I have done a small amount of smelting (someone who has more experience, please chime in) if you have a propane forge (it does depend on the max temp of the forge, though copper you want 2000 F min), they get hot enough to smelt bronze, brass(this is dangerous to smelt without proper PPE due to the zink) and even copper(hard to cast) aluminum (have not tried it yet). here are some of the ugly things I have cast in copper, and I think the guard is brass...and I got sick from casting that one. you dont nessasarly need a crucible I just used this (see image) (but if you're going in a charcoal forge, get one made of graphite). I did not use proper modes, but you can make one from soapstone or buy them on Amazon.

Mr. Stinson,

Thanks for the tips! I do have a propane forge, I was just thinking a coal fire would get it hotter. Another reason was that I couldn't think how a crucible would fit in the forge I have now, but I see that you could make a metal container for the forge. I know about the dangers of zinc in brass and galvanized steel, but thanks anyhow! Google said to get a graphite crucible as an all around crucible. I might try coal or propane then.

In Christ,  Spencer

Spencer Phillipson,

I highly suggest just getting a budget Smelting Forge, even if its on a budget and putting it outside during use if possible. My experience with even trying to use my forge for normal material has built up a lot of unwanted material inside the forging area. And just like Kevin Stinson said; this is dangerous, both for the fumes and for idea that you are working with a controlled explosion with forging. Don't be afraid to type in "crucible" and ask some of the more senior smiths about their expertise, but take heed to every warning and specific advice they give you. I will say what I have found from trying to make guard/handle material, etc. It is always more expensive than you think it will be to make it yourself (time commitment, producing materials). 

https://a.co/d/jdBzf6X, or this one: https://a.co/d/fs744aN

Here is a video I pulled some smelting info from for making guard material.

https://www.youtube.com/watch?v=q7z3ap0nDrc

Mr. Samdahl,

Thanks for the advice! I see the advantage of having a little smelting forge kit, I might need to start budgeting that if I want to get serious at doing this sort of stuff. True, it probably is more expensive to make it yourself, but then again, so is the actual knives we're making! I plan (when I actually cast the metal) to make bronze, aluminum bronze, and some of that brass/copper alloy Mr. Jeff Royer makes. Thank you for the links: an amazon smelting kit might be the way to go. (Its actually kind of funny you sent that video, as I am a huge fan of Kyle Royer and his dad's work!) 

In Christ, Spencer

First things first. We need to define terms.

"Smelting" is the act of reducing raw ore to metal. This means taking rocks, sand, gravel, and other raw materials out of the ground and removing the impurities while retaining the desized metals.

"Casting" is the act of taking known metals, melting them in some form of crucible and pouring the molten metal into a form, also called a mould.

One does not "smelt" alloys such as bronze, nickel-silver, or shibuichi. To make these alloys, you need to combine known metals in a melting dish, crucible, or other container and mix them together. The mixing part happens upon the materials melting and needs no further action from the smith other than initially combining the different metals in the same container in set proportions.

The original question was about casting metals for making parts from, or casting the parts directly, not about smelting these metals from ore. A true smelting furnace is a rather large affair, and usually is only good for one to 4  operations, while casting known alloys can be done with minimal equipment that is reusable many times.

Casting comes in a variety of forms. There is investment casting, lost wax, sand casting, clay, or steel mould casting. I have experience doing the steel mold and sand casting. I use an oxy-acetylene torch, but depending on what metals you are casting and what quantities you are working with, you might be able to use a small butane jeweler's torch, just an acetylene torch, or a Smith Torch.

Plate mould casting is taking small pieces of known metals and combining them in a small melting dish, melting them into an alloy and casting the liquid metal into a plate mould. I make my own shibuichi this way and you can see the process and equipment here or here. Sand casting, also called delft clay casting, is a process where you create a model of the part you wish to cast, press it into a special sand, and pour molten metal into the sand mould. I usually carve my models from casting wax. I have a post on the forum somewhere showing the equipment and the process, but I cannot find it. I did find this post that shows the finished casting and the casting after clean up and assembly. The quipment required is basically the same as for plate casting, except the mould is called a frame, and that frame is filled with the sand medium. I use Petrabond clay sand. All of this equipment and the sand is available through online suppliers.

This is a video demostrating the sand casting method: https://youtu.be/u5iAOkZgzLw?si=6-q0k0hvuGS8HYi7

aCTUALLY, MY SAND CASTING SET UP IS ON PAGE 2 OF THE SEAX BUILD THREAD: My Latest Adventure – Page 2 – Work in Progress (WIP) and Tutorials – American Bladesmith Society Forum

Mr States,

Thanks for all the information you sent! My original plan was not really to cast specific/custom pieces (i.e. the spacers, guards, or pommels), but have more of an ingot that I could process later. The position that I'm coming from is more of a scrapper: taking junk copper and tin or whatever for later use. I'm thinking that a small jewelers crucible would not be big enough... Though just as I am typing this I'm thinking how I could save more material with that, so it doesn't get lost in grinding, cutting, etc. Which way would better in the long run?

In Christ, Spencer

Now that I know what your ultimate goal is, I can better help you. 
I save all of my non-ferrous scrap, and most of my High-C steel scrap to reprocess and use again. One thing to consider is that melting dishes (what I thinkyou mean by jeweler's crucbles) come in various sizes.
https://www.riogrande.com/search-page/?q=melting+dish&tab=products
The largest may suit your purposes. The same goes for ingot molds.
https://www.riogrande.com/search-page/?q=ingot+molds&tab=products

If your are looking to produce something larger, without the need to pour molten metal from one container into another, you might consider doing what I have done in the past which is to make a larger vessel to place the scrap into the forge and melt it down, remove the vessel and let it cool enough to remove the resulting ingot. I use a rectangular steel melting dish made from a piece of square tubing with one side cut off and welded ends. I line this with a piece of stainless steel foil which has been oxidized with a handheld plumber's torch. The foil keeps the molten metal from sticking to the steel vessel and oxidizing the foil keeps the ingot from sticking to the foil.

Here is the set up.

That pan was actually made from flat steel stock tack welded (MIG) around the foil liner. This is placed in the forge to melt the material. A word of warning about this process: The forge atmosphere must be a reducing one or the melt will oxidize significantly and ruin the ingot. Also, the melt tends to expel some of the alloy material first and it floats to the top of the ingot in the form of unsightly greenish sludge that must be removed prior to processing.

This is not a problem with the traditional melting dish and torch approcah as the flame used is neutral and the force of the torch expels any air out of the dish. So the melt is fairly clean and free of oxidized material. Some folks use a little charcoal in the melting dish to ensure a clean melt, but generally this is only done with precious metals and can lead to inclusions of charcoal that does not burn away.

In the forge, you keep an eye on the vessel and remove one the material has become molten.

Let it cool until it becomes solid, and tip it upside down to remove the ingot with the foil liner. This is then quenched in the slack tub and the foil peels off the ingot fairly easily.

Huh, so it could work in a forge.... I feel kind of embarrassed asking this question, but I'm fairly new to bladesmithing. What do you mean by a reducing atmosphere? The square tubing idea might work with the lowest cost of equipment. Also, where do you get stainless foil?

The forge atmosphere quality is a description of the ratio of fuel to air mix inside the forge.
An oxidizing atmosphere has more oxygen that the fuel needs to burn and will bond to the materials and form oxides. This is most notably seen as excessive scale build up on your steel as the iron bonds with the excess oxygen and forms FeO3, commonly called forge scale.
A neutral atmosphere is one where the oxygen level inside the forge is exactly or very close to, the proper amount required to fully combust all of the fuel.
A reducing atmosphere doesn't have enough oxygen to combust the fuel so the gas seeks more oxygen outside the forge body, This presents as the "Dragon's breath". This is the flames that come out the mouth of the forge as the hot fuel finds oxygen to ignite. 

This is primarily related to propane burner forges. Mind you even a slightly oxidizing atmosphere will produce some dragon's breath because the pressure inside the forge pushes the flames outward. A solid fuel forge, like coal or charcoal, will have different atmospheres in different layers of the burning pile of fuel.

Stainless steel heat treat foil is available at a variety of suppliers and is pretty spendy stuff. I think you can get it by the foot from a few knife making suppliers.Do a Google search for Heat treat wrap and you will find some.

Ok, thanks! Thanks, that makes sense, I think. This has given me a lot to think about. I guess if I'm going that route I can fiddle with the air intake on top of my forge. All this information has shown me lots of other ways than I might have thought to cast.  Thank you guys! I will give a follow up when I cast.

In Christ, Spencer

Glad I checked this as i forgot to subscribe, as I got some good info. However, i thought I wanted to put this out you can get a budget electric furnace, and that, to me, feels like the best bet over a propane furnace (or your forge, which turns out can get copper vaper to build up, which can inhibit forge welding) and even an oxyfuel torch(they are dangerous tools if you dont know how to use them) since there is really little to no chance of oxidation as they are sealed vessels. I plan on getting this model next month. Tyrell Knifeworks recommended it on YouTube for what that is worth. incase the link does not work the name is OAUTO 3KG Gold Melting Furnace TGF3000,1400W 2000F Digital Electric Melting Furnace with Graphite Crucible for Melt Scrap, Silver, Gold, Copper, Aluminum 110V Refining Casting Furnace. i will just throw his affiliate link down.

https://www.amazon.com/dp/B0814HF9DV?linkCode=ssc&tag=onamztyrellkn-20&creativeASIN=B0814HF9DV&asc_item-id=amzn1.ideas.1QL71366FJUVC&ref_=aipsflist_aipsftyrellknifeworks_asin