I was looking around, after I saw a tutorial on how to hollow out a lightbulb, specifically this one: http://www.teamdroid.com/diy-hollow-out-a-light-bulb/
In the comments section of that article, some one mentioned that electric tape and a lid would provide a water tight seal and this idea hit me.
With all the terrariums and plant growing bulbs on here, let's do something different.
Step 1: Materials
So this is the Materials list:
-Light Bulb (The bulb I used was the frosted looking 60 Watt one from GE.)
-Coke Lid (In my case, I had to use one from a 2-Liter bottle. The 20oz ones were too wide to fit)
-Candle or other flame
- (optional) Round File
- (optional) Coat Hanger
Step 2: Hollow Out the Bulb
Once you have all your tools, hollow out the bulb.
Look at the bottom of the bulb and notice the solder point (Pic 1). This is held to a layer of non-conducive glass by a metal disc. Grab the metal disc with the wire cutters and work it so the edges curl up (Pic 2 & 3). After that, pull up on the metal disc and break the copper wire that is attached to it. After this you should be left with the glass "dome" of sorts that protects the bulb (pic 4).
Slowly chip away at it (Pic 5 & 6) until you have a clear view of the back fill tube (Pic 7). The black glass is very sharp and sharp shards of glass hurt, so take caution. After you have a good view of the back fill tube, take your screwdriver and stick it next to the back fill tube (Pic 8) and push down. The wedge of the screwdriver should break the fill tube and you should hear a small pop. This is air rushing into the previously inert gas filled light bulb. The fill tube should just shake out of the bulb (Pic 9). Now you should have a clear view of the bulb innards if you look down the small opening (Pic 10)
What you're going to do from here, is use any implement you have to slowly chip away at the inner bulb. I used a long screwdriver to get down in there and slowly chip away at the glass. When you have a big enough hole to pull the filament out, stop chipping. Pull out the filament assembly (Pic 11) and pull it off with the pliers (Pic 12). Carefully shake out the glass shards.
Step 3: Cleaning the Bulb
Now, your bulb will probably look a bit scratched up (Pic 1). This is from the glass shards scraping the white powder called "Kaolin". Kaolin is a non toxic dust they use to frost the inside of the bulb. If your bulb doesn't look scratched up, you might have an acid etched bulb, which means the frosted effect is built into the glass.
More on Kaolin here.
There are many ways to wash the inside of the bulb. Many people say salt works, rice, a bit of sand, but I find that water works the best and is less wasteful. So fill your bulb with water (Pic 2 & 3), swish it around a bit and then dump the water. This may have to be done a couple times to get all the kaolin out. A clear bulb is what we're going for here (Pic 4). Any left over white can be cleaned with a napkin and a small piece of wire.
Step 4: Prepping the Bulb
After hollowing and cleaning the bulb of any kaolin, grab the electrical tape and wrap the metal screw of the bulb a few times making sure to press the tape into the grooves and wrap the OPPOSITE direction of the screw.
We wrap the opposite direction so that when we place the cap on, the tape doesn't get in the way of the cap.
Step 5: Making the Cap
1. Light your heat source (I used a candle)
2. Take your pliers and grab the nail
3. Heat the nail until hot
4. Stab the cap with the nail a couple times
The amount of holes and the width of them is completely up to you. Something you have to keep in mind is that you have to make the holes big enough for standard table salt to come out of so you may find yourself widening them.
(I ended up taking the end of a coat hanger and heating it and using it to widen the holes.)
Step 6: Fit the Cap
Now it's time to fit the cap.
Fill the bulb with water and place the cap on tight, but not so tight that you break the bulb. (Don't want glass shards in our hand now do we?)
See if water comes out when you turn it upside down.
1. The cap won't fit/keeps falling off
A. Add a bit more electrical tape.
2. The water isn't coming out
A. Check to see if the holes are large enough and check to see if there is something blocking it.
After doing the water test, make sure to dry out the bulb with a napkin or thing towel and then set it aside, somewhere safe, to dry for at least 12 hours. (Never said this was a fast project, did I?)
After it's dry, fill with salt, cap it, and shake to see if the salt comes out at an acceptable rate. If it doesn't, widen the holes.
Step 7: Optional Step: Make a Stand
Really anything that allows this to stand up straight could be used as a stand. As a stand for taking pictures, I used my roll of electrical tape. I've also been shown someone using a shot glass to hold it up and I actually made a nice little stand out of a coat hanger, which is shown in the picture below.
I've always thought this base: https://www.instructables.com/id/Light-Bulb-Lamp/step4/Making-the-Base/ made by bumpus for his Light Bulb Oil Lamp, which involves seating a magnet in the middle of a washer, via the use of tape, and then using another magnet inside the bulb to keep it stable, was pretty ingenious. The only problem I see is that the magnet would clog the salt's way through the cap.
There's also this one made by "Mad inventor" who made his stand out of a piece of bamboo, but to me, it looks like cork: https://www.instructables.com/id/Light-Bulb-Lamp-1/