On the subject of building cheap, simple, handcraft, non-flammable electronics cases suitable for prototyping, there was an important oversight of mine that I was thinking about for quite some time but did not yet discuss in detail: clay. At the outset from an arts and crafts standpoint, clay is simply Playdough’s heavier, harder, more difficult to work, and more traditional counterpart. Alas, on the subject of flammability and fire resistance, the differentiation is obvious. Just as the ground beneath your feet does not burn, dried clay does not burn, ever. Clay that is baked into ceramic is especially fire resistant. A thermite reaction does nothing to melt or burn through a ceramic gardening pot. Intuitively, if clay or a substance of clay is used correctly, it can also be used as an adhesive for paper and cardboard, in place of the typical combustible carbon-based adhesives.
20190301/https://en.wikipedia.org/wiki/Clay
20190301/https://en.wikipedia.org/wiki/Clay_minerals
Clay, fundamentally, is composed out of “clay minerals.” Some of these clay minerals, i.e. Kaolin group minerals, are used in the production of Portland cement. Clay contains water, and when the water is dried out, the clay hardens. When clay is heated in an oven, permanent changes occur to it that turn it into ceramic.
20190301/https://en.wikipedia.org/wiki/Kaolin
20190301/https://en.wikipedia.org/wiki/Montmorillonite
20190301/https://en.wikipedia.org/wiki/Nontronite
20190301/https://en.wikipedia.org/wiki/Saponite
20190301/https://en.wikipedia.org/wiki/Illite
20190301/https://en.wikipedia.org/wiki/Chlorite_group
20190301/https://en.wikipedia.org/wiki/Sepiolite
20190301/https://en.wikipedia.org/wiki/Attapulgite
As it turns out, although I learned about rocks and minerals in one class of my previous school education, and I learned about chemistry in other classes, somehow I never really learned about the two put together. So, here I will put the two together, and do a quick review of the previous subjects where applicable.
20190301/https://en.wikipedia.org/wiki/Mineral
20190301/https://en.wikipedia.org/wiki/Silicate_mineral
20190301/https://en.wikipedia.org/wiki/Silicate
20190301/https://en.wikipedia.org/wiki/Obsidian
20190301/https://en.wikipedia.org/wiki/Volcanic_glass
Rocks are made out of one or more minerals. Minerals are the more pure form and material of rocks, which can either be described by a specific chemical formula, or a range of chemical formulas with minor variations. Certain kinds of minerals may also incorporate additional chemical impurities into their structure. But, the fundamental rule at play here with the chemistry of minerals is that of the most abundantly available elements and compounds. Silicate minerals compose approximately 90% of the Earth’s crust, and according to the book The Mystery of the Periodic Table by Benjamin D. Wiker, a little over 98.5% of the Earth is made up of only eight elements: iron, oxygen, silicon, magnesium, nickel, sulfur, calcium, and aluminum. “Oxygen and Iron by themselves make up about 65% of the earth.” In addition to the Earth’s dry crust, we literally have oceans full of salt water. Add hydrogen and sodium to the mix and you’ve pretty much covered all the elements used in most minerals. Despite the abundance of carbon in your own body, the places you live in, and the materials you work with, carbon is actually not that abundant on the Earth’s surface as a whole.
You can look at some of the previously mentioned Wikipedia articles on clay minerals for more information, but you need not be surprised that many minerals are composed predominately out of the elements that I’ve mentioned just previously.
So, now the revelation…
I thought I heard of a such thing as “silica glue.”
20190301/DuckDuckGo slica glue
20190301/https://en.wikipedia.org/wiki/Sodium_silicate#Adhesive
20190301/https://en.wikipedia.org/wiki/Metasilicate
20190301/https://en.wikipedia.org/wiki/Sodium_metasilicate
20190301/DuckDuckGo sodium silicate cement flammable
20190301/https://www.artmolds.com/artmolds-sodium-silicate.html
20190301/http://fosterproducts.com/wp-content/uploads/2017/01/Childers-PDS-CP-97-R0915.pdf
20190301/https://en.wikipedia.org/wiki/Calcium_silicate
20190301/https://en.wikipedia.org/wiki/Vermiculite
Ah, yes, indeed there is something similar to what I was thinking. Sodium silicate, also known as water glass, can be used as an adhesive. Especially advantageous is that it has been successfully used for applications such as building insulation fusion where non-flammability is required. Its constituent elements are sodium, silicon, and oxygen. No carbon is included. The anions are often polymeric, so despite the exclusion of carbon, it can function similar to more familiar glues nonetheless. Even better, sodium silicate is a proven adhesive used in the manufacture of cardboard. Sodium silicate does not work well for gluing paper together, though, as the adhesive is hard and brittle.
Application of sodium silicate glue is simple. Apply the paste by brush to the components to be glued together, and join the components within 5 minutes of application. Wait one hour for drying and hardening time. To clean up excess, simply use warm soapy water… before hardening is complete, otherwise it cannot be removed from some surfaces such as glass. Sodium silicate is soluble in water, so it can be washed away from some surfaces even if it has hardened. The commercial adhesive CP-97 that I linked to is actually a fibrous adhesive that gets stronger as it ages.
Also, be careful with sodium silicate because it is alkaline and can be quite an irritant to the skin and eyes. Wear waterproof gloves and safety goggles while handling, and wash thoroughly after handling. “KEEP OUT OF REACH OF CHILDREN” is stated by one supplier’s website. After opening the storage container for the first time, sodium silicate has 18 months of shelf life. Because sodium silicate is soluble in water, if it gets wet after it’s been applied, it can form a strong alkaline solution that can be quite an irritant to someone who touches it.
20190301/DuckDuckGo water glass
20190301/https://www.lehmans.com/product/water-glass-liquid-sodium-silicate
20190304/https://www.britannica.com/science/water-glass
Interestingly, you can make your own sodium silicate relatively easily by mixing silica gel beads, used as desiccants for electronics, and drain cleaner, which contains sodium hydroxide. Wear excellent eye protection, a face shield, gloves, and work in a well-ventilated area since this involves a caustic ingredient. Crush the gel beads, mix water with the sodium hydroxide, and gradually add the gel beads into the mix, stirring and heating. Do not let the solution over-boil. Consult the following references for more precise details.
20190301/https://www.thoughtco.com/make-sodium-silicate-or-water-glass-608271
20190301/http://www.instructables.com/id/How-to-Make-Sodium-Silicate-Water-Glass/
20190303/https://en.wikipedia.org/wiki/Silica_gel
Also, when wet sodium silicate is applied to egg shells or the surface of cured concrete, “it chemically reacts with calcium hydroxide or calcium carbonate to form calcium silicate hydrate.” Again, calcium silicate is often used in fire protection, owing to its non-flammability, so naturally it also works well for creating non-flammable electronics cases.
Note that borax is a good fire retardant additive for paper and cardboard. But be careful! It is a reproductive hazard too. Potassium silicate can also be used as a fire retardant, but maybe it is less preferable to work with as it is strongly alkaline.
20190301/https://en.wikipedia.org/wiki/Borax
20190301/https://en.wikipedia.org/wiki/Potassium_silicate
Speaking of sealants, what is the chemical composition of the typical glaze used for pottery? Fundamentally, this glaze is glass, so the chemical is a silicate. Word.
https://en.wikipedia.org/wiki/Ceramic_glaze
https://en.wikipedia.org/wiki/Vitreous_enamel
So, after all this discussion, I thought of it as a good idea to summarize an inventory non-flammable earthenware. That is, materials composed out of the predominant materials available in the Earth’s crust.
- Sand
- Vermiculite
- Gravel
- Rocks
- Granite
- Clay
- Ceramic
- Concrete
- Plaster
- Glass
- Quartz
- Portland cement
- Sodium silicate
- Calcium silicate
- Aluminum
- Glass wool
It really is quite simple… but it’s surprising that, due to our human exposure with many carbon-based constructions and lifeforms, it’s so easy to forget about this alternative world of abundant chemicals beneath our feat. It’s also interesting to think about the sharp contrast between typical chemical inertness of silicon-based compounds versus carbon-based compounds. Carbon-based compounds burn readily, but silicon-based compounds are curiously inert against combustion. Perhaps that partially explains why, despite the plausibility of silicon-based lifeforms, only carbon-based lifeforms are known to exist on Earth, and our animated, silicon-based, computerized creations are distinctively the product of intelligent human construction.
These metals are not very useful in their pure form, but can be quite useful when used in alloys.
- Iron, its pure form is prone to rusting
- Magnesium, its pure form is prone to burning
Interestingly, reading about thermite on Wikipedia notes that under the correct conditions, metals can burn quite similar to how wood or gas burns. So, for sure, chemical compounds are very instrumental in making a highly reactive pure element chemically inert, relatively speaking.
20190301/https://en.wikipedia.org/wiki/Thermite
20190301/https://en.wikipedia.org/wiki/File:Thermite_residues_%28railway_welding%29.JPG
What about fiberglass? Alas, don’t get confused here… the term fiberglass is commonly used to refer to a plastic that is reinforced by the addition of glass fibers. Glass fibers together as a pure material is most commonly used in “glass wool” as home insulation. Glass wool insulation hurts the hands to the touch, so it is not commonly used in many other materials, enough said.
20190301/https://en.wikipedia.org/wiki/Fiberglass
20190301/https://en.wikipedia.org/wiki/Fiberglass_molding
20190301/https://en.wikipedia.org/wiki/Glass_wool
20190301/https://en.wikipedia.org/wiki/Glass_fiber
20190301/https://en.wikipedia.org/wiki/Fiberglass_mesh
Here is some related information that I found when searching for the previous article information, but it is not quite on the same topic. Geologists classify clay versus silt by particle size. Loam is a mixture of clay, silt, and sand, and it is very useful for agricultural soil. It can also be used for building construction.
20190301/https://en.wikipedia.org/wiki/Loam
Geotextiles? This is just a fancy name for the applied use of textiles to geo-scale projects. No special materials are used that were not previously covered.
20190301/https://en.wikipedia.org/wiki/Geotextile