PAST PRIMITIVE OUTDOORS POCKET STOVE
TEST SERIES BY NANCY GRIFFITH
July 24, 2011
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Northern California, USA
5' 6" (1.68 m)
130 lb (59.00 kg)
My outdoor experience began in high school with involvement in a local canoeing/camping group called Canoe Trails. The culmination was a 10-day canoe voyage through the Quebec wilds. I've been backpacking since my college days in Pennsylvania. I have completed all of the Appalachian Trail in Georgia, Tennessee and North Carolina. My typical trip now is in the Sierra Nevada in California and is from a few days to a week long. I carry a light to mid-weight load, use a tent, stove and hiking poles.
PRODUCT INFORMATION & SPECIFICATIONS
Manufacturer: Past Primitive Outdoors
Year of Manufacture: 2011
Manufacturer's Website: http://www.pastprimitive.com
MSRP: $24.99 US
Stove only: 0.75 oz (21 g)
Carrying Case: 1.375 oz (39 g)
Pot Stand: Not listed
Total package: 2.25 oz (64 g)
Stove: 0.8 oz (23 g) with pot stand
Carrying Case: 1.4oz (40 g);
Pot Stand: 0.2 oz (6 g)
Total package: 2.2 oz (63 g)
Not included in above measurements:
10 ml Syringe: 0.2 oz (6 g)
The Past Primitive Pocket stove is a pressurized jet alcohol backpacking stove which is 1 in tall x 2.7 in diameter (25 mm x 68 mm diameter). It is made of aluminum and claims to withstand 100 lb (45 kg) of load. The stove appears to be constructed from the top and bottom of a Pepsi can since I can read the 'P' and recognize the markings and color. There are 24 small jet ports around the circumference which seem to be hand punched pin holes since the spacing is slightly uneven. In the very center of the top there is a small threaded hole which is the fuel port. There is a 6-32 thumb screw which threads in to close off the hole.
The primer pan is a Ball canning lid which is riveted to the bottom of the stove. It is stated to prime in 20 seconds with just a few drops of fuel placed in the priming tray. The pot stand is a separate piece of a narrow strip of steel with alternating large and small holes in it. It appears to be a piece of standard pipe hanger strap.
When not in use the pot stand can expand to fit around the stove. It all then fits into a round tin 1 in tall x 3.3 in diameter (29 mm x 85 mm diameter) to hold the stove and pot stand for carrying and storage protection. The screw has to be removed to fit in the carrying case. The carrying case lid screws on to the base for a secure connection.
The advertised boil time is 5:35 for 16 oz (0.47 l) of water which is to be achieved using 0.6 oz (18 ml) of fuel. The burn time is listed at 7:30 - 11:00 for 1 oz (30 ml) of fuel which is the maximum fuel capacity of the stove. Priming time is listed at 20 seconds.
Fuels that can be used are typical of alcohol stoves: ethanol, methanol or isopropyl alcohol. The recommended fuel type is denatured alcohol with high-ethanol content (90 - 95%). Low-ethanol denatured alcohol may also be used but will not burn as hot resulting in longer time to boil.
INITIAL IMPRESSIONS & TRYING IT OUT
My initial impression was how small and light the stove is. Secondly I noticed the 'home-made' construction quality. I haven't made my own alcohol stove, but I have read quite a bit about them and this one appears to have similar qualities.
Generally speaking the stove was what I had expected based on the website. However, Past Primitive included a 10 ml (0.3 oz) syringe which isn't noted as being included but was a nice surprise. I also noticed two different claims for time to boil a pint (0.47 L) of water: 4:30 and 5:35.
The first thing that I had to do was to buy some fuel and found some at the local hardware store. They carried Klean Strip S-L-X and Klean Strip Green denatured alcohols. I chose the Green since Past Primitive's website says that it has a higher ethanol content than S-L-X. I have read that HEET, an automotive fuel line anti-freeze also works well, so I bought some at a discount store in order to give it a try. I have also read that Everclear (or pure grain alcohol) can work well and plan to try it out later in the test: all in the name of thorough testing of course.
I waited all week for a break in the rainy weather to set up a test and finally resorted to a test in the garage to do some time trials. There was no wind, the altitude is 1,900 ft (579 m) and the temperature was 43 F (6 C). The fuel had been in the house so it was approximately 65 F (18 C). The water came from the tap and was cold, probably 45 - 50 F (7 - 10 C) and was measured with a kitchen measuring cup. I heated the water in a Snow Peak 900 titanium pot and left the mating lid on except to check boil status.
I ran trials to check the advertised priming time of 0:20 and boil time of 5:35 for 16 oz (0.47 L) of water. I measured out 3 full syringes or 1 oz (30 ml) of fuel and inserted it into the fuel port and then put approximately 0.4 ml (0.01 oz) in the primer pan. No windscreen was used for Test 1 and 2. After noting the boil times, I let the stove burn out to check the advertised burn time for a full 1 oz (30 ml) of fuel of 7:30 - 11:00.
Test 1: Klean Strip Green denatured alcohol
0: 50 to prime; flames coming out of all jet ports
5:30 to see lots of bubbles on pot surface
6:00 to start boil
6:30 to rolling boil
11:00 total burn time for 1 oz (30 ml) denatured alcohol
Test 2: HEET automotive fuel line anti-freeze
2:00 to prime; stove sputtered quite a bit and had to be re-lit at each port to get flames from all jet ports
6:45 to see lots of bubbles on pot surface
7:30 to start boil
8:30 to rolling boil
9:35 total burn time for 1 oz (30 ml) HEET
Test 3: I tested the time to boil 20 oz (0.59 L) water with 1 oz (30 ml) denatured alcohol using a windscreen since this is our typical on-trail situation.
1:00 to prime; flames coming out of all jet ports
6:00 to see lots of bubbles on pot surface
7:40 to start boil
8:30 to rolling boil
12:50 total burn time for 1 oz (30 ml) denatured alcohol
Test 4: I put 0.6 oz (18 ml) of fuel into the stove to test whether it would boil 20 oz (0.59 ml) of water.
1:00 to prime; flames coming out of all jet ports
6:30 to see lots of bubbles on pot surface
8:00 to start boil
8:30 to rolling boil
9:00 total burn time for 1 oz (30 ml) denatured alcohol
In all cases it took about 2 minutes for the stove to cool enough to be handled with bare hands. The stove seemed to cool completely between tests such that I didn't see any indication that warmth was retained such as a reduction in priming time.
Overall, I found the advertised burn time to be accurate, but I never saw a 5:35 boil time. This is possibly because my water was fairly cold, but it was typical of what I'll see while backpacking. I also didn't see the stove prime in 0:20 but again that may be that the air temperature was fairly cool.
The fuel port is pretty small, so I can't see any way of trying to save and retrieve unused fuel. I'll simply have to learn how much fuel to use each time and let it burn out.
Being that the priming tray is a canning jar lid, I wondered how the seal would hold up to being covered with alcohol and lit. After the four tests, the seal was slightly bubbled and black in a few places.
READING THE INSTRUCTIONS
Included in the carrying case was a folded up set of instructions which include safety warnings about using the correct fuel type, operating on a flat surface free of combustibles, having adequate ventilation, allowing stove to cool before touching, not overfilling, not leaving unattended, manufacturer not responsible for misuse, not refilling while burning, aluminum windscreens placed too close will melt, store in case to prevent damage. There is also a caution that some fuels burn with an invisible flame and to read the priming instructions since overfilling can be dangerous.
The information about recommended fuels is listed along with a part diagram. Lastly there are detailed priming and lighting instructions.
The Past Primitive Pocket Stove is a lightweight compact pressurized jet alcohol stove.
Likes so far:
Quiet so I can hear when fuel vaporizes and when water boils
Easy to find fuel and lower cost than canisters
Dislikes so far:
FIELD LOCATIONS AND CONDITIONS
Over the Field Testing period, I used the stove on one 3-day backpacking trip, 3 day hikes and 2 snowshoe hikes for a total of 15 lightings. Elevations ranged from 1,200 to 6,237 ft (366 to 1900 m) and temperatures ranged from 32 to 70 F (0 to 21 C). Conditions were usually breezy. All tests were done using a titanium pot with lid, windscreen and base as shown in the photo.
Ohlone Trail, Northern California; 30 mi (48 km); 390 to 3,800 ft (119 to 1,158 m); 36 to 60 F (2 to 16 C); clear to cloudy with breezy to windy conditions
Auburn Recreation Area, Sierra Nevada foothills, California; 11.5 mi (18.5 km); 1,200 to 1,500 ft (366 to 457 m); 55 to 65 F (13 to 18 C); clear with breezy conditions
Middle Fork American River, Sierra Nevada foothills, California; 10 mi (16 km); 1,200 to 1,700 ft (366 to 518 m); 65 to 70 F (18 to 21 C); clear with breezy conditions
Western States Trail, Sierra Nevada, California; 6 mi (10 km); 1,800 to 3,520 ft (550 to 1,073 m); 65 F (18 C); partly cloudy with very breezy conditions
University Falls, Sierra Nevada, California; 4,032 ft (1,230 m); 32 F (0 C); overcast conditions with light breeze
Loon Lake, Sierra Nevada, California; 6,327 to 6,500 ft (1,928 to 1,981 m); 32 F (0 C); snow, sleet and breezy conditions
PERFORMANCE IN THE FIELD
The first thing that I did was find another 6-32 screw in our tool box in case I lose the thumb screw that came with the stove. The spare screw with a couple of nuts attached actually was easier to use than the thumb screw, so it became the one to use and the thumb screw became the spare.
When I first received the stove, I had a few questions about it and e-mailed Customer Service using the address on the Past Primitive website. I quickly received a friendly and helpful response.
Wind/ Fuel Type:
I immediately found that the stove (as typical of alcohol stoves) is very susceptible to wind. It is possible to blow it out with a strong wind or at least redirect the flame from my pot in lighter wind, so I always used it with a windscreen and base to maximize the efficiency. I used denatured alcohol for 12 of the lightings and HEET fuel line anti-freeze for 3 of them. The denatured alcohol burned much stronger and hotter, so it is my preferred fuel to date. The HEET worked ok and was able to heat water to a nice drinking temperature but it did not bring the water to a rolling boil.
I used the stove to prepare meals in multiple ways. Mostly I used it for boiling or heating water for soup, oatmeal or hot beverages. I used it to heat my beef stroganoff dinner which had been rehydrated ahead of time. For jambalaya, I added my meal to the water just as I lit the stove and heated and hydrated it at the same time. For noodle soup, I boiled the water, added the noodles and cooked them for several minutes. I made one meal of rehydrated scrambled eggs which had me holding the pot up away from the flame with one hand and stirring constantly with the other. It was quite tricky to get the eggs cooked without them burning and getting stuck to the pot.
On the trail I carried the stove wrapped in a small towel inside my cooking pot. At first I stored it between trips in the carrying case provided by removing the pot stand and slipping it over the stove. As time went on, I didn't bother to remove the pot stand and just stored the stove with the pot stand attached. The stove doesn't fit in the carrying case with the stand attached, so I stored it in my pot. I also eventually didn't bother to remove the pot stand during use. I was able to remove the screw and fill the stove without removing the pot stand.
I find the syringe to be fairly easy to use, but I needed to add a piece of tubing to allow me to reach into my fuel bottle. I would really prefer to have a way to insert fuel without the need of the syringe/tubing and know how much fuel I've added. I tried marking my fuel bottle with graduation marks and finding a bottle top that allows me to squeeze fuel directly from the bottle into the stove. However, it is very difficult to get an accurate measurement and the stove doesn't have any way of showing how full it is.
Since the stove is silent and usually the flames are invisible, I learned to assess the lit condition by holding my hands a safe distance above it and feeling the heat. I could usually tell my water was starting to boil by the sound (a creaking heat sound not a water sound) and could usually tell when the stove went out by the sound just prior to extinguishing (a sputtering sound). I really liked that these sounds tipped me off since I hate to keep removing my pot lid to check for boiling water (thus allowing the heat out) and it is nice to know when a potentially dangerous flame is no longer present.
On my first use while snowshoeing, I forgot to re-insert the screw prior to lighting. This is NOT advised as I have read that alcohol stoves can explode in this condition since the flame shoots from the screw hole in an uncontrolled manner. In a quick-thinking mild-panic move, my husband grabbed my hat from my head and easily extinguished the stove. I then re-lit it with the screw now inserted and realized that I had forgotten to insert the pot stand. Once again the stove had to be extinguished which was easily done with a bandana this time rather than my hat! Incidentally there was no damage to either my hat or my bandana. I'm proud to say that I've apparently learned my lesson and haven't done either thing since. However, as noted above, keeping the pot stand attached has eliminated that possibility.
Over multiple tests, I found a rule-of-thumb for me to be that a full 10 ml (0.3 oz) syringe of fuel is capable of boiling 8 - 10 oz (250 - 300 ml) of water and heating to a drinking temperature 10-12 oz (300 - 350 ml) of water. Of course with this formula I simply adjust the fuel amount based on the amount of water and its temperature that I desire. I tested out my theory on the 3-day backpacking trip and found it to be remarkably accurate. I had originally estimated that I could possibly use a maximum of 8 oz (250 ml) of fuel over the trip but ended up only using 4.5 oz (133 ml).
Priming & Burn Times:
I attempted to time the stove on every use for priming time, boil time and total lit time. However, things being what they are in the field, I would forget or get distracted and don't want to quote my times exactly. Several times especially in the coldest conditions, I found that the stove didn't light from my initial priming and I had to re-prime.
Using denatured alcohol, I found that boiling time for 16 oz (0.5 L) of water ranged from 6 to 8 minutes. I did have one data point of 4.5 minutes which I am quite sure was accurate, but I haven't duplicated it. Total lit time for denatured alcohol ranged from 12 to 14 minutes for 30 ml (1 oz) of fuel. As mentioned above, HEET did not bring the water to a boil, but the total lit time was longer than for denatured alcohol at 16 to 21 minutes per 30 ml (1 oz) of fuel.
I didn't find a difference in times based on initial water temperature, air temperature, stove base (snow vs. rock vs. dirt) or altitude. In fact I had the exact same boil time for one trip at the highest altitude and lowest temperature vs. another test at nearly the lowest altitude and highest temperature.
Overall, I really like using this stove. I try to pinpoint exactly why and haven't been able. I don't believe that it is the novelty of it. So, I did a side-by-side comparison to a canister stove to just lay out the facts since a canister stove was my previous favorite.
PROS vs. a Canister Stove:
1) Weight: The Pocket stove is 0.75 oz versus my canister stove which is 3 oz. This isn't a big difference, but every ounce can add up. My empty 8 oz (250 ml) fuel bottle weighs 0.5 oz (14 g) vs. an empty small canister which weighs 3 oz.
2) Fuel Cost: Canister fuel is $3.50 to $4.50 for the small canister. The Klean Strip Green denatured alcohol that I used is $6 to $7 per quart (1 L) which is approximately $1.42 for the same heating capacity as a small canister.
3) Refillable Fuel: I can carry the exact amount of fuel that I need for any given trip. Since the fuel can be stored in any plastic bottle, I can tailor my container(s) to the amount of fuel needed. I'm not left with partial canisters to use up on a future trip.
4) Fuel Availability: Given the variety of alcohol types that can be used, the Pocket stove fuel can be purchased in any town which has either a hardware store (denatured alcohol), an auto parts store (HEET fuel line antifreeze) or a liquor store (grain alcohol). Canister fuel is only available in specialty outdoor stores. On previous out-of-town backpacking trips, I've had to plan ahead to find where we would be able to buy our preferred canister fuel and make sure there would be enough of it.
CONS vs. a Canister Stove:
1) Time to set-up: There are more steps to using the Pocket stove. Removing the center fill screw is equivalent to screwing a canister stove onto the canister. Then assembling the pot ring is equivalent to opening the pot tangs on a canister stove. From there the Pocket stove has the additional steps of filling the syringe and inserting fuel (multiple times), re-inserting the screw and priming the stove.
2) Time to eat: It takes longer to boil the same amount of water. I don't have a ton of data for my canister stove, but generally 2- 3 minutes is what I've seen for 16 oz (0.5 L). The Pocket stove takes more like 6 -7 minutes. So adding that to the additional time to set-up, I'd say that it can take 5-10 minutes longer to begin eating dinner.
Well, I guess that really does explain why I like the Pocket stove so much. I'm frugal, like to minimize my pack weight (though I'm not an ultralighter) and don't really care if dinner takes a few minutes longer. So far, I find the extra steps to be intriguing and a challenge to guess just how much fuel it's going to take to get a particular meal prepared just right.
THINGS I LIKE:
Prompt Customer Service
Simple stove design
Low Cost of Fuel
Refillable so I can carry just the fuel I need
Availability of fuel
THINGS I DISLIKE:
Can't measure fuel directly into stove (need syringe/tubing)
LONG-TERM TEST LOCATIONS AND CONDITIONS
During the Long-Term testing period, I used the stove for an additional 2 backpacking trips and a 4-day boat camping trip. This amounted to an additional 12 lightings.
Desolation Wilderness, Sierra Nevada, California: 2 days, camping at 7,520 ft (2,292 m) elevation, operating stove at 45 to 60 F (7 to 16 C); still to breezy conditions
Rubicon Trail, Sierra Nevada, California: 2 days, camping at 6,327 ft (1,928 m) elevation, operated stove at 40 to 64 F (4 to 18 C); light to moderate breeze conditions
Loon Lake, Sierra Nevada, California: 4 days, camping at 6,400 ft (1,951 m) elevation, operated stove at 60 F (16 C): breezy conditions
PERFORMANCE IN THE FIELD
I didn't have any new experiences during this portion of the testing period. I did try to use the thumb screw that came with the stove instead of my own version of a 6-32 screw with two nuts attached. The thumb screw is much harder to use and I often felt like I was getting the threads crossed.
I continued to use my base and windscreen but tried using the stove several times with no windscreen at all. For meals that required cooking in a different pot (see photo), I used the windscreen more as a wall than completely surrounding the pot. I didn't see a marked difference in boiling time without the windscreen unless the breeze was really strong.
I was able to estimate the amount of alcohol to use pretty accurately and didn't find myself using much more alcohol than was necessary. I never used the full capacity of 30 ml (1 oz) in the stove at one time so I found this smaller stove size to be plenty for me. Although I was always cooking for two, our maximum fuel use was 20 ml (0.7 oz) for one use.
The boiling time with this stove is noticeably longer than with a canister stove. I only noticed this because we used the stove several times while our friends used their canister stove. They were drinking hot beverages long before our water was heated. However, other than noticing this difference due to the direct comparison, I never found the extended time to be any issue to me.
The durability of the stove has been great. On the boat camping trip I stored it in the canister that came with it. Otherwise I store it in my cook set along with the windscreen, sporks, lighter and syringe. Other than the paint on the can being scratched by the pot ring when stored in the canister, there is no noticeable wear on the stove.
The Past Primitive pocket stove is a minimalist cook stove which appeals to my frugal nature.
This report was created with the BackpackGearTest.org Report Writer Version 1.
Copyright 2011. All rights reserved.
Things I like:
Low cost of fuel
Good fuel availability
No half-empty canisters (no canisters period)
Things that I dislike:
Thumb screw is difficult to use
This concludes my Long-Term Report and this test series. Thanks to Past Primitive Outdoors and BackpackGearTest.org for allowing me to participate in this test.
Read more reviews of Past Primitive gear
Read more gear reviews by Nancy Griffith