I have never seen a project like this here on NCWW so I thought I would contribute.
This is a simple 3/4” plywood box like anyone can make. What makes it different is the exterior covering. First we used heavy duty aluminum foil to wrap the entire box and provide for an interrupted skin of foil then followed that up with a covering of aluminum screen wire. Both coverings were tucked into grooves cut into the underside of the box and lid and are held in place by screen window/door flexible splines. The groove keeps the external coverings from coming inside the box. I was very careful to ensure that nothing penetrated the skin to the interior of the box. Had something penetrated to the interior, the box would have been worthless.
As a test once the box was complete, I placed my smart phone inside the box and closed it with the latches I installed. The phone didn’t ring which makes the box secure against EMP’s and CME’s. I realize that aluminum foil is very thin but the accepted electrical theory is that all it takes to protect electronics inside the box is a skin of electrical conductive material. Both the foil and screen wire provide that conductivity.
What is an EMP or a CME? (Electro Magnetic Pulse – Coronal Mass Ejection or Solar Storm) Both are high energy electrical fields produced by various means. An EMP is produced when a nuclear device is exploded and will disrupt and/or destroy electronic circuits. It has been determined that an EMP explosion about 400 miles over the USA will cripple most if not all electronic devices in the entire country.
A CME is a high energy blast produced by the sun and is what causes the Northern Lights. We have been hit four times this year so far and one blast which missed us was enough to rival the 1859 event. A CME can be as harmful as an EMP and we are far more likely to be hit with a CME that an EMP.
In this box will be placed a solar generator which I want to protect. An EMP or a CME would destroy the circuitry and make the generator a 100 pound boat anchor. The box will stay closed and will only be opened monthly to top off the batteries inside. I have another box for the solar panels and another to protect any electronic components I find to be vital.
Questions and comments are appreciated.