I'm planning on trying to make some Field's metal. I need that specific
alloy and can't substitute anything else. I'm going to make about seven
ounces of it.

I've never made an alloy before, or worked with molten metals, so there's a
good chance I'll fail. However, I was hoping some folks here could point
out any obvious pitfalls in advance.

I'm planning to melt tin, bismuth and indium together in the proper
proportions. After putting chunks of each metal into the ceramic crucible,I
assume I'll have to heat the crucible (with a propane torch) to around 520
degrees, which is hot enough to melt all three metals. At that point... I
don't know. Do I have to mix them, or will they just spontaneously mix? Is
there any risk that the metals will oxidize from the heat and air, and ruin
the alloy?

On Oct 4, 8:02 pm, "Ernie Sty" wrote:
I'm planning on trying to make some Field's metal. I need that specific
alloy and can't substitute anything else. I'm going to make about seven
ounces of it.

I've never made an alloy before, or worked with molten metals, so there's a
good chance I'll fail. However, I was hoping some folks here could point
out any obvious pitfalls in advance.

I'm planning to melt tin, bismuth and indium together in the proper
proportions. After putting chunks of each metal into the ceramic crucible,I
assume I'll have to heat the crucible (with a propane torch) to around 520
degrees, which is hot enough to melt all three metals. At that point... I
don't know. Do I have to mix them, or will they just spontaneously mix? Is
there any risk that the metals will oxidize from the heat and air, and ruin
the alloy?


melt the low temp metal 1st then add the others, you shouldn't need to
raise the temp above 313
indium melts at 313F $1000/kg or $100 for the 3.5 oz you need but
certainly more expensive by the ounce
Bismuth melts at 520 F $5/lb
Tin melts at 450F $7/lb

Pricey if you screw up, Wood's metal with no indium is a whole lot
cheaper

Carl Boyd

Carl wrote:

On Oct 4, 8:02 pm, "Ernie Sty" wrote:

I'm planning on trying to make some Field's metal. I need that specific
alloy and can't substitute anything else. I'm going to make about seven
ounces of it.

I've never made an alloy before, or worked with molten metals, so there's a
good chance I'll fail. However, I was hoping some folks here could point
out any obvious pitfalls in advance.

I'm planning to melt tin, bismuth and indium together in the proper
proportions. After putting chunks of each metal into the ceramic crucible,I
assume I'll have to heat the crucible (with a propane torch) to around 520
degrees, which is hot enough to melt all three metals. At that point... I
don't know. Do I have to mix them, or will they just spontaneously mix? Is
there any risk that the metals will oxidize from the heat and air, and ruin
the alloy?



melt the low temp metal 1st then add the others, you shouldn't need to
raise the temp above 313
indium melts at 313F $1000/kg or $100 for the 3.5 oz you need but
certainly more expensive by the ounce
Bismuth melts at 520 F $5/lb
Tin melts at 450F $7/lb

Pricey if you screw up, Wood's metal with no indium is a whole lot
cheaper

Carl Boyd


I didn't stay in a Holiday Inn Express last night so I ocbiously don't
know what I'm talking about...

But is is considered ok to put all this together as chunks?

Or should it be ground down like coffee first?

Richard

Carl wrote:

melt the low temp metal 1st then add the others, you shouldn't need to
raise the temp above 313

Are you sure? How do you get a higher melting point metal to melt at 313F?
Seems to me the tin and bismuth would just sit there in a puddle of indium.

Now I wonder if one melted the tin with the bismuth, what that alloy would
melt at.

Wes

Wes wrote:

Carl wrote:

melt the low temp metal 1st then add the others, you shouldn't need to
raise the temp above 313


Are you sure? How do you get a higher melting point metal to melt at 313F?
Seems to me the tin and bismuth would just sit there in a puddle of indium.

Now I wonder if one melted the tin with the bismuth, what that alloy would
melt at.

Wes

The higher melting point metal can dissolve in the molten lower melting
point one. Just the same way that sugar dissolves in water. It hadn't
occured to me before until I asked a guy that made pewter how they go
the copper into the mix when it melts above 1000C IIRC and tin is about
300C.

According to cavelamb himself :
Carl wrote:

melt the low temp metal 1st then add the others, you shouldn't need to
raise the temp above 313

[ ... ]

I didn't stay in a Holiday Inn Express last night so I ocbiously don't
know what I'm talking about...

???

But is is considered ok to put all this together as chunks?

Or should it be ground down like coffee first?

As in the quoted bit above, you start by melting the lowest
temperature metal first, then progressively add the others (probably in
order of melting point) and they dissolve in the metal which is already
melted -- perhaps changing the meting point in some direction or other.
No need to grind it up first, but stirring might be beneficial, if you
can find something to stir it with which won't also dissolve into the
alloy you are building.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 6 Oct 2007 04:07:36 GMT, (DoN. Nichols) wrote:

According to cavelamb himself :
Carl wrote:

melt the low temp metal 1st then add the others, you shouldn't need to
raise the temp above 313

[ ... ]

I didn't stay in a Holiday Inn Express last night so I ocbiously don't
know what I'm talking about...

???

But is is considered ok to put all this together as chunks?

Or should it be ground down like coffee first?

As in the quoted bit above, you start by melting the lowest
temperature metal first, then progressively add the others (probably in
order of melting point) and they dissolve in the metal which is already
melted -- perhaps changing the meting point in some direction or other.
No need to grind it up first, but stirring might be beneficial, if you
can find something to stir it with which won't also dissolve into the
alloy you are building.

Enjoy,
DoN.
In my experience with babbit and with alloys melting below 200F it is
wise to stir before pouring and to be careful not to overheat or to
keep molten for long periods of time. The metals will stratify over
time so the alloy composition will change with depth. Even in a
shallow container.
ERS

"David Billington" wrote in message
...


Wes wrote:

Carl wrote:

melt the low temp metal 1st then add the others, you shouldn't need to
raise the temp above 313


Are you sure? How do you get a higher melting point metal to melt at
313F?
Seems to me the tin and bismuth would just sit there in a puddle of
indium.

Now I wonder if one melted the tin with the bismuth, what that alloy would
melt at.

Wes

The higher melting point metal can dissolve in the molten lower melting
point one. Just the same way that sugar dissolves in water. It hadn't
occured to me before until I asked a guy that made pewter how they go the
copper into the mix when it melts above 1000C IIRC and tin is about 300C.


Thanks!!

"DoN. Nichols" wrote in message
...
According to cavelamb himself :
Carl wrote:

melt the low temp metal 1st then add the others, you shouldn't need to
raise the temp above 313

[ ... ]

I didn't stay in a Holiday Inn Express last night so I ocbiously don't
know what I'm talking about...

???

But is is considered ok to put all this together as chunks?

Or should it be ground down like coffee first?

As in the quoted bit above, you start by melting the lowest
temperature metal first, then progressively add the others (probably in
order of melting point) and they dissolve in the metal which is already
melted -- perhaps changing the meting point in some direction or other.
No need to grind it up first, but stirring might be beneficial, if you
can find something to stir it with which won't also dissolve into the
alloy you are building.

Enjoy,
DoN.

Crap! I forgot all about that. I got a ceramic crucible, but the tongs are
stainless--I don't know what'll happen if they contact the liquid... Come
to think of it, doesn't Field's metal wet glass? I hope not too much of it
sticks to the ceramic. This would all be merely interesting if it weren't
for price I paid for the indium...

Oh, well.