Underwater lights can be used for many purposes, like lighting up your home pond. They can also be used on a boat to attract fish, or to search the bottom of a lake or pond. Photographers use underwater lights to capture images several fathoms deep, where sunlight does not penetrate as well. Since there are so many uses, it is smart to make your own homemade underwater lights to suit your specific need.
Basic Underwater Lights
The most simple underwater lights can be made from a mason jar, rubber gasket and light bulb. One strategy is to contain the light bulb and fixture inside the mason jar. To do this, you need to buy a battery operated light bulb like you would find in a flashlight or a bank of LED lights that run from corded power. The lights can be positioned inside of the mason jar so they point down and shine out from the bottom. Then a rubber gasket is installed around the top, and the lid screwed on very tight. Silicon caulking can also be used to seal the lid on the jar and keep them water tight.
A better option for boaters, scuba divers and fishermen is to build a waterproof box from plastic and glass and install LED lights inside. The LED light bank will face towards the glass cover. The box can be constructed of 1/2 inch thick plastic boards. The best strategy is to glue the plastic boards together with acrylic glue and seal them with silicone caulking. Then install the LED lights and place the glass cover over them. Secure the glass to the box with adhesive (acrylic glue or PVC cement), then caulk the edges with silicone.
The cords that run from the underwater lights to the power connectors can be waterproofed in several ways. First, a small hole is drilled into the unit so the cords can be passed through. Once the cords are passed through the hole, you must create a water proof seal around them. One way to do this is to fill the hole with silicone caulking. Another is to install a rubber gasket in the hole, pull the cords through and then fill the remaining area with caulking. You can also use plumber's putty to seal the holes. Every hole should also be coated with another layer of clear-coat sealant and checked for leaks.
Materials for Housing
The housing of your water lights can be made from a host of different types of materials. One of the best is plastic acrylic, which is sold in sheet boards that can be cut using a table saw. Another material that can be used is wood, as long as it is sealed in three to four coats of clear-coat sealant. A fiberglass enclosure box is also an option. One can be made from a simple box form, and a glass or plastic lens can be fitted over the top. The edges must be cut straight with a table saw to ensure the lens fits tightly, however.