Subject: Lava Lamp Plans Here.
\nDate: 13 Jan 1995 08:08:15 GMT<\/p>\n
I’ve had SEVERAL requests for the plans, so here they are.<\/p>\n
Sorry, I guess I lost the name of the guy who gave ’em to me.
\n(I recieved two versions, and I liked this one best).<\/p>\n
WARNING!! This electronic document deals with and involves subject matter
\nand the use of materials and substances that may be hazardous to health
\nand life. Do not attempt to implement or use the information contained
\nherein unless you are experienced and skilled with respect to such subject
\nmatter, materials and substances. The author makes no representations as
\nfor the completeness or the accuracy of the information contained herein
\nand disclaim any liability for damages or injuries, whether caused by or
\narising from the lack of completeness, inaccuracies of the information,
\nmisinterpretation of the directions, misapplication of the information or
\notherwise. <\/p>\n
Please note: The information contained in this electronic document can
\nbe found in the 1992 Edition of Popular Electronics Electronics Hobbyists
\nhandbook, published annually by Gernsback Publications Inc, USA.<\/p>\n
Inside a lava lamp are two immiscible fluids. If it is assumed that fluid 1
\nis water, then fluid 2 must be:<\/p>\n
.1) insoluble in water;
\n.2) heavier than water;
\n.3) non-flammable (for safety);
\n.4) non-reactive with water or air;
\n.5) more viscous than water;
\n.6) reasonably priced.<\/p>\n
Furthermore, fluid 2 must not be:<\/p>\n
.1) very poisonous (for safety);
\n.2) chlorinated;
\n.3) emulsifiable in water (for rapid separation).<\/p>\n
In addition, fluid 2 must have a greater coefficient of expansion than
\nwater. Check a Perry’s handbook of Chemical Engineering, and the above
\nlist eliminates quite a few possibilities.<\/p>\n
Here is a list of possible chemicals to use:<\/p>\n
.1) benzyl alcohol (sp.g. 1.043, bp 204.7 deg. C, sl. soluble);
\n.2) cinnamyl alcohol (sp. g. 1.04, bp 257.5 deg. C, sl. soluble);
\n.3) diethyl phthalate (sp. g. 1.121, bp 298 deg. C, insoluble);
\n.4) ethyl salicylate (sp. g. 113, bp 233 deg. C, insoluble).<\/p>\n
If desired, use a suitable red oil-soluble dye to color fluid 2. A
\npermanent felt-tip pen is a possible source. Break open the pen and put
\nthe felt in a beaker with fluid 2.<\/p>\n
It is recommended to use benzyl alcohol as fluid 2. (Caution!! Do not
\ncome into contact with benzyl alcohol either by ingestion, skin, or
\ninhalation.) In addition to water, the following items will be necessary:<\/p>\n
.1) sodium chloride (table salt);
\n.2) a clear glass bottle, about 10 inches (25.4 cm) high;
\n.3) a 40 watt light bulb and ceramic light fixture;
\n.4) a 1 pint (473 ml) tin can or larger;
\n.5) plywood;
\n.6) 1\/4 inch (0.635 cm) thick foam-rubber;
\n.7) AC plug with 16 gauge lamp wire;
\n.8) hardware;
\n.9) light dimmer (optional);
\n.10) small fan (optional).<\/p>\n
The performance of the lava lamp will depend on the quality of the water
\nused. A few experiments must be conducted to determine how much sodium
\nchloride is necessary to increase the water’s specific gravity. Try a 5%
\nsalt concentration first (50 g of salt to 1 liter of water). Pour the
\nred-dyed benzyl alcohol mixture in a Pyrex beaker. Add an equal or
\ngreater amount of water and heat slowly on a hot plate. If the benzyl
\nalcohol floats to the top and stays there, decrease the salt
\nconcentration. If it stays at the bottom, add more salt. <\/p>\n
Construct the lamp by fastening the ceramic lamp fixture to a 5 inch (12.7
\ncm) diameter piece of plywood. Attach the lamp wire to the fixture.
\nScrew in the 40 watt bulb. Cut one end off the tin can, remove its
\ncontents, and clean thoroughly. Drill a hole in the tin can for the wire
\nto go through. Invert the can over the bulb (open end down) and affix to
\nthe plywood with epoxy. Cut a round gasket from the foam-rubber and fit
\nit into the top lip of the can. <\/p>\n
Fill the bottle partially with brine, add about 150 ml of benzyl alcohol,
\nthen fill up the bottle with brine. Leave about 1 inch (2.54 cm) of
\nairspace on top for expansion. Bubble size will be influenced by amount
\nof air space. Tightly cap the bottle and place on gasket.<\/p>\n
The light dimmer is used to control the amount of heat in the bottle. It
\nis helpful if the bottle is too short and the 40 watt bulb makes the
\nbenzyl alcohol accumulate at the top.<\/p>\n
The fan can also be used to cool the top of the bottle and help the benzyl
\nalcohol to sink to the bottom. <\/p>\n
If desired, add a trace of an antioxidant such as BHA or BHT to the brine
\nto add color and contrast.<\/p>\n
Enjoy and good luck.<\/p>\n
