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Bronze anti-stone chipping tools


#1

Bronze Anti-Stone Chipping Tools made by your self

Hi There!

First of all, I want to apologize because of my English (Spanish is
my main language), I’ll do my best anyway.

So, I wanted to share with you guys what I happily discovered trying
to make a prong pusher and a burnisher for safely fixing the stones
in gypsy setting.

After chipping some sapphires and rubies with a steel burnisher and
pusher, I finally pissed off and decided to dedicate some hours to
make my own tools out of bronze.

I found a very simple recipe used for jeweller’s punches which is:
Cu - 83,3 parts & Sn - 16,7 parts.

But out of my expectations I had a LOT of trouble when rolling it,
it always cracked! I tried different annealing temperatures,
quenching methods and so on, without success after I discover that
annealing to a dull red, quickly quenching and rolling ONLY one pass
per side in the rolling mill’s grooves each time, was the way to do
the job.

So i guarantee you that following those steps you will be able to
make your own “Safe Bronze” tools.

Hope it helps.

Greetings!
Nicolas.


#2
I found a very simple recipe used for jeweller's punches which is:
Cu - 83,3 parts & Sn - 16,7 parts. 

Try 90 parts Cu, and 10 parts Sn :wink: CIA


#3

When making this bronze I assume one melts the copper first and then
the tin. Is that correct? Thanks, Vince LaRochelle


#4
When making this bronze I assume one melts the copper first and
then the tin. Is that correct? 

Nope, you’ll lose a lot of tin to vapor that way.

The best way to alloy bronze is to melt the tin first.

I alloy my bronze this way.

I use a furnace to alloy bronze, and use a bilge type crucible. I
don’t alloy in those flat crucibles.

I load the tin in first, then I cover with granulated copper. The
tin melts, but as the copper heats it crusts up, the tin melts, the
copper melts into the tin at a lower temperature.

Regards Charles A.


#5
Nope, you'll lose a lot of tin to vapor that way. 

Not unless you grossly overheat the copper, tin has a surprisingly
high boiling point (vaporization temperature) of 2602 C (4716 F).
Melting temperature does not correlate to boiling temperature.
Considering that copper has a boiling point of 2562 C (4643 F) you
would actually be vaporizing the copper before vaporizing the tin.

James Binnion
James Binnion Metal Arts


#6

Hi Vincent,

Instructions I have read say to melt the tin first and then add the
copper because it can dissolve in the tin at a lower temperature than
the melting point of pure copper and thus have fewer oxidation
problems

All the best
Jen


#7

Hi Vincent,

Tin has a higher boiling point than copper, i think it doesn’t matter
which metal you melt first. I melted them at the same time and then
brought the mixto a high temp as i slowly shoke the crucible. It
worked out nice for me.

Regards.


#8

Aluminium bronze (10 per cent Al) could be a good alternative where
tin is not available. As usual the copper is melted first.

Thanks.
Kofi
Ghana


#9
Nope, you'll lose a lot of tin to vapor that way. Not unless you
grossly overheat the copper, tin has a surprisingly high boiling
point (vaporization temperature) of 2602 C (4716 F). Melting
temperature does not correlate to boiling temperature. Considering
that copper has a boiling point of 2562 C (4643 F) you would
actually be vaporizing the copper before vaporizing the tin. 

Interesting, we did some casual experiments with this.

We were concerned about this, and wanted to test that putting the
lower melt point metals in first makes a difference.

And it does make a difference. My friend melts the copper first then
puts the tin into the molten copper, I load a crucible with tin then
cover with granulated copper. I melt mine faster, and the colour is
better.

We always assumed he was vaporising his tin. He wasn’t boiling the
metal by any means, we uses an electric burnout furnace (not to
worry I’m making him a better furnace), and struggling to get the
copper to melt.

I’d have more chance of vaporising the tin in my setup, yet his
bronze is pink, mine is. well… bronze.

Do you have any ideas why our observation are as they are?

Regards Charles A.


#10
And it does make a difference. My friend melts the copper first
then puts the tin into the molten copper, I load a crucible with
tin then cover with granulated copper. I melt mine faster, and the
colour is better. 

Of course you do, the copper starts to dissolve into the tin as soon
as the tin is molten. He has to wait for the copper to melt and then
add the tin.

We always assumed he was vaporising his tin. He wasn't boiling the
metal by any means, 

If it is not boiling then no significant loss to vapor.

we uses an electric burnout furnace (not to worry I'm making him a
better furnace), and struggling to get the copper to melt. I'd have
more chance of vaporising the tin in my setup, yet his bronze is
pink, mine is. well. bronze. 

He has oxidized the hell out of the copper so likely what you are
seeing is the red copper oxide in the bronze. Unless you are using a
very exotic furnace you could not possibly get the tin hot enough to
vaporize.

James Binnion
James Binnion Metal Arts


#11
Do you have any ideas why our observation are as they are? 

Faster melt is probably because the molten tin forms bronze at the
interface, at 100C or more lower than melting copper. Your other
observations? Not a clue. It would be interesting to see a
metallurgist’s comments.

Al Balmer
Pine City, NY


#12
Aluminium bronze (10 per cent Al) could be a good alternative
where tin is not available. As usual the copper is melted first. 

Personally I try to steer clear of aluminium bronze, it’s too hard
to machine. CIA


#13
We always assumed he was vaporising his tin. He wasn't boiling the
metal by any means, If it is not boiling then no significant loss
to vapor. 

Yet his bronze is very pink, almost like a silicon bronze, not a tin
bronze at all.

he uses an electric burnout furnace (not to worry I'm making him a
better furnace), and struggling to get the copper to melt. I'd
have more chance of vaporising the tin in my setup, yet his bronze
is pink, mine is. well. bronze. 
He has oxidized the hell out of the copper so likely what you are
seeing is the red copper oxide in the bronze. Unless you are using
a very exotic furnace you could not possibly get the tin hot enough
to vaporize. 

It’s an electric burnout kiln, it has the plug at the top, which he
leaves in when melting. No added air flow. It’s so gentle that he
can only melt small quantities of metal. It’s not the most efficient
device.

It’s possible that he’s oxidising the copper, it needs more
investigation.

Regards Charles A.


#14
It's an electric burnout kiln, it has the plug at the top, which
he leaves in when melting. No added air flow. It's so gentle that
he can only melt small quantities of metal. It's not the most
efficient device. 

Furnace insulation is about as airtight as a screen door. As I said
he is severely oxidizing the melt.

James Binnion
James Binnion Metal Arts


#15
Furnace insulation is about as airtight as a screen door. As I
said he is severely oxidizing the melt. 

Gotcha, I’m putting a furnace together for him at the moment, so he
should have more joy soon.

Thanks regards Charles A.


#16
Try 90 parts Cu, and 10 parts Sn

Hi Charles, doing so would not the hardness be diminished?


#17
Try 90 parts Cu, and 10 parts Sn Hi Charles, doing so would not the
hardness be diminished? 

Yeah a little bit, but the alloy rolls perfectly, and will still be
strong enough.

Regards Charles