Copper tubing to be exact. I have a couple rolled lengths of soft
copper tube. One length is about 20 years old and the other about 4
years old. Both are the soft copper tubing commonly used for
refrigeration or water. It comes with a plastic cap on each end.
Anyway, my old rolled length, which I discovered the other day when
cleaning out some junk, is much stiffer than the new roll. So I am
wondering if the copper got stiffer over time because the older stuff
is quite a bit harder to bend than the newer stuff.
Eric

On 06/24/2015 12:27 PM, wrote:
Copper tubing to be exact. I have a couple rolled lengths of soft
copper tube. One length is about 20 years old and the other about 4
years old. Both are the soft copper tubing commonly used for
refrigeration or water. It comes with a plastic cap on each end.
Anyway, my old rolled length, which I discovered the other day when
cleaning out some junk, is much stiffer than the new roll. So I am
wondering if the copper got stiffer over time because the older stuff
is quite a bit harder to bend than the newer stuff.
Eric

You sure it isn't just K or L over M, maybe? I've no reason to think it
will harden just with age; I've pieces around that are at least 50 or 60
yo that I use chunks off of periodically and never noticed any real
difference.

--

Except for certain alloys it doesn't age harden.
But refer tube has a pretty wide tolerance in wall thickness. Typically
+-10% of the thickness.
My guess is that when copper was cheaper, they erred on the plus side, now
they lean to the minus.

One could as much as 20% thicker than the other.

Paul K. Dickman

wrote in message
...
Copper tubing to be exact. I have a couple rolled lengths of soft
copper tube. One length is about 20 years old and the other about 4
years old. Both are the soft copper tubing commonly used for
refrigeration or water. It comes with a plastic cap on each end.
Anyway, my old rolled length, which I discovered the other day when
cleaning out some junk, is much stiffer than the new roll. So I am
wondering if the copper got stiffer over time because the older stuff
is quite a bit harder to bend than the newer stuff.
Eric

On Wed, 24 Jun 2015 13:00:41 -0500, dpb wrote:

On 06/24/2015 12:27 PM, wrote:
Copper tubing to be exact. I have a couple rolled lengths of soft
copper tube. One length is about 20 years old and the other about 4
years old. Both are the soft copper tubing commonly used for
refrigeration or water. It comes with a plastic cap on each end.
Anyway, my old rolled length, which I discovered the other day when
cleaning out some junk, is much stiffer than the new roll. So I am
wondering if the copper got stiffer over time because the older stuff
is quite a bit harder to bend than the newer stuff.
Eric

You sure it isn't just K or L over M, maybe? I've no reason to think it
will harden just with age; I've pieces around that are at least 50 or 60
yo that I use chunks off of periodically and never noticed any real
difference.
Maybe that's it, different types. I thought all the coiled copper
tubing for refrigeration was the same. Thanks.
Eric

On Wed, 24 Jun 2015 13:15:47 -0500, "Paul K. Dickman"
wrote:

Except for certain alloys it doesn't age harden.
But refer tube has a pretty wide tolerance in wall thickness. Typically
+-10% of the thickness.
My guess is that when copper was cheaper, they erred on the plus side, now
they lean to the minus.

One could as much as 20% thicker than the other.

Paul K. Dickman

wrote in message
.. .
Copper tubing to be exact. I have a couple rolled lengths of soft
copper tube. One length is about 20 years old and the other about 4
years old. Both are the soft copper tubing commonly used for
refrigeration or water. It comes with a plastic cap on each end.
Anyway, my old rolled length, which I discovered the other day when
cleaning out some junk, is much stiffer than the new roll. So I am
wondering if the copper got stiffer over time because the older stuff
is quite a bit harder to bend than the newer stuff.
Eric

Greetings Paul,
I can check that. I just checked, both coils have the same wall
thickness and O.D. I think it must just be different types of copper
tube.
Eric

On Thu, 25 Jun 2015 09:51:29 -0700, wrote:

On Wed, 24 Jun 2015 13:15:47 -0500, "Paul K. Dickman"
wrote:

Except for certain alloys it doesn't age harden.
But refer tube has a pretty wide tolerance in wall thickness. Typically
+-10% of the thickness.
My guess is that when copper was cheaper, they erred on the plus side, now
they lean to the minus.

One could as much as 20% thicker than the other.

Paul K. Dickman

wrote in message
. ..
Copper tubing to be exact. I have a couple rolled lengths of soft
copper tube. One length is about 20 years old and the other about 4
years old. Both are the soft copper tubing commonly used for
refrigeration or water. It comes with a plastic cap on each end.
Anyway, my old rolled length, which I discovered the other day when
cleaning out some junk, is much stiffer than the new roll. So I am
wondering if the copper got stiffer over time because the older stuff
is quite a bit harder to bend than the newer stuff.
Eric

Greetings Paul,
I can check that. I just checked, both coils have the same wall
thickness and O.D. I think it must just be different types of copper
tube.
Eric

More likely it's different degrees of annealing. Copper readily work
hardens, and the soft type has to be thoroughly annealed so it will
freely bend.

Heat treating isn't always consistent.

--
Ed Huntress

On 06/25/2015 11:45 AM, wrote:
On Wed, 24 Jun 2015 13:00:41 -0500, wrote:

On 06/24/2015 12:27 PM, wrote:
Copper tubing to be exact. I have a couple rolled lengths of soft
copper tube. One length is about 20 years old and the other about 4
years old. Both are the soft copper tubing commonly used for
refrigeration or water. It comes with a plastic cap on each end.
Anyway, my old rolled length, which I discovered the other day when
cleaning out some junk, is much stiffer than the new roll. So I am
wondering if the copper got stiffer over time because the older stuff
is quite a bit harder to bend than the newer stuff.
Eric

You sure it isn't just K or L over M, maybe? I've no reason to think it
will harden just with age; I've pieces around that are at least 50 or 60
yo that I use chunks off of periodically and never noticed any real
difference.
Maybe that's it, different types. I thought all the coiled copper
tubing for refrigeration was the same. Thanks.
Eric

I think the only difference the HVAC line-specific line is it is
specially cleaned/produced to minimize any oil contaminants. AFAIK wall
thicknesses are K and L (no M, the cheapie box store variant usually
found) but that's still enough between the two to make a noticeable
difference in stiffness. I suppose there could be some difference in an
alloy between manufacturers, too, not sure how much variation there
might be in that regard.

--

On 06/25/2015 3:20 PM, dpb wrote:
On 06/25/2015 11:45 AM, wrote:
....

Maybe that's it, different types. I thought all the coiled copper
tubing for refrigeration was the same. Thanks.
Eric

I think the only difference the HVAC line-specific line is it is
specially cleaned/produced to minimize any oil contaminants. AFAIK wall
thicknesses are K and L (no M, the cheapie box store variant usually
found) but that's still enough between the two to make a noticeable
difference in stiffness. I suppose there could be some difference in an
alloy between manufacturers, too, not sure how much variation there
might be in that regard.

OK, _now_ I see that you have measured wall thickness; I concur on
likely treating differences is the difference...

--

wrote in message
news
On Wed, 24 Jun 2015 13:15:47 -0500, "Paul K. Dickman"
wrote:

Except for certain alloys it doesn't age harden.
But refer tube has a pretty wide tolerance in wall thickness.
Typically
+-10% of the thickness.
My guess is that when copper was cheaper, they erred on the plus
side, now
they lean to the minus.

One could as much as 20% thicker than the other.

Paul K. Dickman

wrote in message
. ..
Copper tubing to be exact. I have a couple rolled lengths of soft
copper tube. One length is about 20 years old and the other about
4
years old. Both are the soft copper tubing commonly used for
refrigeration or water. It comes with a plastic cap on each end.
Anyway, my old rolled length, which I discovered the other day
when
cleaning out some junk, is much stiffer than the new roll. So I
am
wondering if the copper got stiffer over time because the older
stuff
is quite a bit harder to bend than the newer stuff.
Eric

Greetings Paul,
I can check that. I just checked, both coils have the same wall
thickness and O.D. I think it must just be different types of copper
tube.
Eric

http://www.g-w.com/pdf/sampchap/9781566379656_ch03.pdf
"Soft copper tubing has a tendency to harden as a
result of vibration, oxidation, and bending. This is
called work-hardening."

-jsw