Gold Conductor Paste - Please Advise

[NeoRock]

Even for the same gas, not all torch heads or brands are alike, some are just better quality than others, some will burn much hotter than other brands on the same gas, but if working properly will melt gold.

Propane/air is will melt gold in the proper setup, but it is more difficult, it is not as hot as propane oxygen or Mapp gas, acetylene/oxygen...

You might try taking your torch head apart and cleaning it.

You do not need a furnace to melt gold.
I like the small ceramic melting dishes, they work good with a good Mapp gas torch.

You may not need the borax or flux agents since you have a graphite crucible, the borax flux can help lower the melting temperature and help the melt flow, or raise the viscosity of the melt so the metals combine better in the melt, it would also provide some glass to cover the melt and help to keep it from sticking to a ceramic melting dish.
In a flux melt, it is a part of the flux recipe used to control the chemistry going on in the melt.

With a ceramic melting dish, and melting pure gold we will sprinkle just a little borax on the red hot dish, just to coat it with molten glass so the molten metal will not stick to the dish and the molten can be poured from the dish.

In a flux melt, we use much more borax is used along with other flux components like oxidizing or reducing agents...
When using graphite melting fairly pure gold the borax is not needed to keep the gold from sticking.

As far as modifying your furnace with another hole and adding oxygen, you could make it into a cute little bomb if you do not know what you were doing. I would mix gas and air before it enters the furnace.

A couple of scheduled days in nature turned into a week. Anyhow, just got back and went through your posts as well as the others. Thank you so much Butcher, again.. And everyone else. Even beyond this paste, I have learned so much from you guys. Much appreciated.

So I took apart the torch head, cleaned it as you suggested, although, the torch head was farily new. After cleaning, I tried the direct approach trying to melt just a tiny tiny amount of the paste in the ceramic melting dish, directly aiming the torch on it. But again, even after 5 minutes of directly hitting it with the torch, no melting at all. The blue flame stayed very consistent, keeping the gold glowing hot, but never got to melting. I took a video of a few seconds:

https://youtu.be/-vqx7iV1qEY

Only thing I did see more prounonced gold "spots" (see attached images). At this point, perhaps it is the binders causing me issues.

I did get a reply from Dupont, saying "please see attached for MSDS". But my luck, nothing was attached, I just replied to the email informing the guy his email was empty, so hopefully this time they attach it. I will post as soon as I receive.

I downloaded the images from your other post, Butcher.... If I got a second torch, would that drive up the temperature significantly and/or faster melt perhaps??

Also, going back...i had tested the paste by pouring a bit of the 22K solution(nitric acid & muriatic acid) on it, & there was absolutely no reaction. Is there any way those tests ever give a false positive? Even though I was told its pretty close to pure, I ask this because after heating, the material turns very hard and I thought 22K gold is "softer". Could that small amount of the binding agents make it that hard?

Thank you Butcher...and everyone else.. Truly appreciate everyone's time and input.

 

[NeoRock]

I believe for a furnace like that to work well, the gas/flame/torch inlet should be ofset from the center, creating a vortex of flames around the crucible in the center. This distributes the heat a lot better, increasing the temerature. your's looks like it is aimed exactly to the center. It could make a lot of difference.

The issue is that the Mapp gas is running at not that much higher a temperature than the melting point of gold. The nozzle on the bottle is designed to get the most efficiency out of that gas. Once you start altering things and introducing a whole host of other variables it's only decreasing in efficiency.

Thank you guys for the info...That had occurred to me in the beginning looking up the melting point of gold and then reading the max temp for the Map gas. The mapp gas max temp was not much higher. I did try directly aiming the torch at a small speck of the paste while it sat inside the a ceramic dish... But never could get it to melt, just stayed "glowing hot.:

I just got some "Ceramic Fiber Blanket 8# Density, 2300F" and used this as the lining insulation in addition to getting rid of the plastic tubing and directly connecting the torch head to the can. The crucible is also raised sitting on a little metal stand I made.... see attached images please. Would this possibly be a better setup?? I haven't tried it yet...
The one thing I am not sure of is "torch head should be off center" instruction... Should the torch be aimed at the one side of the crucible? or am I way off?

Thank you guys!, much appreciated.

 

[butcher]

That is not a ceramic melting dish, that is a thick block of graphite made into a crucible (or melting cup not a dish shape). the graphite is thick and you will need to get the graphite crucible also glowing red hot.

Looks like you were just at the melting point of the gold but the crucible was still absorbing the needed heat and convecting it out into the atmosphere of air.
so close but no cigar.

I would say you will need another torch to heat up the crucible to glowing cherry red hot while the second torch swirls its flames on the gold.
Or
Get yourself a ceramic melting dish (sit it on top of the k-wool insulation blanket), the ceramic melting dish will absorb and keep more heat than the graphite can or will...

in the melt of impure gold or base metals and salts of base metals with a torch, many of the base metals can form gases burn off in the acidic environment of melting these base metals salts or impure gold, also form acids as the gases hit the cooler air full of moisture, these gases will attack the torch, and corrode it making it dirty or even inoperable...
Melting pure gold, the torch will not corrode or get as dirty...

 

[anachronism]

Richard

I have to disagree. A Mapp gas torch will melt gold in a ceramic dish like the one he had in the previous picture with no lagging. Given, it takes a while but you can melt up to an ounce like that.

 

[g_axelsson]

You need more heat. The gold have sintered together and is conducting the heat away.

In your picture showing the overview of the melting dish you have it on a can filled with sand? And with a big metal piece sticking up. Everything will suck the heat away from the melting dish.

Use the ceramic wool to make a resting pad for the melting dish. Isolate it over the edge and also make a heat reflector out of the ceramic blanket.
This might give you some hints. I made a small cavern of fire brick and it was the difference between sintering my gold on the surface or melting it. And I used propane with air.
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=61&t=19840

And the binding agent... at red heat it's all gone. Nothing to worry about,it's designed to evaporate before the gold start to sintering into a solid conductor.

Göran

 

[butcher]

Yes, more heat or less of a heat loss through convection is needed.

A good Mapp gas torch has enough heat to melt gold, in the right conditions, but with the conditions sucking up the heat away from the gold, it will not be quite hot enough.

 

[rickbb]

For not a lot of money you can get a small oxy/acetylene torch at the local big box home store and solve the problem.

You are clearly getting the gold to melt and form little beads, but not getting it hot enough to carbonize whatever the binder is.

I vote for more heat, lots more.

 

[snoman701]

Ya'll need to learn to use the heat you have.

Jon has attested that a MAPP torch produces enough heat to melt the gold in an open dish...so if you can't get it to work, it's technique. Just change your technique. As Butcher suggested, a small amount of insulative material can isolate and reflect the heat of your flame so that it is used for the melt, not to heat the room.

Lazersteve had a nice little insulating fire brick furnace that was nothing more than a hollowed out fire brick that held the melt dish.

 

[NeoRock]

That is not a ceramic melting dish, that is a thick block of graphite made into a crucible (or melting cup not a dish shape). the graphite is thick and you will need to get the graphite crucible also glowing red hot.

Looks like you were just at the melting point of the gold but the crucible was still absorbing the needed heat and convecting it out into the atmosphere of air.
so close but no cigar.

I would say you will need another torch to heat up the crucible to glowing cherry red hot while the second torch swirls its flames on the gold.
Or
Get yourself a ceramic melting dish (sit it on top of the k-wool insulation blanket), the ceramic melting dish will absorb and keep more heat than the graphite can or will...

in the melt of impure gold or base metals and salts of base metals with a torch, many of the base metals can form gases burn off in the acidic environment of melting these base metals salts or impure gold, also form acids as the gases hit the cooler air full of moisture, these gases will attack the torch, and corrode it making it dirty or even inoperable...
Melting pure gold, the torch will not corrode or get as dirty...

Thank you Butcher. The small white dish in the attached image is what I was melting it in, that is what you were referring to, correct? I see in the previous photos, it is a top view, in the dark, so I think it makes it look like a crucible. Sorry about that, should've taken better photos.

But I realize, my biggest mistake was forgetting what you guys were teaching me about heat loss, all along. In my rush, I had it sitting on the cover of the little furnace I made. I will try again with it sitting on top of the insulation, as you mentioned. In respect to the other base metals, the torch head got a bit dark, but not really dirty and definitely no corrosion. I am assuming that from your explanation...that is a tell, that it is fairly pure.

And Dupont finally sent me the MSDS, I am attaching the PDF to this post. I believe the relevant info is on the 2nd page..rest seems like safety guidelines and exposure warnings...

Thank you again.

 

[NeoRock]

You need more heat. The gold have sintered together and is conducting the heat away.

In your picture showing the overview of the melting dish you have it on a can filled with sand? And with a big metal piece sticking up. Everything will suck the heat away from the melting dish....

Thank you g_axelsson. I am reading through your other post about the Brick Cavern you made, very cool... I'll be ecstatic if I could get anywhere even remotely close to the gold button you got.

In respect to what you said about the binding agents burning off, others mentioned this as well and that they would burn off even prior to melting. Although, I am puzzled why the end result (image attached), is so hard, isn't close to pure gold supposed to be somewhat soft... I will assume this is due to my lack of knowledge and I am not realizing some aspect of it.

I will try your and Butcher's suggestion about using the insulation blanket to reflect the heat back to the dish.

....Thank you again, much appreciate it.

 

[NeoRock]

For not a lot of money you can get a small oxy/acetylene torch at the local big box home store and solve the problem.

Thanks rickbb.
Does this seem like what you were referring to:

https://www.amazon.com/Soldering-Practical-Acetylene-Flexible-Repairing/dp/B07VQNLLXX/ref=asc_df_B07VQNLLXX/?tag=hyprod-20&linkCode=df0&hvadid=385504784560&hvpos=1o4&hvnetw=g&hvrand=4889599926612717231&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031159&hvtargid=pla-824124821680&psc=1&tag=&ref=&adgrpid=73872202490&hvpone=&hvptwo=&hvadid=385504784560&hvpos=1o4&hvnetw=g&hvrand=4889599926612717231&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9031159&hvtargid=pla-824124821680

Most others I seemed really expensive, such as on the home depot site. But I am assuming those are not the "mini" versions.

 

[butcher]

You are correct that is a ceramic melting dish, it will work fine, get it hot and sprinkle lightly some borax (20 mule team borax soap will do in a pinch) to glaze the dish...

I did think you were still using the graphite crucible.

The only thing in the MSDS that I would be concerned about is the lead which makes gold to brittle for use in jewelry, there is nothing that I can see in the MSDS that would give you any problem melting this gold into a button.

 

[NeoRock]

You are correct that is a ceramic melting dish, it will work fine, get it hot and sprinkle lightly some borax (20

The only thing in the MSDS that I would be concerned about is the lead which makes gold to brittle for use in jewelry, there is nothing that I can see in the MSDS that would give you any problem melting this gold into a button.

Thanks Butcher. Will the lead make it "unsellable"? Should i look up how to separate it on this forum?

I will try with the dish, but I think you were spot on about the torch being the issue, in your earlier post... as I looked up the torch I have been using (bernzomatic WT2301) & many people online said they had problems with it.. I am going to home depot to buy the ernzomatic TS8000 which many said is a good torch.
But again, now I am worried about what you said about the lead, don't wanna go thru all this & end up not being able to sell it at all.

Thank you again, much appreciated...

 

[Williamjf77]

I think the torch is your problem, you are using mapp gas on a propane torch.

I don’t know what the difference is but there is a difference as to how much fuel and air are delivered

 

[anachronism]

I'd just concentrate on getting the gold out in a blob then worry about the impurities later. One step at a time.

Jon

 

[anachronism]

I think the torch is your problem, you are using mapp gas on a propane torch.

I don’t know what the difference is but there is a difference as to how much fuel and air are delivered

I'll be honest William I didn't notice that. Good catch.

 

[NeoRock]

I'll be honest William I didn't notice that. Good catch.

I think you guys are right, even online many had issues with this specific torch, even using it with propane. Going right now to buy the bernzo 8000 - map gas combo from home depot.

Thank you guys.

 

[butcher]

Like watching a movie, we just all want to see a good ending.
They are good torch's.

 

[Williamjf77]

I believe the mapp torch head has a swirling action from what I have read while the other handle is just a handle with an igniter.
I know my mapp torch howels and makes a lot more noise then the plain propane torch. You can really tell the difference in the swirling style torches

 

[NeoRock]

Hello guys,

Got the gas/ts8000 combo, wow this torch is orders of magnitude better...
But following up on Butcher's "movie" analogy, this is turning into a horror flick for me....lol

This time temperature is definitely not an issue. I followed the dish glazing video as best as I could, but I think I messed up the dish, gold never melted, but did stick to the bottom. So I gave it a go on the crucible as well. Please keep in mind, each time I had the insulation "cuddling" around the dish & crucible.




This 3rd image is of the dish a few seconds after I moved it from sitting on the insulation blanket getting torched, but you can see how hot each got.



Even the dish and crucible get red hot as you can see from the pics above but I never get to the the gold melting so I can pour it. It just stays glowing red hot no matter how long I aim the torch at it.

Here is the end result - its very hard and brittle...anyone know if I could just sell it like this to a pawn shop or something?








Also here is a 10 second portion of it in video:
https://youtu.be/9YMUFALxXoI

Any thoughts? Thank you everyone. Again much appreciated...I will now got pull my hair out lol.