Turmeric Ink

Interesting experiment I did yesterday, though probably not one that will end up in my book. It is interesting enough that I thought I should write about it here though.

I don't know if I have mentioned it yet, but one of the subjects that will be in my book is soap making. This requires lye. My problem was that I need some means of measuring the concentration of lye in solution. So, I started looking up how to make acid/base indicators. On a page I found on a totally unrelated subject, they had a note at the end pointing out that turmeric turns red when exposed to a base. It did not take long before I knew a whole lot about curcumin, the chemical in turmeric that gives it the yellow color (and that turns red in a base).

So, it turns out that this chemical is not water soluble (or at least, not significantly), but it is soluble in alcohol. I happened to have some 91% rubbing alcohol (for making black powder, which I may write about in the future) around, so I put some turmeric in a small cup of the rubbing alcohol. The liquid turned yellow (ie, clear yellow, after the turmeric powder settled to the bottom). I messed around with this solution by mixing a bit with some baking soda, and also with some of the lye that I made for making soap. It turned pretty dark red.

So, next I made a larger batch and soaked some small squares of paper it in, to make indicator strips. I set the paper squares on some wax paper to dry and then decided to play with the leftovers. I poured just a little bit of lye into the white ceramic container that the solution was in, and the liquid turned blood red, literally (it was actually mildly disconcerting).

Well, I wanted to see how it would handle on paper, as ink (you know the whole "signed in blood" thing). Well, I discovered that this red solution bleeds out on the paper quite quickly (due to the alcohol). Not all of the solution had turned red, but since both parts were mixed, the yellow portion was not obvious. When the solution bleed out into the paper though, the yellow flowed better, thus the red spot had a yellow "halo" around it (I suspect the water in the lye solution made the red flow through the paper slower than the yellow part that was mostly in alcohol). Also, over time the red spot turned mostly yellow. Now, it is possible that this is partially because the lye concentration was reduced as it was absorbed into the paper. However, the largest effect comes from acid in the paper partially or entirely neutralizing the lye. Experiments with acid free paper actually confirmed both of these. The red ink immediately becomes orange, telling me that the affect on lye concentration had some effect, but it did not turn entirely yellow (or become more yellow over time), telling me that the acid in the other paper was also playing a large part. My solution to this will be to add stronger lye to make more of the ink red and to counter the dilution of the lye as it soaks into the paper (the lye is in a water solution, so I don't want to add enough to affect the solubility of the chemical, so stronger lye means more base with less water). First though, I will have to evaporate down my lye to increase the concentration.

Ok, so next I wondered how easy this would be to use in a printer cartridge. I had a black cartridge that had recently run out, as well as a replacement waiting to be installed, so I figured that if it damaged the cartridge, it would be no great loss. So, I cleaned out the cartridge (with water, since the HP black ink is not alcohol soluble, but is water soluble) and refilled it with another batch of the ink (carefully strained so that the turmeric particles would not block the jets). Besides the fact that my homemade plug is not very good, so air leaks into the cartridge, causing smearing from too high of ink flow, it actually worked pretty well. Ironically, printing from my Windows XP computer uses color ink for gray-scale, even when set for black only, so gray-scale gradients did not use the cartridge properly, but my Linux computer worked perfectly when set to use black only.

There are a lot of cool uses for this ink. If you got the concentration right, it would probably make a fine replacement for yellow printer ink (assuming your prints would not be exposed to alkaline environments). A better application though, is security. First, if you put a basic solution on the print, this ink will turn red (or pink, if the ink volume is not very high). Acid will turn it back yellow. Second, evidently, this chemical fluoresces under black light. Printed at a low volume, you could essentially use this ink to make security "watermarks" that could be authenticated using a black light and simple chemical tests. I have also seen suggestions for using this as highlighter ink, which would probably work extremely well at the right concentration.

Since most of the above applications are not currently important to me, what I have now is a cartridge that allows me to print acid/base indicator paper which I can cut into strips for use in my experiments. (This is actually pretty cool, since the printer should be able to always get the same ink volume, once I fix my plug, and also uses a lot less solution per strip.)

A big note here: This stuff is messy. There are few things that it will not stain (it did not stain the ceramic sink, but other smooth surfaces did stain). Since it is not water soluble, it will only wash off extremely smooth surfaces (and, with a lot of pressure and the rough side of the dish washing pad). You can soak your sponge or rag with alcohol and it will wash off most smooth surfaces this way, but may still leave light stains. If the stains are slightly orange to red, you can wash with vinegar to turn it yellow (less visible), but exposure to a base should turn it red. Oh, and I would not expect this to wash out of clothes easily. And, if you do the printer thing, if the jets clog when you don't use it for a while, try cleaning with alcohol, since water will not help much.

I do not know the long term effects of using an alcohol based ink in inkjet cartridges. Also, since I did this yesterday, I don't know if this ink will decay or discolor over time. As of now, this is extremely experimental.

Lord Rybec

Publish Post

Plastics, continued

I've managed to do a lot more work and gather a lot more information on plastics since my last post. Here is what I have learned:

The ideal method for making the casein (milk protein) plastic uses 2% milk. 1% works also, but may require some blending to get the majority of it dissolved. Just heat the milk to simmering and then add some vinegar. I forget the exact amount, but if you don't add enough to totally separate it within one minute, just add a little more (see my previous post on plastics for ideal measurements).

If you do not add some baking soda to dissolve it a little bit (don't add too much, or you get glue; again, fairly exact measurements should be in the previous plastics post), it will be very difficult to mold. Once the stuff is dissolved into a very thick goo, you can let it sit for a bit to make it less sticky (this also allows the vinegar/baking soda reaction to finish). I found that it is easiest to work with if you let it sit for around 10 minutes (in a humid climate, it might need more), then work it with wet hands. You should definitely knead it, to get the bubbles produced by the vinegar/baking soda reaction out (bubbles will weaken it). Since it tends to warp a lot when drying, the best use is to make a flat sheet of plastic (put weight on it while drying, but make sure it gets enough air for it to dry; good luck). At 1-1.5mm thick it is brittle enough to break easily, but strong enough to use as a guitar pick (I am not good enough to "rock out", so it may not handle more active playing). At .5cm thick, it is still brittle, but much harder to break. Much thicker takes a very long time to dry (I have a piece that is almost 1cm thick that is still not dry after 5 days). If you prevent the surface from drying for too long, it can mold (I was cycling between weight that restricted air access with open air drying with no weight), but it can easily be sanded off once it is dry.

Casein plastic is extremely easy to shape and cut with a Dremel tool. It is reasonable to assume that it could be shaped with a CNC grinding machine. With a Dremel, you can etch artwork into the surface of the pieces.

If you have a good coffee grinder (that you do not intend on using for coffee ever again), you can grind cardboard into a fluffy powdery substance (similar in texture to cellulose insulation; also, avoid breathing the dust). If you mix this with the plastic before shaping and drying it, it will be many times stronger and far less brittle. You will need to add some water when mixing, but only add as much as you need to keep it moldable (otherwise it will take too long to dry). You will need to add quite a bit of the ground paper fiber to get the strength indicated above, but even a little should make a difference. (I used cardboard from cereal boxes. It was a little lumpy, but worked fine. I also happen to know that corrugated cardboard grinds really well.) Using longer cellulose fibers should work even better (things like cotton or hemp should perform far better than the paper fiber).

Note that adding the baking soda makes this plastic mildly water soluble. You can fix this by soaking it in vinegar for a few minutes, after it is dry (you might be able to do this wet as well, but I have not tried it). Don't leave the paper plastic composite in vinegar for too long, because the paper wicks the vinegar in deep, and bubbles will form within the plastic from the reaction. After this, you have to let it dry again (a few hours or so). This makes it water resistant. More than a few minutes exposure to water will still soften the plastic (and it will probably warp while drying), but it will not make the surface slimy or make the plastic dissolve.


I also tried making plastic from wheat gluten (yes, that is the thing that some people are allergic too; I am not sure how exposure to the skin would affect someone with such and allergy, so be careful if you are one of those people). I extracted the gluten manually. First, I mixed white (not bleached) flour with water (you can use whole wheat flour, but it takes longer as there is more fiber to get out). You want enough flour that you end up with a thick doughy mixture. It should not be significantly sticky (if it is, keep kneading in more flour until it is not). Once it is kneaded out well, make a ball and put it into a bowl of water that entirely covers the ball of dough. You can refrigerate this, but you do not have to. After several hours, you begin kneading it again, in the water this time. You will notice the water turns milky (this is wheat starch and other non-gluten wheat products). The surface will start to become loose pieces that are slightly sticky and extremely stretchy. This is the gluten. It sticks to itself well, so if pieces come off, just stick them back on. When the water becomes really white, dump it out (you can actually collect this and evaporate the water to get wheat starch) and put new water in (or, if you have a fairly large bowl, you can run the water while kneading). Eventually, the ball will no longer make the water white when kneaded or squeezed hard. At this point, you have fairly pure gluten. This gluten can be kneaded into a ball and then flattened and dried. It tends to shrink a lot when drying and thus warps a lot like casein, and so should be treated similarly when drying. This should work with reconstituted gluten powder that can be bought at the store, but I have not tried it yet.

A good note here is that gluten reacts oppositely to ph levels as casein. In other words, if you soak it in a little vinegar, it will dissolve, while a base (like baking soda) will return it to the rubbery insoluble that it started as. I have a few experimental applications for this property that I will discuss in a future post.

This plastic is also fairly hard, but brittle. I have not tried making a piece thicker than 1.5mm, but that thin piece worked fine as a guitar pick. The color is translucent, dark brown, as opposed to the opaque ivory color of casein. The gluten plastic also held a lot of air bubbles. I don't know if these are removable without the use of a vacuum jar or similar vacuum device. This plastic is naturally water resistant, but like the vinegar processed casein, it will still become soft with more than brief exposure to water. It is also easily workable with a Dremel, or similar rotary tool.


My next experiment with plastic is a fairly common bioplastic (the above are also technically bioplastics, though you would probably not find them on a list). It is made from starch, vinegar, and glycerin. The vinegar breaks down the part of the starch that is not a good polymer, so that it can become a good polymer. The glycerine makes if flexible. The amount of glycerine determines the flexibility, so a harder plastic can be made with less, or a more flexible with more. See: http://www.instructables.com/id/Make-Potato-Plastic!/ Note that this is a good application for the starch removed from the wheat gluten.

Starch is easy to obtain, as is vinegar. Glycerin is a bit harder to find. So I have gone to efforts to determine how to make it. In short, you make lye from wood ashes. With lye, fat/oil, and salt, you make soap. The byproduct is glycerin (which is sometimes mixed into the soap, but not for this application). An interesting note is that if you add the right amount of methanol to the lye, you will get biodiesel instead of soap, still with a by product of glycerin. So, instructions for making biodiesel will be in my book as well.

Lord Rybec

Composites

Composites are materials that are made from two components, one of which is a matrix and the other a binder (often called the resin). The matrix is some sort of fiber, while the binder is typically some sort of epoxy resin. Fiberglass composite is made with fiberglass for the matrix and fiberglass resin as the binder.

The benefit of composites is that the combination of matrix and resin can create substances that have most of the good physical properties of both substances, and few or none of the poor physical properties. It is also common for composites to have additional good properties that neither of the original materials had. For instance, fiberglass resin by itself tends to be weak and brittle and fiberglass is extremely flexible and easily pulled apart. Together though, they create a strong, rigid, slightly flexible substance that is also fairly hard.

When making composites, you generally entirely soak the matrix in resin, then remove as much resin as possible. This minimizes the negative properties of the resin, while still effectively binding the matrix (the ratio of matrix to resin is sometimes used as a measure of quality of a composite). In industry this is often done using vacuum bags. (The composite is put into a large plastic bag, then the air and excess resin is vacuumed out.) In a post apocalyptic setting it will probably not be feasible to use a vacuum bag, even if you do happen to have the proper equipment. Instead, a tight fitting mold would work (one with two parts that compresses the material between the parts).

As an experiment, I am going to try using casein glue (see the previous post) with cotton or some other fiber that is commonly used in fabrics (I have to see what my wife has that she does not need). Since casein seems to bind well with cellulose (it was originally used as wood glue), cotton or some other natural fiber would probably be ideal. I think I actually have some scrap cotton around, so I'll use that for the first test.

Another common type of composite is wood laminates. (Look at the edge of a piece of plywood. Notice that it is made from several layers of wood glued together? This is a wood laminate. Plywood has several layers that alternate the grain direction, to make the sheet strong in all directions, instead of just directions that do not follow the grain.) In theory, casein would be a suitable glue for this as well, though probably not as good as the thermal epoxies commonly used now.

Plastics, glues, and paints

In a few more weeks, I will have a chance to test the forge. In the mean time, let's discuss plastics.

In a post apocalyptic world, it is likely that you will eventually discover something you need that would not be suitable made from metal, or something that would be extremely difficult to make from metal. Plastics are ideal for a lot of products and are generally easier to mold or cast. The problem here is that most modern plastics are made from crude oil products, which will not only be extremely difficult to obtain in a post apocalyptic world, but which also require chemicals which are dangerous and will be equally difficult to obtain. Thankfully, you will likely have at least limited access to ingredients to make plastics that were used as far back as ancient Egypt.

Milk contains a protein (or actually a class of proteins) called casein. This protein can be extracted by making the milk acidic. Generally the easiest way to do this is to add vinegar. My research has yielded many different formulas for this. The one I tested was 2 teaspoons of vinegar for every cup of milk. This was the lowest vinegar to milk ratio. The recipe with the highest ratio recommended 12 teaspoons per cup of milk. The 2 teaspoons to 1 cup of milk worked relatively well for me and in a post apocalyptic setting, I would go with the smallest amount that works well, to conserve resources.

The recipe I used said to warm the milk to simmering, then add the vinegar (2 teaspoons per cup of milk) and remove it from the heat. I did this on an electric stove, though if electricity was not available, you would be doing this over a fire. The protein separated from the milk very quickly (note that you should stir the milk as it heats and as the vinegar is acting). Once the milk had separated entirely into clear whey and lumpy, white curds, I strained out the liquid. This can be done with whatever is available (I used a plastic coffee filter; a paper one would probably have worked better). The instructions then said to add 1 more teaspoon per cup of milk (original volume, not the new volume) and to let it sit for an hour or two (it said to do this in a jar). The curds were supposed to separate further from the remaining water and the added vinegar, but it did not happen the way it was supposed to. Now I'll get back to this in a moment.

It turns out that casein can also be used to make glue (and paint). The previous instructions are actually the first part of making glue, except that you do not add any vinegar after filtering (I am not even sure that adding the extra vinegar after filtering is useful for making plastic; it could probably be skipped without any problems). Once it is filtered, you add some baking soda to neutralize the vinegar. This allows the casein to dissolve in water once again and the result is a sticky mess. I do not recall the exact amounts, but you can add 1/4 of a teaspoon per cup of milk (original volume again, not the new volume) at a time, mix it well, then give it 5 minutes for the reaction to finish. If it is not a sticky, gluey consistency after 5 minutes, do it again. Once you have the right consistency, you can add water to dilute it if needed (there should not be any curds or lumps). This can also be used as paint, by adding more water until you have the consistency you want for paint (food coloring or other pigments can be added for color). Casein glue was originally used as a wood glue, so this stuff has some construction applications (though I would not trust it to hold a lot of weight, without extensive testing).

Ok, back to the plastic. Even after a lot of kneading (as recommended in the instructions), I was unable to get the curds to stick together well enough for molding or casting (it is possible I gave up too soon). So, knowing about the glue recipe, I decided to try something else. I added around 1/8 of a teaspoon of baking soda to the mixture. This allowed some of the casein to dissolve, but not all of it. At first, the result was a sticky, rubbery, fluffy substance. The reaction between the vinegar and the baking soda produced a lot of CO2 bubbles, which made the casein mixture fluffy and airy. Of course, this is not good for a plastic as it will dramatically weaken it. So, I waited for the reaction to finish. This took around 5 minutes. After that, I kneaded the bubbles out of the mixture. It was no longer sticky, but it was still quite rubbery. At this point it was perfect for molding or casting. So, I rolled it into a ball, then flattened it between two pieces of wax paper. It is now between 1/8-1/4 of an inch thick, with a diameter of around 3 inches (this was from 1 cup of milk). It is currently setting. For flat pieces, you should put some weight on it while it cures, to avoid curling or warping. In the morning I will check it and maybe post the results (though, it may not be finished curing).

Some extra notes:

• This plastic is not very strong without a little bit of extra processing. Thick pieces should be fine, but thin pieces like the one I am making will probably be easy to bend until they break. If you happen to have access to formaldehyde, soaking the plastic in a 5% solution will strengthen it. This can take a long time however. One source said that plastic 25mm thick can take over a year of soaking to be entirely strengthened. Also, this process tends to cause warping. I can think of a few other ways of strengthening this plastic.
• Adding some kind of fiber should improve the strength. Cotton would probably work, fiberglass might work as well. If you want to make actual composites, you should probably use a thick mixture of the casein glue on cloth made from the chosen fiber. More on this in the next post. Also, this is supposed to be water proof once it is totally dried and is porous enough to paint.
• Casein is a food protein and as such will eventually spoil if left wet. Refrigerating it will extend its usable life. These products should last around a week or so refrigerated. Generally, it is probably best to only make them as they are needed.
• Even after it is dried, casein plastics will decompose if left wet for long periods of time. This is not generally enough to be a problem in daily use and is actually a good thing. Unlike petroleum plastics, Casein plastics are biodegradable.
  
• As this plastic can warp when drying, it has been common to cast a piece in a large chunk, then grind it to the desired dimensions. Historically, casein plastics used to make buttons were cast into long rods, cured using the above formaldehyde solution, then sliced and drilled to make the buttons (with additional grinding for more complex patterns). I will probably end up grinding the piece I am making into something, though I have not decided what yet. In theory, you could use a CNC milling machine to mill this plastic into useful objects (though, this would not be that useful in a post-apocalyptic world).
  

Forge: 12 Quart Pot

My 12 quart pot forge is nearly finished. It has been lined with 3cm thick of the refractory cement discussed in the last post (5cm on the bottom). Since one of the ingredients is concrete, I am having to give it time to cure, so I have not tested it yet. Once curing is finished and the lining appears dry, I will be cooking it, starting at 200F and working slowly up to 450F. When that is finished, I will line the forge with a thin layer of fireplace cement (to protect the refractory cement lining). I'll have to go through the cooking process again to purge the water introduced in the fireplace cement, then it should be ready for firing.

Again, I am using a blow dryer for air. It is possible that I might need to use more than one, given that the volume of this forge is around 10 times the volume of the flower pot forge. (I am using bigger pipe this time, though, so the ability of the blow dryer to provide airflow will be increased.)

In addition to the forge, I used the leftover refractory to make a lid. There was only enough for a 1.5cm thick lid, which may not be sufficient, but I can always add more cement to one side (the only ingredient I do not have a lot of left is sand and that is pretty easy to come by). Also, I will have to cut a hole in the middle of the lid to allow air flow. Since the lid is pretty thin, this may be difficult without cracking it. The benefit of the lid is that I can use it to contain heat when melting metals.

Once the forge is fired, and the refractory mixture tested, I'll post complete instructions on how to make the refractory (assuming it works properly).

Forge: Final Refractory Research

Ok, so the experiment with the clay and perlite is finally finished. Perlite already contains a lot of alumina, so I tried just mixing clay with powdered perlite (I used the bottom of a metal cup to crush it; a better option would have been a ball mill). The first brick was even parts (by volume). It cracked into two pieces and had a lot of spalling. The second was 2 parts perlite to 1 of clay. It broke in two, with only a little spalling. The last was 3 parts perlite powder to 1 part clay. The surface melted slightly, but there was no cracking or spalling. (I believe the last brick was tested after I started using fuel pellets, so the temperature was probably considerably higher than with the first two.)

So, my plan was to line the next forge with the 3 to 1 mixture of perlite powder and clay. I was also going to add some non-powdered perlite, but only pieces between 1mm and 3mm. I ran into a problem with this. Powdering perlite takes a long time. Also, perlite is mostly air, which means that an 8 quart bag of perlite yields only about 2-3 cups of powder. So, I started looking around for alternative refractory mixtures again.

This time I found a mixture that looks really good. The recipe is 2 parts clay, 2 parts silica sand (beach sand is primarily silica; play sand at hardware stores is also mostly silica), 1.5 parts perlite, and 1.5 parts Portland cement. I used this mixture, but I added the 3-4 cups of powdered perlite to the mix, and I also increased the portion of regular perlite, to improve its insulating properties.

I have not tested this mixture with heat yet, but I have finished the forge and will be testing it once it is totally cured and dried.

Forge: New Design

Ok, scratch the paint can. A while back I bought a 12 quart stainless steel pot. Originally I intended on using it for making charcoal, but then I realized that it would make a much better forge than the gallon paint can. It is also much larger, giving me more work space.

For air input I cut a hole in the side just large enough to accommodate steel plumbing pipe.

More on this later today.