Mercury vs. aluminum
 

I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.



http://tinyurl.com/286pl63

Mercury vs. aluminum
 

Phil Kangas wrote:
I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.



http://tinyurl.com/286pl63

aluminum is pretty reactive and forms an oxide coating when it touches
air.

The mercury forms a liquid alloy or amalgam with the aluminum that
disrupts the formation of an oxide layer that self passivates or protects
the aluminum.

I've performed tests with aluminum and mercury and the results are quite
impressive- just like in the video. There's other interesting alamgams
too.

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.

The really thin and almost perfect oxide layer that can be formed on
aluminum is also the basis for aluminum electrolytic capacitors.

Mercury vs. aluminum
 

On Mon, 20 Dec 2010 21:12:54 -0500, "Phil Kangas"
wrote:

I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.



http://tinyurl.com/286pl63




And now you know why it is illegal to bring mercury filled
thermometers onto commercial aircraft flights.
Dave

Mercury vs. aluminum
 

On Tue, 21 Dec 2010 06:00:10 -0500, lid wrote:

On Mon, 20 Dec 2010 21:12:54 -0500, "Phil Kangas"
wrote:

I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.



http://tinyurl.com/286pl63




And now you know why it is illegal to bring mercury filled
thermometers onto commercial aircraft flights.
Dave

Just a guess. If mercury alloys with or dissolves aluminum, then the
dissolved aluminum would react rapidly with oxygen to aluminum oxide,
and being dissolved be unable to form the tough aluminum oxide coating
that normally stops this reaction. So the aluminum is depleted in
solution, more dissoves, and so on.

Pete Keillor

Mercury vs. aluminum
 

"Pete Keillor" wrote
in message
...
On Tue, 21 Dec 2010 06:00:10 -0500,
lid wrote:

On Mon, 20 Dec 2010 21:12:54 -0500, "Phil
Kangas"
wrote:

I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.



http://tinyurl.com/286pl63




And now you know why it is illegal to bring
mercury filled
thermometers onto commercial aircraft flights.
Dave

Just a guess. If mercury alloys with or
dissolves aluminum, then the
dissolved aluminum would react rapidly with
oxygen to aluminum oxide,
and being dissolved be unable to form the tough
aluminum oxide coating
that normally stops this reaction. So the
aluminum is depleted in
solution, more dissoves, and so on.

Pete Keillor

So the mercury has a greater affinity for oxygen
than the
aluminum? What is the grey matter produced from
the
reaction? Is it a hazardous substance?
phil k.

Mercury vs. aluminum
 

On Dec 21, 4:00*am, wrote:
On Mon, 20 Dec 2010 21:12:54 -0500, "Phil Kangas"

wrote:
I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.

http://tinyurl.com/286pl63

And now you know why it is illegal to bring mercury filled
thermometers onto commercial aircraft flights.
Dave

We had a mercury spill team at the shipyard to clean up when somebody
busted a thermostat or flourescent tube. Makes brass and copper
brittle as well as reacting with aluminum, not too good on a submerged
sub where they've got a bunch of all those metals.

Stan

Mercury vs. aluminum
 

On Dec 21, 11:17*am, "Phil Kangas" wrote:
"Pete Keillor" wrote
in messagenews:6181h6dc1kckpq4c4ed9g7ph26fuk3okgo@4ax .com...





On Tue, 21 Dec 2010 06:00:10 -0500,
wrote:

On Mon, 20 Dec 2010 21:12:54 -0500, "Phil
Kangas"
wrote:

I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.

http://tinyurl.com/286pl63

And now you know why it is illegal to bring
mercury filled
thermometers onto commercial aircraft flights.
Dave

Just a guess. *If mercury alloys with or
dissolves aluminum, then the
dissolved aluminum would react rapidly with
oxygen to aluminum oxide,
and being dissolved be unable to form the tough
aluminum oxide coating
that normally stops this reaction. *So the
aluminum is depleted in
solution, more dissoves, and so on.

Pete Keillor

So the mercury has a greater affinity for oxygen
than the
aluminum? What is the grey matter produced from
the
reaction? Is it a hazardous substance?
phil k.- Hide quoted text -

- Show quoted text -

At a guess, probably aluminum oxide mixed with metallic mercury and
maybe some oxides of mercury. You can get a scum on metallic mercury
just sitting in a bottle from oxidation, it's dark grey.

Mercury does similar things with sodium and potassium, the amalgams
have some uses in chemical synthesis reactions.

Stan

Mercury vs. aluminum
 

On Tue, 21 Dec 2010 13:17:11 -0500, "Phil Kangas"
wrote:


"Pete Keillor" wrote
in message
.. .
On Tue, 21 Dec 2010 06:00:10 -0500,
lid wrote:

On Mon, 20 Dec 2010 21:12:54 -0500, "Phil
Kangas"
wrote:

I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.



http://tinyurl.com/286pl63




And now you know why it is illegal to bring
mercury filled
thermometers onto commercial aircraft flights.
Dave

Just a guess. If mercury alloys with or
dissolves aluminum, then the
dissolved aluminum would react rapidly with
oxygen to aluminum oxide,
and being dissolved be unable to form the tough
aluminum oxide coating
that normally stops this reaction. So the
aluminum is depleted in
solution, more dissoves, and so on.

Pete Keillor

So the mercury has a greater affinity for oxygen
than the
aluminum? What is the grey matter produced from
the
reaction? Is it a hazardous substance?
phil k.


No, I don't think the mercury is oxidizing. It's just providing a
source of aluminum to oxidize, and the aluminum can't form a stable
oxide coating, which on bare aluminum happens in seconds. The only
role of the mercury is to form a semiliquid alloy with the aluminum,
and keep doing that as aluminum in the alloy reacts with oxygen.

If I'm correct, the grey stuff would just be aluminum oxide, probably
contaminated with mercury. The mercury would make it hazardous.
Aluminum oxide by itself is a very good insulator to very high
temperatures, also very good against corrosion. Which is why when it
forms directly on aluminum metal it protects the metal quite well. It
just can't form a tightly bonded layer to aluminum when forming on the
mercury alloy.

In 1980 I worked on an experimental cell to electolytically produce
magnesium and chlorine gas from a molten salt bath at 700 C. Steel
lasted days at best in there. The 99.5% alumina (aluminum oxide)
brick the cell was constructed from was as good at shutdown as when
the thing was constructed. There were about 200,000 bricks in that
cell. It wasn't cheap.

Pete Keillor

Mercury vs. aluminum
 

Cydrome Leader wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 05:29:00 +0000 (UTC):

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.

We get shipments of aluminum at work all the time. Just open in a
stake side truck. I think your confusing aluminum with sodium.
--

Dan H.
northshore MA.

Mercury vs. aluminum
 

On Tue, 21 Dec 2010 10:37:25 -0800 (PST), wrote:

On Dec 21, 11:17*am, "Phil Kangas" wrote:
"Pete Keillor" wrote
in messagenews:6181h6dc1kckpq4c4ed9g7ph26fuk3okgo@4ax .com...





On Tue, 21 Dec 2010 06:00:10 -0500,
wrote:

On Mon, 20 Dec 2010 21:12:54 -0500, "Phil
Kangas"
wrote:

I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.

http://tinyurl.com/286pl63

And now you know why it is illegal to bring
mercury filled
thermometers onto commercial aircraft flights.
Dave

Just a guess. *If mercury alloys with or
dissolves aluminum, then the
dissolved aluminum would react rapidly with
oxygen to aluminum oxide,
and being dissolved be unable to form the tough
aluminum oxide coating
that normally stops this reaction. *So the
aluminum is depleted in
solution, more dissoves, and so on.

Pete Keillor

So the mercury has a greater affinity for oxygen
than the
aluminum? What is the grey matter produced from
the
reaction? Is it a hazardous substance?
phil k.- Hide quoted text -

- Show quoted text -

At a guess, probably aluminum oxide mixed with metallic mercury and
maybe some oxides of mercury. You can get a scum on metallic mercury
just sitting in a bottle from oxidation, it's dark grey.

The wiki said it attacked only the elemental aluminum, not the oxide.
http://en.wikipedia.org/wiki/Aluminium_amalgam

--
If the only prayer you ever say in your whole
life is "thank you," that would suffice.
-- Meister Eckhart

Mercury vs. aluminum
 

"Pete Keillor" wrote
in message
...
On Tue, 21 Dec 2010 13:17:11 -0500, "Phil
Kangas"
wrote:


"Pete Keillor" wrote
in message
. ..
On Tue, 21 Dec 2010 06:00:10 -0500,
lid wrote:

On Mon, 20 Dec 2010 21:12:54 -0500, "Phil
Kangas"
wrote:

I'm going to try this url to see if it works.
This video is of mercury attacking aluminum.
Can you explain the reaction?
phil k.



http://tinyurl.com/286pl63




And now you know why it is illegal to bring
mercury filled
thermometers onto commercial aircraft flights.
Dave

Just a guess. If mercury alloys with or
dissolves aluminum, then the
dissolved aluminum would react rapidly with
oxygen to aluminum oxide,
and being dissolved be unable to form the
tough
aluminum oxide coating
that normally stops this reaction. So the
aluminum is depleted in
solution, more dissoves, and so on.

Pete Keillor

So the mercury has a greater affinity for oxygen
than the
aluminum? What is the grey matter produced from
the
reaction? Is it a hazardous substance?
phil k.


No, I don't think the mercury is oxidizing.
It's just providing a
source of aluminum to oxidize, and the aluminum
can't form a stable
oxide coating, which on bare aluminum happens in
seconds. The only
role of the mercury is to form a semiliquid
alloy with the aluminum,
and keep doing that as aluminum in the alloy
reacts with oxygen.

If I'm correct, the grey stuff would just be
aluminum oxide, probably
contaminated with mercury. The mercury would
make it hazardous.
Aluminum oxide by itself is a very good
insulator to very high
temperatures, also very good against corrosion.
Which is why when it
forms directly on aluminum metal it protects the
metal quite well. It
just can't form a tightly bonded layer to
aluminum when forming on the
mercury alloy.

In 1980 I worked on an experimental cell to
electolytically produce
magnesium and chlorine gas from a molten salt
bath at 700 C. Steel
lasted days at best in there. The 99.5% alumina
(aluminum oxide)
brick the cell was constructed from was as good
at shutdown as when
the thing was constructed. There were about
200,000 bricks in that
cell. It wasn't cheap.

Pete Keillor

For some crazy reason I can't stop thinking about
this experiment.
The mercury appears to head for the saw cut end
first and reacts
with it pretty fast. But then it stops producing
that gray stuff on the
cut end and goes to work on the stock oxide layer.
Then it is
bubbling at the entry line which leads me to think
there must be
gas that is being released by the reaction.
Oxygen? The oxide
layer on the cut end would not be as thick as the
stock layer.
And the dark gray color? WTF Was the aluminum
surface
scratched after the mercury was put on giving it a
path to go to
work?
phil k.

Mercury vs. aluminum
 

"dan" wrote in message
...
Cydrome Leader wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 05:29:00 +0000 (UTC):

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.

We get shipments of aluminum at work all the time. Just open in a
stake side truck. I think your confusing aluminum with sodium.
--

Dan H.
northshore MA.


What you are getting delivered is aluminium with a nice thin layer of oxide
on the outside.

Mercury vs. aluminum
 

"dan" wrote in message ...

Cydrome Leader wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 05:29:00 +0000 (UTC):

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.

We get shipments of aluminum at work all the time. Just open in a
stake side truck. I think your confusing aluminum with sodium.
--

Dan H.
northshore MA.


Aluminum is as reactive as sodium. From my college chem days. The thing
that stops if from the fast oxidation / explosive oxidation with water like
sodium is the quickly formed oxide coating. Which protects the aluminum.

Mercury vs. aluminum
 

On 2010-12-22, Califbill wrote:
"dan" wrote in message ...

Cydrome Leader wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 05:29:00 +0000 (UTC):

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.

We get shipments of aluminum at work all the time. Just open in a
stake side truck. I think your confusing aluminum with sodium.

Dan, I think that his point was that if not for the oxide layer,
aluminum would also be one of those metals that react violently with
air and water. With the oxide layer, it is safe enough to transport in
a stake side truck.

i

Mercury vs. aluminum
 

Ignoramus1592 wrote:
On 2010-12-22, Califbill wrote:
"dan" wrote in message ...

Cydrome Leader wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 05:29:00 +0000 (UTC):

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.
We get shipments of aluminum at work all the time. Just open in a
stake side truck. I think your confusing aluminum with sodium.

Dan, I think that his point was that if not for the oxide layer,
aluminum would also be one of those metals that react violently with
air and water. With the oxide layer, it is safe enough to transport in
a stake side truck.

i


That oxide layer forms is less than a minute on fresh surfaces!

--

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

Mercury vs. aluminum
 

Sodium and Magnesium . Magnesium touches Aluminum and you get trouble.

We used to have a machine - like an electronic microscope - but for
semiconductor - repairing metal lines in IC's used Aluminum and the
Magnesium to drill vias between layers. Then fill with Al and see
if the part works. A really cool machine being
able to activate lines and actually measure voltages.

Anyway - consumable part. Order another - and all of a sudden,
we can't ship by air. We had to jump through hoops and have triple
layers of protection. The fear was it would melt through the plane!

Until that time, we had book cases containing 3 and protection hand
carried at great expense.

Martin

On 12/21/2010 4:43 PM, dan wrote:
Cydrome Leader wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 05:29:00 +0000 (UTC):

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.

We get shipments of aluminum at work all the time. Just open in a
stake side truck. I think your confusing aluminum with sodium.

Mercury vs. aluminum
 

Ignoramus1592 wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 21:55:43 -0600:

On 2010-12-22, Califbill wrote:
"dan" wrote in message ...

Cydrome Leader wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 05:29:00 +0000 (UTC):

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.

We get shipments of aluminum at work all the time. Just open in a
stake side truck. I think your confusing aluminum with sodium.

Dan, I think that his point was that if not for the oxide layer,
aluminum would also be one of those metals that react violently with
air and water. With the oxide layer, it is safe enough to transport in
a stake side truck.


OK. So it's not "normally ships in a tank of kerosene or oil to keep
air and water away from it" like Califbill said?

--

Dan H.
northshore MA.

Mercury vs. aluminum
 

"dan" wrote in message ...

Ignoramus1592 wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 21:55:43 -0600:

On 2010-12-22, Califbill wrote:
"dan" wrote in message ...

Cydrome Leader wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 05:29:00 +0000 (UTC):

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.

We get shipments of aluminum at work all the time. Just open in a
stake side truck. I think your confusing aluminum with sodium.

Dan, I think that his point was that if not for the oxide layer,
aluminum would also be one of those metals that react violently with
air and water. With the oxide layer, it is safe enough to transport in
a stake side truck.


OK. So it's not "normally ships in a tank of kerosene or oil to keep
air and water away from it" like Califbill said?

--

Dan H.
northshore MA.


Wasn't me that said it ships in oil. I have an aluminum river jetboat, and
it gets towed on a tandem axle aluminum trailer with oil only in the motor
and the bearings. I said aluminum is as reactive as sodium, except it
quickly builds an oxide layer which stops any reaction. Get an aluminum
fire and squirt water on it and watch the violent reaction.

Mercury vs. aluminum
 

Califbill wrote in
rec.crafts.metalworking on Wed, 22 Dec 2010 20:29:33 -0800:

"dan" wrote in message ...

Ignoramus1592 wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 21:55:43 -0600:

On 2010-12-22, Califbill wrote:
"dan" wrote in message ...

Cydrome Leader wrote in
rec.crafts.metalworking on Tue, 21 Dec 2010 05:29:00 +0000 (UTC):

It's really more accurate to watch the video and realize aluminum is one
of those crazy metals that normally ships in a tank of kerosene or oil to
keep air and water away from it, and that the truly amazing part is that
the thin oxide layer it forms really seals the rest of the metal from
basically rusting away, or catching on fire or other stuff like that.

We get shipments of aluminum at work all the time. Just open in a
stake side truck. I think your confusing aluminum with sodium.

Dan, I think that his point was that if not for the oxide layer,
aluminum would also be one of those metals that react violently with
air and water. With the oxide layer, it is safe enough to transport in
a stake side truck.


OK. So it's not "normally ships in a tank of kerosene or oil to keep
air and water away from it" like Califbill said?

Wasn't me that said it ships in oil.

Sorry. I guess I got confused by your newsreaders way of quoting.
But someone said that aluminum normally ships in oil.
That's BS. That's all I'm saying.
--

Dan H.
northshore MA.

Mercury vs. aluminum
 

Here's the answer I received from a retired
material science guy.
phil k.


Hi Phil,

A few comments to get you started. You probably
have a Chemistry textbook to consult to add some
details.

Most metals are soluble in mercury and the alloys
they form are call amalgams. Dentists use amalgam
filling materials, which are alloys usually
containing silver, tin and copper that have been
amalgamated with mercury. Aluminum also forms an
amalgam, that is an alloy formed on contact which
is aluminum dissolved in mercury.

As you know, aluminum readily forms a thin oxide
layer at surfaces in air, which is then very
protective against many environments including
air. In this case, there was likely a scratch or
other defect in the oxide layer that allowed
contact between the mercury and aluminum leading
to amalgamation. Amalgamation of this type has
often been cited as possible means of aircraft
sabotage during WW II.

Beyond formation of the mercury-aluminum alloy in
the reaction shown in the video, one could surmise
that because aluminum is a reactive element, the
apparent gas evolution could result if there was
some water present that would permit the aluminum
in the amalgam to oxidize and hydrogen gas to form
as part of the reaction to form aluminum hydroxide
or aluminum oxide.

Hope this helps.

Merry Christmas,
Don

Mercury vs. aluminum
 

On 2010-12-23, Phil Kangas wrote:
Here's the answer I received from a retired
material science guy.
phil k.


Hi Phil,

A few comments to get you started. You probably
have a Chemistry textbook to consult to add some
details.

Most metals are soluble in mercury and the alloys
they form are call amalgams. Dentists use amalgam
filling materials, which are alloys usually
containing silver, tin and copper that have been
amalgamated with mercury. Aluminum also forms an
amalgam, that is an alloy formed on contact which
is aluminum dissolved in mercury.

As you know, aluminum readily forms a thin oxide
layer at surfaces in air, which is then very
protective against many environments including
air. In this case, there was likely a scratch or
other defect in the oxide layer that allowed
contact between the mercury and aluminum leading
to amalgamation. Amalgamation of this type has
often been cited as possible means of aircraft
sabotage during WW II.

Beyond formation of the mercury-aluminum alloy in
the reaction shown in the video, one could surmise
that because aluminum is a reactive element, the
apparent gas evolution could result if there was
some water present that would permit the aluminum
in the amalgam to oxidize and hydrogen gas to form
as part of the reaction to form aluminum hydroxide
or aluminum oxide.

Hope this helps.

Merry Christmas,
Don




Also check this out :

http://en.wikipedia.org/wiki/Aluminium_amalgam

Mercury vs. aluminum
 

"Ignoramus30015"
wrote in
message
...
On 2010-12-23, Phil Kangas
wrote:
Here's the answer I received from a retired
material science guy.
phil k.


Hi Phil,

A few comments to get you started. You probably
have a Chemistry textbook to consult to add
some
details.

Most metals are soluble in mercury and the
alloys
they form are call amalgams. Dentists use
amalgam
filling materials, which are alloys usually
containing silver, tin and copper that have
been
amalgamated with mercury. Aluminum also forms
an
amalgam, that is an alloy formed on contact
which
is aluminum dissolved in mercury.

As you know, aluminum readily forms a thin
oxide
layer at surfaces in air, which is then very
protective against many environments including
air. In this case, there was likely a scratch
or
other defect in the oxide layer that allowed
contact between the mercury and aluminum
leading
to amalgamation. Amalgamation of this type has
often been cited as possible means of aircraft
sabotage during WW II.

Beyond formation of the mercury-aluminum alloy
in
the reaction shown in the video, one could
surmise
that because aluminum is a reactive element,
the
apparent gas evolution could result if there
was
some water present that would permit the
aluminum
in the amalgam to oxidize and hydrogen gas to
form
as part of the reaction to form aluminum
hydroxide
or aluminum oxide.

Hope this helps.

Merry Christmas,
Don




Also check this out :

http://en.wikipedia.org/wiki/Aluminium_amalgam

And to think that there are people out there that
consider metalworking boring...... ! Not around
here though, eih? phil

Mercury vs. aluminum
 

On 2010-12-24, Phil Kangas wrote:

"Ignoramus30015"
wrote in
message
...
On 2010-12-23, Phil Kangas
wrote:
Here's the answer I received from a retired
material science guy.
phil k.


Hi Phil,

A few comments to get you started. You probably
have a Chemistry textbook to consult to add
some
details.

Most metals are soluble in mercury and the
alloys
they form are call amalgams. Dentists use
amalgam
filling materials, which are alloys usually
containing silver, tin and copper that have
been
amalgamated with mercury. Aluminum also forms
an
amalgam, that is an alloy formed on contact
which
is aluminum dissolved in mercury.

As you know, aluminum readily forms a thin
oxide
layer at surfaces in air, which is then very
protective against many environments including
air. In this case, there was likely a scratch
or
other defect in the oxide layer that allowed
contact between the mercury and aluminum
leading
to amalgamation. Amalgamation of this type has
often been cited as possible means of aircraft
sabotage during WW II.

Beyond formation of the mercury-aluminum alloy
in
the reaction shown in the video, one could
surmise
that because aluminum is a reactive element,
the
apparent gas evolution could result if there
was
some water present that would permit the
aluminum
in the amalgam to oxidize and hydrogen gas to
form
as part of the reaction to form aluminum
hydroxide
or aluminum oxide.

Hope this helps.

Merry Christmas,
Don




Also check this out :

http://en.wikipedia.org/wiki/Aluminium_amalgam

And to think that there are people out there that
consider metalworking boring...... ! Not around
here though, eih? phil




That would NOT be me!