So I've seen a lot of posts all over the internet
lamps in boats, cabins, and generally indoors. There's lots, and I mean lots, of misinformation out there about the differences between kerosene, paraffin, and lamp oils in general.
I've done some research
into it all and thought I'd share.
Here in Southern California
I can purchase
Lamplight Farms "Ultra-Pure" Paraffin Lamp Oil
which the Lamplight web site says is "99% pure paraffin." But of course what is paraffin and how does it compare to kerosene?
There are lots of posts on this topic not only in cruising forums
but all over the 'net, and every single
one I've run across is wrong.
First off you need to know what ALKANES are. They are simple hydrocarbons with one or more carbon atoms strung together, and hydrogen atoms connected to them.
The simplest is methane. We all have heard of that. Methane is "C1" because it has one carbon.
You go up from there. From light to heavy. Methane is a gas at room temp. As you string more carbon atoms together the molecule gets heavier, oily-er, and eventually waxier.
The issue is that few people realize that what we consider kerosene, paraffin, mineral oils, jet fuel
, etc. are not one substance but a range of alkanes that may vary from locale to locale or even from batch to batch.
As the book "Toxological Chemistry" by Stanley E. Manahan states, Kerosene is a mixture of primarily C8-C16 hydrocarbons. "General, Organic, And Biological Chemistry" by H. Stephen Stoker states that Vaseline (petroleum jelly) is a mixture of predominantly C25-C30 alkanes. Much heavier, much waxier.
Mineral oil (NOT mineral spirits) involves alkanes in the C18 to C24 range. Paraffin oil has no real defined usage but may be somewhere between kerosene and mineral oil.
Interestingly, Lamplight's own MSDSs (Material Safety
Data Sheets) on its "Ultra-Pure" lamp oil show a change in the product over the past few years.
The MSDS from 2003 states that Ultra Pure Lamp Oil at the time was made from a "Mixture of Tetradecane, Pentadecane, and Hexadecane" which means it had C14-C16 alkanes in it only. A fairly refined product. That same MSDS shows that its flashpoint was 250°F (121° C) which is quite high. Its melting point was 48-50°F meaning it was very waxy and would easily gum up in colder weather
A more recent MSDS from 2007 states that the same Ultra Pure Lamp Oil by Lamplight Farms is made up of "C5-20 Paraffins." This means that the tolerance of compounds has increased substantially and that it's not nearly as refined as it was. You get very light alkanes along with very heavy, waxy ones in the same bottle. The flashpoint has dropped to 207°F (97° C) and the melting point has also dropped to around 32 degrees F.
This is a substantial change in the composition of the product over a short span of time, and a certain percentage of the product apparently now consists of alkanes that are lighter and more volatile than typical kerosene!
But the point of all this is that separating "kerosene" and "paraffin" lamp or heating
oils into two distinct substances is foolish. They are actually made up of an overlapping range of alkanes and most likely they change depending not only on where you are in the world but what materials happened to go into the container on a specific manufacturing date.
And finally I'd like to turn my attention to the assertion that you shouldn't use "paraffin" oil in flat-wick lamps, only in oil-candles with round wicks. This may have been true at a time when paraffin oil consisted of heavier alkanes. Now it appears that at least the Ultra-Pure brand is "cut" with simpler alkanes, so gummed-up wicks may be a thing of the past. I know that I use my current
batch of paraffin oil in lamps with wicks of 7/8" with no problems whatsoever.
However, by the time you read this, the formulation may have changed on this product, or similar products may have widely different ingredients.