Glass Block Lights – Make Your Own

Glass Block Walkway Lights

Make Your Own

This site describes a project to build outdoor landscape lights from glass blocks. These lights are used to illuminate a flagstone path/patio around a Koi pond, which is also built using glass block.

The block used is Pittsburgh Corning Premiere series Decora LX Filter block, 8" x 8" x 4". This block contains a thin sheet of white fiberglass that acts as a light diffuser. Similar blocks made by Seves and Mulia are sold by Home Depot and Lowes.

The block is first painted with decorative scenes using FuseMaster Transparent glass paints. These are not paints in the traditional sense, but are actually finely powdered colored glass. The powder is mixed with a liquid medium, painted on the glass, then fired in a kiln to 1175 degrees Fahrenheit. The result is a finish that will not fade soon in sunlight or scratch off, as it is actually glass itself.

After the painting is completed and fired onto the glass block the block is drilled so that a light bulb can be inserted. Drilling is done using a 1/2-inch diameter diamond core bit. The hole for the light is drilled on the side of the fiberglass diffuser opposite the image painted on the block.

1/2-inch diamond core drill

The lights use 12 volt 50 watt quartz halogen bulbs. The sockets are fashioned from Mill-Max pin sockets, hobby brass tubing, and a silicone rubber stopper. This assembly is pushed into the drilled hole and powered at half-wave rectified voltage so that the lamps are running at about 12 Watts which results in an extremely long lifetime. The socket assembly is made long enough so to position the bulb at the top of the block. The 'roof' of the finished glass block light will shield the glare from the bulb from the viewer.

The roof of the glass block light is made from slate floor tile. The tile is sawn into strips using a diamond blade and a circular saw and glued to a sheet aluminum form bent to the roof pitch.

Roof made from slate floor tile

The two sides of the glass block are covered with sheet copper and allowed to naturally form a patina. 20 mil (0.020-inch) copper sheet is used.

Sides made from sheet copper.

The block sits on a base made from the same Arizona Sandstone flagstone as the walkway/patio that the glass block lights illuminate.

Flagstone base.

NOTES & DETAILS:

The scenes I chose to paint on the glass blocks were inspired by large (5 1/2 inch diameter) stamps once made by Zia Rubber Stamps.
Five different scenes were made. Two blocks were made with each scene to provide the ten needed block lights for this project.

A variety of mixing agents were used with the FuseMaster glass paint - squeegee oil, clove oil, and their own "Water Friendly Medium" were used the most. Many agents were tested, including vinegar, sugar, thyme oil, sodium silicate, and gum arabic. Rubber stamping the black outlines was done with moderate success. In some cases a lot of touch-up was needed as glass paints are not intended to be applied by that method. The colored paints were all applied by brush.

As the glass block contains a slight vacuum one has to be careful that when the drill bit breaks through the inside of the block that a minimum amount of lubricant (water) and glass dust gets sucked inside of the block. When the bit gets nearly through I periodically remove the excess lubricating water and glass dust slurry with a shop vacuum. This reduces the amount of material that gets sucked inside. One has to be careful handling the block after drilling as the glass core that will fall inside of the block may have sharp burrs that can easily make cuts through the delicate fiberglass diffuser. The core is pulled back through its hole with a tweezers and any glass chips are shaken out of the block through the hole just drilled. The hole is drilled through the bottom edge of the block where the glass is about 1/4-inch thick.

The copper sheet, the silicone rubber stoppers, and the brass tubing were purchased from McMaster-Carr. This is an industrial supply house but will sell to individuals. McMaster-Carr... http://www.mcmaster.com

The ten lights are powered from a 12V 25A transformer. The output of the transformer is half-wave rectified using a large diode bridge wired so that half of the string of lights runs off of the positive output of the diodes while the other half is powered by the negative output. This way the 50W bulbs run at 1/4 power and should last practically forever. Schematic Diagram. http://www.kissingfrogs.tv/lowvoltage.jpg

Firing is done in an AIM 1709 kiln with side and top heat and a Fuji PXV3 controller.

The diamond core drill bit is a DT-516 from Diamond Drill Bit and Tool ($18.95). They sell diamond core bits (hole saws) up to 4-inches in diameter, along with diamond files, diamond grinders, diamond saws, diamond Dremel bits, you name it. Prices are quite reasonable.

A great book on permanent glass painting is Contemporary Glass Enameling by Kay Bain Weiner. Image of Contemporary Glass Enameling.

Still another great book is The Art of Painting on Glass by Albinas Elskus. This book also covers painting glass with real “glass” paints that will be permanent in weather, not regular paints that will fade. Image of The Art of Painting on Glass.

I got the Fuse Master transparent glass paints from Fusion Headquarters: Fusion Headquarters -- http://www.fusionheadquarters.com

(C) 2023 Steve J. Noll