Brasslite Alcohol Stove Primer
If using an alcohol stove for backpacking is a new concept for you, you may be concerned about whether or not alcohol will perform well enough to meet your cooking needs in the backcountry. This is a valid concern. Alcohol stoves have been popular in Europe for many years but they have only recently become popular in the USA. You’ll read below that the major advantage an alcohol stove has over a white gas stove is saving weight. That being said, alcohol stoves have a reputation for being slow, difficult to operate in cold weather, and sensitive to wind. The most popular commercial brand of alcohol stove is made by Trangia. Trangia has effectively addressed the wind problem with its (relatively heavy) integrated cook pot and windscreen system. However the Trangia burner design has changed very little since its introduction in 1951 and it remains slow to boil and difficult to light in cold weather. Recently in the USA home-made alcohol stoves (made from beverage or pet-food cans) have become quite popular, especially among long-distance hikers. The most popular of these is a double-wall design that mimics the Trangia burner. If you want to try to make your own there are a number of excellent DIY sites available on the internet. Many weight-saving DIY projects for other gear such as packs, tents and clothing are also available. Many backpackers have neither the time nor the inclination to make their own gear, and some cottage manufacturers have responded to this need by offering truly lightweight gear, including beverage can stoves. The beverage and pet-food can stove designs do have disadvantages. They are fragile, sometimes develop leaks, and don’t simmer well. Brasslite stoves were developed to combine the advantages of homemade designs with the sturdiness and aesthetic appeal of commercial stoves.
Which Brasslite Stove Is Best For Me?
The Turbo I-D has a maximum fuel capacity of 1 US fluid ounce (30 ml) and is designed for solo hikers that take a minimalist approach to their backcountry cooking. Minimalist hiking means trying to carry the lightest of everything (whenever sensible and safe), including both stove and cook pot. With the optional extensions added, the Turbo I-D can be used with larger pots and has excellent stability. Without extensions, the Turbo I-D is designed primarily for use with cups and smaller pots.
The Turbo II-D (“D” is for double-wall) is designed for solo hikers and couples doing more typical backcountry cooking. It has a larger fuel capacity of 2 US fluid ounces (60 ml) and will boil and up to 1.5 liters of water without refueling. The Turbo II-D will simmer for up to 30 minutes on 1 US fluid ounce (30 ml) of fuel. Given a little practice the flame control of the Turbo II-D rivals the cooking performance of butane cartridge stoves, at a fraction of their weight and expense. The Turbo II-D will prepare anything from simple to complex meals and everything in-between.
Which Pot(s) Are Best For Brasslite Stoves?
Pot choice is important to maximize fuel efficiency and cooking performance. All backpacking stoves (not just alcohol stoves) apply heat only to the bottom of the pot. A wider pot base diameter means a broader bottom surface area for heating, resulting in shorter boil times and better fuel efficiency. When comparing different pots of equal capacity, one that is shorter and wider is always preferable to another that is taller and narrower. You may have to consider replacing the cook pot you’re currently using with another that will maximize the efficiency of your new Brasslite stove. A tight-fitting lid and properly used windscreen are also essential for successfully operating any alcohol stove. It’s also recommended that the windscreen be set up with a minimum 1 inch (2.5 cm) opening around the pot to prevent excessive heat formation, which can result in reduced burn time and wasted fuel.
The Turbo I-D has a pot stand that is 2 inches (5 cm) and the Turbo II-D has a pot stand that is 2.5 inches (6.25 cm) in diameter. The Turbo I-D can be used with cups such as the Snow Peak 600 and similar vessels with a base in the
4 inch (10 cm) range. For best results with the Turbo II-D, a pot with a minimum base diameter of 4.0 inches (10 cm) is recommended. Narrower cups may have a problem with flame spilling out the sides and into the air, wasting fuel and lengthening boil times. The flame profile may be controlled by adjusting the simmer sleeve. Pots with base diameters more than 6 inches (15 cm) are not recommended with the Turbo II-D because of possible stability/tipping problems, unless the optional stand extensions are added.
Is Alcohol A “Better” Stove Fuel Than White Gas?
Alcohol stoves have some definite advantages over white-gas stoves. The most important advantage is reduced weight. One of the lightest white-gas stoves currently available is the MSR Simmerlite, which still weighs 3 times as much as the
Turbo II-D. The second most important advantage is simplicity. Alcohol stoves have few or no moving parts, pumps, seals or other components that can fail. Denatured alcohol is very clean-burning and will never deposit soot on the cook pot. Alcohol is also less volatile and therefore less prone to “flare-up”. Finally, in some remote areas alcohol may be easier to find. Brasslite stoves make efficient use of the available fuel energy found in alcohol, but alcohol does not contain the heating value (BTU quantity) of white gas or gasoline, as noted in the chart below:
Property | Regular Grade Gasoline | Octane* | Methyl Alcohol | Ethyl Alcohol |
---|---|---|---|---|
Chemical Formula | Complex | C8H18 | CH3OH | C2H5OH |
Molecular Weight | Complex | 114 | 32 | 46 |
High Heating Value (Btu/lb) | 20,250 | 20,570 | 9,770 | 12,780 |
Low Heating Value (Btu/lb) | 19,00 | 19,080 | 8,640 | 11,550 |
Latent Heat of Vaporization (Btu/lb) | 140 | 141 | 474 | 361 |
Specific Gravity (@60F) | 0.745 | 0.702 | 0.796 | 0.794 |
Stoichiometric Ratio | 15:1 | 1.1:1 | 6.45:1 | 9:1 |
Boiling Temperature (º F) | 100-400 | 258.2 | 148.5 | 173.3 |
Octane Number (Research) | 80 | 100 | 106 | 106 |
Energy of Stoichiometric Mixture (Btu/lb) | 94.8 | 95.4 | 94.5 | 94.7 |
* Can be considered as "ideal" high-test gasoline. |
Alcohol stoves do have limitations. For example, if you intend to backpack with more than two people (such as a family or group) and intend to carry only one stove for the group, or camp in winter conditions where snow melting is required, Brasslite stoves are not recommended (nor is any other alcohol stove). In some circumstances, carrying a white-gas stove is the best logical choice. In those type of conditions, Brasslite recommends using a (relatively) lightweight white-gas stove such as those made by MSR, which will boil large quantities of water quickly. Another alternative is a wood burning stove such as the ZipZtove. The tradeoff is that those stoves weigh significantly more than a Brasslite stove, but weight is not the total concern. Choose your stove wisely based on your real needs, not what you think you can get away with while you’re searching the internet or standing in the store trying to decide.
Why Are Brasslite Stoves Made With Brass?
The idea is to get heat into the fuel to make it vaporize and burn. After the pre-heat fuel has been spent, the heat is coming only from the top where the fuel is burning. Thermal conductivity is therefore very important. A metal is needed that will spread the heat as evenly as possible over the entire surface of the container. There are other alcohol stoves currently on the market; one made out of titanium and another made out of steel. Both stoves have problems related to the materials. One is relatively slow to boil and the other does not use up all its fuel before extinguishing. This is because the heat cannot spread to the bottom of the container. If you refer to the chart below, you will see that steel and titanium have relatively poor thermal conductivity; not a good material for spreading heat over the whole surface. Copper has the best thermal conductivity of the non-precious metals, but copper is much too soft to be used in its pure state. After copper, aluminum is next highest in thermal conductivity; almost twice as much as brass. There are several homemade stove designs constructed from soda cans, and we all know soda cans are made of aluminum. They conduct heat very well. But the idea is also to have a sturdy product that holds up over time. Soda can stoves use epoxy or furnace tape to seal the joints but these can and will fail if exposed to open flame. Aluminum cans also often develop leaks as a result of pitting from corrosion. Manufacturing a stove with slightly heavier aluminum presents significant technical challenges. It oxidizes very rapidly and cannot reliably be soldered except with expensive special solders, and even then with great difficulty. Soda cans have no welded seams. It can be TIG welded, but it’s technically difficult to weld if the gauge is thin. My attempts to TIG weld thin aluminum with a borrowed welder were a dismal failure most of the time. TIG welders are also VERY expensive to buy and operate. Next to aluminum, brass is the best choice. Because of its high copper content it conducts heat well, and is easy to solder and finish.
Thermal Conductivity of Metals
Metal | W/cm-K of Metal | Metal | W/cm-K of Metal |
---|---|---|---|
Aluminum | 2.165 | Nickel | .906 |
Beryllium | 1.772 | Platinum | .734 |
Brass | 1.220 | Silver | 4.173 |
Copper | 3.937 | Stainless Steel | .146 |
Gold | 2.913 | Steel - Low Carbon | .669 |
Iron | .669 | Tin | .630 |
Lead | .343 | Titanium | .157 |
Magnesium | 1.575 | Tungsten | 1.969 |
Molybdenium | 1.299 | Zinc | 1.024 |
Acceptable Fuels for Brasslite Stoves
S-L-X Brand Denatured Alcohol is widely available in the paint department of most Home Depot stores in the USA. Available in both quart and gallon, this is the least expensive and highest quality choice for fueling alcohol stoves. Pure Methanol (such as HEET brand auto gas-line deicer (yellow bottle, or its generic equivalent) is sold at virtually every “mom and pop” convenience store, grocery store, and gas station in the USA. Other denatured alcohol brands (ethanol/methanol mixtures) are sold in paint and hardware stores, but their quality varies widely. Several brands (eg. Sunnyside, True Value, and methylated spirits from UK, and Australia) have proven to contain undesirable organic compound residues that cause flaring and inconsistent flame patterns. Pure ethanol (i.e. 200 proof grain alcohol sold in liquor stores and pharmacy supplies (very expensive!) also works very well. Note: Isopropanol (ie. ISO-HEET (red bottle), aka pure “rubbing alcohol” is not recommended because it burns with a very sooty flame.
Stove Maintenance
Brasslite stoves require very little maintenance. If sooty deposits form on the top or sides, gentle scrubbing with an old toothbrush, abrasive cleanser, and hot water will usually remove them. If soot is really stubborn, boil the stove in a pot of soapy water for 5 minutes then scrub the stove gently with a steel wool soap pad. Follow up with the brushing described above. Be careful and gentle. Remember that the metal is thin and if you press too hard you can dent or deform the stove chamber.