Glow Powder Key Fob: Never Lose Those Keys Again!

Never lose those pesky keys again! This Instructable will teach you how to make a simple and stylish glow fob that can easily be attached to your keys or anything else you may want to keep track of more efficiently in the dark.

I’m the type of person that misplaces everything, keys, pocket knives, wallets, glasses, cell phones; nothing is safe once I’ve laid my hands on it.  After losing my keys for the millionth time I decided I needed to do something about it.  For a while I tried one of those gadgets that beeps loudly when you whistle allowing you to home in on the location of your keys, the problem with that was that it would go off at any loud noise and after it decided to go off several times during class I decided it was time to find a better solution.  What I came up with was a simple yet effective glow in the dark fob.  Now I know what some of you are thinking, “What use is a glow in the dark fob when I’m trying to find my key’s during the day?” and the simple answer is that it isn’t very much use at all, but there have been many times when I misplaced something during the day, searched for it without any luck, and found it by the bright glow of the fob once it got dark.
So for those of you out there who share my inability to keep track of things please feel free to read on and learn how to make a glow in the dark fob that is both functional and stylish.

Step 1: Materials & Tools

Materials
20 minute epoxy: You need at least 20 minutes of working time, instant and 5 minute epoxy sets up way to fast.

Glow Powder: There are many colors to choose from, however, I suggest V10 Green it glows the brightest and longest.  Glow powder can be purchased on Amazon or Ebay, I bought a ½ ounce for around 8 dollars.

¼” outside diameter flexible clear plastic tubing: can be purchase very inexpensively at any hardware store. 1 foot of tubing should be more than enough.

Metal or plastic tubing that will snuggly fit the outside diameter of the rubber tubing. (I used an aluminum arrow that I got for free from the local archery shop).

Spring rings (key rings): you probably have some lying around the house.

Tools

Pipe cutter (can be purchased an any home improvement store for under 5 dollars).

Xacto knife or other sharp blade.

6ml syringe (can be purchased for under a dollar at tractor supply).

Sand paper (220 grit would be fine). The blue pencil length tool in the picture is my sand paper, it's called a sanding stick and can be purchased from jewelry supply companies like Rio Grande.

Jeweler’s files (not necessary but helpful).

Power drill and 3/32” or 1/8” drill bit.

Power sander (not necessary but helpful).

Something to thoroughly mix epoxy with, (I use an old sculpting tool, but a tooth pick or popsicle stick would work fine).
Wax paper or small disposable container to mix epoxy in.

Step 2: Cutting the Rubber Tubing.

Once you have all of your materials collected and ready to go, you need to find a suitable work space.  Remember you’re going to be working with epoxy which means fumes, so find a place that has adequate ventilation.

Start off by cutting your clear plastic tubing into 1” to 2” sections depending on how long you want to make your glow fob.   I cut several pieces so that I could make more than one glow fob and so that I didn't have to waste any extra epoxy or glow powder.

Step 3: Mixing the Glow Powder and Epoxy

The main thing to remember about any project involving epoxy is that as soon as you start mixing you’re on the clock and that means you have to work fast and work efficiently.  In the materials list I advise that you use at least a 20 minute epoxy, which should give you plenty of time to do what you need to do. 
Before you begin mixing make sure that you have your syringe, mixing tool, glow powder and cut pieces of plastic tubing handy so you don’t have to frantically search for them in the minutes to come.  Start by putting a dime sized glob of the epoxy compounds down in your mixing bowl or on the wax paper.  Right beside the epoxy place a pile of glow powder, as for measurements, I used roughly a 60/40 mixture, 60% epoxy and 40% glow powder by volume.  This is by no means an exact measurement, I just eyeballed it and did a few tests with different amounts and found this to be the best combination for me.
With the epoxy and glow powder ready, start mixing the epoxy while slowly incorporating the glow powder. Keep mixing until you have added all of the glow powder and the epoxy appears to be thoroughly combined.  Remember that the more you mix the faster the epoxy will set up, so don’t go nuts, mix just enough to combine everything evenly.

Step 4: Getting the Mixture in the Plastic Tube.

Now it’s time to fill up those pieces of tubing you cut earlier.  Start by pulling the plunger out of the syringe and setting it aside.  Now take your mixing tool and begin scooping your epoxy glow powder mixture into the top of the syringe.  Take care to scoop in as much as possible so that you don’t waste ingredients.  Once you have all the mixture scooped into the syringe reinsert the plunger and start filling up the pieces of plastic tubing.  Hold one end of the tubing firmly against the end of the syringe and depress the plunger, if everything goes well the tubing should fill up with no air bubbles or other problems.  Stop filling the tube about 1/8th of an inch from the end.  Once you have one tube filled set it aside and move on to the next, keep going until you are out of the epoxy and glow powder mixture. After all your tubes are filled immediately clean your syringe and mixing tool, otherwise the epoxy will cure and they will be ruined.  I use cold water and regular dish soap to clean off epoxy, it doesn’t get things perfectly clean but it does a good enough job for me, and honestly I’d rather have a bit of epoxy on my tools than have to mess with thinners and solvents to get things perfectly clean.

At this point the glow pellet part of your fob is basically complete.  The last thing I did with mine was to slide them into the metal tubing so that the mixture would dry straight instead of following the curve that some of the pieces of plastic tubing had.  Allow your epoxy and glow powder mixture at least an hour to set up and remember to read the epoxy packaging to find information about proper set up and cure times.

Step 5: Making the Casing

This part of the Instructable is where your creativity comes in.  The way I did it is one solution and it works well for me, but there are thousands of different ways to accomplish the same goal.

For my casing I started with a 2217 aluminum arrow (the numbers relate to the dimensions and wall thickness of the arrow but all I cared about was that the plastic tubing fit perfectly inside the aluminum tubing of the arrow).  I got the arrow for free from a local archery shop; it was bent in one section and was no good for shooting but worked well for my purpose.

Using the pipe cutter I cut the aluminum arrow tubing to my desired lengths, usually making the tubing about ¼” longer than the glow pellet I planned on using; i.e.  1” glow pellet = 1 ¼” aluminum tubing, (this allows room for drilling holes to attach spring rings later on).  To use the pipe cutter start by turning out the set screw until the pipe can slide between the wheels on one side and the cutting disk on the other.  Then tighten the set screw until the cutting wheel just makes contact with the tubing. Make about 2 rotations of the tubing and then tighten the set screw by a quarter turn and make another 2 rotations. Keep doing this until the pipe is cut, this will result in a nice even cut with little clean up.  NOTE: what you don’t want to do is crank down on the pipe cutter like you’re the world’s strongest man and try to cut the pipe in one rotation, that’s not how the tool is designed to work and all you’re going to accomplish is ruining a piece of tubing.

Now that your tubing is cut it’s time to make the windows so you can see your glow pellet. I did this by holding the tubing against the top drum of my belt sander which created a very nice clean oval window.  If you plan on using this method remember to have a bowl of water close by so that you can quench the tubing when it gets hot from the friction of the sanding belt.  If you don’t have a belt sander at home you can make your windows by clamping your tubing in a vise and using different types of files to create different window shapes.

Once your window(s) is/are finished it’s time to drill holes for connecting the fob to a spring ring. Starting about 1/8” down from the top of the fob, mark and drill a hole straight through one side of the tubing and out the other. Note: drilling tubing can be tricky, to help you get started, use a small round or triangle file to create a groove for the tip of the drill bit to set in.  After drilling your holes in the top, use some sand paper or a jeweler's file to lightly rough up the inside of the bottom of the tube.  This will help hold the glow pellet in place once we start putting things together.

Step 6: Putting It All Together

You should now have:

A dry/cured glow powder and epoxy pellet

A metal tube to contain the pellet (with a variety of interesting windows)

A spring ring

Start by opening the spring ring and threading it through the two holes on the top of the metal tube. With the spring ring in place, insert the glow pellet through the bottom of the tube. Note: if you’re having a hard time getting the pellet into the tubing you can put a small drop of dish soap on the outside of the pellet, this will help it to easily slide into place.  If the pellet is a bit too long give it a trim with your Xacto knife.  Lastly to hold everything in place we are going to mix up a small batch of epoxy, no glow powder this time.  Mix up the epoxy and smear it into any remaining space inside the bottom of the metal tubing (this is why we roughed up the walls in the previous step, so that the epoxy would have something to adhere to. Finally set your completed glow fob on end for an hour to allow the epoxy to dry and you are done.

Step 7: Done

You’re glow fob is now ready to begin its work of making your life just a little easier. To charge the fob simply expose it to any light source, the brighter the better, with sunlight being the best option. If you decided to use the same type of powder that I used, V10 Green, you can expect your fob to glow very bright and to keep glowing for roughly 8 to 10 hours before it needs to be recharged. One of the great things about glow powder is that it doesn't wear out so your fob will continue to work for years to come.

(In case you were wondering I put two black O-rings on the bottom of the glow fob just to change things up.)

Thank you for checking out my first ever Instructable, I hope you found the information within useful and interesting.