RepackboxReloading EverythingRotoMetals2MidSouth Shooters Supply
Inline FabricationLoad DataWidenersTitan Reloading
Lee Precision
Page 1 of 2 12 LastLast
Results 1 to 20 of 39

Thread: Smelting alum brass copper ?

  1. #1
    In Remembrance - Super Moderator & Official Cast Boolits Sketch Artist

    RP's Avatar
    Join Date
    Mar 2008
    Location
    Nahunta NC
    Posts
    3,410

    Smelting alum brass copper ?

    I picked up a metal lathe awhile back and been learning to use if for a few months now making simple items I needed for the shop like top punch for my sizer. And I went to price some alum billet 45 bucks for a 2 inch dia 24 inch long to costly to practice on for me. Heck I am cheap main reason I started reloading to save money still working on that plan.
    So I got to looking into making my own with scrap so I built me a oil fired burner with a blower and all the items needed to melt it down.
    So what I have learned so far all scrap is not the same my first melt was everything from drink cans gutters and what ever piece of alum I had laying around. What I got was alum that was worthless to turn it tore instead of cut and ripped out chunks.
    My next try I added some brass to the mix what I got would turn and was fair to work with or practice I cast this batch in green sand I made up my self. Big problem I found was voids right down to the middle not some that would turn out. I degassed and fluxed and my temp was high enough as far as I could tell.
    My third try I used some tanks that were tested at 3000 psi nothing added my thinking was it had to be a better grade of metal. Well I got my green sand ready to cast and a few pieces of pipe with no weld seam to fill. I poured several different sizes so I would have a mix to pick from for my stock. All looked well until I chucked up one of the green sand pour to clean it up and see what I had to work with. It cut will and I got nice chips with a smooth finish but voids not as many but still to many to use it for anything useful. I was getting kind of down about the entire effort and decided to check out one I pour in the pipe. I had two voids and it turned very well cutting clean and smooth only issue I found was I would get a mirror finish for a section then dull then mirror again. I think this was caused by a chip rubbing work piece but as of now I am just trying to get workable material.
    So I think the voids in the green sand casting was moisture in the sand causing the void oh my homemade green sand is well sand cat litter and water until it holds it shape not oil or store bought casting sand. The voids in the pipe one I think was cutting oil or chip left in the pipe since they were right at the out side of the material.

    I have seen U Tube where people have cast different item with sand and turn it on a lath to make a pulley or gear and that turn out fine from what I can see so anyone have any input on what may be causing my voids with that method. And I plan of casting using pipe since I got good results with that so far just to build up some stock.

    So if anyone else here has been down this road any advise would be great not much to find on the net as to fixing problems just people say look what I did.
    Reloading to save money I am sure the saving is going to start soon

  2. #2
    Banned
    Join Date
    Aug 2017
    Posts
    340
    how well are you venting your molds? you must vent the **** out of the molds to let the steam and air out or you will end up with a lot of holes in the poured metal.

  3. #3
    In Remembrance - Super Moderator & Official Cast Boolits Sketch Artist

    RP's Avatar
    Join Date
    Mar 2008
    Location
    Nahunta NC
    Posts
    3,410
    The molds are really just sand packed around different sizes of pipe in a stock pot I then pull the pipe out and pour the alum in the top. I removed the pipe and let the mold air dry while I melt the metal I also cast ever other one and let the heat dry out the sand even more as a test. I had about 10 in the stock pot. I know they use vents in molds and gates for flow which is to help with the air I think and shrinkage which may be my problem. But I did not have the problem just filling the pipes but I did have shrinkage but I just trim that off. I really thought a open mold some as large as 2 1/2 inch down to 1 inch would vent out while I was pouring.
    But this is all new to me and I do not know the answer I am just guessing it was moisture in the sand could be how fast it was cooling trapping the air.
    Reloading to save money I am sure the saving is going to start soon

  4. #4
    Boolit Grand Master
    bangerjim's Avatar
    Join Date
    Apr 2013
    Location
    out of here, wandering somewhere in the SW.
    Posts
    10,163
    I have years of expereince casting different metals over the years. Al is one of the hardest ones to get clean void-free usable castings for.

    Everything I turn and mill in my machine shops from Al is from aircraft grade hard aluminum from the local scrap yard. Having aircraft manufacturers and other manufacturing around the area, there is a vast selection of 1-6” barstock/rounds in any length I wish to buy (at very reasonable prices) and square/rectangual blocks also in any shape I need for projects.

    Most industrial grade Al is vacuum cast so there are no voids or cavities in it. Also most is extrusion molded. Just pouring it into a hole in a cope & drag sand mold will yield very low quality porous castings. Been there. Done that many years ago in college and beyond. That method of rendering scrap is OK if your are sand casting ornamental and decorative shapes (or simple pullys), but not for accurate turned precision items.

    Also many commercial items are rotationally molded to rid them of internal voids and cavities.

    In other words.....buy your Al and brass turning stock from a reliable industrial supply house. Leave the home-brew castings to the back-woods artists casting trinkets for tourists.

    Good luck!

    Bangerjim

  5. #5
    In Remembrance - Super Moderator & Official Cast Boolits Sketch Artist

    RP's Avatar
    Join Date
    Mar 2008
    Location
    Nahunta NC
    Posts
    3,410
    Well dang Jim rain on my parade that is not what I wanted to hear but was in the back of my mind. I searched around my area for anyone that would have some drops or scrap I could buy for my projects but no luck. That was my first path then I went online to find some to order a 2 inch dia 24 inchs was 45.00 and I am sure shipping would have it over 50 real quick. That is why I was playing with casting my own.
    I am not ready to give up yet to much time invested and casting in pipe did give me a fair piece of stock that turned well. I am not making precision items with this material really learning how to and items that a small void would have not effect on how it works. I may just start casting fire ant nest and selling them on ebay to buy me some good stock lol.
    Reloading to save money I am sure the saving is going to start soon

  6. #6
    Boolit Master


    Omega's Avatar
    Join Date
    Jul 2014
    Location
    Clarksville, TN
    Posts
    1,318
    I'd look into venting, trapped air needs somewhere to go, I think the better you vent, the fewer voids you will have.
    "Freedom is the sure possession of those alone who have the courage to defend it."
    ~Pericles~

  7. #7
    Boolit Master Drm50's Avatar
    Join Date
    Jun 2016
    Location
    SE Ohio
    Posts
    2,361
    I live in the Rust Belt and junk yards are full of stock for small projects you can buy cheap. I worked in a large Alumilum plant as a carbon setter. They don't know exactly what they have
    until they draw a sample. A small mold is used to pour a sample billet. This is taken to lab and
    shavings burnt in a spectrograph. The metal is then labeled when it's poured and the purchaser
    must remelt and add whatever alloys required to bring the Alumilum to the specs needed for the
    purpose. Guys would throw in pennies or a sledge hammer when they were mad at management.
    This would produce a pot full that wouldn't bring the money that pure metal would. Melting odd
    scrapp you don't know what you are going to end up with.

  8. #8
    Boolit Buddy Ateam's Avatar
    Join Date
    Mar 2017
    Location
    Northern MI
    Posts
    349
    I have tinkered with doing exactly what you are trying. What I learned;
    -Venting is important
    - Use cast aluminum as your base material, engine blocks, kitchen machines, pots, etc anything that was cast originally will give better results than the random/extruded stuff.
    -If you are getting tear out/problems with soft material, you need to lube the cut, an old timer told me to use lard, crisco seems to work ok
    - the dull/ shiny pattern you are seeing is likely a harmonic vibration (causing chatter) set up in the piece.

  9. #9
    Moderator Emeritus

    MaryB's Avatar
    Join Date
    Jun 2013
    Location
    SW Minnesota
    Posts
    10,304
    Online Metal sis resonable for AL pieces most of the time. And check eBay! I have gotten a LOT of the AL tubing I use for antenna stuff from there!

  10. #10
    Banned
    Join Date
    Aug 2017
    Posts
    340
    it don't matter if you let the mold dry. i have worked with pottery and even letting the stuff dry for several days there is still moisture trapped in the structure of the clay. sand is no different. there is still molecular water content and that will create problems. the temperature required to get the molecular moisture out is around 600*F.. so letting it just sit there will not do it and you will still get steam and outgassing when the 1,400*F aluminum hits the sand. that is why it does not happen with the pipe but does with the sand, there is still moisture trapped in the molecular structure of the sand. must vent the mold to allow it to escape. but the open of the mold does not mean much. what will happen is that being the top is allowed to cool faster it will form a skin over the top while the bottom is still molten as the sand holds the heat in. while this is happening it plugs the mold off and allows steam and other gasses to be trapped in pockets in the aluminum.

  11. #11
    Boolit Grand Master
    bangerjim's Avatar
    Join Date
    Apr 2013
    Location
    out of here, wandering somewhere in the SW.
    Posts
    10,163
    I would suggest using REAL casting sand that does NOT involve any water at all! Black casting sand uses oil-based liquids to bond the sand. My local cast iron foundry had tons of it, so I could “borrow” a few dozen pounds!

    Back when I was casting brass and aluminum on a regular basis, I could make up a cope & drag of black sand, and cast in it immediately because there was NO water involved. Black nasty stuff........but it really works. I have never used “green” sand. Takes too much time.

    Water in any casting proceedure is just trouble looking for a place to happen!!!!!!!!

    Commercial casters sure do not have the time to wait days and days for molds to dry out!!!!!!

    Check it out!

    Bangerjim

  12. #12
    In Remembrance - Super Moderator & Official Cast Boolits Sketch Artist

    RP's Avatar
    Join Date
    Mar 2008
    Location
    Nahunta NC
    Posts
    3,410
    Helpful information people thanks for the replies you do not know somethings until you ask thanks.
    Reloading to save money I am sure the saving is going to start soon

  13. #13
    Boolit Master
    Join Date
    Nov 2017
    Location
    brisbane ,qld,australia
    Posts
    2,125
    One difficulty with alumin alloys is the oxide is the same weight as the metal,and so doesnt float on top of the melt......castings with oxide corrode quickly and break up....De oxidising and metal cleaning is normally done with fine bubbles of argon just before pour......as mention ,you need proper sandcast alloy,Al.10%Si,for a good easy casting.Even cast metal will not necessarily be right......When I was a kid,I worked with a neighbour who made good pulleys,esp cone pulleys with scrap ally from old motorbike crankcases,heads and gearboxes.......the bikes were old Indians and Harleys.,he especially like the WW2 Indian Chiefs....plenty of metal.

  14. #14
    Boolit Master
    Join Date
    Nov 2017
    Location
    brisbane ,qld,australia
    Posts
    2,125
    Brass is much easier to cast than ally,probably because mix isnt critical,and the poured metal is a lot heavier.In fact its pretty hard to get bad results with brass.......but heat is much higher,and just the heat from the crucible will singe your short and curlies right thru heavy clothes.....Always pour brass on a floor of loose sand,then it wont splash if something goes wrong.White heat takes a bit of getting used to..........finally,pure copper dont cast,you need some tin or zinc to make it work.

  15. #15
    Boolit Master
    Join Date
    Apr 2005
    Posts
    4,900
    Quote Originally Posted by john.k View Post
    One difficulty with alumin alloys is the oxide is the same weight as the metal,and so doesnt float on top of the melt......castings with oxide corrode quickly and break up....De oxidising and metal cleaning is normally done with fine bubbles of argon just before pour......as mention ,you need proper sandcast alloy,Al.10%Si,for a good easy casting.Even cast metal will not necessarily be right......When I was a kid,I worked with a neighbour who made good pulleys,esp cone pulleys with scrap ally from old motorbike crankcases,heads and gearboxes.......the bikes were old Indians and Harleys.,he especially like the WW2 Indian Chiefs....plenty of metal.
    You and he would be interested in Burt Munro of New Zealand, one of whose records, set in 1967t the age of 68, still stands. He used to gravity-cast his own pistons etc. under the most primitive conditions, and his base machine was an Indian nowhere near as modern as WW2.

    https://en.wikipedia.org/wiki/Burt_Munro

    The trouble with aluminium for casting has two main sources. Some alloys aren't meant to be cast at all, and may respond badly to the process. Also they are too light, and gas bubbles don't rise as easily as they would with other metals.

    While sand-casting often does involve a moisture content, this is something on which you should obtain concrete information, rather than proceed by the light of nature. Too much moisture can be dangerous, and not a little, but very. So-called sands are complex products, embodying a binding substance which is usually a type of clay.

    https://en.wikipedia.org/wiki/Sand_casting#Green_sand

    Brass or bronze are easier to work with, although they have higher melting-points. As to safety, you aren't in any more danger priming a bunker-buster bomb than a hand-grenade, but proper procedure will keep you safe. Some of the precolonial African bronzes are at least the technical equal of the best European renaissance work. You have to be pretty civilised to be a primitive.

  16. #16
    Boolit Master
    Join Date
    Dec 2010
    Posts
    586
    casting metals is an art. i was involved in steel and bronze casting design for years, and can tell from your write-up that you need 2-5 years experience in a foundry shop and a much higher budget to get reliable product. not picking on you, as your efforts are great for an amateur, but metals casting of this nature is not lead casting simple. it is a complex art with significant expense.

  17. #17
    In Remembrance - Super Moderator & Official Cast Boolits Sketch Artist

    RP's Avatar
    Join Date
    Mar 2008
    Location
    Nahunta NC
    Posts
    3,410
    Maybe this is getting over thought gave some background on what I was doing and how and for what reason.
    I am not trying to get factory results just material that I can use to practice on and make something that it would not matter if it had a void.

    From what I am getting is the green sand gives me lots of voids caused by venting moisture and gas, The pours I did in pipe did not have voids all over them or inside them just a few on the outside from what I have found so far.
    The last thing was the alloy tearing instead of cutting which is coming from what I melted for the most part but still a unknown mix. The better material I start with the better I end with for the most part.

    Looks like green sand is going to have that problem since its in it nature and metal molds will give me better results and last material is also key.
    I have seen post that people suggested for alloy what was tearing to add about 10 to 15 percent brass.
    I am not trying to cast works of art just some billet to feed my lathe.
    Reloading to save money I am sure the saving is going to start soon

  18. #18
    Boolit Master
    Join Date
    Nov 2017
    Location
    brisbane ,qld,australia
    Posts
    2,125
    Green sand at a low/correct moisture level will give good results with sufficient risers and vents......I suggest you get a beginners book on "hobby casting"..it will contain all the hints and tips you need for useful results.As to the naysayers,I have cast large bronze bearings out on site to repair an old crane,and for slipway winches ,that had to be kept going,using the exhaust from a diesel engine as a blower into a mound of dirt for a furnace.It aint rocket science,but it can be dangerous.

  19. #19
    Boolit Master


    Omega's Avatar
    Join Date
    Jul 2014
    Location
    Clarksville, TN
    Posts
    1,318
    Watch this guys series, he does motor parts and stuff but the technique is what you are after.
    https://www.youtube.com/user/myfordboy
    "Freedom is the sure possession of those alone who have the courage to defend it."
    ~Pericles~

  20. #20
    Boolit Master




    EMC45's Avatar
    Join Date
    Jun 2007
    Location
    East TN Mountains...Thanks be to God!
    Posts
    4,549
    Have you tried dry sand "lost foam" casting? Seems like it may work for turning stock.
    You can miss fast & you can miss a lot, but only hits count.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check