Making your rubber bracelet smaller might seem like an impossible task, but it can be done without too much effort or mess using only glue and electrical shrink wrapping. Whether your bracelet is just for fun, or because you have a cause to support, too often it comes in a "one size fits all" category, which means they generally only fit people with large wrists or hands. Making your rubber bracelet smaller will make wearing it easier and more comfortable, and it'll only take a few minutes.
Measure for sizing. Use a piece of string to measure another bracelet you already own that fits well, then add 1 inch for overlap. Make two marks on the rubber bracelet to indicate how much of the rubber bracelet is to be removed to make it the same length as the string.
Cut out a chunk of the bracelet. Use the X-acto knife to cut both marks on the rubber bracelet all the way through. Discard the chunk of the bracelet left behind.
Pare down the end pieces. Use the X-acto knife to pare down the inner side of one end of the bracelet and the outer side of the other. The objective is to slice away portions of the rubber to cause a gradual thinning or tapering of both bracelet ends so that when they are pressed together, there will be a smooth fit between them, with no bulging or overhang. This process is similar to making rubber stamps out of rubber erasers.
Glue the two end pieces together. Slip the shrink-wrap connector onto the bracelet, then apply a layer of glue to the bottom end of the bracelet. Gently press the top end of the bracelet against the bottom end to form a connection, then hold the connection between your thumb and forefinger for a full minute to ensure a solid bond.
Shrink-wrap the connector. Slide the shrink-wrap connector over the glued connection then hold the bracelet over a lit candle with only the connector being directly over the flame. Keep the bracelet moving so the rubber part doesn't burn or melt and keep the bracelet at least 2 inches above the flame at all times so that it doesn't get too hot.
Shrink-to-fit electrical connectors can be found at any big hardware store. They are normally used to splice wires together in places that need to be water tight, such as with water pumps. They look similar to very short straws and can be purchased in various gauges, and generally come in red or black. They shrink to fit when heat is applied.
Turn the bracelet as the connector heats up to make sure that all parts of it are heated and shrink properly so that it will hold tight to the bracelet.
If you have trouble paring the rubber down with an X-acto knife, try using a file to taper the band edges, if you have one. Be sure to buy a shrink-connector in the size that will fit over your bracelet. Measure carefully before cutting the band; you want it to be just big enough to stay on. The shrink-wrap connector can be coloured or painted after it has been shrink-wrapped, but not before.
Use a pair of oven gloves when heating the connector to keep from burning yourself. Super or Krazy Glue can adhere very quickly to skin, so be extra careful to not get it on you. Be very careful when using an X-acto knife; it can cut quickly and deeply, causing severe injuries. Never leave a candle unattended.