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  1. #1
    Join Date
    Aug 2002
    Location
    Casper, Wy, USA
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    804

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    Hello Everyone,

    I have finished my tests on suitability of a ceramic foundation mold.
    The test was quite successful. Melted beeswax can be poured, molded
    and easily released from a ceramic mold fired to the bisque stage. At
    this stage the ceramics are porous and retain moisture much like a
    sponge.

    When the ceramic plates are soaked in water for a few minutes, water
    is retained within the ceramic structure. The surface of the plates
    are not wet. This water acts as a super release agent and also cools
    the mold.

    Molten wax is poured onto the bottom ceramic mold and then the upper
    part of the mold is placed on top of the wax. Heat from the wax is
    readily transferred into the water within the mold and transferred to
    the outside surfaces of the mold.

    After about 30 to 45 seconds the upper part of the mold can be very
    easily removed without any wax adhering or sticking to the mold. The
    molded wax foundation can then be easily removed by simply grabbing a
    corner and pulling it up without any sticking or adhering. None!

    I stopped the test after molding about 8 sheets of foundation so I
    don't know how many could be molded before more water would need to
    be brushed or sprayed on the mold.

    I estimate that a person familiar with pottery could make a very
    decent mold for less than $10. If you had a potter make one it should
    cost less than $50. Any student in a high school ceramics class could
    do it.

    Next Post, some thoughts on construction.

    Best Wishes
    Dennis Murrell


    [This message has been edited by BWrangler (edited March 23, 2003).]

  2. #2
    Join Date
    Aug 2002
    Location
    Casper, Wy, USA
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    Hello Everyone,

    A ceramic foundation mold is very easy to build but some factors must
    be taken into consideration. First the clay will shrink when it is
    fired. Shrinkage is usually somewhere between 8 and 14 percent
    depending upon the amount of moisture in the clay and the temperature
    to which it is fired.

    Clays from art supply companies are generally formulated with known
    shrink rates. Other clays would need to be tested for shrikage. This
    can be an advantage if small cell foundation is needed. Regular
    foundation can form the pattern for the mold and after shrikage could
    produce foundation in the small cell range.

    My test mold was formed by rolling out two layers of clay 3/8" thick.
    A sheet of 5.4 foundation was placed on top of one of the layers.
    Another layer of clay was then placed on top of the wax and the
    layers pressed together with a rolling pin to a total thickness of
    3/4". A couple of the edges should be marked so the mold can be
    reoriented later on.

    This sandwich was allow to dry slowly. A flat board and a little
    weight should be placed on top of the sandwich to prevent the edges
    from curling up during drying. Most potteries have a drying room or
    box for this function.

    The clay sandwich is placed in a kiln and fired to the bisque stage.

    That's it. You have got a foundation mold.

    Soak it in some water for a few minutes. Place it in a baking pan. Pour
    molten wax over the lower mold surface. Press the upper mold surface
    onto the molten beeswax. Wait a little and remove the mold and
    foundation without any sticking of wax or excessive force needed.

    Now any country or beekeeper in the world can have small cell
    foundation regardless of import restricts, economic conditions, etc.

    Next post, mold enhancements.

    Best Wishes
    Dennis Murrell


    [This message has been edited by BWrangler (edited March 23, 2003).]

  3. #3
    Join Date
    Aug 2002
    Location
    Casper, Wy, USA
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    Hello Everyone,

    Enhancements to the very basic ceramic mold might include some kind
    of guttering and collection area to catch any overflow wax within the
    mold itself. The wax would not stick to mold but it sure sticks to
    the metal baking pan I used in the test case even when it's wet.

    Another feature could include a means to self align the upper and
    lower parts of the mold. In the test case I used alignment marks
    scribbed on each side of the sandwich when the clay was damp. The
    upper piece could be constructed to fit inside a recessed area on the
    lower piece or it could override the lower piece like a lid or ??.
    As the wax doesn't stick to the mold lots of alignment options are
    available.

    Top bar hive or nonstandard sized hive owners can easily build a mold
    for their unique needs.

    The lack of wax adhesion would also allow very large molds to be
    constructed as very little force is needed to seperate the parts. The
    surfaces of the mold could be mounted on hinged surface which would
    support the additional weight and multiple sheets could be cast at
    one time.

    Some other applications of this concept might include ceramic rollers
    for a hand mill. Very easy to build and replace. Maybe the lower
    roller could contact molten wax in a pan. The wax would then embossed
    by both rollers which could be cooled by a water spray or drip on the
    back side.

    Any ideas or comments?

    Best Wishes
    Dennis Murrell
    Freely it has been given to me, so freely I give.

  4. #4
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    Aug 2002
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    Casper, Wy, USA
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    Calling Everyone,

    Anybody a potter or have experience with building preproduction clay models? Maybe foundry experience? Maybe just good old common sense? I could sure use your input here.

    I bet the ideas and enhancements for a ceramic foundation mold could keep up the flow of really great design ideas and enhancements that is happening on the TBH forum among others.

    Any thoughs, comments, suggestions, questions?

    Dennis


  5. #5
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    Aug 2002
    Location
    Nehawka, Nebraska USA
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    Post

    You made it with 5.4mm foundation for the pattern, with shrinkage, what cell size did you end up with?

  6. #6
    Join Date
    Aug 2002
    Location
    Casper, Wy, USA
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    Hello Michael and Everyone,

    I used 5.4mm and the result was 5.0mm. I had originally purchase this specific clay for it's known shrikage rate back before small cell foundation was commercially available. It had been stored in my garage for 5 years so I'm sure the shrikage rates were not accurate due to loss of moisture.

    There were lots of clays with shrikage rates less and more than the one I purchased.

    I'll bet there are clays with very little shrinkage rates. I did not investigate them at the time as I was interested in producing small cell foundation.

    Anybody have any good sources for clays with specific shrikage rates. I got mine at Art Studio Clay in Chicago, Il.

    Dennis


    [This message has been edited by BWrangler (edited March 23, 2003).]

  7. #7
    Join Date
    Aug 2002
    Location
    Nehawka, Nebraska USA
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    I'd need to figure a way to get something bewteen 4.9mm and 4.85mm. 5.0 is nice for a first regression, but according to Dee, not small enough to solve the mite problem.

    This is a facinating concept. Cheap, reasonably easy on a small scale. If you came up with a really good mold for one with a rim to catch the excess and have the opposing one fit inside the rim for register, then you could mass produce the molds cheaply too and they would have more appeal.

  8. #8
    Join Date
    Aug 2002
    Location
    Casper, Wy, USA
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    804

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    Hello Michael and Everyone,

    The easiest way would be to measure the master. Determine what shrikage would be needed to get to the desired result and buy a clay with that shrikage property.

    With a little experimentation almost any desired size could be produced from a given clay. Moisture content can be varied as well as the firing temp which changes the amount of shrikage. Small test tiles of half a dozen square inches can easily be prepared and fired.

    From my limited experience it would be better to undershoot the desired size by just a smidge rather than overshoot it.

    I am going to add more moisture to my old, rather stiff clay and try again to get at about 4.8 to 4.9. I could purchase a new batch but I'm just cheap.

    As most clays shrink around 10-12% it shouldn't be too hard to get it right the first time.

    Just don't let the clay sit in the garage for years before using it :> )

    Happy Molding
    Dennis


  9. #9
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    Nov 2002
    Location
    Sapulpa,OK USA
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    Post

    Do you have any photos?

  10. #10
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    Aug 2002
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    Casper, Wy, USA
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    Hello Beekeeper28 and Everyone,

    I thought about it, but my test case is really just two rectangular ceramic plates 3/8" thick with cell impressions on one side sitting in a baking pan. Not too impressive.

    I hope to construct a "production" version incorporating lots of great ideas from everyone and with a final cell size slightly less than 4.9mm. I will take some photos of that process.

    I have read that molded foundation is more brittle than that produced by milling. It is more brittle especially if it's molded thick.

    I could hold a piece in my hand and flap it about 20 times before it would break. I have read that freshly milly foundation can be wadded up like a sheet of paper and would spring back when released. My molded foundation is not like that but is more than useable.

    Dennis




  11. #11
    Join Date
    Sep 2001
    Location
    Neodesha, Ks
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    Dennis, I think that a hinge on the 2 plates might work. That way they would always be located right in relation to each other. Maybe use a hinge with a slot between the 2 halves so you could raise the top portion up first and then press it down onto the wax. Just thinking out loud. Good luck with your experments and let us know how things come out. Dale

  12. #12
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    Sep 2001
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    Neodesha, Ks
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    Post

    Who knows, after you get this thing perfected there may be a demand for something like this out there. More thoughts. Dale

  13. #13
    Join Date
    Apr 2003
    Location
    Milford, NJ, USA
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    73

    Post

    Just curious..., but why is it that you don't use a hard plaster, like hydrocal, to make the mold?
    You would not have the shrinking problem, nor to mention firing... and it would last a long time anyway.
    I would imagine you could just pour it on an existing foundation sheet to make the mold.



    ------------------

  14. #14
    Join Date
    Mar 2001
    Location
    Jameson, MO USA
    Posts
    76
    What a wonderful thread!

    Would the hydrocal moulds have the same easy release qualities as the bisque moulds?

    Joel

  15. #15
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    Aug 2002
    Location
    Casper, Wy, USA
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    Greetings,

    I orginally tried 60psi hydrocal. I attempted a thin mold to avoid problems with heat deforming the wax master. They were to be mounted on hinged plates. The hydrocal was too thin in my test and didn't release like the bisque fired clay. But it might work if a thicker stand alone mold were constructed and the mold soaked for awhile in water.

    I think the plastic small cell foundation would make a better master than the beeswax foundation. It wouldn't be affected by heat as the wax is. The plastic has almost no cell wall compared to the beeswax. There would be no change in size with the plaster.

    I have experimented bisque firing with several different kinds of clays. Some of them were much too soft after the firing to make a good foundation mold.

    Some warping occures on the corners in the larger sized tests. I sure it's my own lack of skill in this area. I have thrown lots of pots but know very little about slab and form work.

    The shinkage "problem" could be an advantage for the person who lives in a country that restricts imports of bee products including small cell foundation. If local foundation or comb is available a small cell foundation mold could be produced. Otherwise, for the rest of us it's a pain.

    Regards
    Dennis


  16. #16
    Join Date
    Sep 2001
    Location
    Neodesha, Ks
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    Post

    Dennis, Have you tried placing something like saran wrap between the wax and the mold. I noticed that Dee uses this. Dale

  17. #17
    Join Date
    Nov 2002
    Location
    Ames, Iowa
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    97

    Post

    What do you think about changing the design to include hinges, some type of handle and a pouring spoute on the vertical edge? Like a fishing weight mold. A lazy-susan type holder could easily be designed to accommodate several molds, and could simply be turned to pour wax into the next mold.

  18. #18
    Join Date
    Mar 2003
    Location
    sc
    Posts
    47

    Post

    I find this post very interesting. I love to work with clay but i do not have access to a kiln....any sugestions on that.

    Also, how about a latex mold ...can the latex handle the heat of the molten wax. No fireing...just a thought
    chris

  19. #19
    Join Date
    Apr 2003
    Location
    Milford, NJ, USA
    Posts
    73

    Post

    Latex will certainly handle molten wax and even 212F without any problem.

    ------------------

  20. #20
    Join Date
    Aug 2002
    Location
    Casper, Wy, USA
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    Greetings,

    Just another little bit of information. Most shrink rates available for clays are at final firing temps. Shrinkage rates for bisque firings are about half the final firing temps.

    Lots of great ideas are coming through on this thread, but way too many for me to try expecially with my limited experience. One great factor with using ceramics is lots of trials can be conducted relatively cheaply although they do take some time.

    Regards
    Dennis

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