Mini Charcoal Furnace.
In this instructable I will explain how I made my second bigger foundry yet again mostly constructed from scrap I collected and recycled it into something more usefull.
The biggest advantage of this design is that it has a very strong body made from an empty gas cylinder and the best part is that it will last for a long time, the only thing that might have to be changed or repaired is the inside refractory.
As I wrote on my last ible my aim is to create some aluminium sand casting of differrent objects.
At this stage I piled my aluminum ingots and did a few experiments with my foundry, some successful others went wrong which I have learned from. It is really exciting to create some new aluminium object knowing what it was in its former "life" cycle.
I will also try and explain a little bit about sand casting to my knowledge.
I am no expert it is all based on my hobby experience so I hope you enjoy it.
A few Saftey words: Coming into contact with fire and boiling melted metal can be very dangerous so always work safe using proper full body protection including respirator mask against toxic fumes and dust from mixing refractory materials. Never melt in a wet area or near water, if water comes into contact with the boiling aluminium it might "blow" in your direction.
The info in this instructable is based on my experience.
I disclaim any responsibility for any resulting damage, injury, or expense.
All use by you of this website is at your own risk, work safe.
Step 1: Cutting the gas Cylinder
When using a grinder it is recommended you wear eye and ears protection.
If you dont know what you are doing take it to a professional. Mis-use of pressured gas cylinders can cause injury and even fatalities.
This not an instruction or a guide how to do it, I am sharing with you how I used a gas cylinder based on my own experience and knowledge.
Anyone who attempts this he/she will do it on their own risk
I will not be liable for any injuries in anyway.
Step 2: Inlet air hole
Step 3: Lid Hinges
Step 4: Refractory Support
Step 5: Refractory
Step 6: First time lighting the foundry
After the furance body was cured I welded handles for the furnace lid and welded 4 support washers to hold the refractory in the lid.
Step 7: Foundry Trolley
Step 8: Aluminum is everywhere
Step 9: Foundry tools, Ingots and clip.
I made some tools for my old furnace and they are still good for this one. To get rid of the dross I used a big spoon with holes as a dross skimmer. I'm starting my first melt with charcoals and in the near future I hope to make a waste oil burner.
After the charcoals where red I checked the temp with my multimiter and it showed over 1000�igh temperature.
My first successful melt were parts of an aluminum ladder, I used my muffin tray to cast the aluminum ingot.
The second time I used the pot it broke under the heat and all the molten aluminumn spilled out. Not too bad news It could have been much worse if it happend when I lifted the crucible.
Now I just have to chop the chunks of aluminum and throw them back into a new and much thicker cruicible made from metal pipe and steel plate.
This is a short clip of my furnace in full action...
Step 10: My First Aluminum Sand Casting
I started experimenting with sea sand casting which wasn't very successfull so I decided I wanted a good quality mold so I purchsed a 25KG bag of PETROBOND and I have to say it is super for aluminum casting. It was a bit expensive but I will reuse it many times.
I made a simple Flask for the sand mold made from timber.
I was delighted with my first ever aluminum Star Trek Federation Insignia that I duplicated from a custom plastic resin kit I bought a few years ago.
For more info and links to Metal / Sand casting I made a new blog and everyone is welcome to have a look: