We made sun jars using these instructions by Cre8tor at Instructables: Home-made Sun Jar. It’s based on the Sun Jar design by Tobias Wong. These notes are what we learned along the way.
The short version:
– Ikea Slom jar, smallest size, about $3
Disassemble the Ikea jar and spray the bottom half with glass frosting spray. Get the solar panel and battery pack out of the solar garden light and mount it on the underside of the jar lid (see below for specifics). Reassemble the jar and you’re done.
The long version:
The guts of the homemade sun jar are made using a solar garden light. These can be found at hardware and garden stores, and there are lots of types to choose from. Obviously since we’re ripping it apart we’ll be using the cheap ones. I love the solar garden lights for their intended purpose and will probably get some for our front walk. They work like this: the solar panel charges the NiCAD battery during the day, the batteries power the LED light when it turns dark, and a little diode turns the light off during the daylight hours. You put the jar on a sunny window sill and that’s it, it runs itself.
After my first try where I discovered that the components had been glued into place, I compared a few kinds until I found one that worked. I found that the components needed to unscrew easily, and have one battery. My unscientific testing and general assumptions bring me to say two batteries take longer to charge during the day. These are the ones that didn’t work: set of 4 Hampton Bay lights from Home Depot, glued in place; set of 6 Malibu brand lights from Fred Meyer, had 2 batteries; set of 4 Westinghouse brand lights from Sears, I was completely unable to get open. There might be other kinds out there that work just great, but at this point I was tired and running up against a deadline.
update: In the years since I wrote this tutorial it’s become easier to find individual garden lights that pop off their ground stake and are small enough to fit inside the lid of a jar. See the update note at the end of this page for pictures. End of the update.
I settled on Malibu brand lights from Lowes which come individually packaged, about $10 each:
These come apart easily and there is no separate light sensing diode as shown in the Instructables site, if you cover the solar panel the light comes on. The LED light is mounted underneath the battery already, making it very simple to assemble for the jar. Also the solar panel is just the right size to fit inside the jar lid and still allow it to close. The light in these is amber.
However, after this initial happy find I bought six boxes of these (we were making them as gifts) and found that the components inside were not always the same! Tragedy! Here are the three kinds we found:
If you feel like you can get away with it while in the store, open the box and peek inside. You want the one that looks like the picture just above.
Unscrew the four (or sometimes two) screws that are holding the solar panel into the frame, you’ll need a tiny phillips head screwdriver. Do not unscrew the screws holding the battery pack to the electronic bits, that can stay just as it is. The solar panel and battery bits which are attached to one another with wires. Discard the protective plastic sheet and plastic frame, as well as the rest of the bits that come in the box, let’s hope they are recyclable in your area.
We used Ikea jars – the smallest in the Slom series (about $3) which you can find in the kitchen marketplace area. The jars seem really small in the store but we found the medium jar too large for the reach of the LED light to do a good job.
Happy surprise: the Ikea jar wire bits come off easily with a little pushing and pulling.
The only part which needs some help is the hinge:
This makes painting the jars far easier. We used a glass frosting spray paint which worked nicely. You don’t want to spray the jar top, it needs to stay clear as that is where the solar panel will be mounted to collect sunlight. We put the jars up on some skewers so they wouldn’t stick to the paper.
Now we prepare the light guts. In these pictures we used a silicone sealer glue (it’s essentially clear caulking, I think), but the Instructables project uses Blue Tak, aka that sticky moldable stuff you used to hang posters in high school. We decided to use glue because we were shipping the jars across the country and didn’t want them to shake apart in transit, but when we make our own I’m going to use the tacky stuff as it worked plenty well in my test. Also, if the battery should need to be replaced it will be easier to get to.
This is what we’ll be doing: attach the solar panel to the inside of the jar top so that it catches light during the day. But first we’ll attach the battery and light to the bottom of the solar panel so that when the jar is closed the light is pointing down inside.
Stick the battery and light to the bottom side of the solar panel with the light at the center, pointing straight up:
Then dot the four compass points of the inside of the jar lid with the sticky stuff of your choice:
And put the solar panel, with the top of the solar panel facing towards what will be the top of the jar, on the sticky bits, centered carefully:
Now, reassemble the jar and you’re done.
This was a lot of fun, but of course the homemade jars won’t look as good at the real thing. Also, we tested these during a rainy, overcast Seattle December and found that the battery was barely charged by the end of the day. We got a few hours of light before it faded. We’re sure there will be stronger light during the summer months, but we’re pretty happy anyhow.
update April 2007: My homemade sun jar made it into the pages of ReadyMade Issue 28, thanks ReadyMade.
UPDATE: It’s been a few years since I first made this tutorial and the option for lights to fit inside a jar are easier to find. I found the following at Lowe’s, they are individually sold garden lights and the small top portion simply pops off of the ground stake they are mounted on. The top component is small enough to fit inside the top of a jar and wouldn’t need any modification. All you need is some glue to mount it underneath the lid of the jar. Neat, eh?
I also found these being sold individually: