Reviews > Cook Gear > Stoves > Past Primitive Pocket Stove > Test Report by Michael Pearl

PAST PRIMITIVE POCKET STOVE
TEST SERIES BY MIKE PEARL
LONG-TERM REPORT
August 02, 2011

CLICK HERE TO SKIP TO THE FIELD REPORT
CLICK HERE TO SKIP TO THE LONG-TERM REPORT

TESTER INFORMATION

My backpacking experience began six years ago, after years of car camping. Most trips are for two or three days, some lasting a week. I hike with a group of two to four, with plans for a multi-day solo hike this summer. I pack a tent or tarp depending on availability of trail shelters. A average day is 12 miles (19 km). While aware of weight, it is not my primary concern. I strive for enjoyable outings with functional, reliable gear. I usually travel in woodland mountain terrain. I am a three-season camper, but enjoy hiking all year.

INITIAL REPORT

PRODUCT INFORMATION & SPECIFICATIONS

Manufacturer: Past Primitive
Year of Manufacture: 2011
Manufacturer's Website: www.pastprimitive.com
MSRP: US$ 24.99

Listed Weight of Stove: 0.75 oz (21.25 g)
Listed Weight of Carrying Case: 1.375 oz (38.98 g)
Listed Dimensions of Stove: 1 x 2.7 in dia. (25 x 69 mm dia.)
Listed Dimensions of Carrying Case: 1 x 3.3 in dia. (25 x 84 mm dia.)

Measured Weight of Stove (after use): 0.8 oz (22.68 g)
Measured Weight of Carrying Case: 1.4 oz (39.69 g)
Measured Dimensions of Stove: 1.57 x 2.76 in dia. (40 x 70 mm dia.)
Measured Dimensions of Carrying Case: 1.1 x 3.3 in (28 x 84 mm dia.)

Listed Priming Time: approximately 20 seconds
Listed Boiling Time: 1 pt (0.47 L) of water 5:35 minutes
Listed Average Burn Time: 7:30 - 11:00 min for 1 fl oz (29.6 ml) of fuel

Measured Priming Time: 20 seconds
Measured Boiling Time: 1 pt (0.47 L) of water 5:40 minutes

Listed Fuel Type: Alcohol (ethanol, methanol, or isopropyl)
Listed Fuel Capacity: 1 fl oz (29.6 ml)
Listed Fuel Efficient: 0.6 fl oz fuel per pt of water to boil (17.7 ml fuel per 0.47 L of water to boil)

Also including: 10 ml (0.34 fl oz) syringe for fuel filling
Measured weight: 0.3 oz (8.5 g)
Measured Dimensions: 4.4 x 1.3 in (112 x 33 mm)

The Past Primitive Pocket Stove is a closed pressurized jet alcohol stove. It works by creating pressure inside the stove as it is heated during priming. The fuel is then vaporized and forced through the ports on top of the stove. The vapor ignites producing hot almost invisible and very quiet flames.

Peformance statement on company website;
"Note: All burn and boil times are based on nominal conditions. Performance may very depending on fuel type, weather and other conditions. For any questions please use the contact form on the contact page."

All Included Parts

INITIAL IMPRESSIONS

The Pocket Stove arrived in its own carrying case. The carrying case is a screw top metal canister that contains the stove with affixed primer pan, pot stand, fuel screw and instructions. Also provided was a standard 10 ml (0.34 fl oz) medical syringe.

The Pocket Stove is a good example of material re-purposing. The stove itself is made of aluminum soda cans. And the primer pan is the lid to a canning jar. The stove and the primer pan are riveted together. There are 24 small jet ports around the outer edge of the stove. The fuel port is a rivet nut in the center of the stove. The fuel port is closed with a small steel thumb screw. The pot stand is a flexible strip of steel shaped into a circle and fits in a groove atop the stove. All parts fit nicely into the sturdy steel carrying case. An image of the stove as well as company name and website address are on the case.

I have made a few alcohol stoves myself. The closed pressurized ones are the most difficult to construct. The Pocket Stove is well a designed and built version of one. All parts are tightly fitted and assemble easily. There are no rough, sharp or jagged edges.

While I give the Pocket Stove bonus points for containing upcycled parts. Aesthetically I would remove all lettering and paint that remains from the stove parts past lives.

READING THE INSTRUCTIONS

The instructions are clear and concise. Directions on assembly and use of the stove are easy to follow. The information provided on alcohol as a fuel source is very useful. The usual safety warnings that apply to the combustion of any fuels are listed. As well as two that seem to be unique to some styles of stoves and alcohol as a fuel. First being not to overfill the primer pan. This causes rather large flare of flames. Second being alcohol burns with invisible flame.

TRYING IT OUT

I was very excited to try the Pocket Stove and it was the perfect time of day for a cup of tea. So I raced out to the shed to fire up the stove. I used Ace Hardware brand denatured alcohol. I was unable to find any information on its ethanol content.

The syringe provided made filling the Pocket Stove simple. Measuring the required amount of fuel couldn't be easier. The fuel port and syringe mate perfectly so that no fuel is spilled. I filled the Pocket Stove with 30 ml (1 fl oz) of fuel. The fuel screw and pot stand attached to the stove without any problems. Filling the primer pan with 0.4 ml (0.01 fl oz) of fuel was a different story.

The tip of the syringe isn't narrow or long enough to fit between the stove and primer pan. The result was a fair amount of fuel spilling around the outside of the primer pan. So I moved the stove away from the spill and lit the priming fuel. The fuel burned without igniting the stove. I added more fuel to the priming pan and again had some spill out. This time I lit the priming fuel with the stove in the spill. The fuel in the primer pan and around to outside of the stove burned igniting the jet ports of the stove.

Priming

Ignition

5m 40s later

Heating

In full day light the flames were invisible. Only in low light was I able to see and photograph the flames.

The Pocket Stove primed in 20 seconds. I placed a 5.5 in (14 cm) diameter stainless steel pot with 2 cups (0.48 L) of cold tap water on the pot stand. It reached a rolling boil in 5 minutes and 40 seconds. Tea was served as I thought about the Pocket Stove in the field.

I have two concerns. First is finding a way to fill the primer pan without spilling fuel. The second and more worrisome is the thumb screw. It being rather small I fear dropping and losing it. And no screw could mean no flames.

TESTING STRATEGY

While snowshoeing this Spring I will take the Pocket Stove to heat snacks and make hot tea. I will test the stoves ability to perform at lower temperatures and hopefully while snowing.

While backpacking the Pocket Stove will be my primary resource for preparing all hot meals and drinks for my breakfast and dinner needs. I will evaluate performance on several points including but not limited to; ability to heat water/food, fuel efficiency, durability, packablilty, ease of set up, stability while in use and susceptibility to wind.

SUMMARY

The Past Primitive Pocket Stove is a well crafted alcohol stove. I like the simple yet efficient design. It's lightweight and compact but it's a sturdy little inferno. Just hope I don't drop the fuel screw.

This concludes my Initial Report. Please return in two months to see how things go in the field. Thank you to Past Primitive and BackpackGearTest.Org for the opportunity to test the Pocket Stove.

FIELD REPORT

FIELD LOCATIONS AND CONDITIONS

Mt. Peg 1100 ft (335 m) the temperature was 25 F (14 C) with clear skies, no wind or precipitation. Hard packed snow was still present with areas of bare ground.

Lookout Cabin 2440 ft (744 m) on the Appalachian Trail in Vermont, evening temperature was 66 F (19 C), sunny and windy. The morning temperature was 45 F (7 C), cloudy and still windy.

Gifford State Park, Vermont at 1600 ft (488 m) the evening temperature was 71 F (22 C), cloudy with light breeze. The morning temperature was 51 F (11 C), cloudy and moist as it rained overnight.

PERFORMANCE IN THE FIELD

During field testing I have used the Pocket Stove on three outings. The same fuel and cook pot was used as in the initial report. One change has been made to the set up, the addition of a homemade windscreen.

While snowshoeing on Mt Peg I used the stove to boil water for tea. Slight trouble was encountered lighting the stove. I had to prime the stove twice to get it to ignite. While the tea steeped I toasted two slices of bread over the remaining flame and made a cheese sandwich.

Amount of Primer: 0.5 ml (0.2 oz)
Prime Time: 30 seconds on 2nd attempt
Amount of Fuel: 25 ml (0.85 oz)
Amount of Water: 1.5 cups (0.36 L)
Boil Time: 6:00 minutes
Total Burn Time: 8:00 minutes


On an overnight trip to Lookout Cabin I used the Pocket Stove to prepared two meals. Both meals were made inside the cabin as the wind prevented the stove from priming. On my next trip I will definitely pack a windscreen.
At dinner I boiled water to heat hot dogs. The water was then used to rehydrate soup. While waiting on the soup I used the remaining flame to "grill" the hot dogs.

Amount of Primer: 0.5 ml (0.2 oz)
Prime Time: 20 seconds
Amount of Fuel: 25 ml (0.85 oz)
Amount of Water: 2 cups (0.48 L)
Boil Time: 5:25 minutes
Total Burn Time: 8:30 minutes
At breakfast I boiled 2 cups (0.48 L) of water. I used one for oatmeal and the other went to tea. I snuffed the flame out after the water reached a boil. After the stove cooled I tried to salvage the remaining fuel. Tilting the stove over my fuel bottle I captured all that poured out from the jet port. When unpacking I found the bag containing the stove canisters and all parts wet with fuel, not a good thing as denatured alcohol is toxic.

Amount of Primer: 0.5 ml (0.2 oz)
Prime Time: 25 seconds
Amount of Fuel: 20 ml (0.68 oz)
Amount of Water: 2 cups (0.48 L)
Boil Time: 5:30 minutes
Total Burn Time: N/A


On an overnight at Gifford State Park the Pocket Stove was again used to make dinner and breakfast. This time for four, my wife and two children wanted to be a part of the fun! On this outing I used a improvised windscreen. A section of aluminum clothes dryer vent tube measuring 4.25 in (11 cm) in diameter and 1 in (2.5 cm) tall served as a windscreen.
Dinner was hot dogs, the kids loved toasting the dogs and buns. The remaining hot water was used to cook dehydrated veggies.

Amount of Primer: 0.5 ml (0.2 oz)
Prime Time: 25 seconds
Amount of Fuel: 20 ml (0.68 oz)
Amount of Water: 2 cups (0.48 L)
Boil Time: 5:30 minutes
Total Burn Time: 7:30 minutes

Breakfast was instant oatmeal for four, six packets. On the first attempt to prime the stove the flame burned for 35 seconds. The second priming lit the stove. Full boil was not achieved. Many small bubbles gathered on the bottom of the pot. A few rose to the surface. The water was hot enough to make instant oatmeal.

Amount of Primer: 0.5 ml (0.2 oz)
Prime Time: 5 seconds on 2nd attempt
Amount of Fuel: 20 ml (0.68 oz)
Amount of Water: 3 cups (0.72 L)
Boil Time: 13 minutes
Total Burn Time: 13 minutes

A second batch of water was needed to make coffee.

Amount of Primer: 0.5 ml (0.2 oz)
Prime Time: 25 seconds
Amount of Fuel: 20 ml (0.68 oz)
Amount of Water: 2 cups (0.48 L)
Boil Time: 6:30 minutes
Total Burn Time: 7:30 minutes

SUMMARY

The Past Primitive Pocket Stove is a simple yet functional stove. It has been consistent and reliable for boiling water and preparing food. Several things make this a choice stove for me. I like its light weight and how easily it packs. I have carried it in a small pouch inside my mess kit and side pocket on my pack. The Pocket Stove is easy to set up, three simple pieces. The cook pot is easy to balance on top of the stove.
Alcohol flames are rather sensitive to wind. The Pocket Stove is no exception. The addition of a windscreen is a big plus.
I have run into two problems with the Pocket Stove. Judging the correct amount of fuel to use and recovering unused fuel are difficult. The boil and burn times can vary with conditions making exact measures hard. This has been a drag on fuel efficiency.
Both concerns in my initial report have been resolved. I have not lost the thumb screw as feared. And I have gotten better at loading the priming pan, just squirting it faster works best.

TESTING STRATEGY

I plan to use the Pocket Stove on longer trips. I hope more consecutive days of use will help me gauge fuel amounts. I would like to test the stove with other fuels, if I can obtain grain alcohol.

This concludes my field report. I would like to thank Past Primitive and BackPackGearTest.org for the opprotunity to test the Pocket Stove.

LONG-TERM REPORT

LONG-TERM TEST LOCATIONS AND CONDITIONS

Since last report I have used the Pocket Stove on one seven-day backpacking in Yellowstone National Park, Wyoming, USA.

Weather encountered included overnight lows around 40 F (4 C) and daytime highs ranged from 50 - 85 F (10 - 29 C). The first two days were wet. First a rain storm that began with small hail after dinner. Then light rain that began the next morning while eating breakfast and ending late afternoon. Over the course of the week the weather gradually progressed to cloudy, partly cloudy and ending with dry and hot.

While operating the stove winds were either light or calm.

Elevation ranged from 7300 - 8000 ft (2225 - 2438 m).

Stove fuel on this trip was Everclear 190 proof, 95% alcohol. Fuel container was a Nalgene bottle.

PERFORMANCE IN THE FIELD

The Pocket Stoves performance on this trip was very similar to that previously experienced. It remains an easy to use, sturdy little stove. The only preparation my meals required was a bath in boiling water. This was successfully accomplished everytime.

Over the course of the week I made thirteen meals and thirteen hot drinks. I used 30 ml (1 fl oz) in the stove and 0.5 ml (0.2 fl oz) in the priming pan each time. This allowed me to boil 2 c (0.48 L) of water to rehydrate food and then boil 1 c (0.24 L) of water for herbal tea or coffee. I used approximately 400 ml (13.5 fl oz) of fuel total. The extra was due to priming twice a few times and spilling some. I was not as worried about spilling fuel on my hands this time. Skin contact with Everclear is nontoxic.

This method of cooking eliminated the guessing at amounts or recovery of fuel. If the stove was still burning when tea or coffee was finished, I returned the food to the flame.

My hiking partner used a white gas stove. While we prepared meals I noticed three differences. Two were already known to me: white gas has faster boil times and is louder. The third I had not thought of before, the Pocket Stove cools down much faster. I was able to pack away the Pocket Stove much sooner.

SUMMARY

The Pocket Stove has served my cooking needs well. It continues to function as well as on its first day of use. All parts are in good condition and working order. As a bonus the ability to prepare meals with a nontoxic, renewable fuel on a repurposed stove is awesome.

CONTINUED USE

I ended the long-term test period very pleased with the Pocket Stove. I will continue to use it as my three season stove.

Reviews > Cook Gear > Stoves > Past Primitive Pocket Stove > Test Report by Michael Pearl