We're going to start with an inexpensive wooden box, and turn it into something with more desirability. In the photo on the left is a box, 2 sections of RGB LEDs, and a jack.
Using a 3/8" drill bit, drill a hole where you would like to position your incoming power supply. Using a piece of masking tape helps to keep the edges of the hole edges come out a little cleaner.
Because we don't want the jack to protrude into the box any further than needed, we'll snip off the legs of the jack, leaving plenty to solder our wires. There are three legs on this particular jack, Cat# DCJ21. The center leg is for positive, while the other two are negative. Either of the negative legs will work just fine.
Cut two sections of wire, (I like to use telephone wire) long enough to reach where your lighting will be, and trim off about 1/16" of the insulation from the ends with your cutters or an Exacto blade. Using Rosin core solder, "tin" the ends of the wires with just enough solder so that the ends now look silver instead of copper.
Next, tin the center leg of the jack, being careful that your solder does not accidentally connect this leg with any of the others.
Now tin the negative leg in the same manner.
Attach your wires to the legs, still watching that your solder does not cross from one to the other. This action does not require much time, or much heat. You only need to melt just enough of the solder to create a bond. This is where you will see the benefit of "tinning".
Because the RGB lights are waterproof, they have a silicone membrane over the upper surface that will need to be carefully trimmed away from the area where you want to attach your wires. An Exacto, razor blade, or any sharp knife will do fine, but you must be careful to cut away only the silicone, not the metal circuits below. I have, on occasion, cut too far, and was unable to solder wires to what was left. So far, I've always been able to go to the other end of the segments and fix my mistakes.
When looking at RGB segments, you can see the circuits in the sections. Along one edge, there is one circuit that runs in a long straight line. (red arrow) This is the positive side, and you should tin this connection (green arrow) being sure that your solder does not goop over and make connection with any of the other circuits. Once again, you do not want to do any more than tin the circuit.
The other three circuits are red, green, and blue. your choice of these should be tinned and connected to NEGATIVE. You can choose red, green, blue, or any combination of the three, to get the color you want. Connecting all three gives white. In this case, I have soldered red and green together to get an apple green color.
Once you have soldered the wires in place, plug them into your power supply and test to make sure your connections are secure, and you are getting the color you want.
Insert the jack through the hole in the box, securing it with the nut that came with it. Gently remove the liner from the adhesive on the back of your LED segments, and firmly press them down where you want them. If they do not stick well to your surface, you can use other types of adhesive, (hot glue works well), or mechanical fasteners such as staples, but be careful not to damage any of the circuits while nailing them down.
I'm going to line the inside of the box with red crushed velvet, so I cut a piece a little larger than the box.
Using Contact cement, coat the bottom and three sides being sure to get plenty of the cement on your fingers, ears, and anyone who happens to be within shouting distance. Do not smear it on the LEDs. Be sure your wiring is tucked up out of the way, as you can see here, I did not. Lighter fluid, paint thinner, or acetone can be used to clean up stray adhesive. BE CAREFUL OF FUMES! When the adhesive is ready, fold the edges of the cloth so that when you stick it to the adhesive, the edges are turned under, (You have stuck the pretty side to the adhesive), and all the corners are tucked in. The LEDs should be exposed. ( Ya Think?)
I'm making this box to house a glass knife that I made, and will be giving it to my Grandson, who I have called "Cheeseburger" since he was three years old. He actually likes the moniker, and his best friends use it fairly often.
Anyway, I'm etching that, and his initials in the knife, using 3 mil Image Pro Super washout film from Ikonics.
#100 SC, probably 20-30 PSI, 1 year old Roctec 1/16" orifice nozzle, still showing no wear.
While sandblasting the knife, got a delivery of our new Modular LEDs. These are called sticks, and are much brighter than the others, so, it's change time! De-solder the wires, and instead of wasting a connector, solder the wires directly to the terminals on the stick.
The Sticks come with clips and screws, but in this case, I prefer hot glue. I ran a bead of glue on the back of the Stick, and held it at a slight downward angle to keep more of the light inside the box. ( In the photo, the stick is not yet attached)
Drilling 4 - .065 holes through the bottom of the box, I secured the knife in place with .060 copper wire, tying them together on the bottom of the box.
I put 4 clear rubber "bumpons" on the bottom, so if it is going to be displayed flat the wires will not scratch the surface. I also put 4 bumpons on the front edge so it can be displayed standing as in the picture to the right. The lid is stopped from going back any further by the jack sticking out from the back. We'll leave it on display until we close for the holidays. The little guy in the photo is the Cheeseburger some years back. Today, he is 14 years old, 5'6" and 170 lbs.