Rio Automatic Melting Furnace w/ graphite crucible

[Absolutsecurity]

http://cgi.ebay.com/Rio-Automatic-Melting-Furnace-w-graphite-crucible_W0QQitemZ150211098384QQihZ005QQcategoryZ3360QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Ebay item #150211098384

What does anybody think of this?

Would it be good for melting gold and silver to pour in molds or is a torch better?

Glynn

 

[peter i]

I've used a similar system for melting a kilo (+) of metal at a time.

It is nice, clean, easy.

A little slower than a torch, quite a bit more expensive to purchase, but allows you to handle a relatively scary amount of molten metal with relative ease.



I killed one of those crucibles by melting partly reduced silver chloride in it. It suddently burned very well :shock:

 

[Harold_V]

For the record, I owned one of them, only sold under the trade name Handy-melt. They are strangely nice to use, but are not economical in the least. The crucibles are made from machined graphite and have a relatively short life span. You can see them degrade once they achieve a temperature above roughly 1,100° F.

There are other methods of melting that are far better, so in general I give such melting devices a thumbs down. I ended up not using the one I purchased (new) because of the expense of operation, along with its snail-like speed.

I strongly suggest you put your money into building a small crucible furnace, one that is fired on either natural gas or propane. They're easy to build, and are far more useful.

Restrict your melting to torch work unless you are melting huge volumes. It's faster and easier.

For a clear picture, when I re-refined gold, it was no less than 75 ounces, and often was more. All of it was torch melted with great success. I put my money where my mouth is, in case you'd like to know.

My melting furnace held a #8 crucible. That's large enough to comfortably melt 200 ounces of silver. You may use that as a guideline for the furnace size that would fit your needs.

Harold

 

[mwren]

I don't have this particular unit but we have a similar one and it works great.

I have cut and pasted the catalog page off of the rio website here is the text:

Item: Rio 1-Kilo Automatic Melting Furnaces

Item Number: 704072

Sub Head: Automatic furnaces

Description: Efficiently melt non-ferrous alloys for casting and ingot-pouring. Simply;lift out the crucible with the supplied tongs and easily pour the molten;metal. • Brushed steel and powder-coated steel housing for long shop life. • LED display with touch pad digital readout allows precision temperature control to 2048°F (1120°C; reads in Celsius). • Insulated lid holds heat in, keeps oxygen out for a cleaner melt. • The grooved graphite crucible is designed for easy removal from the furnace using specially designed crucible tongs (included).;Maximum capacity: 1kg;Melting capacity: gold: 821g (26.4 troy oz.) ;

Sold as each.
Specification: Melting capacity: gold: 821g (26.4 troy oz.) Dimensions: 5-3/4"W x 7-1/2"D x 13"H (146 x 191 x 330mm) Power: 110 volts, 50/60Hz, 850 watts Weight: 12.6 lbs.

If I were you I would call rio 800-545-6566 they sell these out of the catalog for about $190.00 less than the ebay site, and they normally offer a decent warranty.

 

[Absolutsecurity]

I just bought a new Lenox air acetylene torch last week so I will play around with it - I also have an older oxy acetylene MC cylinder torch but I have to get a larger acetylene tank to match my oxy tznk and new regulators - I just thought the auto furnace would be cool since I am tyring to melt 7+ pounds of silver right now - but your right Harold I may never need to melt a kilo again - BUT you never know - I am stuck on refining and just made a deal with a friend that owns a pawn shop to start doing some small refining jobs for him! LOL! :roll:

Glynn

 

[Refiner232121]

I have seen this kind of furnace being used
But the problem was to melt something like 5 kilo bar of silver it was slow
So what they did was use a hand torch along with this furnace to make the melting go faster
I am thinking about buying one of these
What do you Folks think
should I buy it or not

http://www.pandoralloys.com/pandora/portals/0/HighRes%5C02_CEIA%20F5D-F9D-F12D.jpg

 

[netseeker]

That's a very nice induction furnace although I didn't see a price list for it anywhere. The company is in Italy so it would have to be imported.

I noticed a new gas furnace at the same web site.



I'm with Harold and personally think building your own furnace is the best way to go. There are plenty of ideas on the web for good designs - along with the pros on this forum - so you could easily build your own furnace to meet your current and future needs.

I built an Aluminum melting charcoal-fired furnace a few years ago that I'm considering converting to propane although it hasn't been used in a while . It could use up a large bag of charcoal very quickly! :lol:

Robert

 

[Refiner232121]

I agree with you that building something would be the best option
But I don't know the basics of working with electric items.
It would be more logical for me to buy something ready
If you have a link I would appreciate having that
Thanks

 

[Refiner232121]

Here they show you how to make a furnace but I cant use this
I would have to have something more powerful
In the links page I see a lot of companies maybe Ill try those

http://www.backyardmetalcasting.com/index.html
http://www.backyardmetalcasting.com/links.html

 

[Refiner232121]

Hi Harold
Are there any companies you would recommend
Your opinion is highly valued and I am having a hard time to make a decision
Thanks

My melting furnace held a #8 crucible. That's large enough to comfortably melt 200 ounces of silver
small crucible furnace, one that is fired on either natural gas or propane

 

[goldsilverpro]

I also had one of those furnaces and hated it. It took forever to heat, the expensive crucibles didn't last long, you couldn't flux in them without destroying the crucible, and they are very expensive for what you get. Like Harold's, mine just sat on the shelf. I guess it depends on what you're doing. Like Harold inferred, you get much more flexibility and value with a torch and/or a gas fired crucible furnace.

 

[Refiner232121]

Hi Gsp and Harold
Thanks for you highly valued opinion
I am in the process of making my purchasing decision and I am having a real difficult time.
If there are names of good companies I think it would be good to post it here
Thanks

 

[goldsilverpro]

Although there are many gas crucible furnaces available commercially, many refiners, even large ones, make their own. Home-made ones are professional and work just as well. They are much cheaper and are fairly easy to construct, once you understand the concepts. There are many plans available free on the internet. Were I you, I would make a #16 furnace. That will hold a #16 crucible, which is about the largest that one man can handle alone, safely, with a pair of charging tongs. You can also use any smaller crucible in that same furnace, even a small clay assay crucible. A #16 crucible is about 7" dia. x 10" tall. A #16 furnace will be about 17" dia x 20" tall, more or less, assuming 3" walls.

 

[Harold_V]

What Chris said!
The only place I might suggest a difference is in furnace size. I used a #8 crucible when I was in business. They served my needs perfectly, even for melting silver.

The reason I make mention is the cost of buying crucibles. Unless you feel you'll use the #16, furnace size can be down-sized a little, so construction cost would be reduced, as would operating expense. You also would not be tempted to use a crucible larger than what would be required, taking life out of a very expensive crucible when it isn't necessary. Because of fluxing, you will come to understand that crucible life is relatively short in the refinery. It's a necessary evil, so it can't be avoided. On the positive side, as crucibles grow in capacity, so, too, does the wall thickness. There is a slight offset in that regard, but if you're using a large crucible at less than acceptable capacity, it's still a mistake. So this makes sense, failure of crucibles that are used with flux occurs at the top of the melt---the junction of the charge and air. The crucible is eroded there, and quickly springs a leak. I used to get about 8 heats from a #8 crucible, which would melt a lot of silver.

Tooling up for various sizes isn't exactly a good idea, either, because of the cost of the handling tools. Crucibles must have proper fitting handling tools, otherwise you risk breaking the crucible in use. The consequences of losing a molten charge of metal should not be ignored. It can lead to a burned down facility, or even death.

While small crucibles can be successfully handled by gripping the rim, larger crucibles can't be. They must be removed from the furnace, then transferred to a pouring shank. Two tools to handle the crucible, for each size you may choose to run.

I built a single tool, a pistol grip device with machined jaws (to match the contour of the bilge crucible I used). That tool permitted removing and pouring with the same handling device. I know, from experience, that a #8 is likely the top end of sizes that would permit such a tool. I could pour 200 ounce anodes (of silver), but it required my full attention, and a careful grip. You can see the tool in the picture posted here. You may also get a few ideas of how to build a furnace. Not a big job, really, and a sense of satisfaction when you use it, knowing it exists because of your efforts.

Harold

 

[Refiner232121]

Hi Gsp
Thanks for your help

Hi Harold
I also thank you for your help
I don't know about others in this forum but I personally like those pictures of your old shop.
This is a picture I had not seen before
They didn't say pictures are worth a thousand words.
Maybe you posted pictures few years ago and since the format change we cant see some of those pictures
It would be nice if you could post a collection of those pictures of your old shop.
Thanks again

 

[Refiner232121]

I thought about contacting the people on this site for purchasing a kit but there is no e-mail address.
Is it there and I don't see the e-mail

http://www.backyardmetalcasting.com/oilburners10.html

 

[jimdoc]

Here is the page for his kit;

http://www.backyardmetalcasting.com/hmkit.html

I have it, but still have not finished it.
Jim

 

[qst42know]

At the bottom of the homepage, his name in blue is an email link.

 

[goldsilverpro]

Harold,

I also used the #8s for pouring pure silver 10 oz and 100 oz bars in book molds. I used a #16 (usually) or #20 crucibles for pouring silver cell bars. It took 27 bars, about 3" x 9" x 3/8" thick to fill the cell. This would take too long with a #8 crucible. I usually used #4s or #6s for gold.

I probably shouldn't admit this, because it is against all foundry safety rules, but I didn't even own tongs that gripped the crucible on both sides. I always used charging tongs (30" ones, I think) to handle the crucibles, including pouring. The charging tongs are normally used to charge (add) ingots of metal to the crucible - they grip very well and have a slight spring action. For the #16s or #20s, I lifted the crucible out and set it on a large upside down cast iron mold. I then gripped the back of the crucible with the tongs, spread my legs out, and poured the metal towards me into a mold. I learned this from a mentor and I got quite good at it. I don't ever remember getting burned or losing any metal on the floor. See the charging tongs in the bottom photo.
http://www.budgetcastingsupply.com/Tongs-Shanks.php

I don't recommend that anyone else do this. Use the recommended tongs that grip both sides of the crucible - see the other photos in the link. Do as I say and not as I do.

The only time I had problems was with a weakened crucible. If the crucible gets damp or if large amounts of niter (or soda ash, when converting AgCl to Ag metal) is used, the crucible can get weak. I melted in this furnace daily and, in 4 or 5 years, this happened about 4 or 5 times. When I gripped the crucible, the tongs tore a chunk out of the top of the crucible. It was then a chore to get the melt out of the furnace and poured, safely, before it froze in the crucible. This, of course, would have been eliminated if I had used tongs that gripped both sides of the crucible. However, I found those type tongs more awkward and slower than the charging tongs. Also, the charging tongs fit every size crucible. Using this method, I never once had any problems using the charging tongs with the smaller crucibles (#8s or below). It was always the #16s or #20s. They were heavier and I fluxed more in them.

 

[4metals]

Harold, I see you had cone molds in your bag of tricks, great tool for refining, one which I haven't seen discussed much on this forum. Honest refiners use them for collecting every last drop in front of the customer, dishonest ones like it when the beads don't end up in the pool.