atcomsystems.ca/forum Forums General General Telephone & Systems Information WiFi Blocking Paint

Skip...... :rofl:

Well, it may sound sci-fi but it's real stuff thats been around for a while. I used to use it to paint the inside of plastic cavities for EMI/RFI shielding (keeping it out as well as in). It's pretty temperamental stuff and only works if you ground it.

I believe the stuff we use to use was some sort of oil based paint. Latex didn't work to well thanks to the non-conductive nature of rubber.

BTW, if you didn't ground it you had one hell of an antenna

It was also pretty damn expensive... a small bottle (like touch-up car paint bottle) was about $20.

My friend and I drove around with his ipod touch...it constantly updates the available wireless signals...surprisingly the majority of people actually changed their SSID and had their networks secured.

why not use lead based paint

ROHS anyone?

Plus too many of us ate the chips as a kid

Several years ago one of our TSCM clients had us create two secure conference rooms. No RF could get in or out. On the surface the thought of creating a secure screen wrap under the carpets, behind the sheet rock and in the ceiling seemed plausible by the client until we explained the RF would travel up each of the sheetrock nails, and all the electrical wiring. Eventually we made it happen, but it was a lot more involved than making a simple screenroom.

In high school I worked with an Electrical Engineer to do EMI/RFI testing. We had to build a 10'x10'x10' shielded test box. Had to be that size for propagation he said. Something to do with a mathematical/harmonic of the actual range that the FCC would do EMI/RFI testing at.

Amazing all the stuff we had to do. And it would boil down to something as simple as not having copper wool (not steel) properly sealing the cracks in the walls. We'd seal the room, fire up the antenna array, find noise on the floor, then spend hours crawling around with probes that had maybe a 2" detection cone. Grueling stuff but once we were done the business paid well.

Sounds very similar James. Once we were done you'd have to check your cell phone or pager at the front desk if you were expecting any calls as they were useless in the conference room.

Trace, I did US Army "clean" rooms....you have "red" pipe and transformers on everything.

You could not even wear a quartz watch into these facilities.

As far as deadheading the walls, we need to discuss a few things sometime.....

Several years ago one of our TSCM clients had us create two secure conference rooms. No RF could get in or out.

Google "Tempest" to see how the government handles such matters.

-Hal