Casting Aluminum?

Discussion in 'Shop Talk' started by Ken Scharabok, Nov 13, 2004.

  1. Ken Scharabok

    Ken Scharabok In Remembrance

    Messages:
    6,844
    Joined:
    May 11, 2002
    I have been trying to get a price quote from a foundry for several months on casting some hardy cone mandrels. Finally told me my order (100) was too small for them to bother with.

    While these would be better if made out of mild or ductile steel, one made out of aluminum would still be useable for many hot bending applications.

    I have access to a scrap yard which will sell scrap aluminum plate at $1.00 per pound. I have a propane forge which I am sure will come up to sufficient melting temperature. I can make a melting pot, if you will, out of 1/2" x 3" mild steel.

    My thought is to make a mold from a mandrel I have now using refractory cement. It would be a two part mold to cast one mandrel at a time. By the time it cooled a bit and I took it out of the mold I should have more molten aluminum ready to pour.

    Can anyone recommend a really good basic how-to book on the above. Needs to be something really easy to understand.

    I would see my market at one to two sales a month so I am not talking much of a production basis for this.

    A friend mentioned he has once seen brass mixed in with aluminum. Said it produced almost a gold color material. Anyone familiar with this?

    What if I were to mix mild steel bandsaw filings or drill shavings with the molten aluminum. What might happen?

    Please keep replies non-technical.

    Ken Scharabok
     
  2. Blu3duk

    Blu3duk Well-Known Member

    Messages:
    1,859
    Joined:
    Jun 2, 2002
    Location:
    central idaho republic
    get a few books from Lindsays Books on the subject, My dad in law melts aluminimum in his foundary he built out of an old steel garbage can and lined with fireclay and uses a vaccum cleaner for a blower.... AL melts at about 1400 degrees, He purs mostly sand cast molds but he also only makes one of any one item so it doesnt matter about repetive molding.

    Lindsays has MANY books covering the very subject you are asking written for the non technical person as well as the professional.

    William
     

  3. Ken Scharabok

    Ken Scharabok In Remembrance

    Messages:
    6,844
    Joined:
    May 11, 2002
    Thank you. I was able to melt some scrap aluminum in my propane forge and poured it into a sardine can as a ingot mold. It is way too soft for what I have in mind, but did prove to me I don't necessarily have to do green sand casting of simple forms. Will try to find some scrap brass next and try it.
     
  4. mikell

    mikell Well-Known Member

    Messages:
    932
    Joined:
    Nov 7, 2002
    Location:
    South West MI
  5. Old Jack

    Old Jack Truth Seeker

    Messages:
    232
    Joined:
    May 21, 2004
    Location:
    West Virginia
  6. Ken Scharabok

    Ken Scharabok In Remembrance

    Messages:
    6,844
    Joined:
    May 11, 2002
    What I have learned so far.

    Yes, refractory cement can be used to make pouring molds. However, it is not very forgiving on quick temperature changes (e.g., pouring molten brass into a cold form). However, I do have the option of 'pre-heating' the mold as the brass melts as the mold size I am envisoning is only about 4" x 4" x 12". As the crucible bakes in the back of the propane forge, I can have the mold at the front with the air blast aimed so it heats up the mold form. Am still looking at casting up only one mandrel at a time in a two-part form.
     
  7. Unregister

    Unregister Guest

    Ken,

    Suggest the following:
    http://www.backyardmetalcasting.com/

    Also, as someone mentioned:
    http://www.lindsaybks.com

    Note: If you are going to cast aluminum, you might want to find some used aluminum pistons. These will produce stonger castings than types of aluminum used in things such as soda cans(which won't be very strong).
     
  8. Ken Scharabok

    Ken Scharabok In Remembrance

    Messages:
    6,844
    Joined:
    May 11, 2002
    I believe the piston aluminum is FONTAL. It is a specially treated and hardened type of aluminum. Even welding it will affect its durability. Remelting it would pretty well turn it into ordinary aluminum. You can buy scrap FONTAL on eBay for machining.

    Am off to the scrap yard today to see what they have in the way of scrap brass.

    Ken Scharabok
     
  9. Ken Scharabok

    Ken Scharabok In Remembrance

    Messages:
    6,844
    Joined:
    May 11, 2002
    Scrapyard also had bronze shavings, so will try both brass and bronze.

    Ken Scharabok
     
  10. Ken Scharabok

    Ken Scharabok In Remembrance

    Messages:
    6,844
    Joined:
    May 11, 2002
    Update: I went into Nashville yesterday to a place which specializes in refractory-related products or services. Don't have sheet with me but picked up a bagged product which is mixed with a hardening agent. One bag and one gallon of hardener will make up about a cubic foot of molding material. Will try half and bag and half a gallon as I don't need that much at once. Problem will be in curing it. Recommendation was to start at 300 degress and increase it 50 degrees per hour for 24 hours. Guy thought I could use my oven for several hours first, and then put the form in my propane forge set at low heat, gradually increasing heat. May not work, but will be a fun experiment.

    Ken Scharabok
     
  11. Darren in TN

    Darren in TN Guest

    Ken,

    Also check out dansworkshop.com. He has some recommendations about casting aluminum at home and I believe recommends a book or two. Best of luck on your project.