Video 1: Pouring a 1 Kilo Cube!
We just wanted to show you a short video of one of our awesome 1 Kilo Cubes being poured (just noticed that it's black and white...we'll get that fixed soon!). So here's a little about the equipment and process for the curious and aspiring silver pouring folks. First, lets start with the furnace, you can't see it in the video but for our large silver bars (>15 troy ounce) we use a MF-3000 melting furnace. This furnace is advertised as a 3 kilogram furnace (hint, hint, the weights are often advertised for gold). Why does the hint matter? Well, silver is about twice the volume of gold so a 3 kilo (gold) furnace will only fit about 1.5 kilo's of .999 fine silver. So, if you are shopping around, be sure to get the correct size furnace! In the furnace we have a 3 kilo (gold) graphite crucible. To remove the crucible from the furnace we have a set of crucible tongs. The final thing we have is a custom graphite mold to pour the molten silver in.
The process is quite simple! We measure out about 1005 grams of silver shot, pour it into the furnace, wait for it to melt then sprinkle a tiny amount of borax on the silver. This is mainly to capture any graphite that degrades and falls onto the silver. Basically, if you pour just right, all of the borax and graphite crud will remain in the crucible. Taking a step back, before pouring we blast the graphite mold with a torch until all water is evaporated from the graphite. How do you know? Well you can actually see the water line as it evaporates. Finally, we pour with a rather quick but smooth technique and end in a way that the crud stays in the crucible. Once poured we shake the crucible over a bucket of water to get the excess flux, graphite and any small amount of silver that may have stayed behind. That's about it for the pouring part!
Video 2: Pouring 10 Gram Silver Bars
Here's a quick video pouring a couple of our 10 Gram Silver bars! Feel free to ask questions in the comments below and we'll answer to the best of our ability!
The equipment we use for pouring our smaller silver bars consists of various sizes of silica dishes and a powerful torch. I'll give away a little known secret for if you are looking for cheap gas for your torch. It is quite common to use the Map-Pro (yellow) torches for smaller scale pouring. They work great but at $5-$10 per 14oz...they become VERY expensive when pouring several hundred ounces a week. We set out to reduce the costs and contacted a commercial gas supplier. What's the verdict? We'll you can learn some of this with a quick search but to break it down....you will often hear folks stating "MAPP Gas" when referring to Map-Pro. This is incorrect! MAPP Gas is no longer manufactured! In fact, Map-Pro is essentally branded Propylene which has similar properties as the old MAPP Gas. Basically, if you want to melt on a larger scale, contact your local welding supply to find out what your options are!
Back to the story...making 1 oz silver bars and anything under 5 oz silver bars is essentially the same process as when using the furnace. We measure out a bunch of bars into individual plastic shot glasses, slowly heat up the silica dish (must be glazed with borax), throw the silver in once the dish is glowing, then melt away! We pour into pre-heated molds with a fast but careful pour after working the flux off the molten ball of silver....repeat, over and over and over and over a few hundred times then call it a day! Enjoy the quick video below of the process!