Rain lamp fluids

Which fluid to use?

1. Mineral oil
   The majority of sources I've seen say to use mineral oil in rain lamps, and the only official sources I've seen implicitly said to use mineral oil:
   • The sticker on my vintage rain lamp says to use "Drakeol #35 oil", and a Penreco site said that Drakeol #35 oil (along with most other Drakeol numbers) is synonymous with mineral oil.
   • The Creators, Inc. assembly instructions that come with the rain lamp say to use mineral oil.
   • Several eBay sellers have said to use mineral oil in their rain lamps.
   • Paraffin oil is synonymous with mineral oil.
   • Grandma Fern's rain lamp
   • The Family Room
   • Tiki Central Forums
     
   • Old-House-Friends Forum
     

   Also, I learned that while mineral oil is readily available at Wal-Mart, Wal-Mart does not carry glycerin at all.

2. Glycerin
   I have seen a few unofficial statements saying that rain lamps use glycerin (= glycerine = glycerol):
   • rain lamp patent by Victor Chatten from 1965
     The patent said glycerin was that inventor's preferred liquid in such lamps.
   • Jamar Restaurant
     A tiny sign in front of Jamar's rain lamp I saw in 1969 said not to touch the strands because they contained glycerin, not water.
   • one eBay seller
     The eBay seller from whom I bought my rain lamp said to use glycerin, not mineral oil, since mineral oil can ruin the motor.
   • E-Ticket magazine
     A 2003 article about Adventure Thru Inner Space described the rain lamp at the end of that ride as using glycerin.
   • The International Guild of Lamp Researchers
     A guess from a shop worker: lamp forum archives (12-4-05)
     
   
   The chemical structure of glycerin.

3. Paraffin oil
   One online source mentioned needing 40 weight paraffin oil for a rain lamp:
   The International Guild of Lamp Researchers (12-4-05)
   

   However, one web site about Paraffin Oil (12-27-05) says that "paraffin oil" is the same as mineral oil.

4. Drakeol #35 oil
   One of the labels at the underside of the top of my rain lamp says to use Drakeol #35 oil. However, at least two Internet sources say this type of oil is synonymous with mineral oil.

5. Ethylene glycol
   The rain lamp inventor for Creators, Inc., Victor Chatten, mentions ethylene glycol in his 1975 patent as his preferred fluid for rain lamps since it doesn't evaporate as readily as water, it has high viscosity, and has low electrical conductivity. However, the instructions manual I have for a Creators, Inc. rain lamp does not mention or imply use of ethylene glycol at all, only mineral oil, and I haven't seen ethylene glycol mentioned in conjunction with rain lamps anywhere else. Ethylene glycol is also moderately toxic, unlike mineral oil that is drunk as a laxative.
   
   The chemical structure of ethylene glycol.

6. Transparent hydraulic oil / transformer oil
   These two types of oil are mentioned as preferred liquids in Jack Balkin's rain lamp patent of 1969. I haven't heard of any commercial lamp that uses such oils, though.

7. Water
   Water is mentioned in at least two patents as being theoretically possible in rain lamps, but water is described as being less desirable than more viscous fluids that don't evaporate as easily and that don't conduct electricity as easily. No commercial rain lamps I have ever heard of use water.
   
   The chemical structure of water.

General concensus...

No official documentation I've found says to use glycerin in commercial rain lamps. The only official mention I've found of glycerin being used in rain lamps is in patents, but such patents tend to be theoretical and not to reflect commercial products. (E.g., such patents also mention nylon lines of thicknesses that are not easily obtainable and that are not found in commerical rain lamps, none of those patents mention the most prevalent commercial rain lamp fluid (mineral oil), and all mention exotic fluids that are toxic and not found in commercial rain lamps.) Also, the officially recommended Drakeol #35 oil for my lamp is equivalent to mineral oil, and the paraffin oil mentioned on another site is also equivalent to mineral oil. Since the only official sources of fluid recommendations I've found come from Johnson Industries and Creators, Inc., and since these two companies were the predominant rain lamp manufacturers in the 1970s, all indications suggest only mineral oil is used in commercial rain lamps.

Mineral oil

1. Wal-Mart
   A commonly quoted source of mineral oil in the USA is Wal-Mart stores. The mineral oil I bought from Wal-Mart was found in their pharmacy section, it's non-prescription, and comes in plastic 1-pint bottles costing only $1.47 apiece (12-22-05). These are pictured below. I can't find any brand name the bottles.
   
   Mineral Oil, U.S.P., from Wal-Mart.

2. K-Mart
   On my last visit to K-Mart (12-26-05) I saw that K-Mart also carries mineral oil in 1-pint plastic bottles in their pharmacy section. K-Mart's brand was American Fare and slightly more expensive ($1.99 per bottle) than Wal-Mart's unnamed brand. Neither K-Mart's brand nor Wal-Mart's brand had viscosity information on the bottle, unfortunately.

3. drug stores

4. veterinary supply houses

5. Southern Lamp and Supply
   This is an on-line supplier of mineral oil, specifically mentioning using it for rain lamps:
   Southern Lamp and Supply (12-4-05)
   

6. Lighting 2 U
   This is an eBay store that sells a fluid specifically labeled "Rain Lamp Fluid."
   Lighting 2 U (12-4-05)
   
   

7. Valleyvet.com
   Since mineral oil is a laxative, often used on animals, it can be found at veterinary supply houses such as this. AgriLabs is the brand of mineral oil this company carries.
   Valleyvet.com (12-4-05)
   
   

8. Xincense LLC
   It sounds like this company's mineral oil for rain lamps is scented, although one Tiki Central forum member believes scented oil is risky for rain lamp motors. This company advertises their rain lamp oil on Canadian eBay, but the company is located in Minnesota, USA.
   Xincense (12-9-05)
   

Where into the lamp is the mineral oil poured?

The only reasonable place to pour the oil is atop the holed plate where the plastic foliage is usually placed. All the oil collects in the inside basin underneath this plate, anyway, via the holes in this plate. Also, the collecting basins underneath and on top are not ordinarily accessible unless unscrewed, and the oil ends up in the same bottom basin whether the holed plate is unscrewed or not.

On top of the holed plate at the bottom of the strands is where the mineral oil should be poured.

How much mineral oil is needed?

The answer is it depends on the size of the lamp. Depending on the type of lamp, the amounts that I've heard were needed range from 1-4 pints. The advice I've seen is to add oil slowly until the lamp begins to work, and not to overload the lamp with more oil than necessary. The motor in my lamp changed sound when it began to pump the oil, which was a fairly accurate indication of how much oil to use, which in my lamp occured at 1 1/2 pints.

I have a large rain lamp. With the motor running, there was no reaction in my rain lamp after I poured in 1 pint (a full bottle) of mineral oil, so I poured in another 1 pint. At about 1 1/2 pints total, the motor sound changed, first slightly louder, then softer, and after a few minutes the strands began to drip correctly. I poured in the entire second bottle and the receptacle held the entire 2 pints without problem. Later I read on the Internet that using too much mineral oil can overload the motor and burn it out, but the label on my lamp says to use 1 quart (= 2 pints), which is more than I found it to need. Therefore there is apparently some flexibility in the amount of oil that is needed. Probably the critical consideration is how much of the pump should be submerged, or where the pump input is located.

The bottom of the pumping tube can be seen if the bottom of the lamp is disassembled, and this tube bottom is positioned towards the top of the basin, so the basin has to be nearly full for the liquid level to reach the bottom of the tube. One forum member said that rain lamps with water wheels have two such tubes, one for turning the water wheel, one for dripping down the strands.

Links

Glycerin

WHAT IS GLYCERIN? (1-10-06)

Glycerol (1-10-06)

glycerin (1-10-06)

Drakeol #35

Mineral Oil USP Properties (12-5-05)
Drakeol 35 = a type of mineral oil

Paraffin oil

http://en.wikipedia.org/wiki/Ethylene_glycol (1-10-06)

http://www.atsdr.cdc.gov/tfacts96.html (1-10-06)

http://ptcl.chem.ox.ac.uk/MSDS/ET/ethylene_glycol.html (1-10-06)
ethylene glycol = glycol

http://www.emedicine.com/emerg/topic177.htm (1-10-06)

http://potency.berkeley.edu/chempages/ETHYLENE%20GLYCOL.html (1-10-06)