Anyone have a good resource for the melting temperatures of gold & silver. I understand it can depend on karat and alloy added from somethings I had read while researching online. I rather get the info from this group of experienced jewelers.
Thanks in advance
I’m a hobbyist and melt silver and gold with a torch and you can tell when it is ready to pour by how it behaves rather than the temp. You get a surface that is very active and when you drop on the last bit of borax before the pour you get what I once heard described as a “sauron’s eye” effect which means you are good to go.
CP
As mentioned before you can judge the melting temperature by how the metal reacts when you apply your torch flame to it.
I use Oxg/Propane torches to melt my Gold and Silver.
Been making my own moulds, casting for twenty years now. It’s all about practice, do it often and the technique becomes like breathing air, just relax, let the torch do the work.
Have Fun
TommyD
Are you melting your metal in a kiln or by torch? If you are using a kiln the melting temps are easy to find online. However be sure that you are looking at what ever gold or silver alloy you are using as the melting temp for .999 purity is much higher.
As for using a torch it’s all done by eye. I always add borax on top of the metal first. If I am melting silver of any alloy I use a rose bud tip on my nat gas and oxy torch. I start with a reducing flame that is soft-ish and bushy. With just a hint of red at the tip. It’s important for silver to do this to reduce fire scale/ fire staining. Less oxygen=less oxidation. As the metal gets warm enough to turn red, I add more oxy. I heat until it’s a totally round blob. I continue to heat with the tighter flame and jiggle the crucible until the metal goes from a honey like consistency until it’s more water like and splashes around in the crucible.
Be very careful at this point to NOT over heat the metal. If you get it hot enough to see tiny sparks you have burned the lower temp alloy out thus leaving some metal alloys to have porosity. Too many folks go in too hot and too close to the metal and end up with bad castings and ingots that have pits or an uneven texture.
As for gold and it’s alloys as well as platinum I use a tighter flame but i continuously mover the torch to keep from damaging the surface of the metal as it’s heated. As with silver when the metal gets water like, that is when I cast or pour an ingot with a fast but steady hand. Do not hesitate when pouring. Also when pouring an ingot before I melt my metal I always oil it first, and then preheat with the torch it until the oil burns off and the mold is seasoned and hot like a cast iron frying pan. This takes longer that you’d think. Since I am an old lady my advice is to always go pee beforehand:-) Once the mold is hot enough I position my crucible next to it to heat the metal while using the excess flame and radiant heat to keep the mold hot while melting the metal. Have fun and make lots of jewelry.
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