What Not To Do

Discussion in 'Lost foam casting' started by oldironfarmer, Jan 20, 2019.

  1. The loading chute for my Mini-Mite muller is a bit small for me so I made a foam one.

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    I added a brace to help hold it square until it was bound by the sand
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    Used my new metal bucket for the first time. Well, it's not new.
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    I was concerned about it filling all the way down, it's about 1/4" thick. It did fill nicely.
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    And fits well
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    But I was in a hurry and didn't get the underside of the top (the rear plate) filled with sand. It was close to horizontal and I meant to help the sand along with a Popsicle stick but forgot. You can see the angle of repose of the sand.

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    Worse, it appears the sheetrock mud may have held the metal for a short time because there's evidence the rear plate collapsed into the void beneath it. At first I thought it was shrinkage but it really looks like collapse of partially cooled metal. Pretty ugly but I'll clean it up and use it.
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    The hook on the left and the angle on the right didn't warp enough to keep it from fitting well and being stable for use.
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    Another learning experience. :rolleyes:
     
  2. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Might have been tempted to pour that is the position/orientation it sits on the machine; hopper interior up.

    Best,
    Kelly
     
  3. Hmmm. I felt it was too wide, it's about ten inches. I've been trying to orient for fill vertical down. Thanks for that suggestion. Obviously you don't think the metal faces meeting would not have created a cold shut. I've never tried to pour anything flat. Might be time to do some experimenting.

    I believe this would have poured had I not had a large void under the infeed. Do you concur? The downward face was about 15 degrees from horizontal. It would have filled had I worked at it.
     
  4. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I probably would have been debating between hopper opening up or down. It would be easier to gate all four sides hopper opening down. If you filled the inside and outside of the pattern evenly the pattern deflection would be minimal.

    Of course, available flask size is a consideration too. When the flask gets big they get heavy and harder to vibrate.

    Best,
    Kelly
     
  5. Thanks for the comments, Kelly. I had not considered multiple gates with lost foam. Now you're making me think.

    I have one large flask I can't move easily. I usually vibrate it like concrete, a rod tied to the vibrator worked down into the sand. Sadly I was in a hurry today and too lazy to get the air pressure turned up on my vibrator, thinking I had enough because of the simple shape.
     
  6. PatJ

    PatJ Silver

    Looks like you are close.
     

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