Faraday's cage

shirel

Hi,

I've wondered if there is a possibility to create a Faraday's cage with a metallic Slinky instead of using a metallic mesh?

Thanks in advanced.

berkeman

Depending on the application, it probably will not work very well. It will be inductive above some frequency, based on its dimensions. If you could do 2 Slinkys and weld them at each crossing, that would be better. But that's close to the mesh. Are you trying to make a Faraday cage that can expand and contract significantly?

shirel

Thank you.
Actually, expanding and contracting aren't my intention. I just need to use a slinky in order to block radio waves/sound waves, which are coming out of a tape recorder.

berkeman

Probably not going to work very well. Why a Slinky? Is it all you have in your dorm room or something? :-)

shirel

haha no

I'm just trying to use a slinky, since I want it to be also a part of an electromagnet.

randeezy

I hope you're not going to try and use to electromagnet at the same time as you use the cage....... Because that would just be taking one step foward and two steps back........

The Dagda

I'm not sure of the spacing between the mesh, but it would probably be possible to knock holes in tin foil, unless you needed it to be more robust, then I suppose you could use thick metal? If you use tin foil of course it would be disposable so no worrying about spacing as you can just adjust the dimensions. Or I suppose you could just buy some mesh to order.

shirel

Thank you The Dagda, I'll consider it.
randeezy, why do you say it is taking one step forward and two steps back?

berkeman

I think randeezy was refering to your desire to shield, but then to introduce noise. You probably have your reasons, but it does sound a bit strange on the face of it.

BTW, Aluminum foil is lousy for shielding material. There is no good way to make electrical contact, either from it to ground, or between edges or multiple pieces of Al foil. To make a good Faraday cage, you need good electrical contact between all sides/surfaces of the enclosure. You can't weld or solder edges of Al foil together, and there is a coating on it apparently that makes pressure contacts not work reliably.

A much better choice if you want to solder up a good cage, is Shim Brass. You can get it at the hardware store in various thicknesses, and it's easy to cut with tin snips into the shapes that you can then solder the seams on, to form a good shield structure.