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Outdoorsy stuff > DIY robust retro backpack stove

This do-it-yourself (DIY) project begins as parts from a big-box, two-burner Coleman® base-camp stove and yields a small single-burner wilderness stove. Scavenge the few needed materials from home or from your local hardware store. Watch the video for more views and hints. Scroll down to Results to see what you can expect at the end.

Coleman stove parts
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Use the removable tank plus generator tube, just as they are, from a Coleman two-burner base camp stove. See photo at right.

Detach both burners from their big box housing. Unscrew the secondary burner, by way of its tube, from the primary burner, and set aside. The main burner is what you’re after. Nothing destructive occurs, and you can easily revert back to your base-camp stove.

Port plug
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So, you're now holding just the main burner assembly, the one you want to use. Flip it upside down, and notice a short port tube extending out. This port needs to be plugged.

On older stoves, such as my 425B from the early 1960s, this tube will have internal threads. If you can find a threaded metallic plug to fit, then great. Good luck: I wasn’t able to. Newer stoves, such as mine from the 1980s, have no such threads.

Regardless of stove model, I found that a ¾-inch copper cap, from the plumbing department of the local hardware store, is the way to go. Notice the cap, installed, in the photo below. Check the fit. It should go on snugly with moderate finger pressure. This is a zone where the fuel vapor has been allowed to expand and mix with air, so pressure is only somewhat above atmospheric. I’ve never experienced fuel vapor leakage in this area when following these instructions. This port plug, though, should also be installed snugly enough to minimize drippings of liquid fuel from the burner assembly, a rare, undesirable event (see Operation page, Issues).

If the fit is too loose, as it was with my older stove, then use some aluminum foil cut in a long, thin strip to create a proper fit. Follow the instructions in the diagram above. Experiment a bit by winding different lengths of aluminum strip various numbers of times around the port tube: two, two-and-a-half, three, or other.

Burner support
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The single main burner assembly, which you want to use, is now missing a support holding it the proper distance off the ground. The main burner, though, has an attachment hole at the rear. To this, attach a triangular support base. This support base will be an equilateral triangle 3¾ in. on each side, plus tabs extending from the two side members up to the attachment hole on the burner. A bolt goes through the tabs and hole. See photo at left. The support can be made from aluminum bracket material. I found my material lying around; I think it’s from a bulletin board frame.

Another part to be added, shown extending off to the right in the photo, is a connector rod, described next.

Connector rod
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The connector rod keeps the tank and burner pulled toward each other. This rod is important for stability and for keeping fuel vapor from the tank flowing properly into the burner and not gushing randomly into the environment. Make this rod from 16-gauge steel wire (your basic shirt hanger). With a properly sized loop on one end, it attaches around the bolt that protrudes underneath the burner. A nut holds the loop on the bolt. See photos above and at right.

Give the rod a slight upward bend in the middle so it clears the bottom of the burner on its way to the tank. On the free end of the rod, give the last ½ inch of rod a 100º bend downward. Measure for this carefully, with the tank’s generator tube firmly inserted into the burner. The bent tip on the free end of the rod should drop down securely through the hole in one of the two tabs (the nearby one) sticking out of the fuel tank (photo at right).

Older model stoves (such as mine) have this hole already drilled in this tab. Newer stoves, such as one of mine from the 1980s, will not. In this case, carefully drill your own hole in the tab.

Pot support (grill)
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A pot support structure, a sort of grill, is made from steel rod material. I made mine from two lengths of 6-gauge rod scavenged from an old oven rack. Eight- or 10-gauge rod may work also. However, don’t try anything thinner, like 16-gauge as I did, to cut weight: warping in stove heat and your subsequent straightening efforts would eventually break the rod. The two pieces of rod are each given a 90º bend. So, rather than one piece crossing over the other, the two pieces meet at their bends. Braze together the two pieces at their junction using inexpensive home “welding” technology: a hand-held torch fitted with a canister of MAPP gas and a bronze brazing rod.

Give each of the four rod ends a bend of 120º at appropriate distances from the cross point (measure carefully), and cut. The resulting structure should be about 4 in. across and stand about 1 in. tall above the burner. At the bottom of each of the struts, file a notch to engage the lip of the burner head.

Make a small, stiff box to (1) protect your other pack items from soot and snags from the pot support and (2) protect the pot support from bending at the hands of your other pack contents. You may, as I did, make such a cardboard box from a Kraft 6-oz. macaroni-and-cheese box (bottom right photo). Or, your ingenuity may result in some other container.

You might find yourself relegating the remainder of your original big-box Coleman stove to the recycle bin and dedicating its main burner to this wilderness stove project. I did. I then brazed my support permanently to the burner (burner is still shown detachable in these photos).

                                

Windscreen

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The windscreen is made from thin sheet metal. A small hole for the generator tube and a slot cutout for one of the tank tabs to pass through steady the windscreen at its near end, next to the tank. A bolt protruding out the opposite (rear) end connects the windscreen, albeit loosely, to the burner support triangle. A hole drilled at an appropriate point on the burner support (see photo below) receives the bolt. Windscreen corners are rounded using tin snips. The windscreen, of course, helps the stove operate efficiently outdoors by saving large amounts of fuel and cooking time while also shielding the tank from excessive stove heat.

Two versions of windscreen are possible depending on your preferences regarding cost, labor, weight, durability, and portability.

Steel. One version may be made from a 5½-in.-wide strip of sheet steel. This version hews to the theme of robustness and sturdiness. It will fold during packing and probably last as long as the rest of the stove. Use stainless steel (preferred) or normal steel (less preferred) of a 22-gauge material. What I used was what I had lying around: a somewhat-heavier-than-22-gauge stainless steel sheet. Cut the strip of material into three rectangles 5, 4¾, and 3¼ in. wide. Cut triangular pieces from the bottoms as shown to save a few ounces of weight and to let the windscreen deal better with ground irregularities. Attach each piece to its neighbor using small brass hinges and pop rivets. The hinge knuckles and rivet heads should face inward. Grind down the rivet tails. Drill holes (left photo, below) to accommodate bolt and rivets for very flat, compact folding (middle photo, below).

Aluminum. Another version (bottom-right photo) is made from 6-in.-wide aluminum residential flashing material cut to a length of 13¾ in. Construction is cheaper and easier, and the resulting windscreen is lighter than the steel version. This version wraps around the fuel tank for packing. Because aluminum melts at 1,220 ºF, a zone at the top will melt during initial use. It won’t melt and drip, but it will melt (or oxidize?) and crinkle, as you’ll see when you first test your project at home. The crinkling will make it impossible to neatly wrap the windscreen around the tank for packing. Observe where the aluminum crinkles after a test run, and cut away the crinkled portion.

The aluminum windscreen version may be considered semidisposable. That doesn’t mean one should trash it in the wilderness, a huge no-no. But figure it may last only a few trips after which it may become too buckled and creased for your standards. Then, it may be tossed in the recycle bin and replaced with a shiny new one with the expenditure of just a buck’s worth of material and a few minutes of work.

            

Results
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The results of your do-it-yourself (DIY) effort will be a stove weighing 2.6 to 2.9 pounds dry, that’s without fuel, depending on what sort of windscreen you choose for it. (I won’t even hint at the weight of my own particular project, in which I used unusually thick materials for the grill and windscreen.) This may seem heavy compared with traditional tank (liquid-fuel) stoves out on the market. For example, the Coleman Exponent Apex II with one basic fuel tank plus an additional tank, both aluminum, both empty, weigh in at some 1.1 to 1.4 pounds less than the project stove.

Consider, however, these benefits of the DIY Coleman-derivative stove:

  • It can carry about 1.3 lbs. of fuel in its tank, which is enough for a party of five for 4 or 5 days.

  • Materials and mechanisms are extremely sturdy.

  • Wind protection is excellent, owing to the windscreen.

  • It blasts away as nothing you may have seen before. It boiled a liter of water for me in 3:20 (min:sec) under standardized conditions (Note a). Coleman rates their base-camp stove outputs at around 14,000 BTU/hr. That’s almost double the output rating (7,500 BTU/hr) of the Apex II.

  • Setup and startup are easy, comparable to that of other available stoves.

  • Cold-weather performance is excellent owing to the use of liquid camp fuel manually pressurized. In contrast, canister stoves (using butane, propane, isobutane, mixtures thereof) perform poorly in cool temperatures, and most quit entirely somewhere between 0 and 32 ºF.

  • Flame control is precise: blast away or simmer or anything in between with a turn of the large control knob.

  • The cooking surface is a mere 4¼ in. up off the ground. Thus, this stove is low and stable.

  • If you have the parts and materials lying around, it’ll cost $0 or pennies out-of-pocket to make. Compare that to stoves out on the market costing some $80 to $220.

  • Operation cost is low, something like 12¢ to the dollar versus canister (butane, etc.) stoves.


Thus you have a high-tank-capacity, powerful, rugged, stable, dependable stove that just laughs at cold, windy weather. Perhaps Coleman, in some parallel universe in which they beat others to market with a remote-tank stove design, would have been proud to put out something like this around 1969.

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a. Air temperature of 70 ºF, no wind. Site elevation 100 ft above sea level. Water from 70 to 212 ºF in covered, stainless-steel pot.


Disclaimer
Execute this project and use any resulting product solely at your own risk.

Disclaimer

This web page and the information therein have received no input, authorization, or endorsement from,
and the author has never had affiliation with, The Coleman Company Inc., or any other mentioned manufacturer.

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