Thanks Thanks:  0
Needs Pictures Needs Pictures:  0
Picture(s) thanks Picture(s) thanks:  0
Results 1 to 11 of 11
  1. #1
    Join Date
    Mar 2008
    Location
    nowra
    Posts
    1,598

    Default how can you melt aluminum without a furnace

    I was wondering if there is a way to melt aluminium with out a furncance. as i have a pile of extrusion i want to cast into ingots. also is i possible to melt aluminium gas cylinders as i have an g size aluminium helium cylinder that i have no use for.
    BETTER TO HAVE TOOLS YOU DON'T NEED THAN TO NEED TOOLS YOU DON'T HAVE

    Andre

  2. #2
    Join Date
    Jun 2011
    Location
    Roxby Downs Sth Aust
    Age
    47
    Posts
    205

    Default

    easy, build a fire in the weber, aluminiums melting point is around 660C and the oxidised layer is slightly higher but, you can acheive these temps in the bbq no worries, all you need is wood, not heat beads and something to fan it with, also will need a crucible of some description. you can use a stainless pot if you got a disused one laying around but your going to lose the handle so get tongs.when your melting dont stir it around, just let it melt and make a spoon with an extra long handle to scrape the dross off the top which will reveal the molten aluminium. take my advice and don't pour it into pipe or rhs, your going to have a hell of a time removing it, will have to slice it in half to get it out. pour the molten metal in, pipe/rhs heats up and expands, when it cools its tighter then you know what.make the mould of two halves either hinged on one side, wired together or bolted together.

  3. #3
    Join Date
    Aug 2010
    Location
    Near Bendigo, Victoria, AUS
    Age
    72
    Posts
    3,102

    Default

    Any container that can be heated to around 700 deg C allows you to melt it.
    However you need good insulation to get things that hot without heating the rest of the town. That kind of insulated container is called a furnace.
    Google "melting aluminium" and you'll find all kinds of solutions.
    You also need a burner - gas, coke or oil. ELectricity is feasible but more complicated.
    You should PM RayG for assistance!

    Please don;t melt the gas cyclinder. The day after you do, you will find a use for the heavy wall aluminium pipe between the ends! Just cut them off and melt them if you really must - and put the pipe section in your metals stock.
    Joe

  4. #4
    Join Date
    Jun 2011
    Location
    Roxby Downs Sth Aust
    Age
    47
    Posts
    205

    Default

    However you need good insulation to get things that hot without heating the rest of the town. That kind of insulated container is called a furnace.
    Google "melting aluminium" and you'll find all kinds of solutions.
    You also need a burner - gas, coke or oil. ELectricity is feasible but more complicated.


    don't worry, char coal will burn at a higher temp then coke, given enough air is pumped into it, only problem is that it's not as efficient as coke. as for heating up the whole town i dont think so. if your sceptical next time you have a bbq, throw in an off cut (when you finnished cooking) and dont even give it any air, it will melt, ive melted copper at home in my coke forge and poured ingots, no problem and as i recall its melting point is around 1200C or more.

  5. #5
    Join Date
    Jun 2008
    Location
    Victoria, Australia
    Age
    74
    Posts
    5,080

    Default

    The simplest I can think of, is dig a trench in the ground, fill it with charcoal, get a hair dryer and some steel pipe, maybe 2-3 ft long that you can fit the hair dryer to, use duct tape to hold the hair dryer in place.

    Get the charcoal burning with newspaper and a bit of air from the blower. Put the aluminium into a steel cooking pot. Adjust the hairdryer speed to give a nice hot bed of charcoal. Before too long (maybe 10 minutes or less) you will have molten aluminium.

    Ok that's the easy part... to cast a particular shape, you need a pattern and some technique. The easiest casting technique for backyard casting is called lost foam, I won't go into detail here, you can google for it. But basically you make a pattern out of polystyrene foam and bury the patten in a bucket of sand, then you pour the molten aluminium into the pattern, the polystyrene foam just evaporates and the aluminium fills the space..

    Now for a safety warning, casting aluminium is potentially more dangerous than casting bronze or copper. The reason for the danger is a bit subtle, aluminium is very reactive, it reacts with air very readily to form aluminium oxide, every piece of aluminium you have ever seen is coated with a thin layer of oxide, when you have molten aluminium, it can't form that protective oxide layer, so it reacts with any oxygen that it can find, if molten aluminium comes in contact with water it's so reactive it will strip the oxygen out out the water (remember water is H2O) leaving hydrogen gas, which in turn will burn ( more likely explode) when it bubbles out of the molten aluminium and combines with the oxygen in the air. (I'ts called a hydrogen explosion)

    It's a problem that is peculiar to the chemistry of aluminium, particularly where scrap aluminium is involved that might include cans that have the dregs of some drink or water trapped inside... some of the biggest foundry explosions are molten aluminium... be careful

    So, make absolutely sure you have NO water where molten aluminium is around.

    Don't let me scare you off from doing it, just use common sense precautions.

    Regards
    Ray

  6. #6
    Join Date
    Jun 2011
    Location
    Roxby Downs Sth Aust
    Age
    47
    Posts
    205

    Default

    your not wrong about it exploding Ray, i had copper pop once when i was pouring it, the boat i had just made to pour it into wasn't wet but slightly darker in colour from cooling it with water 10 minutes earlies, even though there was no visible water present the dampness was enough to make it pop and spray balls of molten copper around my shed.

  7. #7
    Join Date
    Nov 2006
    Location
    Rockhampton
    Age
    62
    Posts
    6

    Default

    Quote Originally Posted by jhovel View Post
    Any container that can be heated to around 700 deg C allows you to melt it.
    However you need good insulation to get things that hot without heating the rest of the town. That kind of insulated container is called a furnace.
    Google "melting aluminium" and you'll find all kinds of solutions.
    You also need a burner - gas, coke or oil. ELectricity is feasible but more complicated.
    You should PM RayG for assistance!

    Please don;t melt the gas cyclinder. The day after you do, you will find a use for the heavy wall aluminium pipe between the ends! Just cut them off and melt them if you really must - and put the pipe section in your metals stock.
    Joe
    Yes, somebody will give you a compressor unit which will go nicely with that motor you have under the bench and all I need now is a reciever, Ahhhh I melted that

    Pete

  8. #8
    Join Date
    Mar 2008
    Location
    nowra
    Posts
    1,598

    Default

    i was planning on using it as an air receiver but i have a steel oxygen clinders for that job.
    BETTER TO HAVE TOOLS YOU DON'T NEED THAN TO NEED TOOLS YOU DON'T HAVE

    Andre

  9. #9
    Join Date
    Jul 2006
    Location
    Athelstone, SA 5076
    Posts
    4,255

    Default

    Quote Originally Posted by RayG View Post

    Now for a safety warning, casting aluminium is potentially more dangerous than casting bronze or copper. The reason for the danger is a bit subtle, aluminium is very reactive, it reacts with air very readily to form aluminium oxide, every piece of aluminium you have ever seen is coated with a thin layer of oxide, when you have molten aluminium, it can't form that protective oxide layer, so it reacts with any oxygen that it can find, if molten aluminium comes in contact with water it's so reactive it will strip the oxygen out out the water (remember water is H2O) leaving hydrogen gas, which in turn will burn ( more likely explode) when it bubbles out of the molten aluminium and combines with the oxygen in the air. (I'ts called a hydrogen explosion)
    I did a lot of work at Castalloy, now owned by Harley Davidson over 30yrs or so, and the video we had to watch for OHWS induction really showed what happend in a sleeper walled bunker ..it was about 1.5 square and about 2 meters high fully enclosed on three sides and top and then dirt ...sort of like being cut into the side of a hill

    certainly opened my eyes as to what a cup full of molten alloy could do when it came into contact with moisture...the little bunker was destroyed

  10. #10
    Join Date
    Jun 2005
    Location
    Helensburgh
    Posts
    618

    Default

    It's easy to melt aluminium, try and weld it with oxy acetylene. I guarantee you will melt a heap of it while you are learning!!
    CHRIS

  11. #11
    Ueee's Avatar
    Ueee is offline Blacksmith, Cabinetmaker, Machinist, Messmaker
    Join Date
    Dec 2011
    Location
    Canberra
    Age
    39
    Posts
    4,515

    Default

    Hi Andre,
    If you have a piece of nice heavy pipe, say 250 or 300mm dia, same sort of length, build a charcoal fire as Ray said and plonk the pipe on its end on top. The bottom edges of the pipe may suffer but you will contain the heat. Just take some more pipe or heavy RHS and weld a cap on the bottom and some lifting rings on the top and side and you have a crucible. Stainless pots are ok, but as they are so thin you will eventually burn a hole through them and lose your ally into the fire.
    Make yourself a "sandpit" and put indentaions in it the size of your wanted ingots and pour into the sand.....just don't use a plastic bucket to hold the sand.....guess how i know that?
    1915 17"x50" LeBlond heavy duty Lathe, 24" Queen city shaper, 1970's G Vernier FV.3.TO Universal Mill, 1958 Blohm HFS 6 surface grinder, 1942 Rivett 715 Lathe, 14"x40" Antrac Lathe, Startrite H225 Bandsaw, 1949 Hercus Camelback Drill press, 1947 Holbrook C10 Lathe.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •