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

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

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

"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)

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!!!!

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

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

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

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

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

"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

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

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

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

"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.

"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/

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

--
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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

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.

"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."

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

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...
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