torque wrench issues

wrote in message
...
On Mon, 01 May 2017 15:08:31 +0700, John B Slocomb
wrote:

SNIPPED


The usually suggested preparation for welding or brazing galvanized
materials is to grind all the galvanizing off!

ACTUALLY, stripping the zinc with acid is much more effective.
Hydrochloric acid makes short work of zinc and produces zinc chloride,
which can be used as soldering flux - - -

Certainly better than the ****wit who suggested grinding it off and
breathing it as dust instead of fumes.

The steel would probably contaminate it, but it'd have some uses.

Zinc really isn't that toxic - its used in baby powder, hundreds of skin
lotions and winter defence vitamin supplements.

And no one is making all that much commotion about all the scrap zinc
batteries that ended up in landfill. The bogeyman most people think of is
mercury.

That rots out the central nervous system.

wrote in message
...
On Mon, 1 May 2017 19:49:36 +0100, "Ian Field"
wrote:

I have never become aware of the dire consequences of welding zinc plated
that are being spouted here.

"galvanised" can be plated with *ANY* metal that has a higher galvanic
affinity than the host metal. Including cadmium and various other toxic
heavy metals.

Cadmium poisoning is cumulative and has various routes into the body - its
a
long slow painful journey to a Darwin award.

For a few years I worked assembling electronic equipment on cadmium plated
chassis - I've seen with my own eyes the extent to which the plating rubs
off on your hands.

But if you're too stupid to take it from someone who's been there - Darwin
awaits you with outstretched arms.

Whenever working with ANY metals, or ANY chemicals, you should wash
your hands well before eating, and never eat in the contaminated
working area. Unless you have breaks in your skin, you are unlikely to
absorb significant amounts of Cadmium

When handling sheet metal assemblies - small cuts to the hands are
inevitable.

Cadmium poisoning is cumulative with no immediate symptoms to warn you.

On 5/1/2017 2:35 PM, wrote:
"Ian Field" wrote:
"John B Slocomb" wrote
wrote:
"Ian Field" wrote:
"AMuzi" wrote
On 4/30/2017 3:30 PM, Ian Field wrote:
"AMuzi" wrote
On 4/30/2017 12:01 PM, Ian Field wrote:
wrote
"Ian Field" wrote:
wrote
"Benderthe.evilrobot" wrote:
"John B Slocomb" wrote
wrote:
John B Slocomb wrote:
"Benderthe.evilrobot" wrote:
wrote
"Benderthe.evilrobot" wrote:
"Emanuel Berg" wrote

-snip much speculation about organic chemistry-


Metallic zinc is not anywhere near as dangerous as the zinc oxide
fumes from over-heated zinc - justlike contact with cadmium metal
itself is "relatively" benign - and touching chrome plated metal is
not dangerous, yet co-valent Chromium is highly toxic.
Same with mercury - although mercury vapour definitely is not GOOD for
you, it is the "organic compounds" of mercury that are particularly
dangerous and insidious.


+1

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Mon, 1 May 2017 21:18:18 +0100, "Ian Field"
wrote:
..............................


Metallic sinc is not anywhere near as dangerous as the zinc oxide
fumes from over-heated zinc

Zinc oxide is the usual filler in heat transfer paste on heatsinks for power
semiconductor devices.

Total burnouts aren't as rare as most people would like - I've never heard
of any casualties from those events.
You haven't been in the right place at the right time, obviously.
I know a few other guys who have gotten dosed with zinc from welding
galvanized and the'll all agree they don't EVER want to experience it
again either!!!

wrote in message
...
On Mon, 1 May 2017 21:18:18 +0100, "Ian Field"
wrote:
.............................


Metallic sinc is not anywhere near as dangerous as the zinc oxide
fumes from over-heated zinc

Zinc oxide is the usual filler in heat transfer paste on heatsinks for
power
semiconductor devices.

Total burnouts aren't as rare as most people would like - I've never heard
of any casualties from those events.
You haven't been in the right place at the right time, obviously.
I know a few other guys who have gotten dosed with zinc from welding
galvanized and the'll all agree they don't EVER want to experience it
again either!!!

Did a metallurgist verify that it was actually zinc?

Its usually put on so thin its almost transparent - it can be
indistinguishable from some other galvanic coatings.

Cadmium isn't always the familiar colloidal gold colouring - sometimes it
can be mistaken for zinc.

Zinc doesn't always have consistent appearance - there's room for error.

"AMuzi" wrote in message
news
On 5/1/2017 2:35 PM, wrote:
"Ian Field" wrote:
"John B Slocomb" wrote
wrote:
"Ian Field" wrote:
"AMuzi" wrote
On 4/30/2017 3:30 PM, Ian Field wrote:
"AMuzi" wrote
On 4/30/2017 12:01 PM, Ian Field wrote:
wrote
"Ian Field" wrote:
wrote
"Benderthe.evilrobot"
wrote:
"John B Slocomb" wrote
wrote:
John B Slocomb wrote:
"Benderthe.evilrobot"
wrote:
wrote
"Benderthe.evilrobot"
wrote:
"Emanuel Berg" wrote

-snip much speculation about organic chemistry-


Metallic zinc is not anywhere near as dangerous as the zinc oxide
fumes from over-heated zinc - justlike contact with cadmium metal
itself is "relatively" benign - and touching chrome plated metal is
not dangerous, yet co-valent Chromium is highly toxic.
Same with mercury - although mercury vapour definitely is not GOOD for
you, it is the "organic compounds" of mercury that are particularly
dangerous and insidious.


+1

Which is saying something...........................AFAIK: zinc oxide isn't
particularly dangerous either.

Some sellers of CPU heat transfer paste pass off zinc oxide as high tech
ceramic filler and charge a lot more money. Its a bit of a grey area - but I
think it more or less is a form of ceramic.

The *REALLY* toxic oxide is beryllium. That also is used for thermal
transfer - RoHS exempted some toxic materials because the impact on industry
would be too severe, beryllium was one of them.

On Mon, 1 May 2017 21:25:07 +0100, "Ian Field"
wrote:



wrote in message
.. .
On Mon, 01 May 2017 15:08:31 +0700, John B Slocomb
wrote:

SNIPPED


The usually suggested preparation for welding or brazing galvanized
materials is to grind all the galvanizing off!

ACTUALLY, stripping the zinc with acid is much more effective.
Hydrochloric acid makes short work of zinc and produces zinc chloride,
which can be used as soldering flux - - -

Certainly better than the ****wit who suggested grinding it off and
breathing it as dust instead of fumes.

The steel would probably contaminate it, but it'd have some uses.

Zinc really isn't that toxic - its used in baby powder, hundreds of skin
lotions and winter defence vitamin supplements.

And no one is making all that much commotion about all the scrap zinc
batteries that ended up in landfill. The bogeyman most people think of is
mercury.

That rots out the central nervous system.
And elemental mercury isn't the serious problem it'd made out to be
either - it's the organic compounds (which CAN form in disposal - if
the mercury combines with carbonaceous materials)

On Mon, 1 May 2017 22:03:24 +0100, "Ian Field"
wrote:



wrote in message
.. .
On Mon, 1 May 2017 21:18:18 +0100, "Ian Field"
wrote:
.............................


Metallic sinc is not anywhere near as dangerous as the zinc oxide
fumes from over-heated zinc

Zinc oxide is the usual filler in heat transfer paste on heatsinks for
power
semiconductor devices.

Total burnouts aren't as rare as most people would like - I've never heard
of any casualties from those events.
You haven't been in the right place at the right time, obviously.
I know a few other guys who have gotten dosed with zinc from welding
galvanized and the'll all agree they don't EVER want to experience it
again either!!!

Did a metallurgist verify that it was actually zinc?

Its usually put on so thin its almost transparent - it can be
indistinguishable from some other galvanic coatings.

Cadmium isn't always the familiar colloidal gold colouring - sometimes it
can be mistaken for zinc.

Zinc doesn't always have consistent appearance - there's room for error.

Electro Zinc coating mat be mistakable for something else, or
something else as Zinc plating. Old weathered galvanizing, only if you
are blind and unfamilliar with the material.
Hot Dipped Galvanize in unmistakable and is DEFiNITELY Zinc.And the
dictionary definition of "galvanizsd" refers EXCLUSIVELY to Zinc
coating of steel.

Welding ANY galvanized metal, but particularly hot dipped, without
removing the coating is something no sane man would EVER do the second
time, particularly in an enclosed or unventilated space. The signature
yellow flame and white "crystaline smoke" is unmistakable.

On Mon, 1 May 2017 22:12:57 +0100, "Ian Field"
wrote:



"AMuzi" wrote in message
news
On 5/1/2017 2:35 PM, wrote:
"Ian Field" wrote:
"John B Slocomb" wrote
wrote:
"Ian Field" wrote:
"AMuzi" wrote
On 4/30/2017 3:30 PM, Ian Field wrote:
"AMuzi" wrote
On 4/30/2017 12:01 PM, Ian Field wrote:
wrote
"Ian Field" wrote:
wrote
"Benderthe.evilrobot"
wrote:
"John B Slocomb" wrote
wrote:
John B Slocomb wrote:
"Benderthe.evilrobot"
wrote:
wrote
"Benderthe.evilrobot"
wrote:
"Emanuel Berg" wrote

-snip much speculation about organic chemistry-


Metallic zinc is not anywhere near as dangerous as the zinc oxide
fumes from over-heated zinc - justlike contact with cadmium metal
itself is "relatively" benign - and touching chrome plated metal is
not dangerous, yet co-valent Chromium is highly toxic.
Same with mercury - although mercury vapour definitely is not GOOD for
you, it is the "organic compounds" of mercury that are particularly
dangerous and insidious.


+1

Which is saying something...........................AFAIK: zinc oxide isn't
particularly dangerous either.

Some sellers of CPU heat transfer paste pass off zinc oxide as high tech
ceramic filler and charge a lot more money. Its a bit of a grey area - but I
think it more or less is a form of ceramic.

The *REALLY* toxic oxide is beryllium. That also is used for thermal
transfer - RoHS exempted some toxic materials because the impact on industry
would be too severe, beryllium was one of them.
Give it up Ian - you are out of your depth. Go get yourself a
galvanized steel bucket and weld a galvanized steel lid to it in your
shop and let me know how it feels when you are done. If you can't
weld, try brazing it. (Cadmium free brazing rod optional)

On Monday, May 1, 2017 at 4:14:24 PM UTC-4, Ian Field wrote:

"galvanised" is galvanic protection - which can include any of several toxic
heavy metals.

Some people here seem to think it can only mean zinc.

In the U.S. "galvanize" means to coat steel or iron with zinc. (Alternate
meaning: to spur into action.)

It may be that British usage is different, I suppose. But I don't find evidence
of that.

- Frank Krygowski