What You Will Need

Han Solo in Carbonite Silicone Mold
Cement/Concrete Mix
Hot Glue (about 3 sticks)
Silver Spray Paint
Black Acrylic Paint
Red Super Bright LEDs (I used 27 red 5mm LEDs)
Resistors (60 ohm for a 12V Supply, 6 LEDs in series)
AC/DC Power Supply (I used a 12V supply, you can use whatever you like with the appropriate resistor)

An alternative option for the LEDs if you don't feel like doing any soldering would be to get a strip with a power supply (Amazon search example: red led strip with power supply)

Step 1: Another Sticky Situation for Solo

The first step is to fill Han with hot glue. The translucent glue makes a great diffusor for the LEDs.

You will need to do it in a few steps, waiting for the glue to set in between each, in order to build up a nice thick body, without the glue running all over the place.

If the glue ends up where you don't want it, you can easily pull it out, or if it hasn't set yet, use a wet finger to remold it.

Step 2: Instead of a Big Dark Blur, I See a Big Light Blur

Wire and Test the LEDs

I had a strip of 27 bright red LEDs which used to be an auxiliary brake light in a car, so if you can get one of those out of the junk that would be perfect. Otherwise, simply wire up as may LEDs as you deem neccessary (25-30 seem's like a good ballpark figure to me).

The actual wiring is simple, The first thing that you need to do is determine what voltage power supply you are going to use and how many LEDs you are going to use.

I will work through the example with similar values to what I used.

The typical voltage drop across a red LED is 1.8V, so a 12 volt supply can handle 6 in series, the rest of the voltage is dropped across the current limiting resistor (see my diagram)

voltage drop across 6 red LEDs = 1.8*6 = 10.8V
voltage drop across current-limiting resistor = 12-10.8 = 1.2V

Most bright red 5mm LEDs are comfortable around 20mA of current, but you should check the datasheet if you have one.

Remembering Ohm's law, current = voltage/resistance, the required resistor can be calculated as follows

voltage across resistor/desired current through resistor = 1.2/0.02 = 60 ohms

You can put as many of these LED + resistor strings in parallel as you like, limited only by the current that your supply can produce (if you used 6 strings which each drew 20mA you would require a 120mA supply)

Glue the LEDs

Not much to it really, just use more hot-glue to glue the LEDs to the back of Solo, making sure to distribute them evenly. I discovered that I had to put an extra LED in each hand to make sure that they too were illuminated, the rest of the LEDs formed a rough line from the head down the torso.

Step 3: Perfect Hibernation

Make a Stand

I decided to set a scrap of aluminium (an old handle) into the concrete, which would stick out the back of the mold and provide a support. You can use whatever looks convenient. Another option would be to set some large nuts or magnets into the back of the cement, to give you something to attach a stand to.

I got mine slightly wrong, so I had to glue some nuts to the bottom of the casting to make it stand the way I wanted to, but in the end I like how it is slightly raised.

As you can see in the pictures, I just used some clothes pegs to support the aluminium handle while the concrete set. Make sure that you get the angle right, because there is no going back once the cement cures.

Mix the Concrete

I followed the instructions on the bag of concrete fairly loosely, choosing to add a little more water and a lot less sand than usual. If your mix is too viscous it is going to be difficult to get it into all of the crooks and nannies around the LEDs and their cables.

Pour the Concrete

Once your concrete is ready and you are triple sure that the LEDs are working to your satisfaction, simply pour the concrete into the mold.

Once the concrete is in the mold it is a good idea to vibrate it as much as possible to get the air bubbles out. Since the mold is flexible it also helps to bend and jiggle it a bit, to make sure the concrete goes everywhere that is needs to. I picked mine up and dropped it a couple of centimeters a few times which seemed to do the trick.

Make sure that the cable is sticking out where you want it to.

Step 4: Shoot First (Coat of Paint)

Silver Base Coat

I used a metallic silver/grey spray paint to coat all of the concrete, while using some scraps of paper to try and prevent getting too much onto the hot glue Han. The metallic paint completely blocks out the light, so if you need to remove any spray that gets on the glue, try an earbud soaked in turpentine (it had not effect on the glue in my experience). I would avoid acetone, since I have read that it can be used to remove hot glue, which means it must dissolve it to some degree.

Black Acrylic Grunge Coat

In order to make the details pop, as well as to make the white-ish hot glue less obvious, I did a "wash" with black acrylic. The idea here is to rub a darker colour all over the casting and then wipe it off with a rag, trying to "clean up" as much as possible. Since you will never get all of the paint out, it will get stuck in the grooves and crevices, much like real dirt, and give the whole thing a lot of depth.

I worked sparingly on the hot-glue section, since the acrylic stuck pretty well and I wasn't sure I would be able to get it off if I put too much on. Unlike the silver though, I was able to use the thin black to mostly hide the hot glue, while still allowing light through.

If you would like to see all kinds of interesting weathering techniques, then I recommend watching the incomparable Adam Savage wax lyrical.

Step 5: Lock in the Auxiliary Power

The last step is to wire up the power supply if you haven't already (and if it was a premade strip of LEDs connected to a power supply you probably still will want a typical lamp switch).

I bought a bog standard lamp switch from the local supermarket. Simply cut through one of the strands of wire and connect the ends to the two terminals inside the switch (take a look at my photo for clarity).

Obviously you need to make sure that your power supply is connected the right way around, but you already figured that out when you were testing the LEDs right? If you get it wrong just swap it around, you wont damage the LEDs.