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Old July 21 2012, 05:52 AM   #14
Sumghai
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Location: Melbourne, Australia
Re: Combadges from a prop perspective - placement and positioning

Gary7 wrote: View Post
you need to make sure the magnet is sealed without any air pockets, otherwise condensation can occur and trigger rust.
Good point - I can degas the polyurethane in a vacuum dessicator jar with a vane pump.

Gary7 wrote: View Post
the polyurethane needs to be thin enough so that it won't impede the magnetic strength. The magnet has to overcome the thickness of the coating plus whatever fabric barrier there exists between that and the metal.
Looks like it's time for me to crunch some numbers pertaining the electromagnetic permeability of polymers and fabrics...
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