Reviews > Cook Gear > Stoves > Brasslite Turbo II-D Alcohol Stove > Jim Sabiston > Field Report

Field Report - Brasslite Turbo II-D Stove

Date: December 1st, 2003

Reviewer Information

Name: Jim Sabiston
Age: 49
Gender: Male
Height: 6' 3" (1.9 meters)
Weight: 207 lbs. (94 kilos)
Email address: JimSabis(at)aol(dot)com
City: Bay Shore (Long Island)
State: New York
Country: USA

Backpacking Background:

I've been camping for several decades. I joined the Adirondack Mountain Club four years ago, the Appalachian Mountain Club a year later and am active in both. I have also expanded my backpacking to include more winter trips, mountaineering and backcountry cross country skiing, and participated in the AMC's Winter Mountaineering training program with Chauvin International Climbing Guides. More recently, I have actively studied ways to backpack lighter and more efficiently. During the summer months, my style tends toward very light, but not quite ultralight. I use a hammock or tarp for warm weather, and a small four-season tent for winter trips. Most of my other gear is very changeable, as I am constantly experimenting with gear and techniques.

Product Information:

Manufacturer: Brasslite
Year of Manufacture: 2003
URL:www.brasslite.com
Listed weight: 2.6 oz. (74 g)
Weight as delivered: 2.6 oz. (74 g)
Specifications for the Turbo II-D: (from the Brasslite Web site)
Width of chamber and stand: 2.4 in.(60 mm)
Width of Preheat Pan: 3.0 in. (75 mm)
Height of chamber: 1.7 in. (43 mm)
Overall Height: 2.75 in.(70 mm)

MSRP: $50.00 US

The Brasslite Turbo II-D:

The Brasslite turbo II-D is very small, approximately 2.75 in (70 mm) tall by 2.9 in (74 mm) wide at the base. It is clearly hand made, with detail variances and minor flaws to be expected in any handmade item, but these add to the feel and character, rather than detract from it. The brass construction also contributes favorably to the overall look and character of the stove. With the exception of the stainless steel pot stand attached to the top of the stove body, construction is entirely of very thin brass sheet metal. The entire stove is held together with silver soldered joints

The only moving part is the ‘simmer sleeve’, which covers most of the stove body. The sleeve has six small triangular cutouts at the bottom. The sleeve can be rotated to move the cutouts so they line up over the six air intake ports, also located at the bottom of the stove body. Rotating the simmer sleeve allows control of the air flow into the stove. The sleeve is also constructed of thin sheet brass and has a small folded tab allowing the sleeve to be rotated after the stove is lit.

The pot stand is attached permanently to the stove body by five very tiny tabs, carefully bent and silver soldered to the stove top around the bottom wire of the stainless steel stand. All tabs butt up against an upright wire of the pot stand, two adjacent to the stand opening, two approximately ¼ of the circumference around on either side of the opening, and the last directly opposite the stand opening.

The Turbo II-D claim to fame, and what makes it different from earlier Brasslite models, is the addition of an inner wall inside the main body of the stove. This reportedly has the effect of improving flame control, apparently in combination with the relocation of the air intake ports to the base of the stove, rather than near the top of the stove body, as in earlier models.

The stove is designed for two types of ignition priming: referred to as ‘warm prime’ and ‘cold prime’ respectively. The warm prime is typical to many alcohol stoves and is simply a matter of pouring a bit of alcohol on the stove top and lighting it. This serves the dual purpose of warming the stove and vaporizing the alcohol, thus starting a continuous burn. The ‘cold prime’ uses the fluted bottom rim of the turbo II-D to hold a larger amount of priming alcohol. In addition to the small amount of fuel poured on top of the stove, fuel is poured into the fluted dish which makes up the bottom of the stove. This larger amount of fuel provides a longer burn, which is needed in colder weather to get the stove warmed and alcohol vaporized.

Brasslite provided a fuel bottle with the Turbo II-D which deserves some mention. The bottle is translucent plastic and has a secondary reservoir which allows very precise measuring and loading of the fuel into the stove with a simple squeeze. It is small and flat (roughly rectangular, 7.5 in X 3.75 in X 1.5 in (19 cm X 9.5 cm X 4 cm), for packing considerations) and has an 8 oz (.24 L) capacity). It is far more accurate than my usual alcohol fuel bottles, but a bit large for the typical weekend excursion. I will be using this bottle almost exclusively for the test series, but will probably revert to my smaller 4 oz (.12 L) bottles for weekend use and save this bottle for longer trips.

Initial Testing:

Laboratory (aka: kitchen) Testing:

I have always been a bit skeptical of the usefulness of testing field equipment in the controlled environment of a laboratory and then using the results to project real world behavior. All too often, the changing conditions experienced in the field render the laboratory results useless, or nearly so. Thus it was that I embarked on my first series of lab tests since high school.

With my well ingrained low opinions regarding lab testing under controlled conditions, I very carefully constructed a test series using, well, controlled conditions. The only variable in this test series was to be water temperature. The object was to determine what, if any, effect the ambient water temperature would have on boiling times. Accordingly, I was very careful about measuring and recording the starting water and ambient temperatures. However, in my attempt to replicate 'real world' conditions as closely as possible, I avoided being overly precise in my measurements of water volume. Instead, I used my 12 oz (.35 L) coffee mug and measured the water to be boiled the same way that I do when cooking in the field. In other words: 'There, that looks about right'. Also, I did not time the boil to the moment that the water started boiling. In the field my cook pot is covered, for maximum efficiency, so I cannot actually see when the water starts to boil. Instead, I watch for the moment when water vapor starts to issue from the vent in the pot cover. This is why my boil times may seem a bit long if compared to other tests. Unfortunately, it also threw in another variable.

At first, the test results confused me, as the colder water temperatures did not necessarily result in a longer boil time, which is the obvious result I expected. After pondering the results and reviewing my test methods I realized what had happened. By introducing field practices into the controlled lab environment, I had accidentally confirmed my original skepticism of lab testing. Real world variables will trash lab projections every time.

All that considered, here is what I did learn: much to my surprise, the ambient water temperature seemed to have a minimal effect on boil times. Only when the water temperature approached freezing did the boil times become appreciably longer, at eight minutes. All other boil times fell in the six to seven minute range. The effect was generally small enough that minor variations in the volume of water being boiled easily masked the effect of changes in water temperature. The real lesson is that ALL ambient conditions must be taken into consideration when guesstimating how much fuel is needed. Fortunately, this has proven to be relatively simple in practice.

For the record, here is a summary of the test conditions:

Location: My kitchen, on top of our glass top electric stove. After each burn, the stove was allowed to cool and moved to a cool portion of the stove top.

Stove setup: I used the full field setup, including the bottom reflector and 3 in (7.6 cm) windscreen. These were made using the directions provided by Brasslite with the Turbo II-D stove. The simmer ring was set to full open.

Environment: Air temperature was a steady 67 degrees F (19 C). The denatured alcohol fuel was room temperature.

The only other observation of interest is that the MSR Titan Kettle definitely has the minimum pot diameter I would consider for this stove, consistent with Brasslite’s recommendations. The flames would occasionally travel up the sides of the pot, but never became uncontrolled.

The Effects of Cook Pot Choice:

As part of the controlled test series, I also tried three different pot types to see if the pot diameter would have any noticeable effect on the efficiency of the Brasslite Turbo II-D. Unlike the water temperature tests, the pot shape test had some clear and fairly dramatic results. I used three different pots: The MSR Titan Kettle, the larger pot from a Snowpeak Titanium 3 Piece cook-set (with pot cover), and a Primus Alpine Kettle.

For the test, the air temperature was 70 F (21 C) and the water temperature was 65 F (18 C). The results were as follows:

Time to boil 16 oz (.47 L) of water:

MSR Titan Kettle - 6 minutes and 40 seconds
The MSR Titan Kettle has a 4.5 in (11.4 cm) diameter flat bottom.

Snowpeak Titanium cook-set - 6 minutes and 10 seconds
The Snowpeak Titanium Cook set has a 5.25 in (13.3 cm) diameter rounded bottom.

Primus Alpine Kettle - 5 minutes 25 seconds
The Primus Alpine Kettle (aluminum) has a 6 in (15.2 cm) diameter flat bottom.

The clear conclusion is that the wider pots allowed a more efficient transfer of heat from the burning alcohol to the water in the pot. In the case of the Primus Alpine Kettle, which is made of hard anodized aluminum instead of titanium, the pot material may have also played a part, as aluminum transfers heat faster than titanium.

I will continue to use the MSR Titan Kettle as my primary cooking pot, as there are other considerations, such as packing efficiency, which cause me to prefer it. But the efficiency trade off is something to be aware of.

Field Testing:

10/18/03: Hunter Mountain overnight
Conditions:
Late afternoon temperature 40 to 45 F. (4 to 7 C) (approximate)
Water temperature : cold spring water.
Very light breeze, cooking on open rock on treed slope.

Dinner was freeze dried chili-mac served over instant rice with fresh sharp cheddar chunks mixed in. Warm weather prime was not enough to get the stove going. Cold weather prime worked nicely. Approximately 1 oz. (30 ml) of fuel boiled 16 oz. (.47 L) of water for freeze dried chili-mac in about 8 minutes with some fuel left over. The stove cooled quickly enough to be immediately refilled and re-ignited. It was still necessary to use the cold weather prime for the re-light.

As the goal was to boil and then simmer 1 cup (.24 L) of instant rice in 16-oz. (.47 L) of water, I loaded a bit more fuel. Once the rice and water mix came to a boil, I turned the simmer ring so the air vents were almost completely closed. The ring slid smoothly and easily. I discovered that it is good planning to orient the simmer ring so that it lines up with the opening in the windscreen. This allowed me to make quick adjustments by slipping my spork into the opening and using the spork's tines to securely grip the simmer ring tab and adjust its position with a minimum of fuss. This proved to be very easy, once I set it up correctly. All I had to do was slip the spork into the windscreen opening sideways, then rotate the spork so the ‘spoon’ was horizontal. This had the effect of spreading the windscreen opening so I could see the vent hole openings as well as the simmer ring tab. Then I just positioned the tines of the spork over the simmer ring tab and, while applying a very light pressure on the Titan Kettle, easily adjusted the simmer ring to the position I wanted. I would then pull the spork out and the windscreen would snap back into its original position. The flame size did not change immediately, but after a moment or two it gradually diminished to a very small flame. This burned for approximately another 10 minutes, which was just right to fully cook the rice.


Fig. #1: Dinner is on the way! The Brasslite turbo II-D simmering rice.

10/19/03: Hunter Mountain overnight
Conditions:
Early morning temperature 30 to 32 F. (-1 to 0 C) (approximate)
Water temperature : cold spring water, standing in tent overnight,
calm , cooking on flat open rock outside tent entrance (not in the tent!)

Much to our surprise, we rose to a heavy snow flurry. I dressed and recovered the bear bag and set about brewing a couple of cups of coffee. I placed the Brasslite Turbo II-D on a small flat rock which I found near the tent and had moved to the tent entrance. This kept the stove off the thick, wet leaf litter which covered the slope, but allowed me to cook while still sitting in the shelter of the tent, but out of the increasingly heavy snow. I boiled 12 oz (.35 L) of water for my wife’s coffee. I did two separate boils, as I had only the one re-usable coffee filter. Again, the cold weather prime was needed. For the first boil, I had to use the cold weather prime twice. For the second boil, I primed with a bit more fuel, and the stove stayed lit on the first try, still using the cold weather prime.

I learned that the stove must be kept level when using the cold weather prime, otherwise the shallow priming dish holds less fuel. In addition, any spillage tends to run off onto the cooking area and can (and will!) ignite when you light the stove. Fortunately, when I did this the spillage burned off quickly without complications.

Other outings were much simpler, as my wife stayed home and I only had to cook for one! I reverted back to my ‘boiled water’ menu and scheduled excursions in an attempt to subject the Brasslite Turbo II-D to a variety of conditions to see how it would perform with the primary variables being temperature and wind. On another overnight, in wet, windless, very humid but mild conditions, the temperature was around 50 F (10 C), the stove ignited easily on the first try without any need for the cold weather prime. I learned that the small size of the stove has limits when it comes to inherent stability. It is absolutely necessary for the stove to be placed in a flat level spot or there is a substantial risk of the stove and pot falling over. A flat rock or similar surface is preferable over a grassy or leaf littered spot. This is the small price one pays for using a very small and lightweight stove. In the Catskills and other upstate New York parks and wilderness areas it is usually a simple matter to find a flat rock to cook on. Grass surfaces or leaf duff surfaces can be very uneven, resulting in an unstable cooking setup.

If the Brasslite Turbo II-D has a potential Achilles’ Heel, it is performance when exposed to wind. I suppose this may be an issue with laminar flame stoves in general, as the flame is non-pressurized and cannot fend off the effects of wind without some protection. To this end, Brasslite updated their windscreen design in the middle of the test series to effectively double the windscreens height to 6 in (15.2 cm). This is an opportune moment to point out one of the main advantages of dealing with a small manufacturer over one of the larger ’brand name’ companies. When Brasslite learned that a taller windscreen aided in the stoves performance, it was a relatively simple matter for them to modify the website information and email us the information on the update. This same change at a larger company would almost certainly take months and they are generally unable to email customers this type of information. Brasslite maintains a customer mailing list which enables them to do provide this service, which I think is a nice touch.

The windscreen re-design caused me a brief dilemma, however. One of my ongoing equipment design goals, in the interest of saving weight and maintaining efficient use of pack space, has been to have my entire stove kit, except fuel, fit into my MSR Titan Kettle. This includes the stove, windscreen and matches. The original Brasslite windscreen design was folded heavy duty aluminum foil, with a finished height of about 3 in (7.6 cm). when loosely rolled up, this fit perfectly into the Titan Kettle. But, how was I supposed to fit a 6 in (15.2 cm) tall windscreen into a 3.5 in (9 cm) tall pot? This plagued me for about a week, until a solution finally came to me. I had already constructed my windscreen to Brasslite’s recommended finished dimensions, but I used aluminum flashing material (used in roofing work) as it is stronger and, to my mind, a more permanent construct than a folded foil screen for very nearly the same weight. I simply made another 3 in (7.6 cm) screen, exactly the same dimensions as the first. But, instead of the vent holes punched along the lower edge, I instead cut a series of vertical slots about 1 in (2.5 cm) apart and 3/8 in (1 cm) deep on what would be the bottom of this ’extension’. Then, by bending each alternate panel either in or out, I was able to fit the extension to the top of the existing windscreen. This resulted in an easily assembled windscreen which both satisfied Brasslite’s design recommendations and my packing requirements.


Fig. #2: The new taller windscreen fitted around the stove and MSR Titan Kettle.



Fig. #3: The new windscreen parts with reflector.>

Fig. #4: The stove and windscreen parts packed.

Aside from the Hunter Mountain trip, where a small two person tent was used (a happy concession to my wife!) all other outdoor uses of the Brasslite Turbo II-D have either been under a tarp or fully exposed, with no shelter at all. The taller windscreen has made a very real improvement to the effectiveness of the Brasslite Turbo II-D in these more exposed conditions, as the stove can now work in wind conditions that would have rendered the stove useless with the shorter windscreen. The stove was used on one weekend where the winds were a steady 25 mph (40 km), gusting to 39 mph (63 km). My tarp was erected in a fairly open area with some trees, and was really straining under the wind load, with anchor stakes nearly pulling right out of the ground on one gust. Even still, the wind shadow of the tarp provided enough shelter, combined with the taller windscreen, to allow the stove to operate without any fuss, still using just the warm weather prime (the temperature was 44 F (7 C)).

In my Initial Report, I commented that a minor disappointment was that the simmer ring tab prevented the stove from fitting inside my titanium coffee mugs. Happily, it turns out this is not correct! My initial tries at doing this where rather delicately done, as I did not want to damage this pretty new stove. Also, I held the stove perfectly level in relation to the mug. As I have continued to use the Brasslite Turbo II-D and gained more confidence in the strength of the materials and construction, I decided to revisit the concept. It would just be too perfect a storage place for the stove and I wanted it to work! This time, I tilted the stove very slightly, keeping the tab side a bit higher, and with a gentle push, the stove slid right in! It works with both my Snowpeak 450 Double Wall Titanium Mug (see photo) and my MSR single wall titanium mug (a slightly tighter fit). Happy days!


Fig. #5: The Brasslite Turbo II-D fits snugly into a Snow Peak 450 double Walled mug.

Things I like:

1 - The quiet burn! My canister stoves, and especially my Svea 123R white gas stove, sound like a rocket launch by comparison! This is very pleasant.
2 - Simplicity/reliability. With the exception of the simmer ring, there are no moving parts to maintain or fail. As long as the stove is intact and I have fuel, I can cook! This is an enormous advantage when a long way from home.
3 - Soot deposits. Or more precisely, the lack of any. Every other alcohol stove I have used has left soot deposits on my stoves. The Turbo II-D has not left so much as a smudge. A real plus when it comes to keeping my gear, and myself, clean!
4 - Fuel availability. A trip to the nearest hardware store is easier, in my case, than a run to the nearest outfitter. Of course, I lose an excuse to browse through the new gear!

Things I Don’t Like:

1 - The ‘invisible’ flame. This is more a characteristic of alcohol and not an issue with the stove, per se. But, when cooking in daylight, it is difficult to tell if the stove is lit.
2 - I would like more stability, but this is inherently an issue in such a small, light, self contained stove and easily rectified with a bit of preparation and care. Of course, this would be cured with a larger, heavier stove! (Some of us are just never satisfied!)

Summary:

It has been very easy to integrate the Brasslite Turbo II-D into my equipment kit and backpacking style and my experience has been almost completely positive. The stove has performed better than I expected in cold weather and wind, especially with the taller windscreen. The brass finish is oxidizing, so it is not as pleasantly shiny as when it arrived, but this is to be expected. I did notice that the oxidation process accelerated considerably when the stove was stored in my pot and the inside of the pot was not dried completely beforehand. The oxidation is normal and is strictly cosmetic and has no effect on the stove operation at all.

The ‘lab results’ notwithstanding, estimating the fuel needs for varying conditions has become fairly easy to do once I developed some experience with the stove. When in doubt, just add a bit more. Should I estimate low and run out before dinner is cooked, it is a simple matter to squirt a bit more fuel in the stove and re-ignite it. Unlike my pressurized alcohol stoves, the Brasslite Turbo II-D flame is easily blown out at any time. I just lift off the pot and give the flame a quick puff. Unfortunately, the design of the stove body makes it nearly impossible to recover any leftover fuel (an eye dropper would likely work, but this is too much bother for me). In warmer weather the excess evaporates pretty quickly, in cooler weather, some left over fuel occasionally remained the next morning and was used to cook breakfast. With practice, this happens less and less often and when there is leftover fuel, it tends to be a minor amount. To date, I have never used more than two ounces (60 ml) of alcohol to cook a meal for two, and 1 oz (30 ml) is generally enough for a solo meal and a cup of tea. The stove easily handles large meals for two or small solo meals as well. This flexibility is one of the main reasons I prefer this model over Brasslite’s solo options.

The simmer ring works like a charm, but my normal cooking style does not require its use very often. I favor the ‘pot cozy’ method (where the food being cooked is transferred to an insulated container straight from the stove and allowed to cook in the container) over the simmer ring, as it saves fuel and requires less attention on the part of the cook. I also can’t burn dinner this way!

Continued Testing:

Winter is just around the corner! The Brasslite Turbo II-D will be brought along on some cold and snowy overnights in the Catskills and Adirondacks to see how it performs as the temperatures continue to decline. The coldest temperature experienced to date while using the stove is about 30 F (-1 C). I expect to see temperatures well below 0 F (-32 C) in the next month or two. Fuel consumption and priming ease in these conditions will be monitored closely.

I do not plan on using the stove to melt snow, as alcohol does not have the energy content to make this practical. Brasslite makes it pretty clear that the stove is not intended for this. At this point and am encouraged by the stove’s cold weather performance and expect to be able to cook with it in much colder temperatures than experienced to date.

Reviews > Cook Gear > Stoves > Brasslite Turbo II-D Alcohol Stove > Jim Sabiston > Field Report