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I've never tried embedding magnets-- but I used one product from Polytek 
to make a rubbing plate that has lasted for over 6 years.  They make all 
kinds of mold and casting products;  you can choose color and many other 
properties.  I cast the 2-part product I used (poly 15-3) in a baking 
sheet (greased with vaseline) and then used a Dremel tool to put the 
pattern in it (Aztecs counted in base 20 using symbols like finger, 
flag, and feather); you can machine this as well.

You can order smaller quantities to try out.  610-559-8620.  As I 
recall, they were pretty helpful on the phone.

Kathy Krafft
Director of Exhibits
Sciencenter
Ithaca, NY

PS I got this information originally by calling another museum- one of 
our volunteers had seen a rubbing plate in another museum.. so the cycle 
repeats itself!
William Katzman wrote:

>I was wondering what medium most people out there used for embedding 
>magnets in.  Specifically, I want to have neodymium (rare earth) magnets 
>pull  items around on the opposite side of a pane of tempered glass &/or 
>acrylic.  So I was going to imbed the magnets in a casting of a urethane, 
>epoxy or some style plastic cast that would allow its use but wouldn't 
>scratch up the glass.  (You might think of the typical flow tunnel 
>magnets).  So...what casting mediums have people out there used with 
>success for this endeavor.  Information on where to get your favorite 
>mediums would be appreciated as well.
>
>-William
>
>William Katzman			[log in to unmask]
>Director of Exhibits			(828) 322-8169 x307
>Catawba Science Center		(828) 322-1585 (fax)
>"Try not to become a man of success, but rather to become a man of value" 
>-A. Einstein
>
>
>
>  
>

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