• Acetylene leak, BOOM!

    From Leon Fisk@21:1/5 to All on Wed Sep 27 16:05:35 2023
    Hi,

    Interesting news article on the power of leaking acetylene😬

    https://www.mlive.com/news/grand-rapids/2023/09/explosion-in-allendale-injures-1-damages-vehicles.html

    ===
    OTTAWA COUNTY, MI – Police believe a leaking cutting torch stored in a vehicle’s trunk caused an explosion early Wednesday morning.

    A 21-year-old Allendale woman suffered minor injuries and two cars were
    damaged as a result of the blast, Ottawa County sheriff’s deputies said.

    Allendale Township firefighters and deputies responded to a 6:30 a.m.
    report of an explosion Wednesday near 68th Avenue and Sunset Drive in Allendale.

    Police said a leaking acetylene torch was stored in the trunk of a car overnight. Investigators determined the explosion was triggered either
    when the electric release was used or when the trunk was opened.

    There was also damage reported to the garage’s structure.

    --
    Leon Fisk
    Grand Rapids MI

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  • From Bob La Londe@21:1/5 to Leon Fisk on Wed Sep 27 16:07:16 2023
    On 9/27/2023 1:05 PM, Leon Fisk wrote:
    Hi,

    Interesting news article on the power of leaking acetylene😬

    https://www.mlive.com/news/grand-rapids/2023/09/explosion-in-allendale-injures-1-damages-vehicles.html

    ===
    OTTAWA COUNTY, MI – Police believe a leaking cutting torch stored in a vehicle’s trunk caused an explosion early Wednesday morning.

    A 21-year-old Allendale woman suffered minor injuries and two cars were damaged as a result of the blast, Ottawa County sheriff’s deputies said.

    Allendale Township firefighters and deputies responded to a 6:30 a.m.
    report of an explosion Wednesday near 68th Avenue and Sunset Drive in Allendale.

    Police said a leaking acetylene torch was stored in the trunk of a car overnight. Investigators determined the explosion was triggered either
    when the electric release was used or when the trunk was opened.

    There was also damage reported to the garage’s structure.


    I have been told more than a certain volume of acetylene in "free air"
    can self detonate or detonate from turbulence. I had an accident here
    at the shop some years back where there was no apparent source of
    ignition. Just somebody in open air sticking their hand in front of the
    flow the flow from a cracked valve. There was no physical contact, and
    no obvious source for static. I mentioned it in this group not long
    after it happened. Gunner and a few others told me there had to be an
    ignition source, but I was standing right there. In fact I was reaching towards the valve to shut it off when it ignited. Then we had a blow
    torch pointed at the corner of my shop building. I went back in the
    shop to grab a welding glove so I could shut it off.

    The person with their hand in front of the valve got burned, but not as
    badly as you might think. Their whole hand was red, and the outer
    layers of skin all sloughed off over the next few days. They got their
    hand out of the fire pretty quick. Worse than a regular first degree
    burn, but not the worst burn I've seen called a second degree burn. It
    was mostly bad because it was over their whole hand.

    We could argue about whether it was an explosion or a conflagration. It
    had a pretty healthy pop for an uncontained event. Faster than a
    whoomp, but maybe not quite a crack.


    --
    Bob La Londe
    CNC Molds N Stuff


    --
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  • From Jim Wilkins@21:1/5 to All on Wed Sep 27 19:40:44 2023
    "Bob La Londe" wrote in message news:uf2cj4$3aqmh$2@dont-email.me...


    I have been told more than a certain volume of acetylene in "free air"
    can self detonate or detonate from turbulence. I had an accident here
    at the shop some years back where there was no apparent source of
    ignition. Just somebody in open air sticking their hand in front of the
    flow the flow from a cracked valve. ...

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

    Acetylene's triply bonded carbon stores a lot of energy and it can explode without burning, by decomposing into carbon and hydrogen or polymerizing (combining with its neighboring molecules) into benzene or a metal-like film called polyacetylene.

    https://www.linkedin.com/pulse/guidelines-handle-dissolved-acetylene-cylinders-safely-rob-moyer
    "This process is referred to as polymerization, and it produces a heat. The reaction attains self-sustenance above atmospheric pressure, still, it is strong enough to initiate an explosive acetylene decomposition. Normally, polymerization commences at atmospheric pressure at temperature 400°C, however, it can also happen at low temperatures, and in the presence of catalysts such as rust, pipe scale, diatomite, silica gel, and charcoal."

    In other words dirty hands may trigger it. In the cylinder it's dissolved in acetone to make it safer. https://rexarc.com/blog/importance-acetoning-dissolving-acetylene-acetone/

    Rapid combustion that's subsonic, slower than a detonation or explosion, is called deflagration. (not flagellation)

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  • From Clare Snyder@21:1/5 to All on Thu Sep 28 00:26:20 2023
    On Wed, 27 Sep 2023 16:07:16 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/27/2023 1:05 PM, Leon Fisk wrote:
    Hi,

    Interesting news article on the power of leaking acetylene?

    https://www.mlive.com/news/grand-rapids/2023/09/explosion-in-allendale-injures-1-damages-vehicles.html

    ===
    OTTAWA COUNTY, MI – Police believe a leaking cutting torch stored in a
    vehicle’s trunk caused an explosion early Wednesday morning.

    A 21-year-old Allendale woman suffered minor injuries and two cars were
    damaged as a result of the blast, Ottawa County sheriff’s deputies said.

    Allendale Township firefighters and deputies responded to a 6:30 a.m.
    report of an explosion Wednesday near 68th Avenue and Sunset Drive in
    Allendale.

    Police said a leaking acetylene torch was stored in the trunk of a car
    overnight. Investigators determined the explosion was triggered either
    when the electric release was used or when the trunk was opened.

    There was also damage reported to the garage’s structure.


    I have been told more than a certain volume of acetylene in "free air"
    can self detonate or detonate from turbulence. I had an accident here
    at the shop some years back where there was no apparent source of
    ignition. Just somebody in open air sticking their hand in front of the
    flow the flow from a cracked valve. There was no physical contact, and
    no obvious source for static. I mentioned it in this group not long
    after it happened. Gunner and a few others told me there had to be an >ignition source, but I was standing right there. In fact I was reaching >towards the valve to shut it off when it ignited. Then we had a blow
    torch pointed at the corner of my shop building. I went back in the
    shop to grab a welding glove so I could shut it off.

    The person with their hand in front of the valve got burned, but not as
    badly as you might think. Their whole hand was red, and the outer
    layers of skin all sloughed off over the next few days. They got their
    hand out of the fire pretty quick. Worse than a regular first degree
    burn, but not the worst burn I've seen called a second degree burn. It
    was mostly bad because it was over their whole hand.

    We could argue about whether it was an explosion or a conflagration. It
    had a pretty healthy pop for an uncontained event. Faster than a
    whoomp, but maybe not quite a crack.


    --
    Bob La Londe
    CNC Molds N Stuff
    Free acetylene is unstable above about 14PSI and can detonate without
    external oxygen. If you are feeling particularly brave or stupid take
    a steel block and drill a hole in it then find a snug fitting steel
    plug/shaft to fit the hole. With the open end of the hole facing down (acetylene is lighter than air) fill the hole with pure acetylene fron
    a torch and insert the steel plug, turn it over on an anvil and hit
    the plug with a hammer. If you are even stupider or braver, use a
    copper "firing pin" as copper acts as a catalyst to promote the
    breakdown of acetylene.

    Just make sure all your various insurances, including life insurance,
    are paid up!!!!

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  • From Mike Spencer@21:1/5 to Clare Snyder on Thu Sep 28 03:32:11 2023
    Clare Snyder <clare@snyder.on.ca> writes:

    Free acetylene is unstable above about 14PSI and can detonate without external oxygen. If you are feeling particularly brave or stupid take
    a steel block and drill a hole in it then find a snug fitting steel plug/shaft to fit the hole. With the open end of the hole facing down (acetylene is lighter than air) fill the hole with pure acetylene fron
    a torch and insert the steel plug, turn it over on an anvil and hit
    the plug with a hammer. If you are even stupider or braver, use a
    copper "firing pin" as copper acts as a catalyst to promote the
    breakdown of acetylene.

    There's another, now obscure copper/acet connection. In the days of
    generating acetylene on the fly for torches, home lighting etc. the
    generator was sometimes made of copper. Over time, the acetylene
    reacted with the copper leaving copper acetylide deposits in the
    seams. A tinsmith, tasked with tightening up leaky seams on a
    generator could be greeted with a very loud suprise when striking a
    seam with a hammer.

    Allegedly, you can make copper acetylide by bubbling the gas through a container of copper sulfate dissolved in water where tiny crystals of
    acetylide vivibly form and settle out. One of those substances, like
    nitrogen triiodide, that's cool but unwise to make.

    In the 70s, I once visited a blacksmith shop that had an oxy tank on a
    dolly with an carbide/acet generator apparatus. I asked the smith if
    perhaps that was a bit dangerous. His reply, "She blows up sometimes"
    and pointed upward. The building had a plastered cathedral ceiling
    ca. 20' in the center and there was a big sooty starburst on the
    plaster over the generator. He was the only blacksmith I ever met who
    drank whiskey while working so maybe a few straws short of a broom.


    Just make sure all your various insurances, including life insurance,
    are paid up!!!!

    --
    Mike Spencer Nova Scotia, Canada

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  • From Bob La Londe@21:1/5 to Joe Gwinn on Thu Sep 28 15:55:39 2023
    On 9/28/2023 3:19 PM, Joe Gwinn wrote:
    On Wed, 27 Sep 2023 16:07:16 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/27/2023 1:05 PM, Leon Fisk wrote:
    Hi,

    Interesting news article on the power of leaking acetylene?

    https://www.mlive.com/news/grand-rapids/2023/09/explosion-in-allendale-injures-1-damages-vehicles.html

    ===
    OTTAWA COUNTY, MI – Police believe a leaking cutting torch stored in a >>> vehicle’s trunk caused an explosion early Wednesday morning.

    A 21-year-old Allendale woman suffered minor injuries and two cars were
    damaged as a result of the blast, Ottawa County sheriff’s deputies said. >>>
    Allendale Township firefighters and deputies responded to a 6:30 a.m.
    report of an explosion Wednesday near 68th Avenue and Sunset Drive in
    Allendale.

    Police said a leaking acetylene torch was stored in the trunk of a car
    overnight. Investigators determined the explosion was triggered either
    when the electric release was used or when the trunk was opened.

    There was also damage reported to the garage’s structure.


    I have been told more than a certain volume of acetylene in "free air"
    can self detonate or detonate from turbulence. I had an accident here
    at the shop some years back where there was no apparent source of
    ignition. Just somebody in open air sticking their hand in front of the
    flow the flow from a cracked valve. There was no physical contact, and
    no obvious source for static. I mentioned it in this group not long
    after it happened. Gunner and a few others told me there had to be an
    ignition source, but I was standing right there. In fact I was reaching
    towards the valve to shut it off when it ignited. Then we had a blow
    torch pointed at the corner of my shop building. I went back in the
    shop to grab a welding glove so I could shut it off.

    The person with their hand in front of the valve got burned, but not as
    badly as you might think. Their whole hand was red, and the outer
    layers of skin all sloughed off over the next few days. They got their
    hand out of the fire pretty quick. Worse than a regular first degree
    burn, but not the worst burn I've seen called a second degree burn. It
    was mostly bad because it was over their whole hand.

    We could argue about whether it was an explosion or a conflagration. It
    had a pretty healthy pop for an uncontained event. Faster than a
    whoomp, but maybe not quite a crack.

    What was the humidity then?

    I'd bet on an unnoticed ESD (electro-static discharge), which can be
    caused by the air causing things to flutter against one another.

    Just walking across a carpet can generate enough static electricity to
    make a sharp crack sound.

    Joe Gwinn


    Standing on concrete outside in one of the driest climates on earth. I
    wear rubber sole shoes pretty much all the time. Either sneakers or
    walking boots. The OP usually wears rubber sole shoes as well. I still
    have very good discrete hearing. (I still have my high frequency
    hearing as well.) The only sound I heard was the detonation. Its
    possible, but it sure didn't seem like it.


    --
    Bob La Londe
    CNC Molds N Stuff


    --
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  • From Joe Gwinn@21:1/5 to All on Thu Sep 28 18:19:57 2023
    On Wed, 27 Sep 2023 16:07:16 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/27/2023 1:05 PM, Leon Fisk wrote:
    Hi,

    Interesting news article on the power of leaking acetylene?

    https://www.mlive.com/news/grand-rapids/2023/09/explosion-in-allendale-injures-1-damages-vehicles.html

    ===
    OTTAWA COUNTY, MI – Police believe a leaking cutting torch stored in a
    vehicle’s trunk caused an explosion early Wednesday morning.

    A 21-year-old Allendale woman suffered minor injuries and two cars were
    damaged as a result of the blast, Ottawa County sheriff’s deputies said.

    Allendale Township firefighters and deputies responded to a 6:30 a.m.
    report of an explosion Wednesday near 68th Avenue and Sunset Drive in
    Allendale.

    Police said a leaking acetylene torch was stored in the trunk of a car
    overnight. Investigators determined the explosion was triggered either
    when the electric release was used or when the trunk was opened.

    There was also damage reported to the garage’s structure.


    I have been told more than a certain volume of acetylene in "free air"
    can self detonate or detonate from turbulence. I had an accident here
    at the shop some years back where there was no apparent source of
    ignition. Just somebody in open air sticking their hand in front of the
    flow the flow from a cracked valve. There was no physical contact, and
    no obvious source for static. I mentioned it in this group not long
    after it happened. Gunner and a few others told me there had to be an >ignition source, but I was standing right there. In fact I was reaching >towards the valve to shut it off when it ignited. Then we had a blow
    torch pointed at the corner of my shop building. I went back in the
    shop to grab a welding glove so I could shut it off.

    The person with their hand in front of the valve got burned, but not as
    badly as you might think. Their whole hand was red, and the outer
    layers of skin all sloughed off over the next few days. They got their
    hand out of the fire pretty quick. Worse than a regular first degree
    burn, but not the worst burn I've seen called a second degree burn. It
    was mostly bad because it was over their whole hand.

    We could argue about whether it was an explosion or a conflagration. It
    had a pretty healthy pop for an uncontained event. Faster than a
    whoomp, but maybe not quite a crack.

    What was the humidity then?

    I'd bet on an unnoticed ESD (electro-static discharge), which can be
    caused by the air causing things to flutter against one another.

    Just walking across a carpet can generate enough static electricity to
    make a sharp crack sound.

    Joe Gwinn

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  • From Jim Wilkins@21:1/5 to All on Fri Sep 29 12:13:02 2023
    "Joe Gwinn" wrote in message news:m4sdhi9cmrad5ah8of9c13o7vmeqn22tmf@4ax.com...

    On Thu, 28 Sep 2023 15:55:39 -0700, Bob La Londe <none@none.com99>
    wrote:

    Standing on concrete outside in one of the driest climates on earth. I
    wear rubber sole shoes pretty much all the time. Either sneakers or
    walking boots. The OP usually wears rubber sole shoes as well. I still
    have very good discrete hearing. (I still have my high frequency
    hearing as well.) The only sound I heard was the detonation. Its
    possible, but it sure didn't seem like it.

    The ESD spark and the detonation would likely be too close in time to
    be told apart, and the boom is far louder.

    Joe Gwinn

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

    High voltage electricity can discharge with little or no sound. https://en.wikipedia.org/wiki/Corona_discharge

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  • From Joe Gwinn@21:1/5 to All on Fri Sep 29 11:45:57 2023
    On Thu, 28 Sep 2023 15:55:39 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/28/2023 3:19 PM, Joe Gwinn wrote:
    On Wed, 27 Sep 2023 16:07:16 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/27/2023 1:05 PM, Leon Fisk wrote:
    Hi,

    Interesting news article on the power of leaking acetylene?

    https://www.mlive.com/news/grand-rapids/2023/09/explosion-in-allendale-injures-1-damages-vehicles.html

    ===
    OTTAWA COUNTY, MI – Police believe a leaking cutting torch stored in a >>>> vehicle’s trunk caused an explosion early Wednesday morning.

    A 21-year-old Allendale woman suffered minor injuries and two cars were >>>> damaged as a result of the blast, Ottawa County sheriff’s deputies said. >>>>
    Allendale Township firefighters and deputies responded to a 6:30 a.m.
    report of an explosion Wednesday near 68th Avenue and Sunset Drive in
    Allendale.

    Police said a leaking acetylene torch was stored in the trunk of a car >>>> overnight. Investigators determined the explosion was triggered either >>>> when the electric release was used or when the trunk was opened.

    There was also damage reported to the garage’s structure.


    I have been told more than a certain volume of acetylene in "free air"
    can self detonate or detonate from turbulence. I had an accident here
    at the shop some years back where there was no apparent source of
    ignition. Just somebody in open air sticking their hand in front of the >>> flow the flow from a cracked valve. There was no physical contact, and
    no obvious source for static. I mentioned it in this group not long
    after it happened. Gunner and a few others told me there had to be an
    ignition source, but I was standing right there. In fact I was reaching >>> towards the valve to shut it off when it ignited. Then we had a blow
    torch pointed at the corner of my shop building. I went back in the
    shop to grab a welding glove so I could shut it off.

    The person with their hand in front of the valve got burned, but not as
    badly as you might think. Their whole hand was red, and the outer
    layers of skin all sloughed off over the next few days. They got their
    hand out of the fire pretty quick. Worse than a regular first degree
    burn, but not the worst burn I've seen called a second degree burn. It
    was mostly bad because it was over their whole hand.

    We could argue about whether it was an explosion or a conflagration. It >>> had a pretty healthy pop for an uncontained event. Faster than a
    whoomp, but maybe not quite a crack.

    What was the humidity then?

    I'd bet on an unnoticed ESD (electro-static discharge), which can be
    caused by the air causing things to flutter against one another.

    Just walking across a carpet can generate enough static electricity to
    make a sharp crack sound.

    Joe Gwinn


    Standing on concrete outside in one of the driest climates on earth. I
    wear rubber sole shoes pretty much all the time. Either sneakers or
    walking boots. The OP usually wears rubber sole shoes as well. I still
    have very good discrete hearing. (I still have my high frequency
    hearing as well.) The only sound I heard was the detonation. Its
    possible, but it sure didn't seem like it.

    The ESD spark and the detonation would likely be too close in time to
    be told apart, and the boom is far louder.

    Joe Gwinn

    --- SoupGate-Win32 v1.05
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  • From Bob La Londe@21:1/5 to Joe Gwinn on Fri Sep 29 14:10:51 2023
    On 9/29/2023 8:45 AM, Joe Gwinn wrote:
    On Thu, 28 Sep 2023 15:55:39 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/28/2023 3:19 PM, Joe Gwinn wrote:
    On Wed, 27 Sep 2023 16:07:16 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/27/2023 1:05 PM, Leon Fisk wrote:
    Hi,

    Interesting news article on the power of leaking acetylene?

    https://www.mlive.com/news/grand-rapids/2023/09/explosion-in-allendale-injures-1-damages-vehicles.html

    ===
    OTTAWA COUNTY, MI – Police believe a leaking cutting torch stored in a >>>>> vehicle’s trunk caused an explosion early Wednesday morning.

    A 21-year-old Allendale woman suffered minor injuries and two cars were >>>>> damaged as a result of the blast, Ottawa County sheriff’s deputies said.

    Allendale Township firefighters and deputies responded to a 6:30 a.m. >>>>> report of an explosion Wednesday near 68th Avenue and Sunset Drive in >>>>> Allendale.

    Police said a leaking acetylene torch was stored in the trunk of a car >>>>> overnight. Investigators determined the explosion was triggered either >>>>> when the electric release was used or when the trunk was opened.

    There was also damage reported to the garage’s structure.


    I have been told more than a certain volume of acetylene in "free air" >>>> can self detonate or detonate from turbulence. I had an accident here >>>> at the shop some years back where there was no apparent source of
    ignition. Just somebody in open air sticking their hand in front of the >>>> flow the flow from a cracked valve. There was no physical contact, and >>>> no obvious source for static. I mentioned it in this group not long
    after it happened. Gunner and a few others told me there had to be an >>>> ignition source, but I was standing right there. In fact I was reaching >>>> towards the valve to shut it off when it ignited. Then we had a blow
    torch pointed at the corner of my shop building. I went back in the
    shop to grab a welding glove so I could shut it off.

    The person with their hand in front of the valve got burned, but not as >>>> badly as you might think. Their whole hand was red, and the outer
    layers of skin all sloughed off over the next few days. They got their >>>> hand out of the fire pretty quick. Worse than a regular first degree
    burn, but not the worst burn I've seen called a second degree burn. It >>>> was mostly bad because it was over their whole hand.

    We could argue about whether it was an explosion or a conflagration. It >>>> had a pretty healthy pop for an uncontained event. Faster than a
    whoomp, but maybe not quite a crack.

    What was the humidity then?

    I'd bet on an unnoticed ESD (electro-static discharge), which can be
    caused by the air causing things to flutter against one another.

    Just walking across a carpet can generate enough static electricity to
    make a sharp crack sound.

    Joe Gwinn


    Standing on concrete outside in one of the driest climates on earth. I
    wear rubber sole shoes pretty much all the time. Either sneakers or
    walking boots. The OP usually wears rubber sole shoes as well. I still
    have very good discrete hearing. (I still have my high frequency
    hearing as well.) The only sound I heard was the detonation. Its
    possible, but it sure didn't seem like it.

    The ESD spark and the detonation would likely be too close in time to
    be told apart, and the boom is far louder.

    Joe Gwinn

    So how for does the invisible arc jump. His hand was 8-10 inches away.
    It wasn't me. My hand was maybe 6 inches away, and I felt no static
    pop. The only time I've seen a normal static arc jump much longer than
    an inch or so was in extreme circumstances. Arc gap generators, St
    Elmos fire discharging off an antenna cable in a fog on boat. That sort
    of thing. In those cases it was quite visible.

    Maybe you are right, and I am full shit, but the detonation happened at
    exactly the moment the OPs hand broke the flow from the valve. I was so surprised that I spent quite a bit of time researching it to see what
    could have caused it. There was no obvious arc source. Not even a
    nearby motor starting up. Closest motor was the AC heat pump condensing
    unit about 15 feet away and it was not running.

    Is acetylene gas conductive? I guess if it is that could have provided
    the "invisible" arc path. I am aware that vulcanisates of acetylene
    black are conductive, but I can't find anything that specifically says acetylene gas is.

    That acetylene "can" detonate from when certain conditions are met not necessarily requiring a spark is established. Whether or not that is
    what happened when a bottle turned into a blow torch outside my shop we
    will never know for sure. I have no desired to perform experiments to
    prove it one way or another. Okay maybe a little but I am not yet
    senile enough to let my curiosity over ride my common sense.


    --
    Bob La Londe
    CNC Molds N Stuff


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  • From Jim Wilkins@21:1/5 to All on Fri Sep 29 18:04:16 2023
    "Bob La Londe" wrote in message news:uf7egr$ek85$1@dont-email.me...

    So how for does the invisible arc jump. His hand was 8-10 inches away.
    It wasn't me. My hand was maybe 6 inches away, and I felt no static
    pop. The only time I've seen a normal static arc jump much longer than
    an inch or so was in extreme circumstances. Arc gap generators, St
    Elmos fire discharging off an antenna cable in a fog on boat. That sort
    of thing. In those cases it was quite visible.

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

    I Googled to see if the flow of an insulating gas could transfer charge like the belt of a van de Graaff generator and what I found was that it has to contain particles, clean gas won't.

    I thought I remembered a small shock from operating air tools.

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  • From Joe Gwinn@21:1/5 to All on Fri Sep 29 18:04:01 2023
    On Fri, 29 Sep 2023 14:10:51 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/29/2023 8:45 AM, Joe Gwinn wrote:
    On Thu, 28 Sep 2023 15:55:39 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/28/2023 3:19 PM, Joe Gwinn wrote:
    On Wed, 27 Sep 2023 16:07:16 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/27/2023 1:05 PM, Leon Fisk wrote:
    Hi,

    Interesting news article on the power of leaking acetylene?

    https://www.mlive.com/news/grand-rapids/2023/09/explosion-in-allendale-injures-1-damages-vehicles.html

    ===
    OTTAWA COUNTY, MI – Police believe a leaking cutting torch stored in a >>>>>> vehicle’s trunk caused an explosion early Wednesday morning.

    A 21-year-old Allendale woman suffered minor injuries and two cars were >>>>>> damaged as a result of the blast, Ottawa County sheriff’s deputies said. >>>>>>
    Allendale Township firefighters and deputies responded to a 6:30 a.m. >>>>>> report of an explosion Wednesday near 68th Avenue and Sunset Drive in >>>>>> Allendale.

    Police said a leaking acetylene torch was stored in the trunk of a car >>>>>> overnight. Investigators determined the explosion was triggered either >>>>>> when the electric release was used or when the trunk was opened.

    There was also damage reported to the garage’s structure.


    I have been told more than a certain volume of acetylene in "free air" >>>>> can self detonate or detonate from turbulence. I had an accident here >>>>> at the shop some years back where there was no apparent source of
    ignition. Just somebody in open air sticking their hand in front of the >>>>> flow the flow from a cracked valve. There was no physical contact, and >>>>> no obvious source for static. I mentioned it in this group not long >>>>> after it happened. Gunner and a few others told me there had to be an >>>>> ignition source, but I was standing right there. In fact I was reaching >>>>> towards the valve to shut it off when it ignited. Then we had a blow >>>>> torch pointed at the corner of my shop building. I went back in the >>>>> shop to grab a welding glove so I could shut it off.

    The person with their hand in front of the valve got burned, but not as >>>>> badly as you might think. Their whole hand was red, and the outer
    layers of skin all sloughed off over the next few days. They got their >>>>> hand out of the fire pretty quick. Worse than a regular first degree >>>>> burn, but not the worst burn I've seen called a second degree burn. It >>>>> was mostly bad because it was over their whole hand.

    We could argue about whether it was an explosion or a conflagration. It >>>>> had a pretty healthy pop for an uncontained event. Faster than a
    whoomp, but maybe not quite a crack.

    What was the humidity then?

    I'd bet on an unnoticed ESD (electro-static discharge), which can be
    caused by the air causing things to flutter against one another.

    Just walking across a carpet can generate enough static electricity to >>>> make a sharp crack sound.

    Joe Gwinn


    Standing on concrete outside in one of the driest climates on earth. I
    wear rubber sole shoes pretty much all the time. Either sneakers or
    walking boots. The OP usually wears rubber sole shoes as well. I still >>> have very good discrete hearing. (I still have my high frequency
    hearing as well.) The only sound I heard was the detonation. Its
    possible, but it sure didn't seem like it.

    The ESD spark and the detonation would likely be too close in time to
    be told apart, and the boom is far louder.

    Joe Gwinn

    So how for does the invisible arc jump. His hand was 8-10 inches away.
    It wasn't me. My hand was maybe 6 inches away, and I felt no static
    pop. The only time I've seen a normal static arc jump much longer than
    an inch or so was in extreme circumstances. Arc gap generators, St
    Elmos fire discharging off an antenna cable in a fog on boat. That sort
    of thing. In those cases it was quite visible.

    Maybe you are right, and I am full shit, but the detonation happened at >exactly the moment the OPs hand broke the flow from the valve. I was so >surprised that I spent quite a bit of time researching it to see what
    could have caused it. There was no obvious arc source. Not even a
    nearby motor starting up. Closest motor was the AC heat pump condensing
    unit about 15 feet away and it was not running.

    It's impossible to tell exactly what happened without high-def videos,
    and memory is famously unreliable about things not noticed.


    Is acetylene gas conductive?

    No.

    I guess if it is that could have provided
    the "invisible" arc path. I am aware that vulcanisates of acetylene
    black are conductive, but I can't find anything that specifically says >acetylene gas is.

    That acetylene "can" detonate from when certain conditions are met not >necessarily requiring a spark is established. Whether or not that is
    what happened when a bottle turned into a blow torch outside my shop we
    will never know for sure. I have no desired to perform experiments to
    prove it one way or another. Okay maybe a little but I am not yet
    senile enough to let my curiosity over ride my common sense.

    It's true that acetylene has all manner of ways to go boom, but most
    such methods are very unlikely in practice. But ESD is not rare.

    Joe Gwinn

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  • From Jim Wilkins@21:1/5 to All on Fri Sep 29 18:13:10 2023
    "Jim Wilkins" wrote in message news:uf7hm2$fkfd$1@dont-email.me...

    "Bob La Londe" wrote in message news:uf7egr$ek85$1@dont-email.me...

    So how for does the invisible arc jump. His hand was 8-10 inches away.
    It wasn't me. My hand was maybe 6 inches away, and I felt no static
    pop. The only time I've seen a normal static arc jump much longer than
    an inch or so was in extreme circumstances. Arc gap generators, St
    Elmos fire discharging off an antenna cable in a fog on boat. That sort
    of thing. In those cases it was quite visible.

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

    I Googled to see if the flow of an insulating gas could transfer charge like the belt of a van de Graaff generator and what I found was that it has to contain particles, clean gas won't.

    I thought I remembered a small shock from operating air tools.

    This says yes: https://www.eevblog.com/forum/chat/does-air-compressor-produce-esd/

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bob La Londe@21:1/5 to Jim Wilkins on Fri Sep 29 15:23:10 2023
    On 9/29/2023 3:13 PM, Jim Wilkins wrote:


    "Jim Wilkins"  wrote in message news:uf7hm2$fkfd$1@dont-email.me...

    "Bob La Londe"  wrote in message news:uf7egr$ek85$1@dont-email.me...

    So how for does the invisible arc jump.  His hand was 8-10 inches away.
    It wasn't me.  My hand was maybe 6 inches away, and I felt no static
    pop.  The only time I've seen a normal static arc jump much longer than
    an inch or so was in extreme circumstances.  Arc gap generators, St
    Elmos fire discharging off an antenna cable in a fog on boat.  That sort
    of thing.  In those cases it was quite visible.

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

    I Googled to see if the flow of an insulating gas could transfer charge
    like
    the belt of a van de Graaff generator and what I found was that it has to contain particles, clean gas won't.

    I thought I remembered a small shock from operating air tools.

    This says yes: https://www.eevblog.com/forum/chat/does-air-compressor-produce-esd/


    "I can imagine it spraying mice all over the place too but I'm not too
    sure how likely either is." HAHAHAHAHAHAHAHA


    --
    Bob La Londe
    CNC Molds N Stuff


    --
    This email has been checked for viruses by AVG antivirus software.
    www.avg.com

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  • From Bob La Londe@21:1/5 to Jim Wilkins on Fri Sep 29 15:21:03 2023
    On 9/29/2023 3:04 PM, Jim Wilkins wrote:
    "Bob La Londe"  wrote in message news:uf7egr$ek85$1@dont-email.me...

    So how for does the invisible arc jump.  His hand was 8-10 inches away.
    It wasn't me.  My hand was maybe 6 inches away, and I felt no static
    pop.  The only time I've seen a normal static arc jump much longer than
    an inch or so was in extreme circumstances.  Arc gap generators, St
    Elmos fire discharging off an antenna cable in a fog on boat.  That sort
    of thing.  In those cases it was quite visible.

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

    I Googled to see if the flow of an insulating gas could transfer charge
    like the belt of a van de Graaff generator and what I found was that it
    has to contain particles, clean gas won't.

    I thought I remembered a small shock from operating air tools.


    We are getting pretty far out in the weeds here. I don't recall ever
    getting zapped by air tools, but wood shop guys have to discharge static
    on dust collection systems. Lots of particles there though. I wonder
    if the minimal oil from the compressor and/or air tool oil counts as
    enough of a particle to create static build up. Maybe if using some
    types of plastic whip lines and an oiler at the wall instead of oil
    dispensed directly into the tool...

    --
    Bob La Londe
    CNC Molds N Stuff


    --
    This email has been checked for viruses by AVG antivirus software.
    www.avg.com

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  • From David Billington@21:1/5 to Bob La Londe on Fri Sep 29 23:44:40 2023
    On 29/09/2023 23:21, Bob La Londe wrote:
    On 9/29/2023 3:04 PM, Jim Wilkins wrote:
    "Bob La Londe"  wrote in message news:uf7egr$ek85$1@dont-email.me...

    So how for does the invisible arc jump.  His hand was 8-10 inches away.
    It wasn't me.  My hand was maybe 6 inches away, and I felt no static
    pop.  The only time I've seen a normal static arc jump much longer than
    an inch or so was in extreme circumstances.  Arc gap generators, St
    Elmos fire discharging off an antenna cable in a fog on boat. That sort
    of thing.  In those cases it was quite visible.

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

    I Googled to see if the flow of an insulating gas could transfer
    charge like the belt of a van de Graaff generator and what I found
    was that it has to contain particles, clean gas won't.

    I thought I remembered a small shock from operating air tools.


    We are getting pretty far out in the weeds here.  I don't recall ever getting zapped by air tools, but wood shop guys have to discharge
    static on dust collection systems.  Lots of particles there though.  I wonder if the minimal oil from the compressor and/or air tool oil
    counts as enough of a particle to create static build up.  Maybe if
    using some types of plastic whip lines and an oiler at the wall
    instead of oil dispensed directly into the tool...

    I've seen 1/2" or more sparks in my old sand blasting booth from the gun
    to the part before I added an earth to the gun.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim Wilkins@21:1/5 to David Billington on Fri Sep 29 20:22:00 2023
    "David Billington" wrote in message news:uf7k0o$g062$1@dont-email.me...

    I've seen 1/2" or more sparks in my old sand blasting booth from the gun
    to the part before I added an earth to the gun.

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

    That's likely what I remembered. However this material on spray can dusters does mention static buildup: https://www.techspray.com/everything-you-need-to-know-about-air-duster-but-were-afraid-to-ask

    "The advantage of the chrome sprayer is more precise control over spray
    force and ESD (electrostatic discharge) control. The standard plastic
    sprayer has the potential to build up a static charge as you spray."

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Clare Snyder@21:1/5 to All on Fri Sep 29 22:50:29 2023
    On Fri, 29 Sep 2023 14:10:51 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/29/2023 8:45 AM, Joe Gwinn wrote:
    On Thu, 28 Sep 2023 15:55:39 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/28/2023 3:19 PM, Joe Gwinn wrote:
    On Wed, 27 Sep 2023 16:07:16 -0700, Bob La Londe <none@none.com99>
    wrote:

    On 9/27/2023 1:05 PM, Leon Fisk wrote:
    Hi,

    Interesting news article on the power of leaking acetylene?

    https://www.mlive.com/news/grand-rapids/2023/09/explosion-in-allendale-injures-1-damages-vehicles.html

    ===
    OTTAWA COUNTY, MI – Police believe a leaking cutting torch stored in a >>>>>> vehicle’s trunk caused an explosion early Wednesday morning.

    A 21-year-old Allendale woman suffered minor injuries and two cars were >>>>>> damaged as a result of the blast, Ottawa County sheriff’s deputies said. >>>>>>
    Allendale Township firefighters and deputies responded to a 6:30 a.m. >>>>>> report of an explosion Wednesday near 68th Avenue and Sunset Drive in >>>>>> Allendale.

    Police said a leaking acetylene torch was stored in the trunk of a car >>>>>> overnight. Investigators determined the explosion was triggered either >>>>>> when the electric release was used or when the trunk was opened.

    There was also damage reported to the garage’s structure.


    I have been told more than a certain volume of acetylene in "free air" >>>>> can self detonate or detonate from turbulence. I had an accident here >>>>> at the shop some years back where there was no apparent source of
    ignition. Just somebody in open air sticking their hand in front of the >>>>> flow the flow from a cracked valve. There was no physical contact, and >>>>> no obvious source for static. I mentioned it in this group not long >>>>> after it happened. Gunner and a few others told me there had to be an >>>>> ignition source, but I was standing right there. In fact I was reaching >>>>> towards the valve to shut it off when it ignited. Then we had a blow >>>>> torch pointed at the corner of my shop building. I went back in the >>>>> shop to grab a welding glove so I could shut it off.

    The person with their hand in front of the valve got burned, but not as >>>>> badly as you might think. Their whole hand was red, and the outer
    layers of skin all sloughed off over the next few days. They got their >>>>> hand out of the fire pretty quick. Worse than a regular first degree >>>>> burn, but not the worst burn I've seen called a second degree burn. It >>>>> was mostly bad because it was over their whole hand.

    We could argue about whether it was an explosion or a conflagration. It >>>>> had a pretty healthy pop for an uncontained event. Faster than a
    whoomp, but maybe not quite a crack.

    What was the humidity then?

    I'd bet on an unnoticed ESD (electro-static discharge), which can be
    caused by the air causing things to flutter against one another.

    Just walking across a carpet can generate enough static electricity to >>>> make a sharp crack sound.

    Joe Gwinn


    Standing on concrete outside in one of the driest climates on earth. I
    wear rubber sole shoes pretty much all the time. Either sneakers or
    walking boots. The OP usually wears rubber sole shoes as well. I still >>> have very good discrete hearing. (I still have my high frequency
    hearing as well.) The only sound I heard was the detonation. Its
    possible, but it sure didn't seem like it.

    The ESD spark and the detonation would likely be too close in time to
    be told apart, and the boom is far louder.

    Joe Gwinn

    So how for does the invisible arc jump. His hand was 8-10 inches away.
    It wasn't me. My hand was maybe 6 inches away, and I felt no static
    pop. The only time I've seen a normal static arc jump much longer than
    an inch or so was in extreme circumstances. Arc gap generators, St
    Elmos fire discharging off an antenna cable in a fog on boat. That sort
    of thing. In those cases it was quite visible.

    Maybe you are right, and I am full shit, but the detonation happened at >exactly the moment the OPs hand broke the flow from the valve. I was so >surprised that I spent quite a bit of time researching it to see what
    could have caused it. There was no obvious arc source. Not even a
    nearby motor starting up. Closest motor was the AC heat pump condensing
    unit about 15 feet away and it was not running.

    Is acetylene gas conductive? I guess if it is that could have provided
    the "invisible" arc path. I am aware that vulcanisates of acetylene
    black are conductive, but I can't find anything that specifically says >acetylene gas is.

    That acetylene "can" detonate from when certain conditions are met not >necessarily requiring a spark is established. Whether or not that is
    what happened when a bottle turned into a blow torch outside my shop we
    will never know for sure. I have no desired to perform experiments to
    prove it one way or another. Okay maybe a little but I am not yet
    senile enough to let my curiosity over ride my common sense.

    Bob - if the acetylene was exiting at significant speed it is very
    possible the "loca; pressure" where the gas hit the hand exceded
    14PSI. Even with no O2 Acetylene can detonate at 14PSI - if local
    pressure reaches 18PSSI detonation is pretty much a given. The flow
    disruption from placing an object or hand in the flow can increase
    local pressure significantly

    --
    Bob La Londe
    CNC Molds N Stuff

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From David Lesher@21:1/5 to Mike Spencer on Tue Oct 10 21:21:47 2023
    Mike Spencer <mds@bogus.nodomain.nowhere> writes:


    In the 70s, I once visited a blacksmith shop that had an oxy tank on a
    dolly with an carbide/acet generator apparatus.

    I was in Haiti in the 90's, and in Port-a-Prince there was a
    street called "Little Detroit" that was lined with all manner
    of mechanics working out in open air. This included body work,
    painting, and frame work. It all folded up every night, save for
    one thing: the large Carbide/Acetylene generators seeemingly
    standing guard...
    --
    A host is a host from coast to coast...............wb8foz@panix.com
    & no one will talk to a host that's close..........................
    Unless the host (that isn't close).........................pob 1433
    is busy, hung or dead....................................20915-1433

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