Silver scrap

[Patstone]

I have melted my scrap to make pendants with quite easily, but as I watched someone put some scrap and make a ring with it by melting it. I thought why not make a bangle with it, so I melted a line of scrap, which when melted was about 8 inches long and quite solid looking, so I gently tried to bend it in my hands and it broke in three places, and looked white inside.
I was contemplating buying a durston at some time in the future to enable me to use my scrap by melting it down and rolling it to use as sheet. Is this just a dream or can you actually do this, for some reason I do seem to get a lot of scrap.

[Goldsmith]

Melting a line of scrap that is 8 inches long is not really the way to melt scrap into a usable length.
If you use a crucible to melt your scrap, you have to melt it until it forms a flat circular shape in the crucible, when it is melted to the right temperature the surface of this melted circle of silver will look like mercury. Then this melted metal needs to be poured into a heated ingot mould, pickled and cleaned before being milled.
I make my own wires by melting silver scrap in a crucible and poured into my ingot mold, which gives me a four inch long quarter inch square ingot, which I then run through my Durston wire rollers.
I use one of these ingot moulds;http://www.cooksongold.com/Jewellery-Tools/Skillet-Or-Ingot-Mould-3-Groove-prcode-999-931
I melt in these types of scorifiers; http://www.cooksongold.com/Jewellery-Tools/Scorifier-2-Square-prcode-999-AKP
You can buy these scoririer holders; http://www.cooksongold.com/Jewellery-Tools/Crucible-Tongs-prcode-999-926

But I made my own, this is my scorifier clamped to an old file for melting and pouring.

James

475647574758

[Patstone]

Oh, not really the sort of thing to do in a spare bedroom then. I only have a propane butane mix handheld and a small sievert with a small nozzle. I have a garage that I could do it in but it sounds a bit more than I could undertake. Thanks for the information anyway.

[Exsecratio]

so I gently tried to bend it in my hands and it broke in three places, and looked white inside.

Did the white core seem to have specular reflections? if so that would be caused in most metals by too much heat / too fast cooling causing the metal to solidify with a crystalline structure rather than a linear structure.

Pretty much all metallics cooled slowly will form a linear and very flexible structure, where-as those cooled quickly will be hard rather than "tough"

Glass = Hard...very hard but not tough.

Titanium = Tough, difficult to bend but unlikely to snap.

The two are very different animals.

best wishes

Dave

[Patstone]

Yes I cooled it quick, so if I heat it again and put it back together and let it cool naturally will I be able to bend it without it breaking. Thank you for that, I didnt know it made a difference to the structure of the metal. So it may be better to let all things cool slowly rather than dunk it to cool it, as it will make it stronger.

[medusa]

I know cast metal is much more brittle than stuff which has been rolled, so maybe you would need to anneal to make it less brittle?

[Wallace]

Here is some info that should help on to quench, or not to quench. This talks about annealing rather than a full on melt. But the metal heating principle and those resulting little crystalline formations still react in a similar way. Link to a Ganoskin Blog (http://ganoksin.com/blog/taogem/2010/02/09/annealing-–-jewelry-design-–-silversmithing/)

[susieq]

Here is some info that should help on to quench, or not to quench. This talks about annealing rather than a full on melt. But the metal heating principle and those resulting little crystalline formations still react in a similar way. Link to a Ganoskin Blog (http://ganoksin.com/blog/taogem/2010/02/09/annealing-–-jewelry-design-–-silversmithing/)

Thanks for the link to this Wallace, very very useful article.

Susie

[Dennis]

Despite the discussion above, I have seen various bits and pieces from the scrap pot, placed in a circle, fluxed and melted into a ring.

With practice you can get near the size you want by drawing a circle of the right diameter on your block first. If they don't all join, you can add more to fill any gaps

The result is hard and brittle and organic looking, but would crack if hammered. I've no doubt that with a large torch you could make a bangle in this way too. Dennis.

[pearlescence]

I've made rings in this way...I'm a bit obsessed with fusing and melting at the moment. I hadn't thought about a bangle.......hmmmm

[Patstone]

That is the look I wanted, organic and touchy feely. It didnt happen though, still I can have another go at it. Thanks for the advice people, that blog is interesting about the sharpie pen because my studio/spare bedroom is also very well lit and it is difficult to see when a piece is too hot, hence my habit of melting things. Lol.



Despite the discussion above, I have seen various bits and pieces from the scrap pot, placed in a circle, fluxed and melted into a ring.

With practice you can get near the size you want by drawing a circle of the right diameter on your block first. If they don't all join, you can add more to fill any gaps

The result is hard and brittle and organic looking, but would crack if hammered. I've no doubt that with a large torch you could make a bangle in this way too. Dennis.

[Exsecratio]

Annealing is basically re-heating to a plasticising temperature and allowing to cool, it reforms linear structures in the metal rather than crystalline.

I've used it on engineering projects to try and get some "toughness" back into a tool after being "hardened" the same with glass, rapid cooling induces stresses into most things,high stress tends to promote high hardness but makes things very brittle.

A good example is the Prince Rupert Teardrop,

Glass is heated to its fluid temperature and then a drop is allowed to fall into a glass of chilled water. It will keep the teardrop shape (a little like a tadpole) and the "head" end will take a steel hammer blow without breaking, flicking the tail end with a finger nail will cause a stress crack to explode across the entire thing and it will burst like a small bomb.


http://www.youtube.com/watch?v=6V2eCFsDkK0

With most metals it's possible to case harden (just have a hard wearing surface) and retain a more resistant, flexible core but it usually requires the addition of other elements (in the case of steels it would be the addition of carbon when the metal is at red heat).

best wishes

Dave

[Patstone]

Thanks for the video, really interesting.

[pearlescence]

Stress and hardness are the big concern with airplanes - manufacturers put a plane in a jig and (for eg) flex the wings millions of times to simulate the wear in service then examine for stress fractures.

I've done some fusing - love doing it for what results when it goes well and of course you don't know quite what you are going to get. 4759

[Patstone]

I love the look of that, its beautiful. The only thing I have made with fused stuff is a slightly melted look where you can see the jump rings and bits that made it up. I work in my spare bedroom and would be a bit scared to do too much in that line as I dont want to set the house alight. The biggest torch I have is a B & Q propane/butane mix hand held replaceable cannister one, it would be hot enough but its a bit of a beast for use in a bedroom.


Stress and hardness are the big concern with airplanes - manufacturers put a plane in a jig and (for eg) flex the wings millions of times to simulate the wear in service then examine for stress fractures.

I've done some fusing - love doing it for what results when it goes well and of course you don't know quite what you are going to get. 4759

[pearlescence]

Oh, thank you <blush>
That one (and a couple waiting to go to assay) are half fused and half D wire. I'm using up all my bits and bobs too!