Hi All, I am based in the UK, I have worked with metal as a hobby for many years with my lathe, mil, shaper ect. But I have never done any foundry work. I have placed an order for a 10Kg devil forge furnace. I have been mulling over this for a while and in readiness I have been saving and crushing drinks cans. Having done a bit more research I gather this is not the best thing to melt? What are your thoughts? Since I have now got several hundred, I think I will still give it ago. The one concern I have is the small amount of liquid that remains in the can, is this going to be an issue or will it evaporate very quickly? Dirk
Take all those crushed cans to the scrapper and trade them for some cast aluminum if possible; cans work, but they aren't the best material to use. Between old engines, some aluminum wheels, and a bunch of camera mounts my former employer tossed out I've managed to accrue a significant cache. The biggest issue with cans is you will lose a lot of mass to dross (slag) and it's casting qualities aren't great. If you toss in material with liquid in it, even a little, there's a chance of a steam explosion so I tend to pre-heat material by placing it on top of the furnace to warm up before dropping it in the crucible. Welcome!
Welcome to the forum Dirk, Where about in the UK are you? I’m in the North East, Darlington. Good advice from dtsh, pistons and cylinder heads are much better than cans. A useful tip to remember, most, if not all, extruded sections in Europe are 6063 ally, this includes aluminium window frames. I’m surprised that with your metal working background, you didn’t have a go at making your own furnace and burner, especially if your starting with aluminium. I cobbled together my furnace, trolley, burner and tools for a pittance.
DF has made a mint off of giving these things out to the idiot youtubers. Power in advertising. Funny, he never offered me or Jeff one.
Welcome Dirk. You'll probably find your devil forge furnace to be perfectly serviceable but once you spend some time here and learn about available refractory related materials you'll see how dead-simple a furnace can be to make. We talk endlessly here about their construction and about different burner designs, etc, but that's why we're here. To each their own. Depending on the direction you go, it might not be your last furnace. I have 3. I have to echo much of the opinions about drink cans. It's like milking a mouse: lots of effort, very little return. They're what I consider dirty metal. The pull tab probably has as much useful metal as the rest of the can. Most metal containers, whether steel or aluminum, have a coating of some type inside to either protect the product from the can or to protect the can from corrosion. Then there's the outside coating. This all has to burn off and not only smokes but leaves an accumulation in the form of crud on the melt. Skimming that off takes a lot of good metal away which for the most part can't be reclaimed. None of this is insurmountable but it is awfully wasteful. Then there is the liquid issue. Water turns to steam in an instant. Entrapped water submerged in 1300f aluminum will steam flash and burp or spew molten aluminum (read explode). This can't be stated strongly enough. Anything going under needs to be completely dry including metal, tools, and ingot trays which can hold moisture under the oxidation layer. The key word is entrapped. Dry by preheating over the furnace or some other means. The guys dunking cans on YouTube in their shorts and flip flops have no idea of the hazard they're exposing themselves and others to, and their cat-like reflexes won't save them. Water to steam ratio: 1:1600 Your alloy selection is going to depend on what you plan to do with the castings. Casting alloys mentioned above are designed for good flow in the mold and shrinkage properties among other things and for the most part are excellent for casting purposes. Some of our more technically savvy members have the desire and ability to heat treat their castings for specific end uses which is outside of my experience and perhaps we'll see more discussion about that. But if you intend to use these untreated silicon aluminum castings for machining stock then be prepared for gummy material and the tool loading and welding and broken taps etc that come along with it. Extrusion alloys like 6061, 6063 and the like perform much better (for me). Window frames, ladders, lawn furniture, and yes, your cans. Perform the same operations on pieces of the different types of alloy and you will see the difference immediately. I have amassed a supply of both, carefully kept separate. Personally I would abandon the cans and find more suitable feedstock. It's all over the damned place. Milk cows, not mice! Pete
Milking a mouse.. lmao. Yeah cans suck! Same for old ladders, window frames and cheap lawn chairs. "Cast to cast"
Hi All, Thanks for all the replies, the cans are going to the tip next time I go. To answer some of the questions, I am in East Riding not far from Selby. My original plan was to build my own, but I’m having an operation on my had next week so will be out of action for a month or so, so the wife said she would buy me one for Christmas, at the moment I am just wanting to melt alli copper and the like whilst I learn what I am doing. Assuming I get into it I will want to be able to do cast iron, at that point I am thinking of building a waste oil furnace, I have a copy of the artful bodgers design so may have a go at that. I’m currently building a small hot air engine and will be starting on the 4 inch 12 spoke brass wheel this week, once up and running with the furnace it would be interesting to cast one and compare the time taken to produce it. Dirk
Surgery sucks, but it sounds like a good opportunity to spend some time on pattern making. If you have access to a 3D printer, I highly recommend learning CAD if you don't know it already. It didn't take long for me to start modelling useful parts and I suspect you'll tire of just melting things very quickly. Plenty of other pattern making options too. Get well soon!
Yes I have a 3D printer, I use autocad at work 2D floor plans ect, for the 3d printer I use Sketchup for my drawings. I am now thinking that I would like a cheap CNC router for foam and lost foam casting. I think I need to learn to walk first before I run.
