How to Make Your Own Lava Lamp!

lava lamp!!!!


Please note: This is part of a section on questionable eBay ads.  The information below has not been tested or verified.  It ia presented as an historical document only.  In other words: try this at your own risk.
 
OVERVIEW:

A container filled with clear or dyed liquid contains a non-water-soluble substance (the "lava") that's just a little bit denser (heavier), and has a greater thermal coefficient of expansion than the liquid around it. Thus, it settles to the bottom of the container. A heat source at the bottom of the container warms the substance, making it expand and become less dense than the liquid around it. Thus, it rises. As it moves away from the heat source, it cools, contracts a bit, and becomes (once again) heavier than the medium. Thus, it falls. Heavy, light, heavy, light.

THE CHEMICAL PART:

Method #1

Use mineral oil as the lava. Use 90% isopropyl alcohol (which most drugstores can easily order) and 70% isopropyl alcohol (grocery-store rubbing alcohol) for the other ingredient. In 90% alcohol the mineral oil will sink to the bottom; slowly add the 70% alcohol (gently mixing all the while; take your time) until the oil seems lighter and is about to "jump" off the bottom. Use the two alcohols to adjust the responsiveness of the "lava."

To dye the lava, use an oil-based dye like artists' oil paints or a chopped-up sharpie marker. To dye the liquid around it, use food coloring.

Two suggestions for better performance:

1) Agitation will tend to make the mineral oil form small bubbles unlike the large blobs we're all used to. The addition of a hydrophobic solvent to the mixture will help the lava coalesce. Turpentine and other paint solvents work well. To make sure what you use is hydrophobic, put some on your hand (if it's so toxic you can't put it on your hand, do you want to put it in a container that could break all over your room/desk/office?) and run a little water on it. If the water beads, it should work fine.

2) For faster warm-up time, add some antifreeze or (I've not tried it) liquid soap. Too much will cloud the alcohol. Keep in mind that the addition of these chemicals may necessitate your readjusting the 90% to 70% alcohol mixture.

Method #2

Several non-water-soluble chemicals fall under the category of being "just a little bit heavier" than water, and are still viscous enough to form bubbles, not be terribly poisonous, and have a great enough coefficient of expansion. Among them: Benzyl alcohol (Specific Gravity 1.043 g/cm3), Cinnamyl Alcohol (SG 1.04), Diethyl phthalate (SG 1.121) and Ethyl Salicylate (SG 1.13). [The specific gravity of distilled water is 1.000.]

We recommend using Benzyl Alcohol, which is used in the manufacture of perfume and (in one of its forms) as a food additive. It can be obtained from chemical or laboratory supply houses (check your yellow pages); the cheapest I could find it for was $25 for 500 ml (probably 2, maybe 3 regular-sized lava lamps' worth). An oil-soluble dye is nice to color the "lava"; We soaked the benzyl in a chopped up red felt-tip pen and it worked great. [Benzyl alcohol is "relatively harmless", but don't drink it, and avoid touching & breathing it.]

We found that the benzyl and the water alone didn't do much, so we raised the specific gravity of the water a little bit by adding table salt. A 4.8% salt solution (put 48 grams of salt in a container and fill it up to one liter with water) has a specific gravity of about 1.032, closer to benzyl's 1.043. I find that the salt tends to cloud the water a bit.. you might want to experiment with other additives. (Antifreeze? Vinegar?)

METHOD #3

MATERIALS NEEDED

Here is a list of materials you may need, and some common sources for them:
WAX: Canning and candle wax is the best source. It is used to make candles, or to seal the tops of canning jars. It can be found in craft and grocery stores, usually in a one pound box. For coloring, use candle dye, I have not had much luck using crayons to color the wax as the crayon tends to form flakes and chunks.

PERCHLOROETHYLENE: Also known as: tetrachloroethylene, ethylene tetrachloride, or ‘Perc’. Dry cleaners will probably sell or give you some, they generally refer to it as Perc (pronounced ‘perk’). Also found in spot removers and degreasers. Carefully check the labels. Perchloroethylene is non-flammable, so if the label says ‘flammable’ or ‘combustible’ keep looking. In these instructions, we will refer to this chemical simply as perc. I found a brake parts cleaner at Autozone that is pure perc. It comes in a red aerosol can and is called Brakleen, and it is made by CRC. The label on the back reads: Tetrachloroethylene 127-18-4, and the product number on the front of the can is 05089.

WATER: Distilled water is the best choice.

CANNING/PICKLING SALT: You must use canning and pickling salt, as ordinary table salt will cloud the water. Canning and pickling salt is PURE salt, it has no additives, and it is not iodized. It can be found in most grocery stores. Sometimes called just canning salt, or just pickling salt.

AUTOMOTIVE ANTIFREEZE: Buy the regular ethylene glycol antifreeze. The "non-toxic" propylene glycol antifreeze has a slightly different specific gravity, so if you use it, you will need to experiment with it some.

DISHWASHING LIQUID: We will only need a drop or two. I have always used the Dove brand, but any brand should do just as well.

MAKING THE LAVA

Several old canning jars with lids are perfect for melting, mixing, and storing your lava. Make sure the lids screw on airtight. The amount of lava needed will depend on the size of your lamp, for ease, we will make 1 cup of lava. If you don’t need a whole cup, use what you need and store the rest in an airtight container. If you need more, simply double or triple the measurements. We will start off mixing 1/3 cup of perc with 2/3 cup of wax. This is only a starting point, as different waxes will have different densities. Unless you have expensive, specialized, laboratory instruments, this is the only way to do it. Take notes while you make the lava. If you use the same brand wax, chances are you can reuse the same amounts if you make more lava.

1) Take 1 cup of water and pour it into an empty jar, and then mark the water line with a marker or tape, and then pour out the water. We will use this line to measure the wax, this saves us the hassle of trying to clean a waxy measuring cup.

2) Get an old pot big enough to fit a canning jar in. Fill the pot part-way with water, and bring it to a boil. Take your candles, and break them into smaller pieces if necessary, and place them in an empty canning jar. Place the canning jar into the pot of boiling water, and wait for the wax to melt thoroughly.

3) Place 1/3 cup of perc into the canning jar with the 1 cup line drawn on it. Then carefully pour the melted wax into the jar until it reaches the 1 cup mark. This will give us 1 cup of lava at a 33% perc, 66% wax solution. Screw the lid on tightly, and be careful, the perc will expand and greatly increase the pressure inside the jar. Gently swirl the jar to ensure the wax and perchloroethylene becomes mixed well. We now have created lava.

4) After the lava has cooled fully, stick a drinking straw into the lava. When you remove the straw, some lava should be stuck inside the straw. Squeeze this lava out of the straw and into the test solutions.

TESTING THE LAVA

I have an easy way to test the specific gravity of your lava without using expensive test instruments. Automotive antifreeze usually has a specific gravity of around 1.1 when it is undiluted. Distilled water has a specific gravity of 1. Mixtures of water and antifreeze will have the following specific gravities:

100% water, no antifreeze = 1.00
90% water, 10% antifreeze = 1.01
80% water, 20% antifreeze = 1.02
70% water, 30% antifreeze = 1.03
60% water, 40% antifreeze = 1.04
50% water, 50% antifreeze = 1.05
40% water, 60% antifreeze = 1.06
30% water, 70% antifreeze = 1.07
20% water, 80% antifreeze = 1.08
10% water, 90% antifreeze = 1.09
No water, 100% antifreeze = 1.10

Commercial lava is usually around 1.03. Mix up an 80% water, 20% antifreeze solution. Also mix up a 60% water, 40% antifreeze solution. If your lava floats in the 40% antifreeze solution, it has a specific gravity less than 1.04. If your lava sinks in the 20% antifreeze solution, it has a specific gravity greater than 1.02. Therefore, your lava is somewhere between 1.02 and 1.04, and should be close to 1.03.

NOTE: You can make your lava any specific gravity you choose, but 1.03 seems to work well.

NOTE: It is important that you let the lava cool thoroughly, as the lava’s density will change with temperature.

NOTE: If the lava does not sink in a 20% antifreeze solution, you will need to add more perchloroethylene. Add an 1/8 of a cup to the jar, screw the lid on, and remelt the lava. Let the lava cool thoroughly and test again.

Once the lava will sink in 20% antifreeze solution, test it in a 40% mix of water and antifreeze. The lava should float.

NOTE: If the lava does not float in the 40% mixture, you will need to add more wax. I suggest that you use petroleum jelly or mineral oil, as it is easier to measure. Place a tablespoon of petroleum jelly or mineral oil into the jar, and remelt the lava. Let the lava cool completely and retest.

Once the lava will sink in 20%, and float in a 40% mix, the lava is ready to go into the lamp. Reheat the lava until melted, and carefully pour it into your lamp. Let it cool thoroughly before you add the water.

MAKING THE LAMP WATER

Make sure the lamp is absolutely cold. Start by filling the lamp with distilled water, leaving an inch or two at the top. Add a teaspoon of canning and pickling salt to the water, and invert the lamp several times to help the salt to dissolve. Let the lamp heat up for several hours. You will now need to add more salt until the lamp operates properly.

ADJUSTING THE WATER’S DENSITY

The whole density thing may cause you problems. It is very easy to get confused and get it all backwards. So again, go slow. Let the lamp heat up for an hour or two before adjusting the mixture. Let the lamp run for an hour between adjustments. Add the canning salt a bit at a time. Check to make sure the salt doesn’t collect on the bottom under the lava, if this happens, let the lamp cool, and gently invert the lamp to help the salt dissolve. As you get close to the correct amount of salt, the lava will start to ‘dome’. Now add a VERY SMALL DROP of dishwashing liquid to the water. (The dome may settle back down, that is OK.) Add more salt until the lava begins to break into bubbles and rise. If the bubbles seem to be rather large, and are moving very slowly, you may want to add one more SMALL drop of dishwashing liquid. If you add too much dishwashing liquid, your lava will become ‘runny’ and not break into bubbles properly. If you add too much dishwashing liquid, you will have to pour out the water, and start with fresh water.

The dishwashing liquid helps reduce the surface tension of the lava slightly. If you don’t add any dishwashing liquid, the lava will form one giant bubble. This giant bubble will rise up, and when it settles back down on the bottom, it will not connect with the coil. This giant bubble will just sit there, and the lamp will not cycle at all. With the addition of a small amount of dishwashing liquid, the giant bubble will flow down and connect with the coil. The lava will break into smaller bubbles, and the lamp will cycle properly. If you add too much dishwashing liquid, the lava will become ‘runny’ and will not form nice bubbles. If you add too much, you will have to start over with new water, as it is impossible to take the dishwashing liquid out once it is added. Go slowly and carefully! Remember: If the lava doesn’t float enough, add more canning and pickling salt. If the lava floats too much, add more distilled water.

CONSTRUCTING THE LAMP:

Any of the above mixtures are placed in a closed container (the "lava lamp shape" is not required, although something fairly tall is good-- we have seen everything from gallon jugs to 2 liter plastic soda bottles used effectively for lava lamps) and situated over a 40-watt bulb (make a stamd over the bulb to hold your container). If the "lava" tends to collect at the top, try putting a dimmer on the bulb, or a fan at the top of the container.

Don’t get discouraged if it takes you several tries to get your lamp working right, this is normal. A motion lamp requires a very close balance. I’ve read that at the factory, they measure the specific gravities down to the ten-thousandth! Patient, small adjustments are needed, but when you get it right, it will be worth it.