Alloying

[prepman]

Any alchemists here? Experimenting with brass alloying (again). Dissolving copper into molten zinc is fiddly to say the least.
I weighed out the Cu/Zn ratios initial to get a 10/90 mix....but struggled.... so took it up to 40/60 and it was easier but oscillilating between burning the zinc off an not getting dissolution. So I bunged in some AI (30%) and Mn (~1%) and ended up with very brittle but decorative alloy. I suspect with with no practiacl purpose....so I'll probably send a sample to Fords for their engines?
Downside solubility of copper into zinc is problematic?

Small piece weighs 97g

 

[Seadog]

How about dissolving zinc into hot (dull red) copper? If it alloys in the same fashion that aluminium does, then will have no need to increase the heat. Cu/Al eutectic has a melting point of 548°C as against 1085 for Cu and 660 for Al.

 

[Seadog]

This will help you

EAP Reading

Using English for Academic Purposes: Information and Advice for Students in Higher Education

www.uefap.com

 

[prepman]

How about dissolving zinc into hot (dull red) copper? If it alloys in the same fashion that aluminium does, then will have no need to increase the heat. Cu/Al eutectic has a melting point of 548°C as against 1085 for Cu and 660 for Al.

That's basically same thing...you're still waiting for the copper to dissolve into zinc. I couldn't understand (12yrs back) why my steel crucibles had holes in. I thought, back then that I'd obtained steel MP but found out it was dissolving into the copper.
One reason graphite crucibles aren't any good for steel is the carbon dissolve into the melt.

 

[Seadog]

No it's not. If you heat above the melting point of the zinc, the zinc melts onto the surface of the copper forming a eutectic alloy with an even lower MP.

 

[prepman]

No it's not. If you heat above the melting point of the zinc, the zinc melts onto the surface of the copper forming a eutectic alloy with an even lower MP.

Yes it is....Exactly...the same thing. Think about it...In fact that was how I started it off. There's youtube video showing proffesional (s)melters doing just that.

 

[8ob]

. There's youtube video showing proffesional (s)melters doing just that.

FFS no

Bob

 

[Brad93]

Zinc probably needs to be melted under an inert atmosphere

 

[prepman]

Zinc probably needs to be melted under an inert atmosphere

Ironically the burner produces an inert atmosphere. When it's off the borax flux achieves the same.
But it's still a fine line when pouring...still get some flash off. Ruined a perfectly good pair of flip-flops.
Ali bronze is a doddle so's traditional (Sn) bronze. It's just zinc.... the melting and boiling points are too close together. Easier with an electric furnace.
Tin melts at ~230C but doesn't boil until ~2,600C

 

[prepman]

Melt the Copper first?

Nope....doesn't work that way round.

 

[prepman]

Perhaps he knows?

 

[prepman]

Is it a lump of copper or copper dust (filings) that are being dissolved? Surface area counts when dissolving.

Only a chemist, not a metallurgist, I’m afraid.

That's a very good point and would work, but shredding copper isn't easy.
The thing with 'You put the Lime in the Coconut' approach is that the end result is the same.

A) If you melt zinc first and add copper you have to wait while copper heats up to dissolve into zinc.
B) If you add copper first you have to wait till copper heats to zinc mp and then add zinc and wait for zinc to melt. Then wait for copper to dissolve.
C) If you put it all in together it all heats up to zinc mp and the copper starts to dissolve.
Z) Melt copper and watch as the zinc flashes off.

I tend to go for errrmmmm..... let me think....perhaps C?

 

[prepman]

Found a use for yet another piece of rusty steel...a chinaman's hat (not racist?). Now the CO alarm doesn't go off anymore. Pleased with the foot pedal and drop gate.


Zinc flashing off from under the borax flux.

 

[prepman]

Modified the burner design and am getting more heat/temp for less gas. It's a fine line to tune. Not having a flue gas analyser it's a case of trial and error. The errors seemed to be winning until now.
The whole thing is a tuned structure, jet size, throat size/length and chamber geometry/vent.
Plus any baffle used. Keep looking for a calc' on the web somewhere for relationship between jet/pressure/barrel/throat. Something you just throw numbers at. There are some that come close.
The high gas pressure is necessary to get the velocity for the venturi. The barrel needs to the correct diameter to mix air and keep gas/air moving higher than the burn back rate (~44cm/sec). Might try a spinner vane in barrel.

http://danielconner.weebly.com/uploads/1/0/6/8/10688534/combustion_characteristics_of_propane_lab_report.pdf

This is a good no nonsense article on burner design. Have used the holder and baffle arrngement.

Gas Forges : Building Your First Gas Forge : anvilfire.com articles for metalworkers

Building Your First Gas Forge. Forge construction basics. FAQ from the anvilfire forum archives.

www.anvilfire.com

 

[prepman]

Seem to have hit on a winner...more by chance than design. Made the jet bracket thick to stabilise jet. Lathe of course keeps everything true and centred. CO alarm has stopped. Turn down is possible. Gas usage has decreased (by virtue of lower pressure). Swirl patterns is brilliant, with about 4 circuits. 1mm jet running at I guess 2 barg from 4 barg?

 

[prepman]

Reduced jet size to 0.7mm can now modulate it. That's a 50% reduction in jet CS area.

 

[prepman]

Just melted another load of beer cans...as well recovering ali it reduces the collection point of shame....no I'm definitely not alcohol dependent....I'd know wouldn't I?
The interesting part is ...I reckon they're ~50% plastic? How do the real recyclers cope with the stuff? The energy used isn't recycled either. Is it all just a myth?

 

[dyno-tron]

Could you make a load of fine copper swarf on the lathe (candy floss style) and use that? It would give a huge surface area for the dissolving.

 

[Windy Miller]

Could you make a load of fine copper swarf on the lathe (candy floss style) and use that? It would give a huge surface area for the dissolving.

Maybe a vertical shear tool would be ideal here?

Google Search

 

[prepman]

Could you make a load of fine copper swarf on the lathe (candy floss style) and use that? It would give a huge surface area for the dissolving.

It would but it's a lot of work.