

A shear is a shear, that wouldn't have anything to do with the SS crumbling. Might be a good idea to pass this experience on to the C37 owners group if there is one. I would want to know if I had one.

Implied in your posts in this thread is that there is something unique about the material or fabrication method Pacific Seacraft used for their chainplates.

According to a PSC 34 brochure (I believe this also applies to the 37) . . .

Chain plates are ¼" thick and 2" wide type 304
stainless steel thru-fastened to the hull with ½"
stainless steel bolts and full hacking plates.

Perhaps anyone with similar chainplates of that age should be concerned? Why aren't we seeing much more widespread problems in actual use if this is a real issue?

[JohnRPollard]

Hi Chuck,

Thanks for the heads up on this. I'm glad you got those chainplates replaced!!

Just to clarify a few details, for posterity:

1) Had your boat's chainplates previously been replaced? (You mentioned the chainplates were 20+ years old, and your boat is an '82.)

2) Just to confirm, but I recall that your boat is a PSC C37, not a Cruising Consultants C37, correct?

3) If your boat is a PSC, do you know whether your boat was factory finished, or sold as a hull/deck kit for owner finish?

4) Are the chainplates/bolts on your boat tied into a grounding system, i.e. wired to a ground that is interconnected with through-hulls, engine, etc?


Again, thanks for the heads up and any additional info/details you think might be relevant.