I typically am melting small 1-2 ounce melts of scrap silver and gold at a time. My Meco does a good job of melting silver and gold. I have started to work a bit in brass and am generating a fair amount of scrap. I also find myself needing shapes that I can only get from pouring odd shaped brass ingots. My meco on propane and an O2 concentrator doesn’t produce enough heat to melt brass in an open crucible. I don’t want to go back to regulated propane and O2 cylinders. I bought and tried a Devil Forge propane melting furnace and it will definitely melt brass, but it is very difficult to keep the brass melted in small amounts while I transition to the ingot mold. I sold the furnace yesterday to a guy who has no idea what he will use it for, but wants it. I thought that my good old trust prestolite acetylene torch would do the trick, so I fired it up and it didn’t, even with making a firebrick tent. So my question is, will an electric melting furnace work for me in the small amounts of silver and gold that I cast and will it be able to melt brass? I am looking for general answers to these questions and recommendations for what electric furnace to buy. Any help is appreciated…Rob
Rob,
I’ve used the Kerr version of this electric furnace for many years. Sadly, as it says in this description that Kerr discontinued their jewelry product line in 2017. This model is supposedly the same as the Kerr version.
I know there are other electromelt furnaces out there, but I’ve never used them.
This will definitely melt gold and silver and will melt brass, but remember that brass is a mixture of copper, tin and zinc. As you have probably learned (for lack of a better way of describing it), brass is a dirty metal to melt. The zinc burns off, creates toxic zinc fumes and will coat the inside of your electric melting furnace with burnt zinc dust. You’ll have to clean out the melting furnace after every time that you melt brass otherwise it will contaminate your silver and gold.
I’ve melted lots of brass throughout my lifetime and these days I strive to never melt it. (I use silicon bronze for casting.)
Hope that helps!!
Jeff
Thanks, I do know about the zinc problem, but hadn’t thought about it screwing up the furnace. Maybe I better look for a hotter torch…Rob
It does seem to me that, for the furnaces with a removable crucible, you would only have to clean the inside of the lid. A question that I don’t know the answer to is, if I am only melting 2 ounces of silver, will it stay melted in the crucible long enough to pour…Rob
Hi,
what about bronze…copper tin…does it have same dirty issues…?…need extra hot torch, etc…?
easy to solder?
Rob, I use the kind of furnace with a removable cylindrical crucible.
Yes you can pour small quantities with it as long as you do it quickly. The last bit out does tend to ‘solidify’ into a kind of slush if the pour is a bit too slow.
Recently I read somewhere, here? of using a torch while pouring the furnace crucible. I haven’t tried that, haven’t needed to, but can see that it would work, make it less important to rush a pour.
I dedicate one crucible per metal type. Argentium, standard sterling silver, Rio’s ancient bronze. Works out well.
The crucibles I’ve bought have a too-small spout in my opinion. Using a round rasp I’ve filed it deeper into the crucible so the melt gets lined up and narrowed down sooner.
Some time ago an Orchid member mentioned weighing new graphite crucibles and checking their weight after each use to help determine when they may be getting too thin.
Neil A
Yes, you’re correct. The molten brass won’t destroy the electric melting furnace. You’ll just have to clean it each time and keep a separate crucible for each metal.
We just had a thread about pouring ingots. One of the things mentioned is being fast & efficient. You’ll just need to practice a bit. I’d recommend heating the metal a bit hotter than usual. 1800F -1830F. Once you get your technique down, you shouldn’t have any problems pouring 2 oz of silver.
Like Neil A says, some folks like to keep a torch on the metal as you pour to eliminate oxidation between the taking the crucible out of the melting furnace and pouring into the ingot mold. This torch doesn’t have to be a high temp casting torch. The metal is already molten. You’re just burning away the oxygen. I think you said that you have an EZ/Orca torch. That should work fine.
I have used those cylindrical furnaces before and not only do they ALWAYS fail, they are difficult to service and require the use of expensive rimmed+grooved graphite crucibles.
I have since started using front-door electric kilns with great success. I require my kilns to go up to 2300°F (1200°C) and these are the only affordable options that aren’t induction. I’ve had the best success with vintage kilns as, in my experience, they were made with kanthal wire which can take the heat required for brass and bronze. The newer, cheap nichrome elements won’t last.
They allow you to use any type of crucible you want. For precious I go with a ceramic sleeve and graphite crucible+lid. For brass and bronze I use a clay-graphite cup crucible. My bronze melting kiln is a Paragon from the 70s. The only downside is they can take a while to heat up. I have melted 2lb of bronze before without problems.
I’ll through in my 2¢…
I purchased this furnace:
The furnace heats up very fast. The only issue is the company is not a company i would do business with again. I’ve had to rebuild it a few times due to less than stellar quality control and they overcharge heavily for replacement parts.
It is a simple design though if someone wanted to make one themselves. (And had a lot of time to burn)
Thanks for the caution…Rob
I had no idea that these furnaces are unreliable? The one we have has been around for over 30 years with no problems at all. Maybe they were better built in the old days?
Jeff
The Tabletop company has only been around for a few years. Looks like they got you with their name. He’s not referring to furnaces that sit on a desk, but the brand name “Tabletop”.
Newer kilns either use Nichrome elements, which burn out at high temperatures and firing intervals, or go too thin on the gauge. It also becomes brittle after firing and can snap and short out. Better kilns will use thick Kanthal elements which last a very long time and are easy to service. Vintage kilns were overengineered.
Nowadays kanthal kilns are catageorized as “high temperature” furnaces and carry a steep premium, for whatever reason. Kanthal is only a bit more expensive.
They have kanthal wire, it’s just some poor engineering choices. I bought a PID and a couple parts and I’m back in business.
But I agree that if you have the money to patronize paragon or a similar brand.
I am familiar with Kanthal. I will use “high temperature” as a descriptor in my search for a furnace. Thanks…Rob
Since my last post, I have done a lot of research (wasted a lot of time on the internet), regarding small electric melting furnaces. Other than variations in size, capacity, quality and price, the main variable that I have yet to resolve is furnaces where you remove the crucible with tongs from the furnace and pour the melted metal vs pouring melted metal out of the crucible by tipping the entire furnace as in the old Kerr design. I would be interested in comments regarding both designs. Thanks…Rob
Rob,
Have you reached out to any jewelry tool companies for info? Most jewelry tool companies have tech support departments that are run by professional jewelers and metalsmith. For the most part those folks are very knowledgeable. They also know the history of various tools and technology.
Kerr really shook up the industry when they quit making jewelry supplies and equipment. Now there are new and different companies filling the void. I think that makes things like what electro melt furnace to purchase be extra confusing.
Jeff
I have talked to the techs at several suppliers and manufacturers. One was very helpful, the others not so much. In their defense, I tend to over think things. I was a physics teacher…Rob
The only electric furnace that I’ve ever used is an older Kerr removable crucible version. It took me a little bit of practice to “dance” with it because if you’re vacuum casting or casting an ingot there are number of components to coordinate, pretty much all at once.
For me, making a comprehensive plan of every step and then going through the motions, practicing with all of the parts while they were totally cold was very helpful. My goal was to create intuitive muscle memory, so when everything was hot & ready my hands knew what to to do without thinking too much. Once I did all of that it was pretty easy to make it work.
Besides all that, the best advice that I could give is to make sure that you have tongs that are easy to work and fit your crucible securely.
I’ve mentioned this before, but most jewelry tool companies have a 30 return policy, if you want to buy an electro melt furnace and try it. From your description it sounds like you’ve done a pile of research. Is there an easy way that you can get your hands on an electro melt furnace to try? A jewelry school, jewelry tool company, friends with jewelry stores within driving distance? Like I said, for me it took a bit of time to practice.
Let’s see what others say.
Good luck figuring it out Rob!
Jeff
Thanks! It is an all but done decision now…Rob
Excellent! Let us know what you decided after you get it and how it works out!