# Melting problems (problem solved!)



## ryanm (Aug 21, 2014)

first off I'd like to say this is a awesome forum. My name is Ryan and I've been buying silver for about three years now. I thought it would be fun to make my own bars but today when I tried to melt a cheap silver round all it did was turn into a blob. Every time it would start to get hot enough to start melting it would only melt a little and then go back to turning hard. I'm using map gas with my bernzomatic ts4000 torch head. Any speculation as to what I'm doing wrong? I sat there for literally 15 minutes with the torch on it and it would melt enough for me to pour it.

Ryan


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## Barren Realms 007 (Aug 21, 2014)

That tourch should melt it. Do you have an insulating blanket between your melting dish and the surface it is setting on if not that will help because the surface it is setting on can act like a heat sink and absorb some of the heat you are generating. How much are you trying to melt at once?


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## ryanm (Aug 21, 2014)

Barren Realms 007 said:


> That tourch should melt it. Do you have an insulating blanket between your melting dish and the surface it is setting on if not that will help because the surface it is setting on can act like a heat sink and absorb some of the heat you are generating. How much are you trying to melt at once?


No insulating blanket being used. I'm only trying to melt an ounce so it's nothing much. I managed to melt it into a blob the size of a quarter. I had to give up because I was using too much of my gas trying to melt it down so I was pretty frustrated.


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## g_axelsson (Aug 21, 2014)

It's not the size of your melt or the temperature of the flame, it's the rate you are loosing heat to the surrounding that stops you from melting your silver.

When you start the silver only makes contact to the melting disk in a few spots so it doesn't transfer so much heat to the dish. When the metal melts the molten metal forms after the surface of the dish and a lot of heat is going out in the melting dish. If the dish isn't well insulated then heat is lost and the metal freezes.

Put some insulating material under the dish and build up a small wall behind the dish (it will reflect back some heat) and you will notice a large difference in how fast it melts.

Göran


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## Palladium (Aug 21, 2014)

Are you trying to melt it in graphite?


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## Claudie (Aug 21, 2014)

Are you even using a melting dish, or just trying to melt it on a solid object?

You said it was a cheap Silver round. Are you sure it is Silver and not a fake?


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## ryanm (Aug 21, 2014)

Positive it's not a fake silver round. Melting in a graphite crucible. I'll try and get a picture of my set up.


Edit: So here's my set up. By no means anything fancy. All that happens when I heat up the silver is it gets red hot, including my crucible but the silver doesn't even melt.


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## butcher (Aug 21, 2014)

The brick can suck up a lot of heat, the brick can hold a lot of moisture, it would not surprise me if it cracked, or would spit chunks of concrete at you when you do heat it enough.

it is hard to tell from the picture but it looks like the flame may have carbonizing flame (lack of oxygen) which is not really bad for silver and normally somewhat desirable, if the torch can produce enough heat to melt the silver at that setting when running with deficient of oxygen, but with a torch just barely able to produce enough heat to begin with, running the torch rich which will produce less heat it may not produce enough heat to get the job done.
Does the torch leave things looking black a sooty?

Mapp gas and a good torch, you should be able to melt the silver, how dirty is the torch you are using, that can also be a problem if the torch is so dirty it is not operating at full potential.

First I would forget about using the building block as some kind of furnace cover, or having the graphite crucible sitting on concrete, if you have nothing else try sitting it on a few layers of sheet rock cut to small blocks and stacked onto each other, the sheet rock will not act as such a large heat sink.
Check the torches flame clean or adjust it if needed, you should have a good volume of bright blue flame, even a brighter blue cone at the base of the flame, with maybe with a little orange or yellow dancing on the flames tips.

you may need a refractory material to sit the dish on like ceramic wool, or soft fire brick refractory (which tend to reflect heat not absorb it as much as the harder more dense refractory will) you may even need a small enclosure to contain a little more heat instead of trying to heat the world around your dish, (atmosphere, or the heat sink materials in that area)....


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## Smack (Aug 21, 2014)

Noticed your heat treating your tongs.


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## ryanm (Aug 21, 2014)

butcher said:


> The brick can suck up a lot of heat, the brick can hold a lot of moisture, it would not surprise me if it cracked, or would spit chunks of concrete at you when you do heat it enough.
> 
> it is hard to tell from the picture but it looks like the flame may have carbonizing flame (lack of oxygen) which is not really bad for silver and normally somewhat desirable, if the torch can produce enough heat to melt the silver at that setting when running with deficient of oxygen, but with a torch just barely able to produce enough heat to begin with, running the torch rich which will produce less heat it may not produce enough heat to get the job done.
> Does the torch leave things looking black a sooty?
> ...


I actually just bought the torch so it shouldn't be dirty or anything like that. I'll make sure to get rid of the cinder block and try what you've mentioned.


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## jonn (Aug 21, 2014)

melting in graphite is not easy unless you can entirely surround the graphite with the same temperature. Use a clay dish wrapped in ceramic wool and pour into graphite. Then try melting that pour in your graphite again just to see how near impossible it is. Graphite is an excellent heat sink.


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## heliman4141 (Sep 20, 2014)

All the decent graphite pours ive witnessed were done with the graphite mould pre-heated in a furnace to at least the same melting temp as the metal, that way no instant cooling happens. Then you turn down the furnace & allow the graphite to cool a bit, the graphite moulds are machined with a slight taper so the metal will just drop out when turned upside down. I have a few ive tested & you must get the graphite really hot, a flame on graphite will contaminate it, an electric furnace won't & is the best bet. Heat your Silver in a crucible then pour it into a heated mould is only way to get a professional pour of a round or bar like the pros do. Its hard to pour rounds & bars without these extra heating devices. One reason buttons are popular. Unless your planning on making rounds from recovered Silver or Gold by the hundreds or more its not worth the investment in a furnace etc...just to experiment. Your better off keeping your rounds as they already are since they are .999 pure & minted already. Your gaining nothing here. Now if you were melting Silver crystals from refining different story. Easier to prove the purity of the minted rounds, something to consider.

Dave


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## ryanm (Oct 24, 2014)

Hey guys. Been working on my bars and it turns out it was just the crucible. I was previously working with a graphite crucible and I switched over to a ceramic one and my silver started to melt almost instantly. Here's my latest work. Mine is the one on top.


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