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- Gather materials. You will need coat hangers to cut into welding rod, silica gel packets (usually labeled "Desiccant: Do Not Eat" and packaged with electronics, shoes, and other things that hate the damp.) and lye to make into sodium silicate, and some decently absorbent paper (I used newspaper).
- Tools: a hotplate to cook the lye and silica gel into sodium silicate, a glass container to heat it in (use glass or a non-reactive ceramic container -- no metal, or Bad Things might happen), a scale, a toaster oven to cook the finished rods (I suspect that hot sunlight or a rod oven would work as well), a pair of pliers, nitrile gloves for safety. Safety glasses would prob be a good idea. I needed a mortar and pestle to grind up the silica gel beads, but I do not have one, so I used a steel rod to roll out the beads.
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- Get smashy with the silica gel beads. I tried to crush them by whacking them with the end of a steel rod, but they flew all over the place. Next step was to rig a paper cover over the "mortar," but that did not work very well.
- A tactic that kind of worked involved folding the beads into paper, then rolling the package with the rod. A real mortar and pestle would have worked better, but this was good enough.
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- Hangers are usually covered with paint or clear varnish to keep them from leaving your clothing wrinkle-free, but stained with rust. (This is actually totally conjecture on my part -- as far as I know, I have never used a hanger for the intended purpose.)
- Sand away the varnish or paint until you are left with a shiny rod of steel.
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Time for some chemistry. Zero your scale.
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- Sodium silicate is made from water, silica gel, and sodium hydroxide (lye). The proportions (by weight) are six parts silica gel (crushed as best you can), four to eight parts lye (four will work, eight is stoichiometric, anywhere in between is fine) and ten parts water. Weigh out the parts individually.
- Wear gloves and goggles for this part. A little lye in the eye or in a cut on your hand will ruin your day.
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- Heat the water, then slowly add the lye while stirring. If you just dump the lye in you will get a solid, hard lump of a brutal base at the bottom of your heating vessel. The only way I found to remove it was neutralizing it with some decently strong hydrochloric acid. It totally looked like Science, but was an annoying waste of time.
- Heat and stir until you get a clear, but ominously thick solution. Be wary, but not too afraid -- it can smell your fear.
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- This next part can be tricky -- you need to add the silica gel powder to the lye/water solution, but just a little bit at a time. Take the solution off the heat when you add the powder, then return it to the heat while you stir. If you leave it on the heat too long it will boil over in an instant. If it gets too cool the silica gel will not go into solution, and clump at the bottom.
- The result will be a gummy gel. Sodium silicate!
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- Roll the saturated paper around the steel rod. Try to get it as consistently tight as possible. For me, this is far harder than one would think.
- Eight to ten layers of paper will do. Smooth the layers as they go, and smoosh the trailing edge into the rest of the wrap.
- Take a pliers and crimp the gooey paper tightly into the rod. Why? The patent states "The principle object of this is to secure uniformity in the density of the coating on all sides and thus prevent the coating from disintegrating faster on one side than another to such an extent as to destroy the crater. The creasing or scoring also tends to retard the transmission of heat and affords a means whereby the disintegrated portions may become detached, assuring the maintenance of a crater rim of uniform or regular contour." That's why.
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I used the recommended settings for a 3/32 (ish) rod -- DCEP, around 100 amps.
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- Weld side is not pretty.
- Back side shows good penetration.
- Chopped the weld up for a closer look.