I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. This one was leaning forward an inch off of vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)
http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

On Sat, 29 Jan 2011 20:59:31 -0600, CaveLamb
wrote:

I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. This one was leaning forward an inch off of vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)
http://www.home.earthlink.net/~capri26/bolt.htm

You'd expect the aluminum to lose in a galvanic couple with SS. There
are several other corrosion mechanisms that affect SS in marine
environments. Google:

crevice corrosion
stress corrosion cracking
chloride stress corrosion cracking

for a few possibilities which are, in my opinion, more likely than
galvanic corrosion in this case.

Carbide precipitation is another possibility, but that would be a
result of faulty manufacturing of the fastener. On the other hand, I
have seen what I'm pretty sure was carbide precipitation in the tubing
in a couple bow pulpits, so it's not out of the question.


As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.


--
Ned Simmons

On Jan 29, 7:59*pm, CaveLamb wrote:
I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. *This one was leaning forward an inch off of vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? *Was this 20 years of dissimilar metal corrosion?
(4 photos)http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.

--

Richard Lamb
email me:
web site: *http://www.home.earthlink.net/~cavelamb

The aluminum would be the loser if it was electrolytic corrosion.
Probably chloride corrosion. Stainless steel -isn't-, at least when
it comes to sea water. You get inter-granular corrosion, basically
chunks fall out, how big depends on the alloy's grain structure. And
checking bolts would probably be a good idea, I'm told a beeswax-
pitch mixture makes a good goop for threaded hardware exposed to
seawater. Hope the stub wasn't hard to get out.

Stan

Ned Simmons wrote:
On Sat, 29 Jan 2011 20:59:31 -0600, CaveLamb
wrote:

I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. This one was leaning forward an inch off of vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)
http://www.home.earthlink.net/~capri26/bolt.htm

You'd expect the aluminum to lose in a galvanic couple with SS. There
are several other corrosion mechanisms that affect SS in marine
environments. Google:

crevice corrosion
stress corrosion cracking
chloride stress corrosion cracking

for a few possibilities which are, in my opinion, more likely than
galvanic corrosion in this case.

Carbide precipitation is another possibility, but that would be a
result of faulty manufacturing of the fastener. On the other hand, I
have seen what I'm pretty sure was carbide precipitation in the tubing
in a couple bow pulpits, so it's not out of the question.

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.




I've heard of crevice corrosion and stress corrosion cracking, but
the third one, chloride stress corrosion cracking, I had not heard
of before. Interesting.. but I doubt we have had that kind of environment
onboard the boat. At least I hope not!


My photos are the limit of my camera.
Aperture priority (about f 3.5) in macro mode - zoomed all the way out
(about 1/4" x 1/4" frame size).

Certainly not 500 X by any stretch of the imagination).

The suspect surfaces look more granular/pitted than fractured.

But if we could zoom in 300 X to 500 x would it look like these?

http://www.atclabs.com/Photos/300%20...ion.%20BSE.jpg
http://www.atclabs.com/Photos/300%20...20Area%202.jpg

Or a simple overload mechanism?
http://www.atclabs.com/Photos/300%20...20Overload.jpg

Well, whatever it was, that screw mess it up for the whole bunch.
They ALL are getting pulled and replaced!



--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

wrote:
On Jan 29, 7:59 pm, CaveLamb wrote:
I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. This one was leaning forward an inch off of vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

The aluminum would be the loser if it was electrolytic corrosion.
Probably chloride corrosion. Stainless steel -isn't-, at least when
it comes to sea water. You get inter-granular corrosion, basically
chunks fall out, how big depends on the alloy's grain structure. And
checking bolts would probably be a good idea, I'm told a beeswax-
pitch mixture makes a good goop for threaded hardware exposed to
seawater. Hope the stub wasn't hard to get out.

Stan


Thanks, Stan.

No, It came out with finger power and a long socket.
Just getting the socket on it was the hard part.

I can't inspect what's in the hole until I can remove the stanchions
completely and dig out all the old sealant.

What kind of "beeswax/pitch mixture" would that be?

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

"CaveLamb" wrote in message
m...
Ned Simmons wrote:
On Sat, 29 Jan 2011 20:59:31 -0600, CaveLamb
wrote:

I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the
lifelines
while docking. This one was leaning forward an inch off of vertical,
but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that
hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)
http://www.home.earthlink.net/~capri26/bolt.htm

You'd expect the aluminum to lose in a galvanic couple with SS. There
are several other corrosion mechanisms that affect SS in marine
environments. Google:

crevice corrosion
stress corrosion cracking
chloride stress corrosion cracking

for a few possibilities which are, in my opinion, more likely than
galvanic corrosion in this case.

Carbide precipitation is another possibility, but that would be a
result of faulty manufacturing of the fastener. On the other hand, I
have seen what I'm pretty sure was carbide precipitation in the tubing
in a couple bow pulpits, so it's not out of the question.
As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.




I've heard of crevice corrosion and stress corrosion cracking, but
the third one, chloride stress corrosion cracking, I had not heard
of before. Interesting.. but I doubt we have had that kind of environment
onboard the boat. At least I hope not!


My photos are the limit of my camera.
Aperture priority (about f 3.5) in macro mode - zoomed all the way out
(about 1/4" x 1/4" frame size).

Certainly not 500 X by any stretch of the imagination).

The suspect surfaces look more granular/pitted than fractured.

But if we could zoom in 300 X to 500 x would it look like these?

http://www.atclabs.com/Photos/300%20...ion.%20BSE.jpg
http://www.atclabs.com/Photos/300%20...20Area%202.jpg

Or a simple overload mechanism?
http://www.atclabs.com/Photos/300%20...20Overload.jpg

Well, whatever it was, that screw mess it up for the whole bunch.
They ALL are getting pulled and replaced!



--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb


A company I worked for had a product made from 316 stainless steel. Often
the product was submerged in a marine enviromment continuously.

A customers returned some with some M3 threaded holes in the body
"stripped". The screws looked ok, just the holes were "stripped". Turned out
it was crevice corrosion. We learnt something new that week!

Dennis wrote:
"CaveLamb" wrote in message
m...
Ned Simmons wrote:
On Sat, 29 Jan 2011 20:59:31 -0600, CaveLamb
wrote:

I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the
lifelines
while docking. This one was leaning forward an inch off of vertical,
but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that
hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)
http://www.home.earthlink.net/~capri26/bolt.htm
You'd expect the aluminum to lose in a galvanic couple with SS. There
are several other corrosion mechanisms that affect SS in marine
environments. Google:

crevice corrosion
stress corrosion cracking
chloride stress corrosion cracking

for a few possibilities which are, in my opinion, more likely than
galvanic corrosion in this case.

Carbide precipitation is another possibility, but that would be a
result of faulty manufacturing of the fastener. On the other hand, I
have seen what I'm pretty sure was carbide precipitation in the tubing
in a couple bow pulpits, so it's not out of the question.
As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.


I've heard of crevice corrosion and stress corrosion cracking, but
the third one, chloride stress corrosion cracking, I had not heard
of before. Interesting.. but I doubt we have had that kind of environment
onboard the boat. At least I hope not!


My photos are the limit of my camera.
Aperture priority (about f 3.5) in macro mode - zoomed all the way out
(about 1/4" x 1/4" frame size).

Certainly not 500 X by any stretch of the imagination).

The suspect surfaces look more granular/pitted than fractured.

But if we could zoom in 300 X to 500 x would it look like these?

http://www.atclabs.com/Photos/300%20...ion.%20BSE.jpg
http://www.atclabs.com/Photos/300%20...20Area%202.jpg

Or a simple overload mechanism?
http://www.atclabs.com/Photos/300%20...20Overload.jpg

Well, whatever it was, that screw mess it up for the whole bunch.
They ALL are getting pulled and replaced!



--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb


A company I worked for had a product made from 316 stainless steel. Often
the product was submerged in a marine enviromment continuously.

A customers returned some with some M3 threaded holes in the body
"stripped". The screws looked ok, just the holes were "stripped". Turned out
it was crevice corrosion. We learnt something new that week!




I'm going to use real BOLTS when they get changed...

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

On Sat, 29 Jan 2011 22:50:57 -0600, CaveLamb
wrote:

wrote:
On Jan 29, 7:59 pm, CaveLamb wrote:
I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. This one was leaning forward an inch off of vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

The aluminum would be the loser if it was electrolytic corrosion.
Probably chloride corrosion. Stainless steel -isn't-, at least when
it comes to sea water. You get inter-granular corrosion, basically
chunks fall out, how big depends on the alloy's grain structure. And
checking bolts would probably be a good idea, I'm told a beeswax-
pitch mixture makes a good goop for threaded hardware exposed to
seawater. Hope the stub wasn't hard to get out.

Stan


Thanks, Stan.

No, It came out with finger power and a long socket.
Just getting the socket on it was the hard part.

I can't inspect what's in the hole until I can remove the stanchions
completely and dig out all the old sealant.

What kind of "beeswax/pitch mixture" would that be?

Like you already know *everything* on a sal****er boats corrodes and
breaks. Good sealant really helps, we use tubes and tubes of that
white silicone sealant from the Marine boat supply. I'll get the name
if you need it.

I've seen pics of your boat. You got life easy. I waste my windy days
working on a 20 year old commercial fishing boat.

On Jan 29, 11:45*pm, CaveLamb wrote:





I've heard of crevice corrosion and stress corrosion cracking, but
the third one, chloride stress corrosion cracking, I had not heard
of before. *Interesting.. but I doubt we have had that kind of environment
onboard the boat. *At least I hope not!


Well, whatever it was, that screw mess it up for the whole bunch.
They ALL are getting pulled and replaced!

--

Richard Lamb
email me:
web site: *http://www.home.earthlink.net/~cavelamb

Stainless does okay in fresh salt water, but not in stagnant salt
water. The stagnant salt water does not have oxygen which is
essential to keep the stainless with an oxide layer. I am no expert
but you might consider Monel bolts.


Dan

On Sat, 29 Jan 2011 20:59:31 -0600, CaveLamb
wrote:

I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. This one was leaning forward an inch off of vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)
http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.

I believe that I'd pull all the bolts and I'd use something other then
aluminum plate as a backer - I know, some of the commercial made
yachts use it - but I've used waterproof plywood epoxied in place and,
if I thought it necessary, capped with thin stainless plate, the
stanchion well bedded with 5200 and the new bolts well coated too. It
seems to last ands last. I'd also stop using all-thread (if that what
they were) bolts and get proper bolts (the kind that only have threads
where the nuts go :-) as they are stronger.

Another thing. Don't let people pull on the life lines when they get
on and off. I even made some lovely lanyards, tied to the hand rails,
with a crown knot and hung them over the lines for fat ladies to use
to haul themselves aboard.

Cheers,

Bruce

Karl Townsend wrote:

Like you already know *everything* on a sal****er boats corrodes and
breaks. Good sealant really helps, we use tubes and tubes of that
white silicone sealant from the Marine boat supply. I'll get the name
if you need it.

I've seen pics of your boat. You got life easy. I waste my windy days
working on a 20 year old commercial fishing boat.

Temptress is 20 years old too, Karl!

But we sail purely for the pleasure of it.

The difference is - who pays whom for what!

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

On Sun, 30 Jan 2011 11:23:25 -0600, CaveLamb
wrote:

Karl Townsend wrote:

Like you already know *everything* on a sal****er boats corrodes and
breaks. Good sealant really helps, we use tubes and tubes of that
white silicone sealant from the Marine boat supply. I'll get the name
if you need it.

I've seen pics of your boat. You got life easy. I waste my windy days
working on a 20 year old commercial fishing boat.

Temptress is 20 years old too, Karl!

I'm surprised, she's been treated like a fine lady.

But we sail purely for the pleasure of it.

The difference is - who pays whom for what!

"Reel Smiles Too" heads out anytime there's $500 on the table, about
250 times a year. She's starting to look rode hard and put away wet.

Karl

In article
,
wrote:

On Jan 29, 7:59*pm, CaveLamb wrote:
I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. *This one was leaning forward an inch off of vertical, but
seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? *Was this 20 years of dissimilar metal corrosion?
(4 photos)http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.

--

Richard Lamb
email me:
web site: *http://www.home.earthlink.net/~cavelamb

The aluminum would be the loser if it was electrolytic corrosion.
Probably chloride corrosion. Stainless steel -isn't-, at least when
it comes to sea water. You get inter-granular corrosion, basically
chunks fall out, how big depends on the alloy's grain structure. And
checking bolts would probably be a good idea, I'm told a beeswax-
pitch mixture makes a good goop for threaded hardware exposed to
seawater.

I read in a book on sailboat rigging that pure lanolin works well in
protecting splices in stranded stainless steel wire. They also
mentioned using pitch and beeswax, but lanolin was the best for inside
the splice.

Joe Gwinn

wrote:
On Jan 29, 11:45 pm, wrote:





I've heard of crevice corrosion and stress corrosion cracking, but
the third one, chloride stress corrosion cracking, I had not heard
of before. Interesting.. but I doubt we have had that kind of environment
onboard the boat. At least I hope not!


Well, whatever it was, that screw mess it up for the whole bunch.
They ALL are getting pulled and replaced!

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

Stainless does okay in fresh salt water, but not in stagnant salt
water. The stagnant salt water does not have oxygen which is
essential to keep the stainless with an oxide layer. I am no expert
but you might consider Monel bolts.


Dan

Absolutely true. the process is called passivating and can occur only
with the presence of oxygen. Monel sounds good, but its gets
expensive. but anyone with a big boat must have a lot of money

John

ARE YOU T-R-Y-I-N-G TO **** ALL US SNOW SHOVELERS OFF!!!!!!!

Kidding of course, but no Key West Race Week for me this year either,
so I'm grumpy.

No metallurgist here, but do you think these are OEM? There were
certainly a lot of "stainless steel" screws used that were definitely
NOT marine grade.

While I am impressed with how well the photos came out, it's a bit
hard to tell from the pix how far below the surface the thread broke,
but heed the other poster that suggested a bolt that is not full
threaded so it has max strength, and use stainless as a backer. It
also appears that these were standard heads, and not flat-head. That
might put a bit more strain on things too, especially if the stanchion
base has countersunk holes..

Take care.

Brian Lawson,
Bothwell, Ontario.

XXXXXXXXXXXXXXXXXXXXXXXXXX

On Sat, 29 Jan 2011 20:59:31 -0600, CaveLamb
wrote:

I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. This one was leaning forward an inch off of vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)
http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.

John wrote:
wrote:
On Jan 29, 11:45 pm, wrote:





I've heard of crevice corrosion and stress corrosion cracking, but
the third one, chloride stress corrosion cracking, I had not heard
of before. Interesting.. but I doubt we have had that kind of
environment
onboard the boat. At least I hope not!


Well, whatever it was, that screw mess it up for the whole bunch.
They ALL are getting pulled and replaced!

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

Stainless does okay in fresh salt water, but not in stagnant salt
water. The stagnant salt water does not have oxygen which is
essential to keep the stainless with an oxide layer. I am no expert
but you might consider Monel bolts.


Dan

Absolutely true. the process is called passivating and can occur only
with the presence of oxygen. Monel sounds good, but its gets
expensive. but anyone with a big boat must have a lot of money

John


Not necessarily, John.

And she's not THAT big anyway...

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

Brian Lawson wrote:

ARE YOU T-R-Y-I-N-G TO **** ALL US SNOW SHOVELERS OFF!!!!!!!

Kidding of course, but no Key West Race Week for me this year either,
so I'm grumpy.

No metallurgist here, but do you think these are OEM? There were
certainly a lot of "stainless steel" screws used that were definitely
NOT marine grade.

OEM, probably yes. Catalina installed them - but it was 20 years ago.

I do take your point, but what is "marine grade"?
Is it anything like "aircraft quality"?

I think the wise thing for something like this is to buy known metals,
not just what's _called_ that.

While I am impressed with how well the photos came out, it's a bit
hard to tell from the pix how far below the surface the thread broke,

The break is about 1/8" above the top of the lock washer.
The deck is about 5/8" thick there.
So it broke just above the inside surface.

but heed the other poster that suggested a bolt that is not full
threaded so it has max strength, and use stainless as a backer. It
also appears that these were standard heads, and not flat-head. That
might put a bit more strain on things too, especially if the stanchion
base has countersunk holes..

The stanchion base plates are not countersunk.
More fastener options there.




Take care.

Brian Lawson,
Bothwell, Ontario.

XXXXXXXXXXXXXXXXXXXXXXXXXX

On Sat, 29 Jan 2011 20:59:31 -0600, CaveLamb
wrote:

I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. This one was leaning forward an inch off of vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal corrosion?
(4 photos)
http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.


--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

On Sun, 30 Jan 2011 18:14:13 -0500, Brian Lawson
wrote:



ARE YOU T-R-Y-I-N-G TO **** ALL US SNOW SHOVELERS OFF!!!!!!!

Kidding of course, but no Key West Race Week for me this year either,
so I'm grumpy.


If it makes you feel any better, it got flat calm most of that week.
Too hot also. If you ever do come down, go fishin' with me.

Karl

Karl Townsend wrote:
On Sun, 30 Jan 2011 18:14:13 -0500, Brian Lawson
wrote:


ARE YOU T-R-Y-I-N-G TO **** ALL US SNOW SHOVELERS OFF!!!!!!!

Kidding of course, but no Key West Race Week for me this year either,
so I'm grumpy.


If it makes you feel any better, it got flat calm most of that week.
Too hot also. If you ever do come down, go fishin' with me.

Karl


Yeah, I followed it on Sailing Anarchy.

Not much "sailing", but a heck of a lot of "anarchy"!

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

On Jan 30, 12:04*pm, Joseph Gwinn wrote:
In article
,





wrote:
On Jan 29, 7:59*pm, CaveLamb wrote:
I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or the lifelines
while docking. *This one was leaning forward an inch off of vertical, but
seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not all that hard!
to straighten it up - And something went POP! Pretty loud too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate buried in the
deck lay-up where the stanchions are attached.

What say ye? *Was this 20 years of dissimilar metal corrosion?
(4 photos)http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be pulled and
re-bedded.

--

Richard Lamb
email me:
web site: *http://www.home.earthlink.net/~cavelamb

The aluminum would be the loser if it was electrolytic corrosion.
Probably chloride corrosion. *Stainless steel -isn't-, at least when
it comes to sea water. You get inter-granular corrosion, basically
chunks fall out, how big depends on the alloy's grain structure. *And
checking bolts would probably be a good idea, *I'm told a beeswax-
pitch mixture makes a good goop for threaded hardware exposed to
seawater.

I read in a book on sailboat rigging that pure lanolin works well in
protecting splices in stranded stainless steel wire. *They also
mentioned using pitch and beeswax, but lanolin was the best for inside
the splice.

Joe Gwinn- Hide quoted text -

- Show quoted text -

Probably the point is to cover the stressed parts with something
waterproof that will stay that way. Cosmoline, heavy grease(lanolin
qualifies!), tar, whatever. Just that some stuff is a little nicer to
handle than others after applying.

As far as pitch and beeswax, it was an equal mixture. Pitch is pine
tar in this case, not oil refining leftovers. Melt on a water bath
and mix it up. If it's too hard, add more wax.

Stan

On Jan 30, 3:01*pm, John wrote:
wrote:
On Jan 29, 11:45 pm, *wrote:

I've heard of crevice corrosion and stress corrosion cracking, but
the third one, chloride stress corrosion cracking, I had not heard
of before. *Interesting.. but I doubt we have had that kind of environment
onboard the boat. *At least I hope not!

Well, whatever it was, that screw mess it up for the whole bunch.
They ALL are getting pulled and replaced!

--

Richard Lamb
email me:
web site: *http://www.home.earthlink.net/~cavelamb

Stainless does okay in fresh salt water, but not in stagnant salt
water. *The stagnant salt water does not have oxygen which is
essential to keep the stainless with an oxide layer. *I am no expert
but you might consider Monel bolts.

Dan

Absolutely true. *the process is called passivating and can occur only
* with the presence of oxygen. * Monel sounds good, but its gets
expensive. but anyone with a big boat must have a lot of money *

John- Hide quoted text -

- Show quoted text -

Are bronze fasteners available? I know monel is nasty stuff to work,
but bronzes usually aren't.

Stan

One fellow I know. He's got a couple pounds of the heaviest
grease I've ever seen. Says he got it from a Erie Canal Lock
repair guy, if I remember right. Anyhow, it's designed to
paint on with a brush, and stay under water for decades.
Some stuff like that could help. Injected into the holes.

Axle grease for boat axles could do the job. From your
nearby marina. You can get a 14 ounce pound can for seven
bucks or so. Stop at the grocery store, pick up a 13 ounce
pound of coffee, a 40 pack of Tampax that contains 32, and a
20 pounder of propane that has 15 pounds in it.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"CaveLamb" wrote in message
m...
I snapped a stanchion bolt the other day!
1/4" stainless steel machine screw actually.

Starboard stanchion by the cockpit. Forward inboard bolt.
The stanchions get abused sometimes, people grabbing them or
the lifelines
while docking. This one was leaning forward an inch off of
vertical, but seemed
sturdy enough.

I had the lifelines loose and was pulling on it (aft) - not
all that hard!
to straighten it up - And something went POP! Pretty loud
too

Inspecting it, it was pretty obvious what had happened, so I
dug the bolt out and replaced it.

This bolt (machine screw actually) had some serious
corrosion issues.
(See the attached photos)

There is quite a bit of old damage on the mating surfaces.
That's the dull gray part.
And quite a bit of sealant over the old damage!

The bright metal tab seems to be the place where it broke.
There was NOT A LOT of metal there!

I have recently learned that there is an aluminum plate
buried in the
deck lay-up where the stanchions are attached.

What say ye? Was this 20 years of dissimilar metal
corrosion?
(4 photos)
http://www.home.earthlink.net/~capri26/bolt.htm

As soon as possible, ALL of the stanchions are going to be
pulled and
re-bedded.

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb

Stormin Mormon wrote:
One fellow I know. He's got a couple pounds of the heaviest
grease I've ever seen. Says he got it from a Erie Canal Lock
repair guy, if I remember right. Anyhow, it's designed to
paint on with a brush, and stay under water for decades.
Some stuff like that could help. Injected into the holes.

Axle grease for boat axles could do the job. From your
nearby marina. You can get a 14 ounce pound can for seven
bucks or so. Stop at the grocery store, pick up a 13 ounce
pound of coffee, a 40 pack of Tampax that contains 32, and a
20 pounder of propane that has 15 pounds in it.


Thoes shrink rays area at it again, hih?

--

Richard Lamb
email me:
web site: http://www.home.earthlink.net/~cavelamb