PDA

View Full Version : Melting down scrap silver



Freya
27-11-2011, 06:36 PM
Hi ,

I'm wanting to melt scrap silver, and have a sievert torch set up but at the moment the nozzle i'm using does'nt seem to create the flame needed, its model 2941, anybody have any tips on what to use? also what solder boards/blocks are needed to create a hearth to put a graphite crucible encased for melting?
would be grateful for any suggestions!

Thanks , Freya

Goldsmith
27-11-2011, 06:59 PM
How much scrap do you intend melting and for what purpose, are you making fresh sheet, fresh wire or casting? If I am melting silver using a torch, I use scorifiers rather than crucibles, as it is easier to melt the scrap by heating the actual metal rather than heating a crucible, and with some crucible tongs it is easy to pour into a mold with these. Most crucibles are heated in a furnace or a kiln. If you are intent on using a crucble and a torch then you will need to make an enclosure with firebricks and get one of the larger heads available for the sievert, Cousins say the 3524 is good for melting metals; http://www.cousinsuk.com/catalog/5/2056/2572.aspx
I melt small amounts of 18ct gold scrap in a scorifier using my Smiths Oxy/Propane small torch and I pour it into an open ingot mold for making wires.I usually melt about 30 grams at a time, adding pieces slowly as it melts and fluxing it with powdered borax while melting it, and keeping the flame on the molten blob while pouring it into a mold.

James

Freya
30-11-2011, 01:04 PM
hi, thanks for the info! will purchase a sievert nozzle 3524, and could you tell me where you can get a scorifier and for future reference a good dealer for a smith/ oxy/propane torch?

Many thanks, freya

Goldsmith
30-11-2011, 01:23 PM
Cookson sell scorifiers, see; http://www.cooksongold.com/Jewellery-Tools/Scorifier-3-Square-prcode-999-ATC
HS Walsh sell the Little Torch see; http://www.hswalsh.com/Little-Torch-Kit-.aspx?i=TB40&c=369
Some of my contacts have bought these torches cheaply on Ebay, see; http://www.ebay.co.uk/itm/SMITH-LITTLE-TORCH-JEWELERS-TORCH-BODY-HANDLE-HOSE-/200651287231?pt=LH_DefaultDomain_0&hash=item2eb7bfaabf#ht_1283wt_905
I do not know how they can be sold so cheap and could not guarantee that they are not copies of the originals, but that is just my opinion.
But please remember if you buy an Oxy/Propane torch you will also have to buy regulators and safety Flash Back valves for each gas line and also hire an Oxygen cylinder, fine if you are setting up a business but a large outlay if you are just a hobby jeweller.
James

mizgeorge
30-11-2011, 02:14 PM
You may find it easier to use a WHIP system for small quantities - and this will work with a large handheld torch (Go system or Rothenburger plumbers type).

http://www.palmermetals.co.uk/shop/tools/whip-wire-handled-ingot-pouring.html

Far, far easier to use (and lighter) than traditional scorifiers.

Freya
01-12-2011, 12:48 AM
hi, had a look at the 'little torch', probably works out the same as ebay prices buying from hwalshes, by the time you've paid ppfrom the states and got the regulators/flash back arrestors separately, checked out the rental price of oxygen at £65 per yr at a local boc dealer, see what you mean it is a dear do! lol. Will get a larger nozzle, and use the whip system/from palmer metals, as posted from mizgeorge for the time being as i've bought a reversible sheet/wire ingot mould and seems easier to pour molten metal into this. But for melting gold in future its gonna be the oxy/propane torch.
Thanks Freya

Freya
01-12-2011, 12:55 AM
hi , thanks for the advice i agree the WHIP system seems alot better to use, especially for pouring into an ingot mould to cast sheet and wire -it looks lighter! can you confirm when pouring into a mould it has to be oiled? and warmed to avoid splatter?

freya

mizgeorge
01-12-2011, 01:53 AM
Freya, if you're looking at a little torch (or similar) consider the option of getting a reconditioned medical oxycon (oxygen generator) rather than renting bottled oxy. It's cheaper, much safer, and very easy to set up.

caroleallen
01-12-2011, 09:53 AM
George, if I were to get an oxycon, would I still need to put the bottles outside?

mizgeorge
01-12-2011, 10:39 AM
You still need bottled propane. However, with reasonable precautions, that's fine kept indoors. I do, and I know a lot of others who do so as well.

Moon Willow
01-12-2011, 08:49 PM
Just a small note,

If you keep gas bottles indoors check your house insurance, my gas is kept outdoors
because there always seems to be a small residue of gas in the house.

Moon Willow

Tabby66
01-12-2011, 10:17 PM
Freya, if you're looking at a little torch (or similar) consider the option of getting a reconditioned medical oxycon (oxygen generator) rather than renting bottled oxy. It's cheaper, much safer, and very easy to set up.

George, where would I start looking for a reconditioned oxycon unit??

mizgeorge
01-12-2011, 11:30 PM
The best bet is Tuffnell Glass - they're used by lampworkers as their oxygen source. Martin does a really good job on these, and also has spare parts if you ever need them. Mine's been going for three years now without any problems at all.

About 2/3 of the way down this page - they're £235 delivered.
http://www.tuffnellglass.com/contents/en-uk/d28_tuffnellglass.com.html

Tabby66
02-12-2011, 08:48 PM
Thanks George.......off to have a look!