This first set of homemade spy gadgets is directed at children and contains projects that can be easily made by kids with minimal parental supervision.
Spies need to see without being seen. The art of being invisible is as easy as being able to see around corners. This homemade periscope is the perfect fix. You’ll need two small mirrors, two one-quart cardboard containers (empty half-and-half containers work great), scissors and duct tape.
Step 1 – Cut the tops completely off the one-quart cardboard container.
Step 2 – Turn the containers over so that the bottoms are facing up. Cut a small rectangle in one side of each container about two inches wide. The rectangle should be the width of the carton.
Step 3 – Directly opposite the rectangles, on the inside of each carton, attach a mirror at a 45 degree angle using the duct tape to secure it from behind.
Step 4 – Slide one carton over the other with the cut-out rectangles facing opposite directions. Make sure that you slide the OPEN ends together.
Step 5 – Secure the two cartons together with duct tape.
Easy-to-Make Fingerprint Kit
Every spy needs to be able to lift fingerprints. To make a simple fingerprint kit all you need is some colored chalk (black makes an authentic looking powder), cornstarch, Scotch tape and a make-up brush. Grind up the chalk and mix it with equal parts cornstarch. Pour a bit of the powder on a possible fingerprint and gently brush it off with the make-up brush. The dust will adhere to the oils in the fingerprint rendering it visible. Lift the print with a piece of Scotch tape.
A spy always needs to be aware of his surroundings, and often this means needing to know whether or not you are being followed. You can’t just turn around and look–if you do, then the person following you will know that you are onto them! In come the special spy rear-view glasses. What do you need to make super rear-view spy glasses? You just need a pair of sunglasses, superglue and a small round mirror. If you don’t have a mirror small enough one can be picked up at a craft store for under a buck. This project is super simple. Put a small dab of superglue on the back of the mirror and adhere it to the inside of the sunglasses on the far right of the right lens.
Spies like to send secret messages. Here are two easy invisible inks for the everyday spy. Lemon juice can be used as ink on any type of paper. It is best used by dipping a paintbrush in the juice and writing your message. It will dry clear and will only be revealed by exposing it to heat. Holding the message to an incandescent light bulb will work. If you don’t have any of these in your home (your mom has gone eco-crazy and replaced them all with fluorescents), you can use a hair dryer or even put your message in the oven on the lowest heat setting.
Another easy invisible ink is vinegar. Vinegar can be applied in the same way as lemon juice but heat will not reveal the hidden message. A chemical reaction is needed, and the best chemical is found in red cabbage. Rubbing a red cabbage on the paper will reveal the message, but a better method is to boil the cabbage and use the red juice. Paint it over the message and the writing will show up in a red tint.
Learn more about how to make your own spy gear at home - homemade spy gadgets - on the next page
In the previous section we looked at several kiddy-level homemade spy gadgets. Those required little or no skill and a very small investment. The following projects are a bit more complicated and may require the purchase of special tools or equipment. You may also need to have a bit of handyman skills in some cases.
Secret Stash Book
One of the most important homemade spy gadgets that any spy can have is a secret place to keep important documents and spy-related materials. A secret stash book is the perfect hiding place. This particular spy accessory has been around for hundreds of years. You’ll need a large, hardcover book, glue, a sponge brush and an eXacto knife.
Making the book is rather simple. Open the book to about page 20 or so. Glue the outside of the remaining pages together by spreading glue over them with the sponge brush; once the glue has dried cut a large rectangular section out of the interior of the large glued section of pages. Leave about an inch on every side so that the book remains solid. If you want to you can glue the interior of the newly created hollow in the book. You now have a seemingly ordinary book to hide all your spy gear.
A bump key is a unique key that burglars have been using for years. This key acts just like an old skeleton key used to; it opens nearly any lock that it will fit into. To create a bump key you’ll need a key that you don’t use anymore, a metal file and permanent marker.
Step 1 – Identify the valleys in your key. Each key will have four valleys between several bumps. The valleys are the four lowest points on the key. Mark these four points with the marker.
Step 2 – Grind the four valleys to the lowest point of the key. Do not go past the horizontal groove that delineates the top and bottom portions of the key.
Step 3 – Grind the remaining hills into triangles. These triangles should resemble jagged teeth when you are finished.
To use the bump key insert it into a lock part way then thrust it upward into the lock. This will push the locking pins into position. Turn the doorknob while you are bumping the lock and if you do it at the right time the lock will open. It takes a bit of practice but once you get the hang of it almost any lock can be bumped. If you want to carry a bump key, be warned that it is not legal in all jurisdictions and simply carrying one might be in violation of the law! We recommend making this for fun and entertainment only.
IR Invisible Face Hat
In today’s society every time you go out in public you are subject to video surveillance. For a spy this can be particularly troublesome. But how can you keep your face off video? It’s really quite simple. You’ll need a baseball hat, eight infrared (IR) LED lights, electrical tape, scissors and a nine-volt battery. Because IR lights are not visible to the naked eye they won’t stand out in your everyday activities. On the other hand, IR lights are extremely bright to a standard or night-vision video camera and will obscure the entire head area if worn on a hat.
How do you do it? Poke eight holes in the front of the baseball hat and insert the wired IR LEDs. Run the wires around the inside of the cap securing them in place with electrical tape. Wire the LEDS to a nine volt battery and secure the battery in the back of the cap beneath the interior flap.
This is a really cheap project, and the hat, lights and battery should run you under $20.
On page 3 we have more homemade spy gadgets in the form of Spy Sunglasses.
These spyglasses will be the most expensive item on the list. You’ll need to pick up an ultra small video spy camera (available on eBay for around $18), a pair of dark sunglasses, some 20-gauge wire, electrical tape, superglue and a wire cutter/stripper.
Step 1 – Cut the cord on the spy camera so that the component output cords and the camera itself are separated. Strip two inches off the ends of the four exposed wires. These wires will be color coded red, yellow, white, and black–for audio, video, power and ground. This doesn’t matter much as you will be connecting the wires back together in the next step.
Step 2 – Add about ten feet of 20-gauge black wire to the end of each of the exposed wires on the video camera end. Connect these wires to the component wires making sure that yellow goes to yellow, red to red, etc. Secure the exposed wire with electrical tape.
Step 3 – Glue the camera to the inside of the sunglasses on either the far left or far right of the corresponding lens.
Step 4 – Run the wire around the end of the glasses, and down to a small recorder in your pants pocket. Connect the component outputs into the video recorder and you’re ready to go.
These homemade spy gear ideas should be used with the best of intentions. They can be fun if used in a non-malicious way. Take care when making any of these items, especially those dealing with electricity–you might give yourself a little shock if you’re not careful. Now go to, have a bit of fun making some homemade spy gear!
TBO Tech.com “Top 25 DIY Spy Gears for Spying on a Budget” retrieved at https://www.tbotech.com/blog/index.php/2009/08/top-25-diy-spy-gears-for-spying-on-a-budget/ (accessed Feb 2011)
YouTube.com “Make Magazine” https://www.youtube.com/user/makemagazine (accessed Feb 2011)
Image of Bump Key Courtesy of https://www.lockbumping.org/bump-key/bump-key.html
Image of Periscope Courtesy of https://thefrugalgirls.com/2010/11/lowes-build-and-grow-workshop.html