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Propane Vs. Waste oil as foundry fuel

Back in 2002 I made non-biased comparisons between charcoal and propane as foundry fuel. This is a non-biased accurate judgment about the pros and cons of propane and waste oil. The beneficial attributes are in green text, while the drawbacks are in red text. -June/20/2005

A propane fueled furnace Vs. A waste oil fueled furnace

Waste oil
Propane must be purchased and stored in a special pressurized steel tank which requires safety testing every few years. Used oil only needs to be poured into a storage or fuel tank (a can, bucket, jug, jar, etc.) straight from the kitchen or garage.
Propane is ready to use as it comes from the supplier. Used oil usually requires a strainer to remove solid particles. Window screen over the funnel makes this simple as the storage or fuel tank is being filled.
Propane burners are usually small. Oil burners are larger than propane burners.
If the burner's flame goes out propane gas can fill the area and cause a potentially fatal and destructive "fuel air" explosion if ignited. If the burner's flame goes out oil will pool inside it and require cleanup (sawdust or cotton rags work well and can be used to re-ignite the burner).
Propane is ready to go as soon as you set the burner in the furnace and open the gas valve. No wasted time. It takes a minute or two to get the oil burner to heat up.
Depending on the quantity purchased propane is very cheap in some areas (around $1.00/gallon or less... more in other places (sometimes a lot more!) but usually not free. Waste (used oil) is usually free from a variety of sources; used cooking oil from your kitchen or restuarants, used motor oil from DIY or commercial oil changes etc.
Burning propane is simply burning up a non-renewable resource further depleating petroleum reserves. Cooking oil is plant based and is totally renewable.
Propane flames are clean without many contaminants. Used motor oil may possibly contain traces of toxic heavy metals (lead, chrome, etc.) from the engine which are dangerous to your health.
Propane burners only burn propane unless the gas inlet is modified. Waste oil burners can (if need be) burn other flammable liquids like; melted butter, liquified animal fat/tallow, solvents, etc. without modification. (Anything more flammable than oil is however not recommended for safety.)
Propane tanks can leave you "stranded" if they run out during usage. Oil tanks can be refilled during usage if they start running out.
Propane is easy to burn "cleanly" since it's a gaseuos material. A waste oil burner better be designed, built and functiuon properly or the oil will be hard to burn and may create A LOT of smoke.
Safe propane systems can be expensive requiring a regulator, special propane hoses and the pressurized tank. Waste oil system can be built entirely from scratch with no expensive or technical equipment or components.
Propane is easily ignited by a match or cigarette lighter. Waste oil can be difficult to ignite unless you have a very hot ignition source.
Propane is manufactured from crude oil. Therefore it's price increases just like gasoline when foreign crude oil prices increase. The price of waste oil stays constant (usually free) since it is considered a waste product to be discarded.
If you will only be casting metal occasionally and especially if you're only melting small amounts (6 pounds or less) then propane may be best for you. However if you intend to melt a lot of metal and/or melt on a regular basis waste oil is a much more ecconomical choice. This is even more true if you plan to melt higher temperature metals like bronze and iron. These metals require a lot of thermal energy to melt and the cost of propane can add up super fast.

Additionally propane is better for small applications such as hand held torches or small foundries specializing in precious metals.


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This site was created Sept. 28, 2000