This is a very interesting iron melting furnace video. Great idea to pour iron from the furnace to the mold.
Probably an induction furnace ? Usually induction furnaces are tiltable with a builtin crucible, but many times a transport ladle is used for intermediate storage of the liquid metal, which is then poured into the mold.
It's fuel burning furnace, you get a glimpse of the burner for a couple seconds in his other video. This furnace looks like an improved version of Dechastain's tilting crucible furnace.
I was wondering the same thing so I asked him what the mold was for, he is building a 1/8 scale "bigboy" live steam locomotive and the part he was casting in the video was the trailing truck frame. Casting all the parts for that locomotive would require a large furnace if you want all the parts in a reasonable length of time.
Here's a construction video for a tilting crucible furnace, the furnace has a side exhaust port and the crucible appears to be held in place by the lid.
I always thought a BIG tilting furnace with a mostly static crucible was the bee's knees. Preheat the proper sized, coated ladle, and off to pouring. A single-person operation could have a foot pedal for tilt. Well, actually even voice command could work these days. Which would eventually lead to...."STOP TILTING ALEXXXXAAAAA" One could simply suspend a ladle on 2 carved plinths (or firebricks). I think for us home-gamers the issue is the upfront cost and wait-time till the first charge? Or the need for such capacity? For Aluminum Casting Setup: A 200 lb "budget" aluminum crucible is $400 plus s/h. https://www.lmine.com/budget-graphi..._374/200-budget-graphite-crucible-p-5733.html Elements with solid-state relays, control, and wiring around $250-300 55 gal drum cut to size with tilting mechanism and preferably on casters for storage. Maybe can be had for sub 200 if you get lucky scrapping or have a suitable gearbox laying around. I know this one is a big variable. Another big variable would be the low mass furnace bodies to keep all the heat going towards the charge and keep tilting weight down.....most likely double or triple of what Kelly spent on his build. And ladles! Almost forgot them. Annnnnd boron nitride or equivalent coating. $200-400 (these are all just guesstimates) So, MAYBE sub 2k for the entire build. Not counting a lick of time spent, which would be a small mountain. To me, this doesn't sound too awful if one was gung-ho on this. 2k is a chunk of change so assuming some coin is being made here. I guess if one needs to cast this big or can keep the metal pouring it would be for-profit, most likely. Or someone with a deep pocket for hobbies. The turn-on-then-tilt-for-metal option seems really appealing for production work, even semi-production work. Another thing to discuss. Could one get enough heat is a reasonable time either fuel or electric to get and keep the charge at whatever pouring temp? Finally, the 100 lb behemoth is cast. Now you have to heat treat and machine....
Another viable option (at least as long as we’re talking aluminum) is a direct heat or reverb furnace. If you haven’t seen it, masteryoda has a setup worth researching. I have one as well but his is more fun to look at. No crucible, large capacity, tilt pour, etc. They’re both built from horizontal tanks as opposed to vertical drums. Mine has a capacity of about 50lbs but his is much larger. One of the downsides is greater exposure of the melt to products of combustion, therefore more dross, but melt time is pretty fast and no expensive crucible. I would expect there to be a depth limit since the pool is being heated from the top only, and higher temp metals like bronze and iron would likely have different depth limitations, but it’s an effective setup. Pete
There's something wrong with the info that page, it says the crucible holds 200kg of Cu or 200lb of Al. The density of Cu is approximately 3.3 times that of Al so if it holds 200kg of Cu, it should hold 200/3.3=60.6kg=133.5 lb of Al or if it holds 200lb of Al it should hold 200*3.3=660lb=299kg of Cu. All of which makes me wonder which set of numbers, if any, are correct.
I noticed this as well. That's why I don't like that most crucible suppliers specify the capacity in kilos or lbs. That is heavily dependant on the metal. A crucible has a fixed volume, so specify (milli)liters or gallons, probably a crucible that big 16" diameter on top and 20" height can contain several gallons. Then it is about 50cm high and 30cm average inner diameter, which is about 95 liters == 25 gallons. Restrict to 80% fill = 76 liters == 20 gallons. 76 liters of Cu is 76 * 8 = 600kg Cu (liquid Cu is about 8g/cm3) and 76*2.5 = 190 kg aluminum. Another downside: liquid metal will attack the refractory more easily and when it cracks, it will leak and seep through the bottom which is not easy to repair. Unless you use premium refractory what the steel industry uses in their BOF (Basic Oxygen Furnaces), tundish or transport ladles. Best option is a tilting induction furnace: convenient, energy-efficient, far less hassle, but probably expensive.
Yeah was just a quick google search. My bad team. This had not crossed my mind, there are options to electrify this as well. I do like it as a concept. The heat-sink distance would have to be measure and sorted out. (pretty easy with a immersion thermocouple) Maybe use a magnetic field to slowly stir the charge(heat) but not break the oxide layer? What about the non-wetting pumpable refractory that some of us use to make our reusable pouring basins? (https://www.distributioninternational.com/refractories/refractories-cement/cfpuhm5) Might get spendy at that quantity but not near what a vertical melter would cost+big ole crucible. I agree entirely. 7k-15k is just out of reach financially(for me). Then there is the power needed. Have a link or know a price/quantity for these?
To power a fueled furnace is much less efficient, particularly at iron temperatures as that is the limit reachable with fuel. But indeed I can understand that it is out of reach for a hobbyist. Induction melting is also my dream (a smaller one suffices), but still too expensive. But another DIY option (for copper or aluminum, not iron) is an electric resistance (Kanthal wire) furnace. Use lots less power than fuel, but takes longer to melt, unless you have an electric supply for business use. I don't have, but just based on the steel industry, although they have to repair ladles and furnaces quite freqently.[/QUOTE]
That depends, for aluminum at least, there are refractories specifically designed for direct contact with molten metal.
For the type of casting I do, I 'd need a 50-100kw induction furnace, and that just isn't happening unless you have a commercial 3ph power. Even then, It's not as simple as you may think if you want to be able to melt any metal.......would love it but those furnaces are expensive and in all out of the hobby realm. If you want to melt a couple kilos, more practical. Nothing wrong with a tipper, be it resistive electric, fuel fired, or induction. The crucible is the cost driver. It could also be used as a dip out with smaller ladle too. Downside is you're usually committed to larger if your average melt is much less than max capacity. For ladles, just make your own and line them with moldable ceramic fiber. You will get many uses before liner replacement is needed. Best, Kelly
Guys I always feel like I come on here to some cool threads. I also realize that I have a bunch of stuff from work that we no longer use and would probably useful to someone here. That said, does anyone have any interest in a large reverb? Can probably do 1000 lbs of aluminum. I'm not sure what powers this. It's mostly kaowool and expanded metal mesh. I also have a large nose pivot tilting furnace that we used to use for melting silver. It will fit I think up to a number 120 crucible although I have a 90 in it now. It's powered by a 800K BTU burner with a honeywell controller and Type S thermocouple. I've had the furnace well into cast iron range before. It's made with 2300 F kiln brick with a 3200 F Mt. Savage monolithic refractory. It's extremely heavy and built like a tank. The outside doesn't even get hot. It's in Akron in our storage building. If anyone wants them for a reasonable price, let me know via a message and I'll send photos.