I've toyed for some time with getting a small casting set up at home and am attracted to the neatness of a Flamefast furance. The initial intention is really to focus on Aluminium. Does anyone have experience of Flamefast furnaces? (I do but that was
25 years ago!). It would have to run on propane rather than natural gas. Also does anybody know of good sources for this sort of ex-school kit.
They crop up on ebay now and then, and never seem to fetch very much. I got mine from the local ad-mag, but ebay is probably a better bet. There are lots of web sites telling you how to make them as well, after all it's just a metal can with refactory material on the inside & a burner to heat it up (you can even make the burner as well).
Kev>I've toyed for some time with getting a small casting set up at home
I have a flamefast propane furnace of the 'lift out' variety. The more modern ones in schools are tilt types. Mine uses a vast air blower and is ok for bronze and aluminium, but although I have melted iron, it takes absolutely ages to get to heat and even then barely is it hot enough. You are welcome to crawl over, in, and around it !
Helped a friend operate his cupola furnace last Sunday and poured some very good iron castings - now there is a furnace that has NO problem melting iron !!!
I have a couple of propane burners that I made up myself using Amal gas injectors, with the intention of making a ceramic kiln. Making a simple burner is fairly trivial - basically all you need is a mixing tube and a flame retention nozzle. The mixing tube in this case was an
18" length of 2" diam "black" pipe threaded to screw onto the end of the Amal injector. The retention nozzle, made from standard pipe fittings, simply constricted the mixing tube to 1/2 its diam and then immediately flared out to twice the mixing tube dial for a couple of inches. The completed burners work a treat - generate a controllable gas flame around 2-3' long at full blast. Scared the hell out of the neighbourhood moggies...
I don't know if Amal are still in business (must be ~15 years ago now), but they were very helpful over the phone - basically designed the burners for me given a description of what I was trying to do, required heat output, etc.
I built Ron Gingery's foundry, lined it with Kaowool 1/8" thick and added Rupert Wenig's mini-mongo burner using propane. I can melt over a litre of aluminium in about 15 mins or less when the foundry is warmed through.
Or you can go for one of these:
designed by my friend Rupert Wenig in Alberta, Canada. All can be built without buying anything outside of a hardware store. Some other references are:
Don't try any of this at home - or if you do, don't blame me if it kills you, sets your house on fire or causes injuries, burns, smells, or marital upsets. For the knowledgeable only, at their own risk.
For small scale melting of Aluminium I use a home-made leectric furnace.
An electric cooker grill element (scrap) is bent to zigzag shape around a stainless steel sugar caddy crucible (£1.99 from Wilkinsons) with a cooker control and knob (scrap), the whole surrounded by home-made ceramic.
Ceramic is made from 4 parts garden perlite (£1.99 for 2 x 5 litre bags, special offer from Wilkinsons - might still be on) and 1 part binder (2 tubs water diluted fire cement @ £1.79, hardware store, plus a tub of Portland cement with a bit of sand, from my handy stuff cupboard).
Assemble element and sugar caddy, cover with thin bubble wrap. Fit into outer shell made from cardboard lined with polythene and covered outside with packing tape, and add refractory. Pound it down a bit, but not too much
- I used the handle of a wooden spoon. With a bit of forethought you can make places for legs, control housing, and a neato lid too - wish I had.
When set remove card and wrap a few turns of wire around the outside. Remove crucible and as much bubble wrap as practical. Leave to dry. Leave some more. Bake for a few hours in a medium oven before adding controller and first gentle firing - bubble wrap stinks!
Cost about a tenner, though I also bought a £8 pipe bender for bending the element - hard work - but didn't use it. I connected up the element and let it get red hot a few times after I'd bent it, then bent it a bit more.
Takes about ten minutes to melt a pound or two of Ali from cold. Uses about
5 pence worth of lekky afaict. Outside just barely gets hot.
This is what I like to hear, hand on experience. With the prices of casting going through the roof, wish I had space for one. Only done aluminium myself using crucible, but what magic the whole process.
What size was the cupola and what did you use for scrap? GeoffH
It was a 10" bore cupola of the Steve Chastain design, and the scrap was mainly worn out ventilated brake disks.
Problem with a cupola is that if you only want a few castings it still takes several hours preparation and slow burning before you can put on the blast and pour. Once at temperature you can tap every 10 mins or so so very good for a long run.
. . . now what I REALLY would like is a small(ish) electric induction furnace. Pop in the charge, throw the switch, 10 mins later pour your casting . . . mmmm
Got his book, but can only drool at the prospect. But do have design for a very small one, but writeup does say something about not getting enough carbon in the melt or suchlike.
I only need a couple of casting so a big'un would be overkill.
Didn't someone in Aus or NZ do one? There was mention in either ME or MEW. Tried searching the net, but nothing worthwhile. Maybe JS could come up with something suitable. How about it John. Something to tax the old cells? GeoffH Norfolk - UK not VA
4 inches diameter, 5 1/2 inches high. It holds a 1 kg bag of sugar.
I am going to build another furnace next week, once I get the last few bits. Will keep you informed. The refractory I used for the last one, perlite and fire cement, is a bit too fragile for my liking, although it does work and it insulates well - but the inside got too hot, and the outside hasn't gotten hot enough to set it properly, so I want to try something other than fire cement.
I'm also planning a small 1550 C furnace, perhaps using quartz-halogen bulbs, the straight type used in floodlights, but it isn't very far advanced yet.