Digest - Glass Blocks Unlimited

Introduction
Although glass block has been defined as a particular "architectural statement"; this multi-functional material transcends any vogue; proves itself as a universal tool of beauty, art and light. The compilation of materials we have brought together here represents a collaboration of the most diverse items, combined to create a catalog of materials from all around the world. Some of these items will never be produced again; and the stock we present is all there is. Enjoy the opportunity to have this material as yours; for it is truly unique, artistic, crafted materials.
Why should I use glass block? Because it eliminates noise, permits light, yet provide us with a sense of security and strength similar to that of brick or concrete block; few if any other building products offer so many of the same aesthetic and functional uses; offering insulation, security, and light. With twice the insulative rating of concrete block, and with the greater versatility of hundreds of various trims, colors, textures and designs; the versatility and ease of installation offer refinement of the raw materials never before available. Certainly technology adds to the development to create the most refined, calibrated, technically outstanding functional materials to surround yourself ; consider the choices: "one way" glass, or magnified, filtered, duel faceted glass (different designs on each face), colored, reflected, curved light walls, bullet proof, fire proof, or dichromatic (multi colored) glass.
Lighting creates mood, forms and transforms our environment. These products redefine or create the understanding of your environment. It is about light, warmth, and design in creating a feeling, making an emotional statement which creates engagement, involvement; One can shape light by scattering or collecting light either away from or toward objects; by admitting or filtering out color; creating designs and patterns, by incorporating various sizes, colors and textures, one has the capacity to transmit design, influence or create a working shape and visual image, so dynamic that it becomes a part, en essence involving us in our environment, our surrounding, our being.
Be a purist, centered in the aesthetic, looking for the unusual, and not for the homogenized . Look deep, and combine the colors, sizes and patterns herein; you will find no other source on the planet that has a greater collection of rare, unique, extinct and more beautifully crafted glass block.
The personal opinions voiced here are merely this author's 20 years experience in glass block; they are what I " feel"; even though it is you who will enjoy the final material, my wisdom and experience in this field, having accumulated the largest inventory and the most diverse collection of glass block on the planet; if I offend some people for it, then produce your own catalog!

Determining the Quality of Glass Block
The Four "C"s
#1 Color
Glass is primarily made of silica sand. If this sand has any impurities the glass will result in discoloration, often as a greenish color. Most manufacturers choose not to discuss the color of their product; because their product is not of a quality substance or origin. This discoloration is not only undesirable, as it obscures the color and light transmission, but it difficult to control the shade of consistency in the glass. The weak direction of factories who in their desire to create clearer glass, use arsenic, lead and selenium (poisonous for air, water, plants, animals, people) to "pull" out the ferrous oxides in the process. There are numerous other bad side effects from poison bleach, such a continuing discoloration of the glass and the reaction to ultra violet (which results in the yellowing). Nearly all glass manufacturers use some arsenic/selenium to maintain a color consistency, but those who use it the most are the ones we should support the least. The value of grading the glass, based upon the effects on our earth, cannot be measured in dollar alone, and we must take part in the practice of discriminating these greedy polluters. These manufacturers will be designated by a thumbs down ( ). After all, if we don't resist those factories who threaten all life, who will?
#2 Optical Clarity
Measured by the amount of light that passes through the glass, the cleaner the glass, the more clear the light. The way the we rate the clarity of the glass vary, but your own observation will instantly tell you which products are clearer, cleaner, more brilliant. We have enclosed herein our consideration of the various manufacturers. The effect of the clarity of the block can only be witnessed when you compare, example, a Weck block (green and dull) to a Fidenza material (clean and brilliant).
#3 Consistency
All glass block are made by fusing pressed and molded halves together. In its process of pressing the hot molten glass, there are often "chill marks" which result. These inclusions result in imperfections, as we look through the glass, as they reflect the light and give the influence of lesser quality. All pressed glass contains some degree of imperfection, but some manufacturers are far better than others. We have termed those block whose consistency in grading out these imperfections with a . The importance of this effect is the standard of quality we see in the marks, scores, and minor defects and which factories are more often to have.
#4 Calibration
In fusing the glass the two halves are "welded" together. (This weld is found between the two faces of the glass, where the block is buried in the mortar.) As the glass cools, the block must be annealed, or tempered; otherwise it becomes brittle. The block may loose its shape and become out-of-square or deformed. This non symmetric block results in uneven faces or halves which are not square. The higher quality block are rated here with a if these block are straight on their face, square, and consistent. Often we will see the lesser quality blocks have wobbly faces or inconsistencies in sizing, thickness, or squareness.

Composition of Glass
72% silica (the primary factor regulating iron content/color)
14% sodium oxide 10% calcium ; a bleach which destroys strength
1.5% alum .5% potassium (added to regain strength)
iron content; creates discoloration; measured in parts per million (ppm);
weck & neg 500ppm
p.c.; mulia; 400 ppm
fidenza & kig ; 150 ppm

Thickness' of Glass Block
Recent demand and increased technology has lead a few of the more conscious factories to develop greater improvements in weight and strength of glass including the expanded range of block's thickness'. With the added 2", 3" 4" and 5" thick materials now available, you can flush out the block to both the interior and exterior of the wall, creating flush surfaces on even 5" drywall-to-exterior finish. No more drip sill, reveals, or need for special flashing, coping, corner bead, and recessed tile work.
1.5" thick block - light weight, practical for areas where space is critical (eg doors)
3" thick block - used most often in basement windows, cost savings
4" thick block - for areas where thickness and strength was most important
5" thick block - designed to flush out both sides; for extra thickness/strength
2" (50mm 1.5")
3" (80mm 3 1/8")
4" (95mm 3 3/4")
4" (97mm 3 7/8")
5" (120 mm 5")
Any of these blocks will work to create an effect, and each is made in the exact same manner, by "welding" two pressed faces. The effect is to create an aesthetically and thermally superior material to duel paned glass, plastic block, and now with the advent of colors, patterns and fire rated materials, the envelope of use is expanded further.


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