I'm new! Talk everything about casting silver.

[Agent911]

Making Nitric Acid:
Using distilled water, Sodium Nitrate, Sulfuric Acid to make Nitric Acid. I'll bring the 100ml of water to an easy boil.
Add 170g of Sodium Nitrate and stir until dissolved. Turn off flame, cool below boil and slowly stir in 56ml of Sulfuric
Acid. Let cool to room temp. then place in freezer until settled. Finally, pour off liquid, leave salt, and I should have suitable NA
for refining. (Questions. sorry if they're simple to answer...here we go...1- Any problems making bigger batches of NA?)

Cementing:
Silver and Nitric Acid goes in beaker. (2- Any problems If I use a very large beaker, 7oz of silver and 1 liter of
acid?...big batch at once). I'll let it sit outside overnight. Without too much trouble I should now have Silver
Nitrate. Filter and add copper. Wait and fool with until all of the silver cement falls out. Pour off Copper Nitrate and
rinse, rinse, rinse and dry the silver cement. I'll use aluminum to get some copper back. (3- Is Aluminum Nitrate good
for anything?)

Preparation for smelting and casting:
First you should know I will be using an electric furance.
I know very little about this. I have a graphite crucible. I know I should slowly heat it some when I first get it. I'm
going to coat it with Anhydrous Borax as I read it makes pouring easier. The silver slides over the glass better and the
crucible will last longer too. (4-I just rub the Borax around on the inside and enough powder will just stick? How hot
for how long to make it glassy enough?)
I have a graphite mold. I want to prepare it for some quality ingots. I don't have an acetylene torch, but if
absolutely necessary I can ask someone from work to put soot on it. (5- Are there any QUALITY alternative to the
torching? Soot by candle? Better alternatives? Anything else to help with the casting such as a small coating of borax
or other chemical in the mold to help reduce porosity/swirls?) Getting ahead of myself but...I know I should get some
kind of torch for keeping the top surface of the ingot hot while it solidifies. I'm just going to see how this goes
without one first. I also know I need to heat my mold and pour quickly.

Smelting:
I don't understand much about flux.
6- People sell pre-made fluxes. They imply it's better than just plain Anhydrous Borax. Do their special formulas really
help to refine better?
7- Does Anhydrous Borax alone pull out impurities? I don't even know what its purpose is besides that...What's the weight
ratio for silver cement:Anhydrous Borax? Should I add extra borax in, just before pouring too?
8- I can get a lot of molten slag out while in the crucible using my graphite rod, it sort of sticks or what?
9-When I pour my bars the excess slag will form at the top of my bars. Will the slag compromise a good, even, appearance of bar tops?

Pouring seems straight forward enough...I want good looking bars like anyone else. Any nice tips will be appreciated!

 

[Harold_V]

Smelting:

You won't be doing any smelting. You will do some melting. They are not one and the same.

Harold

 

[Harold_V]

Cementing:
Silver and Nitric Acid goes in beaker. (2- Any problems If I use a very large beaker, 7oz of silver and 1 liter of
acid?...big batch at once).

You will be well served to do some reading on the forum before jumping in with what you think will work and what actually works. A liter of nitric acid, 68%, can dissolve 30 troy ounces of silver. Do a search on GSP's posts and read those that pertain to the dissolution of silver with nitric acid. He's our resident mathematician and has provided excellent guidance in that regard.

First you should know I will be using an electric furance.

That's a lousy choice. When you melt cement silver, fluxing is a requirement, as you already know. Those electric furnaces, assuming you're talking about one of the Handi-melt or Kerr types, use graphite crucibles that do not lend themselves well to being fluxed. They also enjoy a rather short service life due to the rim burning away rapidly.

I have a graphite mold. I want to prepare it for some quality ingots. I don't have an acetylene torch, but if
absolutely necessary I can ask someone from work to put soot on it.

Not a good idea. The mold should be preheated before use, and smoked just prior to being poured. You can use a candle to smoke the mold. You can also pour directly to a graphite mold, but smoking the surface will slow oxidation. My personal choice would be to not use graphite, but I also am in the position to make my own cast iron molds, unlike many of the readers.

Pouring seems straight forward enough...I want good looking bars like anyone else. Any nice tips will be appreciated!

It is my advice that you put this project on the shelf and start reading. In order to cast acceptable ingots, you'll have to part your silver in a silver cell. You're trying to run when you can't even crawl yet. Read the forum, and maybe investigate the idea of buying the book on silver written by Butts & Coxe (yeah, that's really their names, and it's a great book on silver).

Welcome to the forum. Be patient---you must learn much more before jumping in.

Harold

 

[Agent911]

It's unfortunate I didn't know about this forum before I ordered the furnace. I'm going to go ahead and sell it on ebay once it is delivered then opt for crucible/torch.
In hindsight, I feel good about my first post, I got all my information up until that from ehow and ebay.

I am working on my Thum cell now. I ordered a power source, hope I got this right...Hope 9 amp is enough for my setup!

I ordered this heating plate: http://www.pelletlab.com/distillation_accessories I plan to heat my mold on this.

As far as the torch goes, I'm going to start out trying MEP and propane.

The project is on the shelf until the stuff comes in the mail! That's like asking me to open my Christmas presents on December 26.