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Re:I am going to buy a vacuum chamber soon -- looking for bids and sour

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  • Jim King
    Mike, I have 3 vacuum chambers made from cooking pots and pans with gum-rubber gaskets and a ½” thick plate of Lexan (don’t use acrylic as it’ll shatter
    Message 1 of 2 , Aug 5, 2009
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      Mike,



      I have 3 vacuum chambers made from cooking pots and pans with gum-rubber
      gaskets and a ½” thick plate of Lexan (don’t use acrylic as it’ll shatter
      over time). Frankly, I rarely use them now that I’ve switched to pressure
      curing nearly all of my molds in the same “paint pots” as used for my
      castings. If I only need to pour 1 or 2 small open molds, I just do use the
      vacuum chambers but only for convenience. I de-air the rubber, pour over
      the mold to just cover the tallest part, then pull another vacuum, then top
      it off with more rubber. This way you get a double evacuation .. you DON’T
      want to evac the rubber for the first time ON the mold … it’s a royal mess
      as it expands.



      If you want to investigate paint pots, visit eBay (where I got 4 of the 5 I
      use) and search for “paint pot” or “pressure pot”. I hit perfect timing … a
      broker was selling painting equipment for a paint or body shop that folded
      and I got five 5-gallon tanks dirt cheap. After sandblasting, painting,
      pouring new lid gaskets and rigging for pressure instead of paint, they’ve
      worked like a charm since and saved me about $2000 over new tanks.



      Jim King

      Smoky Mountain Model Works, Inc.

      <http://www.smokymountainmodelworks.com>





      [Non-text portions of this message have been removed]
    • Jack Mc Kie
      Jim, Not sure I agree about acrylic shattering. 1 atmosphere is only 14psi. Acrylic is used on most commercially made bell jars. If the part is properly
      Message 2 of 2 , Aug 5, 2009
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        Jim,

        Not sure I agree about acrylic shattering. 1 atmosphere is only 14psi.
        Acrylic is used on most commercially made bell jars. If the part is
        properly designed (reasonable thickness) it should be just fine.

        Jack



        --- In casting@yahoogroups.com, "Jim King" <jimking3@...> wrote:
        >
        > Mike,
        >
        >
        >
        > I have 3 vacuum chambers made from cooking pots and pans with
        gum-rubber
        > gaskets and a ½" thick plate of Lexan (don't use acrylic as
        it'll shatter
        > over time). Frankly, I rarely use them now that I've switched to
        pressure
        > curing nearly all of my molds in the same "paint pots" as used
        for my
        > castings. If I only need to pour 1 or 2 small open molds, I just do
        use the
        > vacuum chambers but only for convenience. I de-air the rubber, pour
        over
        > the mold to just cover the tallest part, then pull another vacuum,
        then top
        > it off with more rubber. This way you get a double evacuation .. you
        DON'T
        > want to evac the rubber for the first time ON the mold … it's
        a royal mess
        > as it expands.
        >
        >
        >
        > If you want to investigate paint pots, visit eBay (where I got 4 of
        the 5 I
        > use) and search for "paint pot" or "pressure pot". I
        hit perfect timing … a
        > broker was selling painting equipment for a paint or body shop that
        folded
        > and I got five 5-gallon tanks dirt cheap. After sandblasting,
        painting,
        > pouring new lid gaskets and rigging for pressure instead of paint,
        they've
        > worked like a charm since and saved me about $2000 over new tanks.
        >
        >
        >
        > Jim King
        >
        > Smoky Mountain Model Works, Inc.
        >
        > <http://www.smokymountainmodelworks.com>
        >
        >
        >
        >
        >
        > [Non-text portions of this message have been removed]
        >
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