Sandbox on plinth---better stability

Discussion in 'Sand Casting' started by Melterskelter, Sep 19, 2018.

  1. Melterskelter

    Melterskelter Gold Banner Member

    I have been until now using a hard plinth outside my furnace on which I set my hot crucible to transfer it to my trolley. I have noticed that with time the crucible seems less stable that "stuff" gets on the bottom of my crucible and the base of the crucible gets eroded or maybe spalls away. Both factors make for a less solid stability of the crucible. I have not had one tip, but I worry that it might be easy to have that happen.

    So, I decided to try placing a shallow sandbox on my plinth and set my crucible on/in that. I gotta say I really like the way the crucible settles positively solidly into the sand. I use left over green sand in the box and the box is about 2" deep and about 10 inches square. It is sort of like the difference of setting your camera on a bean bag to take a picture vs putting it on a hard surface. The sand just molds itself around the crucible and cradles it.

    Just passing this on in case someone else might find it useful. Since the box does get exposed to a fair bit of radiant heat, I will likely in the near future make up a metal box to hold the sand.

    Denis

    PlinthSandBox (1).JPG PlinthSandBox (3).JPG
     
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  2. Jason

    Jason Gold

    Hmm... Sand. That should work. I use a plinth with a piece of cardboard on it inside and outside the furnace. It's kind of a small foot print, but crucible is still flat on the bottom. I need to upsize my pouring sand box. If it takes a tumble, I'll be in deep doodoo, I pour on concrete!:eek:

    CB.jpg
     
  3. It's just a spalling what could happen.:eek:
     
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  4. I have something similar: an old piston with a dished crown shape that I pour a few inches of sand over
     
  5. PatJ

    PatJ Silver

    I use hard fire bricks to set the hot crucible on.
     
  6. Robert

    Robert Silver

    Me too.
    R
     
  7. myfordboy

    myfordboy Silver

    Good idea for separate tongs and pourer
    My crucible never leaves the tongs/pourer.

     
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  8. Tobho Mott

    Tobho Mott Gold Banner Member

    I've heard it said that type of 2-in-1 design works best for smaller crucibles only, but I'm not sure if it was ever said by anyone who has tried it...

    I'd be interested in your thoughts on that, myfordboy. Do you think it would be awkward to use for, say, my #12, as full of bronze as could be moved around safely?

    I do like the sandbox plinth idea. I set mine down on bricks too for quite a while, but lately I've been putting it down on the heavy grill from my old BBQ (bridged between 2 bricks) to minimize physical contact and sudden cooling of the bottom of the pot.

    Jeff
     
  9. myfordboy

    myfordboy Silver

    Jeff,
    If the crucible full of metal is light enough to be handled by one person the tool will certainly work.
    The long handle gives full control and the bar fitted at the end makes it easy to turn for pouring.
     
  10. Tobho Mott

    Tobho Mott Gold Banner Member

    Thanks. I do like your tongshank design. Maybe I'll try that if/when I get a crucible that my existing lift and pour tools won't fit.

    Jeff
     
  11. Melterskelter

    Melterskelter Gold Banner Member

    Well, that must be a pretty good-sized piston. I doubt it came out of a Honda 50cc cycle! How big is it and what did it originally fit? Pics?

    Denis
     

  12. It's a mystery diesel piston about 5-6" diameter, I grabbed it out of someone's scrap pile for aluminium years ago and it's been corroding in the backyard for a while. It's common to use a piston in this way with a conventional pouring shank/handle. The crucible is about A20 in size for scale, so the piston is a bit wider than the crucible base and I pour a decent amount of sand on top of it while the furnace runs. My crucible lifter is short and lets me steady the crucible on top until I'm certain it won't topple over.

    piston base.jpg
     
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  13. How come your crucible is so clean?

    I think I'll make a new crucible for melting ingots rather than scrap.
     
  14. Petee716

    Petee716 Gold Banner Member

    Ok
    i made a tool modeled after myfordboy's. Close enough to say i ripped off his design. Ive lifted and poured a #10 full of bronze with no trouble. As he said above, if its correctly balanced, if you can handle the weight it pours as easily as a ring shank. One note of caution though. When i went to the heavier (heavier than aluminum) bronze, i noticed a bit of flex in the mechanism, mostly in the hinge and linkage. It felt like the crucible could potentially slip out if it had been heavier.
    Ive gone to a #18 for aluminum and built more conventional lifting and pouring tools for it but the combo tool works fine for my #8 and #10.


    Pete
     
  15. myfordboy

    myfordboy Silver

    The crucible in the video had not been used at the time.
     
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