Ideas to get a controlled temperature of around -40C (also -40F) in a
test sample?

"Robustly" by physics:
100C - boiling water
0C - ice
-17C - brine-ice slurry (?)
??? -40C ???
-80C - "cardice" - solid CO2
-196C - liquid nitrogen

Reason is, found a way to tensile-test fillet welds, and so far always
seeing breaking strength come out at around 560MPa, when you do the
maths relating breaking force to the fracture area.

The 355MPa yield of the Rectangular Hollow Sections (RHS) isn't seen -
and I know they have exactly that yield stress from beam bending
measurements.

Here's the tests - "Alladin's Cave" of misdemeanours and skulduggery ?
;-)

http://www.weldsmith.co.uk/tech/struct/struct.html
"Steel Structural Performance index-page"

Various tests.

Specifically the fillet weld tensile tests

http://www.weldsmith.co.uk/tech/stru...4_fwbeamt.html
"Fillet welds tensile tested in beam test"

http://www.weldsmith.co.uk/tech/stru...t_testrig.html
"Tensile-test rig for beam-configuration fillet-weld samples"

Movie of - 10 seconds - shared on "Dropbox"
https://www.dropbox.com/s/esgwfk5jen..._fwtr.mp4?dl=0

Yup, I know that as a PhD level scientist I have to work as a welder
because everyone already ensconced in "office engineering" jobs
manicured in their white shirts sees me as a "Dennis Hopper like"
(think eg. "Blue Velvet" (1986) film) character of the science and
engineering world ;-)
If you keep the office door closed to all but your own manicured kind,
you can keep reality out. Who can blame them if no-one comes and
hurls them out into the cold hard world their scheme avoids? :-)

It would be helpful to see whether that "no yield event - straight to
local fracture at high(er) stress" is associated with a low
temperature brittleness charactistic.

I could "dam-off" the RHS close to the weld and at the far end, and
fill it with a cooling fluid.
Ice-brine looks good for -17C.

Throw a blanked over the entire sample for a while for all parts of
the sample to be at that temperature, then slide in the hydraulic
cylinder and "pump it up" and see what the temperature causes or does
not cause.

What about for -40C
???

Regards,
Rich Smith

"Richard Smith" wrote in message ...

Ideas to get a controlled temperature of around -40C (also -40F) in a
test sample?

The lowest setting on my Alpicool C20 DC-powered freezer is -40C. Temps
below -20C are accessed with the E1 special setting.
https://www.amazon.com/Alpicool-C20-.../dp/B075R1LH8D

It works well enough but isn't as rugged or hands-off reliable as a normal
AC-powered freezer, and really should have thicker insulation.

On Thu, 04 Feb 2021 11:43:58 +0000, Richard Smith
wrote:

Ideas to get a controlled temperature of around -40C (also -40F) in a
test sample?

"Robustly" by physics:
100C - boiling water
0C - ice
-17C - brine-ice slurry (?)
??? -40C ???
-80C - "cardice" - solid CO2
-196C - liquid nitrogen

Reason is, found a way to tensile-test fillet welds, and so far always
seeing breaking strength come out at around 560MPa, when you do the
maths relating breaking force to the fracture area.

The 355MPa yield of the Rectangular Hollow Sections (RHS) isn't seen -
and I know they have exactly that yield stress from beam bending
measurements.

Here's the tests - "Alladin's Cave" of misdemeanours and skulduggery ?
;-)

http://www.weldsmith.co.uk/tech/struct/struct.html
"Steel Structural Performance index-page"

Various tests.

Specifically the fillet weld tensile tests

http://www.weldsmith.co.uk/tech/struct/201124_fwbeamt/201124_fwbeamt.html
"Fillet welds tensile tested in beam test"

http://www.weldsmith.co.uk/tech/struct/210122_fwtest_rig/210122_fwtest_testrig.html
"Tensile-test rig for beam-configuration fillet-weld samples"

Movie of - 10 seconds - shared on "Dropbox"
https://www.dropbox.com/s/esgwfk5jenhm024/210122_fwtr.mp4?dl=0

Yup, I know that as a PhD level scientist I have to work as a welder
because everyone already ensconced in "office engineering" jobs
manicured in their white shirts sees me as a "Dennis Hopper like"
(think eg. "Blue Velvet" (1986) film) character of the science and
engineering world ;-)
If you keep the office door closed to all but your own manicured kind,
you can keep reality out. Who can blame them if no-one comes and
hurls them out into the cold hard world their scheme avoids? :-)

It would be helpful to see whether that "no yield event - straight to
local fracture at high(er) stress" is associated with a low
temperature brittleness charactistic.

I could "dam-off" the RHS close to the weld and at the far end, and
fill it with a cooling fluid.
Ice-brine looks good for -17C.

Throw a blanked over the entire sample for a while for all parts of
the sample to be at that temperature, then slide in the hydraulic
cylinder and "pump it up" and see what the temperature causes or does
not cause.

What about for -40C
???

Propane boils at -42 C at atmospheric pressure.

Joe Gwinn

"Richard Smith" wrote in message ...

......
Yup, I know that as a PhD level scientist I have to work as a welder
because everyone already ensconced in "office engineering" jobs
manicured in their white shirts sees me as a "Dennis Hopper like"
(think eg. "Blue Velvet" (1986) film) character of the science and
engineering world ;-)
If you keep the office door closed to all but your own manicured kind,
you can keep reality out. Who can blame them if no-one comes and
hurls them out into the cold hard world their scheme avoids? :-)

Rich Smith
--------------------------------

The snobbery of "Two Cultures" exists in the US scientific community too. I
first encountered it as a Chemistry undergrad, from professors who either
worked with government and industry or shunned all but pure academic
research, and tried to convince us theirs was the only ethical path.

As a lab manager in a government research facility I worked with both
hands-on and hands-off engineers, and again the theoretical, hands-off ones
could be somewhat intolerant of people who could be both. I also saw that in
Mensa, mainly from mathematicians. It was fun to watch the confusion after
someone who had binned me as a mere craftsman found I could and solve
engineering math problems mentally faster than they could with a calculator.

Personally I've been glad to stay in the lab, designing and building
hardware, and avoid boring meetings and report writing. Another lab tech
made a bumper sticker "Techs can do what engineers only dream of".

Not all great theoreticians kept their hands clean:
https://www.fromthegrapevine.com/inn...ator-invention

"Joe Gwinn" wrote in message
...

Propane boils at -42 C at atmospheric pressure.

Joe Gwinn

-------------------------------
I checked the weather on Spitzbergen to see if the experiment could be done
at ambient temperature there.
https://www.accuweather.com/en/sj/lo...orecast/310461

Funny, New England USA was that cold over the weekend, and we are at the
latitude of Spain.
https://brilliantmaps.com/cities-transposed-latitude/

"Jim Wilkins" wrote in message ...

"Richard Smith" wrote in message ...

Ideas to get a controlled temperature of around -40C (also -40F) in a
test sample?

----------------------------
The lowest setting on my Alpicool C20 DC-powered freezer is -40C. Temps
below -20C are accessed with the E1 special setting.
https://www.amazon.com/Alpicool-C20-.../dp/B075R1LH8D

It works well enough but isn't as rugged or hands-off reliable as a normal
AC-powered freezer, and really should have thicker insulation.
------------------------------------------
I confirmed it could be set to -40C but didn't leave it there, as it's full
of food and would have taken a long time to settle.

My Alpi wouldn't quite cool to -20C in a hot car so I made an insulated
enclosure for it, 1" foam lined inside with a yoga mat to catch and drain
summer condensation. The exterior is thin birch plywood joined at the
corners with sheet metal angles inside and truss head screws. The lid is a
flap of Harbor Freight moving blanket, doubled.

"Jim Wilkins" writes:

"Joe Gwinn" wrote in message
...

Propane boils at -42 C at atmospheric pressure.

Joe Gwinn

-------------------------------
I checked the weather on Spitzbergen to see if the experiment could be
done at ambient temperature there.
https://www.accuweather.com/en/sj/lo...orecast/310461

Funny, New England USA was that cold over the weekend, and we are at
the latitude of Spain.
https://brilliantmaps.com/cities-transposed-latitude/

Spitzbergen idea - LOL !

Joe Gwinn writes:

On Thu, 04 Feb 2021 11:43:58 +0000, Richard Smith
wrote:

Ideas to get a controlled temperature of around -40C (also -40F) in a
test sample?

"Robustly" by physics:
100C - boiling water
0C - ice
-17C - brine-ice slurry (?)
??? -40C ???
-80C - "cardice" - solid CO2
-196C - liquid nitrogen

Reason is, found a way to tensile-test fillet welds, and so far always
seeing breaking strength come out at around 560MPa, when you do the
maths relating breaking force to the fracture area.

The 355MPa yield of the Rectangular Hollow Sections (RHS) isn't seen -
and I know they have exactly that yield stress from beam bending
measurements.

Here's the tests - "Alladin's Cave" of misdemeanours and skulduggery ?
;-)

http://www.weldsmith.co.uk/tech/struct/struct.html
"Steel Structural Performance index-page"

Various tests.

Specifically the fillet weld tensile tests

http://www.weldsmith.co.uk/tech/struct/201124_fwbeamt/201124_fwbeamt.html
"Fillet welds tensile tested in beam test"

http://www.weldsmith.co.uk/tech/struct/210122_fwtest_rig/210122_fwtest_testrig.html
"Tensile-test rig for beam-configuration fillet-weld samples"

Movie of - 10 seconds - shared on "Dropbox"
https://www.dropbox.com/s/esgwfk5jenhm024/210122_fwtr.mp4?dl=0

Yup, I know that as a PhD level scientist I have to work as a welder
because everyone already ensconced in "office engineering" jobs
manicured in their white shirts sees me as a "Dennis Hopper like"
(think eg. "Blue Velvet" (1986) film) character of the science and
engineering world ;-)
If you keep the office door closed to all but your own manicured kind,
you can keep reality out. Who can blame them if no-one comes and
hurls them out into the cold hard world their scheme avoids? :-)

It would be helpful to see whether that "no yield event - straight to
local fracture at high(er) stress" is associated with a low
temperature brittleness charactistic.

I could "dam-off" the RHS close to the weld and at the far end, and
fill it with a cooling fluid.
Ice-brine looks good for -17C.

Throw a blanked over the entire sample for a while for all parts of
the sample to be at that temperature, then slide in the hydraulic
cylinder and "pump it up" and see what the temperature causes or does
not cause.

What about for -40C
???

Propane boils at -42 C at atmospheric pressure.

Joe Gwinn

Thanks for suggestion. Well rooted in science.
I fear that as the sample gets colder with propane evaporation, we
could get a hair-trim if the evaporated gas ignites.

The sample halves hurl around on sample weld breaking, so putting on a
"vent tube" with the propane burning at the outlet - a "flare" -
doesn't seem a viable solution.

It might be that I have to do something with "cardice" - solid CO2.
Throw-in bits until reaches -40C.

Or cool to lower temperature and pump the cylinder when weld area has is
showing -40C by thermocouple.

Thanks for suggestions.

I just looked online and find
https://en.wikipedia.org/wiki/Brine
that lowest melting point is -21.1C

Something you learn about experimenting - while you do make sure
everything holds together as it should, you don't look for the n-th
degree of accuracy of physical conditions in the proof-of-concept
tries.

To think in planning that a particular exact temperature is important
is the error of thinking that if you specify something enough, "God"
has to conform. Not going to happen. Get a pretty cold temperature
and observe what is there to observe.

Regards,

"Jim Wilkins" writes:

"Richard Smith" wrote in message ...

.....
Yup, I know that as a PhD level scientist I have to work as a welder
...
Rich Smith
--------------------------------

...
tech made a bumper sticker "Techs can do what engineers only dream
of".
...

LOL ;-)

"Richard Smith" wrote in message ...
....
Or cool to lower temperature and pump the cylinder when weld area has is
showing -40C by thermocouple.

-------------------

That's the first method I would try, to check your assumptions and procedure
and shrapnel containment.

This suggests that impurity levels might be a significant uncontrolled
variable in your experiments:
https://www.tf.uni-kiel.de/matwis/am...tr/s9_1_1.html

Is -40C the lowest you expect in European service?
https://en.wikipedia.org/wiki/Operating_temperature

Some industrial temperature controllers have a cooling option that can
operate a solenoid valve to regulate the temperature with evaporating CO2
from a tank of room-temperature liquid.
https://www.linde-gas.com/en/process...ing/index.html
"Liquid carbon dioxide converts to solid carbon dioxide snow at €“79ºC
(€“109ºF)."

If the test chamber is nearly sealed the escaping gas should reduce or
prevent frost covering the sample. US regulations required an oxygen level
sensor and alarm at the test station. The body's breathing mechanism
responds to CO2 level (pH) in the blood, not oxygen level, so you may not
realize you are about to pass out from anoxia, especially with liquid
nitrogen.

On 2/5/21 3:28 AM, Richard Smith wrote:
Joe Gwinn writes:

On Thu, 04 Feb 2021 11:43:58 +0000, Richard Smith
wrote:

Ideas to get a controlled temperature of around -40C (also -40F) in a
test sample?

"Robustly" by physics:
100C - boiling water
0C - ice
-17C - brine-ice slurry (?)
??? -40C ???
-80C - "cardice" - solid CO2
-196C - liquid nitrogen

Reason is, found a way to tensile-test fillet welds, and so far always
seeing breaking strength come out at around 560MPa, when you do the
maths relating breaking force to the fracture area.

The 355MPa yield of the Rectangular Hollow Sections (RHS) isn't seen -
and I know they have exactly that yield stress from beam bending
measurements.

Here's the tests - "Alladin's Cave" of misdemeanours and skulduggery ?
;-)

http://www.weldsmith.co.uk/tech/struct/struct.html
"Steel Structural Performance index-page"

Various tests.

Specifically the fillet weld tensile tests

http://www.weldsmith.co.uk/tech/struct/201124_fwbeamt/201124_fwbeamt.html
"Fillet welds tensile tested in beam test"

http://www.weldsmith.co.uk/tech/struct/210122_fwtest_rig/210122_fwtest_testrig.html
"Tensile-test rig for beam-configuration fillet-weld samples"

Movie of - 10 seconds - shared on "Dropbox"
https://www.dropbox.com/s/esgwfk5jenhm024/210122_fwtr.mp4?dl=0

Yup, I know that as a PhD level scientist I have to work as a welder
because everyone already ensconced in "office engineering" jobs
manicured in their white shirts sees me as a "Dennis Hopper like"
(think eg. "Blue Velvet" (1986) film) character of the science and
engineering world ;-)
If you keep the office door closed to all but your own manicured kind,
you can keep reality out. Who can blame them if no-one comes and
hurls them out into the cold hard world their scheme avoids? :-)

It would be helpful to see whether that "no yield event - straight to
local fracture at high(er) stress" is associated with a low
temperature brittleness charactistic.

I could "dam-off" the RHS close to the weld and at the far end, and
fill it with a cooling fluid.
Ice-brine looks good for -17C.

Throw a blanked over the entire sample for a while for all parts of
the sample to be at that temperature, then slide in the hydraulic
cylinder and "pump it up" and see what the temperature causes or does
not cause.

What about for -40C
???

Propane boils at -42 C at atmospheric pressure.

Joe Gwinn

Thanks for suggestion. Well rooted in science.
I fear that as the sample gets colder with propane evaporation, we
could get a hair-trim if the evaporated gas ignites.

The sample halves hurl around on sample weld breaking, so putting on a
"vent tube" with the propane burning at the outlet - a "flare" -
doesn't seem a viable solution.

It might be that I have to do something with "cardice" - solid CO2.
Throw-in bits until reaches -40C.

Or cool to lower temperature and pump the cylinder when weld area has is
showing -40C by thermocouple.

Thanks for suggestions.

I just looked online and find
https://en.wikipedia.org/wiki/Brine
that lowest melting point is -21.1C

Something you learn about experimenting - while you do make sure
everything holds together as it should, you don't look for the n-th
degree of accuracy of physical conditions in the proof-of-concept
tries.

To think in planning that a particular exact temperature is important
is the error of thinking that if you specify something enough, "God"
has to conform. Not going to happen. Get a pretty cold temperature
and observe what is there to observe.

There are lots of other things besides sodium chloride to make "salt"
baths from :-). See https://en.wikipedia.org/wiki/List_of_cooling_baths
for one list, and look at reference 2 and the reference pdf in ref 2
(https://www.larkinweb.co.uk/science/...ng%20baths.pdf) for
a bit more info. I'd try calcium chloride hexahydrate/water either at
the ratio for -41C or a bit stronger since they say it is difficult to
reach the listed temps. You could also precool your metal with dry ice
and even add some dry ice to the salt bath while it is cooling down, or
put the salt bath in a small tub in a larger tub with dry ice packed
around it. I'd make the starting ice either from distilled water (cheap
at grocery stores) or reverse osmosis water if you have a home system
already. If having the metal dripping with wet calcium chloride is a
problem during your test put the piece in a ziploc bag. Partially seal
the bag so about an inch at one side is still open then slowly submerge
the bag in plain water while holding that corner out of the water. The
air will be forced out so you get good contact between bag and metal for
good heat transfer. Finish sealing the bag when as much of the air as
possible is removed. Just pretend it is a steak you are about to cook
sous vide :-).

--
Regards,
Carl

Carl writes:

... ... ...


There are lots of other things besides sodium chloride to make "salt"
baths from :-). See
https://en.wikipedia.org/wiki/List_of_cooling_baths for one list, and
look at reference 2 and the reference pdf in ref 2
(https://www.larkinweb.co.uk/science/...ng%20baths.pdf)
for a bit more info. I'd try calcium chloride hexahydrate/water
either at the ratio for -41C or a bit stronger since they say it is
difficult to reach the listed temps. You could also precool your
metal with dry ice and even add some dry ice to the salt bath while it
is cooling down, or put the salt bath in a small tub in a larger tub
with dry ice packed around it. I'd make the starting ice either from
distilled water (cheap at grocery stores) or reverse osmosis water if
you have a home system already. If having the metal dripping with wet
calcium chloride is a problem during your test put the piece in a
ziploc bag. Partially seal the bag so about an inch at one side is
still open then slowly submerge the bag in plain water while holding
that corner out of the water. The air will be forced out so you get
good contact between bag and metal for good heat transfer. Finish
sealing the bag when as much of the air as possible is removed. Just
pretend it is a steak you are about to cook sous vide :-).

--
Regards,
Carl

Stunningly good info. Thanks.

I could see what NaCl-brine-ice does for the test, knowing there's
further I could go.

Dam the ends of the Rectangular Hollow Sections to hold the brine-ice
internally = direct contact. Contained. Salt on the sample wouldn't
matter anyway.

Many thanks again.

On Fri, 05 Feb 2021 08:28:07 +0000, Richard Smith
wrote:

Joe Gwinn writes:

On Thu, 04 Feb 2021 11:43:58 +0000, Richard Smith
wrote:

Ideas to get a controlled temperature of around -40C (also -40F) in a
test sample?

"Robustly" by physics:
100C - boiling water
0C - ice
-17C - brine-ice slurry (?)
??? -40C ???
-80C - "cardice" - solid CO2
-196C - liquid nitrogen

Reason is, found a way to tensile-test fillet welds, and so far always
seeing breaking strength come out at around 560MPa, when you do the
maths relating breaking force to the fracture area.

The 355MPa yield of the Rectangular Hollow Sections (RHS) isn't seen -
and I know they have exactly that yield stress from beam bending
measurements.

Here's the tests - "Alladin's Cave" of misdemeanours and skulduggery ?
;-)

http://www.weldsmith.co.uk/tech/struct/struct.html
"Steel Structural Performance index-page"

Various tests.

Specifically the fillet weld tensile tests

http://www.weldsmith.co.uk/tech/struct/201124_fwbeamt/201124_fwbeamt.html
"Fillet welds tensile tested in beam test"

http://www.weldsmith.co.uk/tech/struct/210122_fwtest_rig/210122_fwtest_testrig.html
"Tensile-test rig for beam-configuration fillet-weld samples"

Movie of - 10 seconds - shared on "Dropbox"
https://www.dropbox.com/s/esgwfk5jenhm024/210122_fwtr.mp4?dl=0

Yup, I know that as a PhD level scientist I have to work as a welder
because everyone already ensconced in "office engineering" jobs
manicured in their white shirts sees me as a "Dennis Hopper like"
(think eg. "Blue Velvet" (1986) film) character of the science and
engineering world ;-)
If you keep the office door closed to all but your own manicured kind,
you can keep reality out. Who can blame them if no-one comes and
hurls them out into the cold hard world their scheme avoids? :-)

It would be helpful to see whether that "no yield event - straight to
local fracture at high(er) stress" is associated with a low
temperature brittleness charactistic.

I could "dam-off" the RHS close to the weld and at the far end, and
fill it with a cooling fluid.
Ice-brine looks good for -17C.

Throw a blanked over the entire sample for a while for all parts of
the sample to be at that temperature, then slide in the hydraulic
cylinder and "pump it up" and see what the temperature causes or does
not cause.

What about for -40C
???

Propane boils at -42 C at atmospheric pressure.

Joe Gwinn

Thanks for suggestion. Well rooted in science.
I fear that as the sample gets colder with propane evaporation, we
could get a hair-trim if the evaporated gas ignites.

The sample halves hurl around on sample weld breaking, so putting on a
"vent tube" with the propane burning at the outlet - a "flare" -
doesn't seem a viable solution.

It might be that I have to do something with "cardice" - solid CO2.
Throw-in bits until reaches -40C.

Or cool to lower temperature and pump the cylinder when weld area has is
showing -40C by thermocouple.

Thanks for suggestions.

One dodge is to make a heat pipe using propane as the working fluid,
dry ice as the coolant.

Have liquid propane in the sealed copper boiler with a tube going
uphill to a copper condenser cooled by dry ice in alcohol. The dry
ice boils at -109 C, well above the freezing point of propane, so what
will happen is that the propane will boil at -42 C, with the vapor
rising to the condenser, where the propane will liquefy, and run back
down to the boiler. This process is self-regulating so long as things
are well insulated. But do this outside, and a 2-meter flare tube is
a good idea.

The copper stuff can be ordinary plumbing tubing and fixtures. For a
one-off, plumbers solder is good enough. For a true seal, braze with
phosphorus-copper brazing filler, as used for HVAC systems.

Joe Gwinn

"Joe Gwinn" wrote in message
...
....
Have liquid propane in the sealed copper boiler with a tube going
uphill to a copper condenser cooled by dry ice in alcohol.
....
The copper stuff can be ordinary plumbing tubing and fixtures. For a
one-off, plumbers solder is good enough. For a true seal, braze with
phosphorus-copper brazing filler, as used for HVAC systems.
....
Joe Gwinn

---------------------

The pipe fitting that enables making a condenser or similar concentric tube
structure is a pipe reducer with the smaller end bored through on a lathe.
Brass is easier than copper to chuck and turn. A 6-jaw chuck helps hold the
reducer without (much) distortion, or you can jam a fitted wood plug into
the large end.

When I learned industrial refrigeration in the 1970's this is what we brazed
joints with:
https://www.amazon.com/Lucas-Milhaup.../dp/B06Y1N5517

"Richard Smith" wrote in message ...

I could see what NaCl-brine-ice does for the test, knowing there's
further I could go.

---------------------------------

During a winter power outage I found that a mix of snow and road salt (NaCl
+ ?) fell to 5F, -15C.

On Fri, 5 Feb 2021 17:40:49 -0500, "Jim Wilkins"
wrote:

"Joe Gwinn" wrote in message
.. .
...
Have liquid propane in the sealed copper boiler with a tube going
uphill to a copper condenser cooled by dry ice in alcohol.
...
The copper stuff can be ordinary plumbing tubing and fixtures. For a
one-off, plumbers solder is good enough. For a true seal, braze with
phosphorus-copper brazing filler, as used for HVAC systems.
...
Joe Gwinn

---------------------

The pipe fitting that enables making a condenser or similar concentric tube
structure is a pipe reducer with the smaller end bored through on a lathe.
Brass is easier than copper to chuck and turn. A 6-jaw chuck helps hold the
reducer without (much) distortion, or you can jam a fitted wood plug into
the large end.

I don't visualize this.

What I was thinking was a simple one-pipe system, with vapor going up
and condensate running down. The propane inventory need not be large.


When I learned industrial refrigeration in the 1970's this is what we brazed
joints with:
https://www.amazon.com/Lucas-Milhaupt-95150-Sil-Fos-Brazing-Alloy/dp/B06Y1N5517

Yeah, that's the stuff.

If you braze all the joints, you can hermetically seal the propane
inside the heat pipe. Make sure that the total volume is large enough
to prevent overpressure damage at room temperature. Or provide a
pressure releas valve and refill before each use.

Joe Gwinn

On Fri, 05 Feb 2021 08:36:21 +0000, Richard Smith
wrote:

"Jim Wilkins" writes:

"Richard Smith" wrote in message ...

.....
Yup, I know that as a PhD level scientist I have to work as a welder
...
Rich Smith
--------------------------------

...
tech made a bumper sticker "Techs can do what engineers only dream
of".
...

LOL ;-)
"Techs keep Engineers out of trouble!"

"Jim Wilkins" writes:

...

---------------------------------

During a winter power outage I found that a mix of snow and road salt
(NaCl + ?) fell to 5F, -15C.

Real deal. Thanks for that.

BTW

Mind's been going crazy over this.
Spent yesterday Finite Element Analysis modelling the
"beam-configuration fillet-weld tensile test"
http://www.weldsmith.co.uk/tech/stru...cfwtt_fea.html
"FEA : beam-configuration fillet-weld tensile test"
Just occurred to me - if kept tubes strictly straight in-line with a
frame/guide - could make it a longitudinal tensile - which means you
could fast-load by firing a weight into a "stopper-plate" in the line
of the sample. etc. etc.

If this sounds fanciful - every step of one of these home-spun
investigations seems fanciful, each "next summit" seeming barely
likely to happen. I could say this about this series of mini-projects
so far, my fatigue-resistant welds research, my Doctorate studying
then-new TMCP steels from Germany and Japan (definitely!), etc.

"Richard Smith" wrote in message ...

"Jim Wilkins" writes:

...

---------------------------------

During a winter power outage I found that a mix of snow and road salt
(NaCl + ?) fell to 5F, -15C.

Real deal. Thanks for that.

BTW

Mind's been going crazy over this.
Spent yesterday Finite Element Analysis modelling the
"beam-configuration fillet-weld tensile test"
http://www.weldsmith.co.uk/tech/stru...cfwtt_fea.html
"FEA : beam-configuration fillet-weld tensile test"
Just occurred to me - if kept tubes strictly straight in-line with a
frame/guide - could make it a longitudinal tensile - which means you
could fast-load by firing a weight into a "stopper-plate" in the line
of the sample. etc. etc.

----------------------

http://physics.wm.edu/~labs/110/110_pdf/ch4.pdf
If the metal permanently deforms some of the kinetic energy converts to
heat.

"Jim Wilkins" writes:

http://physics.wm.edu/~labs/110/110_pdf/ch4.pdf
If the metal permanently deforms some of the kinetic energy converts
to heat.

Resilient design - make sure that in an extreme event, there's
not-a-lot / no abrupt breaking (low energy and structure is lost) and
a lot of distributed bending and deformation (high energy, and the
structure is still there)... :-)

Job as a welder - repair a height-restriction barrier at a supermarket
http://www.weldsmith.co.uk/dropbox/m...tS_htbarr.html
"Insert plates" so knocking it over again would be a long energy
consuming process.

"Richard Smith" wrote in message ...

"Jim Wilkins" writes:

http://physics.wm.edu/~labs/110/110_pdf/ch4.pdf
If the metal permanently deforms some of the kinetic energy converts
to heat.

Resilient design - make sure that in an extreme event, there's
not-a-lot / no abrupt breaking (low energy and structure is lost) and
a lot of distributed bending and deformation (high energy, and the
structure is still there)... :-)

Job as a welder - repair a height-restriction barrier at a supermarket
http://www.weldsmith.co.uk/dropbox/m...tS_htbarr.html
"Insert plates" so knocking it over again would be a long energy
consuming process.
--------------------------------

Around here bollards that are expected to stop vehicles to protect buildings
are 4" nominal pipe set in and filled with concrete. 4" pipe is actually
4.50" OD, and I acquired some free 3.5" pipe which is 4.0" OD and was
mistakenly cut and painted yellow to be bollards.

The pipe came with an 8' x 10' wooden shed a neighbor bought at a yard sale
and brought home on his flatbed equipment trailer. He and his
construction-worker friends had used it as rollers to muscle the 2400 lb
shed onto the trailer. Then I was enlisted to hoist the shed off the trailer
and lower it onto its new foundation. The pipe may be useful as rollers this
spring when I move a 4000+ lb oak log off the hillside where it fell and to
somewhere flat enough to set up my sawmill.

When I was building custom industrial machinery we muscled as much as 5000
lbs onto the truck. That's about the average weight of a stone in the
Pyramids. Customer [XY] had his just-delivered machine up on a forklift when
the break time buzzer sounded and the crew just left it there. When they
returned the machine had fallen flat on its face and the forklift was
standing up on end. I salvaged a bucket of electro-mechanical components
like Variacs from the rebuild.

I was in line (queue) at the industrial supply store behind an
inventor/engineer who was picking up the 2" ID bearings he had special
ordered for the 2" water pipe support on his tracking solar array. He was
very unhappy to belatedly discover that 2" pipe isn't anywhere near 2.0" in
diameter. I warned him that although the specified OD is 2.375" it isn't
truly round unless cleaned up on a lathe, which removes the protective
galvanizing.

I machined the thrust bearing for my solar array from stainless plate and
turned the ball race grooves with the sharpened back end of a carbide drill
bit. The housing is a PVC pipe fitting.

This show why engineers and inventors need good techs. The designer of the
Japanese Zero naval fighter complained in his memoir that a wartime shortage
of competent technicians seriously hindered the development of its
replacement, and their Navy depended on its pre-war design long after US
fighters 100 Kts faster had made it a death trap. German designers made the
same complaint, and I believe their late-war proliferation of scatterbrained
schemes was self-preservation. Towards the end even U-Boot crews were being
drafted as infantry for the Eastern Front.
https://www.historynet.com/extremes-amerika-bombers.htm

https://en.wikipedia.org/wiki/Die_Glocke_(hoax)
Like every secret project it needed a misleading cover story. Segway leaked
some whoppers to conceal what we were doing in the lab.
To me the detailed description appears to be of a very powerful X-Ray
source, a Death Ray against bombers, which unfortunately could only shoot
straight up due to its parabolic rotating Mercury anode, Tungsten being too
desperately needed elsewhere.
https://en.wikipedia.org/wiki/Liquid-mirror_telescope
The proof-of-concept demo would of course use visible light, not X-rays.

The special Mercury may have been radioactive waste left from the recovery
of Radium metal by electrolysis, and perhaps the basis of "Red Mercury". The
round structure above would have held a lens or mirror to aim the beam of
X-rays, which is impossible with any known material, but ignorant
street-thug Nazi officials wouldn't know that. A convincing zapping demo
could be faked using a lens of silver chloride, which does focus equally
invisible infrared, and makes a plausible excuse to acquire large amounts of
the precious metal in a soft yellow/white form that could be smuggled into
Switzerland as cheese.

"Richard Smith" wrote in message ...

"Jim Wilkins" writes:

http://physics.wm.edu/~labs/110/110_pdf/ch4.pdf
If the metal permanently deforms some of the kinetic energy converts
to heat.

Resilient design - make sure that in an extreme event, there's
not-a-lot / no abrupt breaking (low energy and structure is lost) and
a lot of distributed bending and deformation (high energy, and the
structure is still there)... :-)

Job as a welder - repair a height-restriction barrier at a supermarket
http://www.weldsmith.co.uk/dropbox/m...tS_htbarr.html
"Insert plates" so knocking it over again would be a long energy
consuming process.

--------------------------

A retired town snowplow driver told me that people who erect very solid
steel roadside mailbox stands that don't protect people or property from
damage have been asked to remove them before someone dies.

It's a difficult call, and I would make the part that breaks be easily
replaceable.

"Jim Wilkins" writes:


Around here bollards that are expected to stop vehicles to protect
...
This show why engineers and inventors need good techs. The designer of
the Japanese Zero naval fighter complained in his memoir that a
wartime shortage of competent technicians seriously hindered the
development of its replacement, and their Navy depended on its pre-war
design long after US fighters 100 Kts faster had made it a death
trap. German designers made the same complaint, and I believe their
late-war proliferation of scatterbrained schemes was
self-preservation. Towards the end even U-Boot crews were being
drafted as infantry for the Eastern Front.
https://www.historynet.com/extremes-amerika-bombers.htm

...

There's a need for a spectrum of people, for sure.
Not the impression you get at the moment in the UK.

On Friday, February 5, 2021 at 6:33:30 PM UTC-5, Joe Gwinn wrote:
On Fri, 5 Feb 2021 17:40:49 -0500, "Jim Wilkins"
wrote:

"Joe Gwinn" wrote in message
...
...
Have liquid propane in the sealed copper boiler with a tube going
uphill to a copper condenser cooled by dry ice in alcohol.
...
The copper stuff can be ordinary plumbing tubing and fixtures. For a
one-off, plumbers solder is good enough. For a true seal, braze with
phosphorus-copper brazing filler, as used for HVAC systems.
...
Joe Gwinn

---------------------

The pipe fitting that enables making a condenser or similar concentric tube
structure is a pipe reducer with the smaller end bored through on a lathe.
Brass is easier than copper to chuck and turn. A 6-jaw chuck helps hold the
reducer without (much) distortion, or you can jam a fitted wood plug into
the large end.
I don't visualize this.

What I was thinking was a simple one-pipe system, with vapor going up
and condensate running down. The propane inventory need not be large.
When I learned industrial refrigeration in the 1970's this is what we brazed
joints with:
https://www.amazon.com/Lucas-Milhaupt-95150-Sil-Fos-Brazing-Alloy/dp/B06Y1N5517
Yeah, that's the stuff.

If you braze all the joints, you can hermetically seal the propane
inside the heat pipe. Make sure that the total volume is large enough
to prevent overpressure damage at room temperature. Or provide a
pressure releas valve and refill before each use.

Instead of the research grade propane, the fuel grade propane (R-290) may have around 5% methane (R-50) and butane (R-600) mixed in.

On Sun, 7 Feb 2021 15:12:01 -0800 (PST), bruce bowser
wrote:

On Friday, February 5, 2021 at 6:33:30 PM UTC-5, Joe Gwinn wrote:
On Fri, 5 Feb 2021 17:40:49 -0500, "Jim Wilkins"
wrote:

"Joe Gwinn" wrote in message
...
...
Have liquid propane in the sealed copper boiler with a tube going
uphill to a copper condenser cooled by dry ice in alcohol.
...
The copper stuff can be ordinary plumbing tubing and fixtures. For a
one-off, plumbers solder is good enough. For a true seal, braze with
phosphorus-copper brazing filler, as used for HVAC systems.
...
Joe Gwinn

---------------------

The pipe fitting that enables making a condenser or similar concentric tube
structure is a pipe reducer with the smaller end bored through on a lathe.
Brass is easier than copper to chuck and turn. A 6-jaw chuck helps hold the
reducer without (much) distortion, or you can jam a fitted wood plug into
the large end.
I don't visualize this.

What I was thinking was a simple one-pipe system, with vapor going up
and condensate running down. The propane inventory need not be large.
When I learned industrial refrigeration in the 1970's this is what we brazed
joints with:
https://www.amazon.com/Lucas-Milhaupt-95150-Sil-Fos-Brazing-Alloy/dp/B06Y1N5517
Yeah, that's the stuff.

If you braze all the joints, you can hermetically seal the propane
inside the heat pipe. Make sure that the total volume is large enough
to prevent overpressure damage at room temperature. Or provide a
pressure releas valve and refill before each use.

Instead of the research grade propane, the fuel grade propane (R-290) may have around 5% methane (R-50) and butane (R-600) mixed in.

Yes. The methane will do nothing, and the butane will freeze in the
condenser. As long as the condenser is large enough, it won't matter.

Joe Gwinn

"Joe Gwinn" wrote in message
...

On Fri, 5 Feb 2021 17:40:49 -0500, "Jim Wilkins"
wrote:

The pipe fitting that enables making a condenser or similar concentric tube
structure is a pipe reducer with the smaller end bored through on a lathe.
Brass is easier than copper to chuck and turn. A 6-jaw chuck helps hold the
reducer without (much) distortion, or you can jam a fitted wood plug into
the large end.

I don't visualize this.

---------------------------------

Boring out the stop in the reducer's small end allows the smaller pipe to
pass through the fitting into the larger one, concentrically. I first did
this to run a cold water feed pipe through a former heating element hole to
near the opposite (lower) side of an old electric water heater tank that I'd
converted to solar and mounted horizontally.

It did adequately heat water for laundry without using electricity, but it
wasn't worth the fuss versus Cold Water Tide.

Are you ready for California-style electric rates and monthly allocations?
https://www.sce.com/residential/rate...ial-Rate-Plans

On Friday, February 5, 2021 at 3:02:33 AM UTC-5, Richard Smith wrote:
"Jim Wilkins" writes:

"Joe Gwinn" wrote in message
...

Propane boils at -42 C at atmospheric pressure.

Joe Gwinn

-------------------------------
I checked the weather on Spitzbergen to see if the experiment could be
done at ambient temperature there.
https://www.accuweather.com/en/sj/lo...orecast/310461

Funny, New England USA was that cold over the weekend, and we are at
the latitude of Spain.
https://brilliantmaps.com/cities-transposed-latitude/

That must mean that the tip end of Narragansett is about the same average temperature as the well known shores of Spain in the summer time.

Spitzbergen idea - LOL !

Wow, images of Spitzbergen are nice. I get words like Spitzbergen and Zugspitze (the highest mountain in German, literally translated as "train peak") mixed up.

"Transition Zone" wrote in message
...

On Friday, February 5, 2021 at 3:02:33 AM UTC-5, Richard Smith wrote:
"Jim Wilkins" writes:

"Joe Gwinn" wrote in message
...

Propane boils at -42 C at atmospheric pressure.

Joe Gwinn

-------------------------------
I checked the weather on Spitzbergen to see if the experiment could be
done at ambient temperature there.
https://www.accuweather.com/en/sj/lo...orecast/310461

Funny, New England USA was that cold over the weekend, and we are at
the latitude of Spain.
https://brilliantmaps.com/cities-transposed-latitude/

That must mean that the tip end of Narragansett is about the same average
temperature as the well known shores of Spain in the summer time.

Spitzbergen idea - LOL !

Wow, images of Spitzbergen are nice. I get words like Spitzbergen and
Zugspitze (the highest mountain in German, literally translated as "train
peak") mixed up.

----------------
Away from the coast the summertime highs here are quite close to Madrid's,
35C and above.

I rode the cable car up the Zugspitze and yes, it's spectacular.

My best memory of European mountains was flying low over the lesser-known
Swabian Jura (Alps) between Stuttgart and Augsburg in an Army helicopter
with a view straight down. Probably the worst was riding a speeding, tilting
van up the winding road to Hohenzollern castle and feeling like we were
about to fly off the road and tumble down the steep slope.

Emperor Frederick the Great was there, in a plain wooden coffin on sawhorses
in the castle's entrance.

On Mon, 8 Feb 2021 07:43:16 -0500, "Jim Wilkins"
wrote:

"Joe Gwinn" wrote in message
.. .

On Fri, 5 Feb 2021 17:40:49 -0500, "Jim Wilkins"
wrote:

The pipe fitting that enables making a condenser or similar concentric tube
structure is a pipe reducer with the smaller end bored through on a lathe.
Brass is easier than copper to chuck and turn. A 6-jaw chuck helps hold the
reducer without (much) distortion, or you can jam a fitted wood plug into
the large end.

I don't visualize this.

---------------------------------

Boring out the stop in the reducer's small end allows the smaller pipe to
pass through the fitting into the larger one, concentrically. I first did
this to run a cold water feed pipe through a former heating element hole to
near the opposite (lower) side of an old electric water heater tank that I'd
converted to solar and mounted horizontally.

It did adequately heat water for laundry without using electricity, but it
wasn't worth the fuss versus Cold Water Tide.

Are you ready for California-style electric rates and monthly allocations?
https://www.sce.com/residential/rate...ial-Rate-Plans
In order to draw compressed air from the upper level of my inverted
propane cylinder storage tank; I bazed a half coupling into the inner
end of a reducing bushing (I don't have a welder) and inserted the
smaller pipe through a 3/4" "T" and nipple in the threaded boss. The
branch of the "T" serves as inlet and drain.

"Gerry" wrote in message ...

In order to draw compressed air from the upper level of my inverted
propane cylinder storage tank; I bazed a half coupling into the inner
end of a reducing bushing (I don't have a welder) and inserted the
smaller pipe through a 3/4" "T" and nipple in the threaded boss. The
branch of the "T" serves as inlet and drain.

--------------------------

Something like this, in effect?
https://www.zoro.com/nibco-2-x-34-x-...x2/i/G1806664/

"Jim Wilkins" wrote in message ...

"Gerry" wrote in message ...

In order to draw compressed air from the upper level of my inverted
propane cylinder storage tank; I bazed a half coupling into the inner
end of a reducing bushing (I don't have a welder) and inserted the
smaller pipe through a 3/4" "T" and nipple in the threaded boss. The
branch of the "T" serves as inlet and drain.

--------------------------

Something like this, in effect?
https://www.zoro.com/nibco-2-x-34-x-...x2/i/G1806664/

-------------------------------
I vaguely remember cobbling up a fitting that let compressed air into and
oil out of a tank that had only one opening, back before I had a lathe. I
may have tapped the small end from the inside and cut the two pipes running
into it short enough to not meet.
https://www.buyfittingsonline.com/pi...eable-iron-ul/

On Tue, 9 Feb 2021 06:18:47 -0500, "Jim Wilkins"
wrote:

"Gerry" wrote in message ...

In order to draw compressed air from the upper level of my inverted
propane cylinder storage tank; I bazed a half coupling into the inner
end of a reducing bushing (I don't have a welder) and inserted the
smaller pipe through a 3/4" "T" and nipple in the threaded boss. The
branch of the "T" serves as inlet and drain.

--------------------------

Something like this, in effect?
https://www.zoro.com/nibco-2-x-34-x-...x2/i/G1806664/
Somewhat similar, but in iron fittings and with the smaller pipe
extending through the nipple into the tank.

On Tue, 9 Feb 2021 06:45:38 -0500, "Jim Wilkins"
wrote:



"Jim Wilkins" wrote in message ...

"Gerry" wrote in message ...

In order to draw compressed air from the upper level of my inverted
propane cylinder storage tank; I bazed a half coupling into the inner
end of a reducing bushing (I don't have a welder) and inserted the
smaller pipe through a 3/4" "T" and nipple in the threaded boss. The
branch of the "T" serves as inlet and drain.

--------------------------

Something like this, in effect?
https://www.zoro.com/nibco-2-x-34-x-...x2/i/G1806664/

-------------------------------
I vaguely remember cobbling up a fitting that let compressed air into and
oil out of a tank that had only one opening, back before I had a lathe. I
may have tapped the small end from the inside and cut the two pipes running
into it short enough to not meet.
https://www.buyfittingsonline.com/pi...eable-iron-ul/
By brazing the half of a coupling into the inner end of the reducing
bushing, I, in effect turned it into a coupling for the smaller pipe
(1/4"IPS, IIRC) with threads on the outside to fit into the end of the
3/4" "T" giving a 3/4" close nipple screwed ito the boss of the tank
with a length of 1/4" pipe extending through it up into the tank.

"Gerry" wrote in message ...

On Tue, 9 Feb 2021 06:45:38 -0500, "Jim Wilkins"
wrote:



"Jim Wilkins" wrote in message ...

"Gerry" wrote in message
.. .

In order to draw compressed air from the upper level of my inverted
propane cylinder storage tank; I bazed a half coupling into the inner
end of a reducing bushing (I don't have a welder) and inserted the
smaller pipe through a 3/4" "T" and nipple in the threaded boss. The
branch of the "T" serves as inlet and drain.

--------------------------

Something like this, in effect?
https://www.zoro.com/nibco-2-x-34-x-...x2/i/G1806664/

-------------------------------
I vaguely remember cobbling up a fitting that let compressed air into and
oil out of a tank that had only one opening, back before I had a lathe. I
may have tapped the small end from the inside and cut the two pipes running
into it short enough to not meet.
https://www.buyfittingsonline.com/pi...eable-iron-ul/
By brazing the half of a coupling into the inner end of the reducing
bushing, I, in effect turned it into a coupling for the smaller pipe
(1/4"IPS, IIRC) with threads on the outside to fit into the end of the
3/4" "T" giving a 3/4" close nipple screwed ito the boss of the tank
with a length of 1/4" pipe extending through it up into the tank.

---------------------------------------

I think I get it now. You made the reducing bushing into a coupler for two
pieces of the smaller pipe by brazing a second female thread to the back
side. I had trouble describing my versions without pictures.

I think the easy way, IF you have a lathe, is to bore out a male threaded
fitting or plug larger than the pass-through pipe and solder or braze it
onto the pipe, then you can easily adjust the fit up of the pass-through
pipe before permanently attaching it. Water pipe ODs don't closely match
fractional drill bit sizes.

Instead of trying to chuck fittings directly I screw them onto a brass pipe
nipple or machined fitting whose threads run truer to their OD than steel
water pipe and cast fittings. The threads of machined steel hydraulic
fittings also run true and they can handle more torque than brass.

Another way is to drill out a compression fitting so the tube can pass
through. This has the advantage that copper tubing OD is the same as drill
bit sizes, 3/8", 1/2" etc, and lathe boring isn't necessary. I did this to
replace the thin spray dip tube of garden sprayers with larger copper
tubing, to attach a sink spray hose. I drilled out the tank fitting but used
a tapered reamer to open up the cap nut which is too small to survive a
twist drill bit, and sealed the connection with an O ring. They serve as
pre-positioned rapid-response brush fire extinguishers in summer and power
outage hot showers in winter, with the water heated on the wood stove, and a
handy rinse-off when working out beyond the reach of a garden hose.

On Wednesday, February 10, 2021 at 8:51:47 AM UTC-5, Jim Wilkins wrote:
"Gerry" wrote in message ...
On Tue, 9 Feb 2021 06:45:38 -0500, "Jim Wilkins"
wrote:



"Jim Wilkins" wrote in message ...

"Gerry" wrote in message
...

In order to draw compressed air from the upper level of my inverted
propane cylinder storage tank; I bazed a half coupling into the inner
end of a reducing bushing (I don't have a welder) and inserted the
smaller pipe through a 3/4" "T" and nipple in the threaded boss. The
branch of the "T" serves as inlet and drain.

--------------------------

Something like this, in effect?
https://www.zoro.com/nibco-2-x-34-x-...x2/i/G1806664/

-------------------------------
I vaguely remember cobbling up a fitting that let compressed air into and
oil out of a tank that had only one opening, back before I had a lathe. I
may have tapped the small end from the inside and cut the two pipes running
into it short enough to not meet.
https://www.buyfittingsonline.com/pi...eable-iron-ul/
By brazing the half of a coupling into the inner end of the reducing
bushing, I, in effect turned it into a coupling for the smaller pipe
(1/4"IPS, IIRC) with threads on the outside to fit into the end of the
3/4" "T" giving a 3/4" close nipple screwed ito the boss of the tank
with a length of 1/4" pipe extending through it up into the tank.
---------------------------------------

I think I get it now. You made the reducing bushing into a coupler for two
pieces of the smaller pipe by brazing a second female thread to the back
side. I had trouble describing my versions without pictures.

I think the easy way, IF you have a lathe, is to bore out a male threaded
fitting or plug larger than the pass-through pipe and solder or braze it
onto the pipe, then you can easily adjust the fit up of the pass-through
pipe before permanently attaching it. Water pipe ODs don't closely match
fractional drill bit sizes.

Instead of trying to chuck fittings directly I screw them onto a brass pipe
nipple or machined fitting whose threads run truer to their OD than steel
water pipe and cast fittings. The threads of machined steel hydraulic
fittings also run true and they can handle more torque than brass.

Another way is to drill out a compression fitting so the tube can pass
through. This has the advantage that copper tubing OD is the same as drill
bit sizes, 3/8", 1/2" etc, and lathe boring isn't necessary. I did this to
replace the thin spray dip tube of garden sprayers with larger copper
tubing, to attach a sink spray hose.

Switching the spigot fittings? Dod gamn good idea.