Ping: Mike Spencer

[HRM Resident]

Did you ever see or use an induction forge? The smith in
this video demonstrates how well they work. It seems to be
a good way to heat steel. I know you do not have the
bandwidth to watch it, but I will put the link here in the
improbable case anyone else wants to watch it.

I never heard of one before in this context, but we had a
device in the late 1970s, where similar technology was used
to concentrate about 2000 watts of RF energy into an argon
gas flow that heated it into a plasma.

Aspirating a mist of water into it caused traces of metals
to emit different wavelengths of light and appropriately
placed photomultiplier tubes measured the intensity of
each after the light was separated by a prism.

You could analyze for up to about 50 elements in well
water simultaneously in about minute. A PDP-11 computer
estimated concentration. The company that made it was located in
Newtonville, MA. An outfit called Jarrell-Ash.
I am sure they are long gone, but there is a picture of
the unit here:

<https://speciation.net/Database/Instruments/JarrellAsh/Plasma-AtomComp-;i2956>

Anyway, it is interesting that the same general technology
is available for blacksmiths in the 21st century. From the
video it appears they are doing the same sort of thing except
they concentrate the RF energy into your steel stock. And the forge unit
looks to be a water cooled thing about the
size of a microwave oven.

[Mike Spencer]

Post by HRM Resident
Did you ever see or use an induction forge?

No.

Some time ago, I looked ionto the possibility of cobbling together
something from junk, Princess Auto & whatever. Not within my budget
or skill set.

Post by HRM Resident
The smith in this video demonstrates how well they work. It seems
to be a good way to heat steel.
http://youtu.be/P_STrnP__D4

Tried to watch it and my net connection siezed up. Maybe coinidence
so I'll try again later.

Post by HRM Resident
I never heard of one before in this context, but we had a
device in the late 1970s, where similar technology was used
to concentrate about 2000 watts of RF energy into an argon
gas flow that heated it into a plasma.
Aspirating a mist of water into it caused traces of metals
to emit different wavelengths of light and appropriately
placed photomultiplier tubes measured the intensity of
each after the light was separated by a prism.

Wow! Plasma flame spectroscopy. I'm familiar with ordinary flame
spectroscopy but this seems specially suited for looking for a wide
range of elements.

Post by HRM Resident
You could analyze for up to about 50 elements in well
water simultaneously in about minute. A PDP-11 computer
estimated concentration. The company that made it was located in
Newtonville, MA. An outfit called Jarrell-Ash.
I am sure they are long gone, but there is a picture of
<https://speciation.net/Database/Instruments/JarrellAsh/Plasma-AtomComp-;i2956>
Anyway, it is interesting that the same general technology
is available for blacksmiths in the 21st century.

I think induction heating has been around for several decades but I
don't really know origin.

Post by HRM Resident
From the video it appears they are doing the same sort of thing
except they concentrate the RF energy into your steel stock. And
the forge unit looks to be a water cooled thing about the size of a
microwave oven.

One of the advantages of living near Boston is that there is a large
number of companies doing research or hi tech production. So there are
businesses who buy obsolete, failed, broken, surplus or any lab, pilot
plant or production machinery and resell it from junkyard-like
warehouses. Projects like a blacksmith's induction forge on the cheap
might be doable if you could grovel through a few acres of old crap
and find the right bits of RF gear. (I only know about such places
because a friend in Marblehead took me to see one when was visiting.)

[HRM Resident]

Post by Mike Spencer
Wow! Plasma flame spectroscopy. I'm familiar with ordinary flame
spectroscopy but this seems specially suited for looking for a wide
range of elements.

We used three "flame/plasma" instruments. Flame Emission
Spectroscopy, is simple and cost-effective. It's ideal for measuring
alkali and alkaline earth metals.

Atomic Absorption Spectrometry (AAS) is the best for detecting
trace amounts of metals. Its precision makes it better for single-
element analysis. They are also about ten times more sensitive than
FES.

As I mentioned, Plasma Emission Spectrometry is the best, but
way, way more expensive than the other two.

Funny story about AAS. We had one in our college lab. They
have a pressed carbon mixing chamber where acetylene is combined
with the oxidant, usually air or nitrous oxide. The air produces a
cooler flame and is used for low melting point metals. Others use
NO. There are two heads for the flame. The one for air has 3
slots, allowing for much more gas flow. The NO head is a narrow
slit. You can't mix them up. The game with NO is to start with air
and get a reducing sooty flame. Then, flip a valve to switch it to
NO, giving a hotter oxidizing flame. Bad things happen if you run
NO into the head designed for air. The carbon mixing chamber is
encased in a steel mesh. Why? Because people in a hurry like me
occasionally mix up the heads. I blew up the carbon mixing chamber
this way. The steel case stops pieces of carbon from flying
everywhere but makes a huge bang when the NO/C2H2 gets sucked into
the mixing chamber and explodes. I blew one up, and the lab
instructor heard the bang on the other end of the hall. He came
down and said, "Again? Someone does that about once a year. That's
why we have a couple of spares in the cupboard."

Oh yeah, NO is laughing gs. Didn't work. 18-20 year olds will try
anything. We used to turn everything off except the NO flow and breathe
it in for a minute or two. Nothing. No relaxed facial muscles, etc.
Maybe we needed a mask to get pure NO, because I believe many dentists
used it, and maybe they still do.

This has nothing to do with blacksmithing. The guy in the video
holds the steel in a 2-3 turn copper RF coil, which gets it to forge
welding temperature in 10-15 seconds. Then he smacks it on the
anvil, and the weld is set. I looked them up, and they are about
$1500. They also draw a lot of current (8-9 amps), even at 240 VAC.
This is why they need a water cooling pump. It's not something I
will ever have.

[HRM Resident]

Post by HRM Resident

Post by Mike Spencer
Wow! Plasma flame spectroscopy. I'm familiar with ordinary flame
spectroscopy but this seems specially suited for looking for a wide
range of elements.

We used three "flame/plasma" instruments. Flame Emission
Spectroscopy, is simple and cost-effective. It's ideal for measuring
alkali and alkaline earth metals.
Atomic Absorption Spectrometry (AAS) is the best for detecting
trace amounts of metals. Its precision makes it better for single-
element analysis. They are also about ten times more sensitive than
FES.
As I mentioned, Plasma Emission Spectrometry is the best, but
way, way more expensive than the other two.
Funny story about AAS. We had one in our college lab. They
have a pressed carbon mixing chamber where acetylene is combined
with the oxidant, usually air or nitrous oxide. The air produces a
cooler flame and is used for low melting point metals. Others use
NO. There are two heads for the flame. The one for air has 3
slots, allowing for much more gas flow. The NO head is a narrow
slit. You can't mix them up. The game with NO is to start with air
and get a reducing sooty flame. Then, flip a valve to switch it to
NO, giving a hotter oxidizing flame. Bad things happen if you run
NO into the head designed for air. The carbon mixing chamber is
encased in a steel mesh. Why? Because people in a hurry like me
occasionally mix up the heads. I blew up the carbon mixing chamber
this way. The steel case stops pieces of carbon from flying
everywhere but makes a huge bang when the NO/C2H2 gets sucked into
the mixing chamber and explodes. I blew one up, and the lab
instructor heard the bang on the other end of the hall. He came
down and said, "Again? Someone does that about once a year. That's
why we have a couple of spares in the cupboard."
Oh yeah, NO is laughing gs. Didn't work. 18-20 year olds will try
anything. We used to turn everything off except the NO flow and breathe
it in for a minute or two. Nothing. No relaxed facial muscles, etc.
Maybe we needed a mask to get pure NO, because I believe many dentists
used it, and maybe they still do.
This has nothing to do with blacksmithing. The guy in the video
holds the steel in a 2-3 turn copper RF coil, which gets it to forge
welding temperature in 10-15 seconds. Then he smacks it on the
anvil, and the weld is set. I looked them up, and they are about
$1500. They also draw a lot of current (8-9 amps), even at 240 VAC.
This is why they need a water cooling pump. It's not something I
will ever have.

Correction: Nitrous oxide is N2O, not NO. I have been
away from chemistry too long. :-(