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A windscreen plus wood stove for about two ounces

The Fire Bucket Stove System

By Jim Wood

Published November 18, 2008

Last revision November 18, 2008

Printable PDF version available here (2.9mb)

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This article discusses a new high-performance windscreen for alcohol stoves that can also serve as an efficient, stand-alone stove for burning wood and solid-fuel tablets. In its lightest implementations, it weighs only about two ounces. The Fire Bucket can be constructed from a variety of inexpensive, easily-obtained materials in either collapsible or permanently assembled models using simple tools.

Also of note is the concurrent publication of a new article about a companion product, the Super Cat Alcohol Stove. First shared with the backpacking community in January, 2005, the original article has been completely rewritten to incorporate many of the design ideas that Super Cat users have contributed over the years, as well as to expand the scope to include new information about fuels, windscreens, stands and other accessories.

When used together, the Super Cat and Fire Bucket form an efficient, lightweight, integrated stove system that's easy to make and fun to operate.

You can navigate directly to each chapter using the links below.

Background

Over the past decade or so, a great many backpackers, especially those who engage in long-distance hiking, have developed an affection for alcohol and tablet-based stoves because of their simplicity, light weight and availability of fuels at re-supply points. 

As the developer of the Super Cat alcohol stove—which has become one of the most popular do-it-yourself alcohol stove designs among hikers worldwide—I find it curious, however, that so much of the online discussion about these devices seems to focus on the stoves themselves, rather than the larger issue of cooking system performance. I use the word "curious" since the advantages of one stove design over another, which are usually discussed in the context of laboratory-like conditions, are often completely lost when it comes to real-world trail use. 

The biggest problem, of course, is the wind.

Wind is public enemy #1 for any backpacking stove system, but because of their low flame velocities, alcohol and tablet-based stoves are particularly susceptible to the disruptive effects of air movement. Unprotected from even a slight breeze, these stoves can quickly become unusable.

To date, the most widely adopted design that attempts to solve the wind problem is a sheet metal windscreen that includes a row of ventilation holes around the bottom.

Traditional aluminum windscreen (+)

It's been my experience, however, that most implementations of this windscreen design don't perform very well and that additionally, many are a hassle to use. So much so, that according to a fair number of the participants in the discussions noted above, windscreen issues have soured them on using alcohol or tablet-based stoves at all.

WINDSCREEN PROBLEMS

In my 2005 article (updated in 2008) entitled Build Your Own KiteScreen, I highlighted some of the problems associated with traditional windscreens that I'll repeat here:

• Because they're not anchored to the ground, most windscreens can blow around in even moderate winds. If one side happens to get pushed too close to the stove's flame, a portion of the windscreen can melt.
  

• Most windscreens cover only part of the cook pot. As a result, some of the wind that strikes the pot from the sides is deflected downward towards the stove (inside the windscreen), causing turbulence in the flame below.
  

• Metal windscreens placed close enough to a stove to be really effective can get quite hot during operation, creating a burn hazard for the user. Because a pot's handle often ends up very near an edge of the windscreen, skin-to-windscreen contact is almost inevitable with some designs. Likewise, these hot windscreens are also great for melting the synthetic fabrics used in expensive outdoor clothing.
  

• Most traditional windscreens must be unrolled, or unfolded and flattened and assembled before deployment, which can make them a hassle to use.
  

• Many windscreens, particularly those designed for use with alcohol stoves, must be populated with multiple ventilation holes in order to provide pathways for oxygen to reach the stove's flame. These same holes, however, can also allow the wind to create turbulence inside the combustion area, thereby reducing the stove's efficiency (sometimes by a lot).
  

This last point is the probably the most important, in my opinion. Unless fairly large in size, the ventilation holes used in most of these designs can offer a fair amount of resistance to air entering the windscreen, which can starve a flame for oxygen. If the holes are large enough to permit the free flow of air, then they probably also contribute to internal air turbulence when the wind blows.

SOLUTION Alternatives

One approach to solving some of these problems, discussed in my KiteScreen article, is a fabric or film-based screen that's anchored to the ground and that's large enough to protect the entire cooking setup. This design works particularly well for top-mounted canister stoves that are otherwise difficult to safely shield from the wind.

Another is to integrate wind protection into the stove design, rather than treating it as an afterthought. Examples of products now available in the canister stove market include the Jet Boil and MSR Reactor systems, both of which work well but which are too heavy and expensive for many. In the commercial alcohol space, the Caldera Cone systems from Trail Designs seem to have gained a following, though the cones can be difficult to store, and the titanium version that permits cooking with wood is very expensive.

The purpose of this article to suggest an integrated, do-it-yourself alternative that overcomes many of the problems associated with traditional windscreens. I call the design the "Fire Bucket" since my early prototypes were made from coffee cans that were bucket-like in appearance.

And as a bonus, the Fire Bucket can serve not only as a high-performance windscreen for almost any kind of alcohol heater, but also as a stand-alone stove that can burn Esbit/Hexamine tablets, wood, coal or almost anything combustible, all at a weight of about two ounces (at least if constructed from aluminum as described below).

Disclaimers and Safety Notes

Before proceeding, I should point out that I am not a chemist, nor an expert in stove technology. I am just a backpacker who has struck upon something interesting that I feel is worth sharing with my fellow hikers. 

All experienced outdoors people already understand that any stove is potentially dangerous and should be handled with care, especially when operated in the vicinity of a tent or tarp. Besides presenting a fire hazard, many stoves (including alcohol stoves) can also emit fair amounts of carbon monoxide which can be deadly if concentrated in closed spaces. 

If you decide to build your own Fire Bucket, you must assume all risks. I obviously can’t guarantee your safety nor indemnify you against accidents. I would, however, warn you not to attempt to use this design with petroleum-based fuels such as automotive gasoline, kerosene or white gas (Coleman fuel). 

These fuels are much more volatile than are alcohol and are dangerous to burn in open containers. Petroleum vapors can quickly pool in low-lying areas, especially within the confines of the Fire Bucket walls, and can explode when exposed to flame. And besides, these fuels work very poorly in unpressurized stoves.

I should also mention that while someone else in the backpacking community may have developed a similar design, I've not found it through the Internet searching I've done to date. Nonetheless, if you're out there and reading this article, I apologize for the lack of attribution, but note that I have arrived independently at all of my conclusions.

The Fire Bucket Design

When I recently began working on an update to the original Super Cat alcohol stove article (which was published almost four years ago), it became clear that developing a better solution to the wind problem was essential. The original article simply pointed users to the Internet for windscreen designs that were created by others, mostly ignoring the fact that wind protection was actually more important than many of the mechanical details of the stove itself.

Needed was the same kind of integrated approach that's been adopted over the past few years by the canister manufacturers mentioned above that would hopefully produce a system that would be lightweight and simple for backpackers to build and use.

DESIGN CHANGES

After a fair bit of trial-and-error, it occurred to me that making two simple changes to the traditional windscreen could not only satisfy my design criteria, but would also enable some interesting new capabilities.

Change #1
The first change would be to elevate the burn platform above ground level so that the stove flame would no longer be directly in line with the air that's entering the screen through ventilation holes. Doing so would help to isolate the stove in a quieter air space above the inbound air, thereby reducing internal turbulence.

If this elevated platform were also constructed of an open, grate-like material, incoming air could pass easily through it from below, allowing it to be evenly distributed around the outside of the stove, improving burn efficiency. In addition, raising the stove would also largely eliminate the performance-robbing conductive heat losses to the cold ground that can happen when an alcohol stove is used in chilly weather. Elevation also helps protect the vegetation or other surfaces beneath the stove.

Change #2
The second change would be to replace the multiple small ventilation holes found in traditional designs with a single large opening that could be positioned on the downwind (leeward) side of the stove. A single large port would virtually eliminate the incoming air resistance that's frequently discussed in connection with small vent holes. It would also make it easier to throttle airflow in order to control heat output, as well as to better manage turbulence inside the screen using the techniques discussed below.

Additionally, this large ventilation port could make it safer and more convenient to light wood, fuel tablets, and many types of alcohol stoves. Rather than having to reach over the top of the screen and into the burn chamber with a lighted match, a user could start the fire or light the stove from the bottom through this opening.

Change Produces Synergy
The combination of these two changes would also permit a design that could serve not only as a windscreen, but also as an efficient stand-alone stove for burning solid-fuel tablets and wood. It would do so largely by optimizing the "chimney effect", where cool air would enter the combustion chamber from below, pass freely up and around the burning fuel to infuse the flame with oxygen, would be heated, and then would flow around the bottom and sides of the cook pot to help transfer thermal energy.

Without getting into implementation details quite yet, you can get a sense of the basic design idea by viewing the brief animation below, created using Google SketchUp. 

By the way, if the Flash player window above doesn't appear in your browser, or if you're otherwise unable to stream Internet video, you can download an AVI version of the animation. Likewise, if you're a SketchUp user, you're welcome to download a copy of the SketchUp model itself.

IMPLEMENTATION OPTIONS

It turns out that a windscreen / stove combination that incorporates these two design changes can built using a wide variety of materials and construction techniques, allowing a builder to tune the design to precisely fit his or her needs.

For example, a Fire Bucket can be either permanently assembled or collapsible, can be constructed from several metals including aluminum, steel, titanium, brass or copper, and can employ burn platforms that are either attached, removable, or even that "float" independently inside the enclosure. It can also accommodate a number of optional accessories (discussed below) that allow for further customization. 

For me, weight is important, so I want a unit that's as light as practical. I also want it to be constructed from widely available, inexpensive materials that are easy to work with. The ability to store it in either an assembled or in a collapsed configuration is also a plus.

Accordingly, the specific implementation that I'll use to illustrate the Fire Bucket design will be as pictured below. As I describe this unit, however, I'll suggest other many other build options that you might want to consider.

JIM'S FAVORITE

Jim's favorite Fire Bucket is of a collapsible design, sized to fit the rather large (at least for solo use) Snow Peak Trek 1400 cook pot, and weighs about 2½ ounces. The photos below are of a unit that's been well-used with alcohol stoves, Esbit tablets and wood.

It's made from 6" wide aluminum flashing that can be purchased from most home supply centers in rolls as short as 10 feet for about $4.00. I like this material because it's lightweight, readily available, easy to work with, and is heat resistant enough for this task. For more about aluminum flashing, see the Materials section below. 

The two ends of the flashing overlap 5/8" and are connected to form a cylinder using three small brass screws with wing nuts that pass through drilled holes, allowing the screen to be easily disassembled (it can be transported either assembled or collapsed).

The burn platform is made from lightweight steel mesh cut with tin snips from a drip grate that's used on top of paint roller trays (available from Wal-Mart for about $2.50). See the burn platform Materials section below for more info.

The platform is supported 1½ inches above ground level by two removable rods that are constructed from heavy-duty coat hangers and that run through four small holes punched in the sides of the screen. Their are four other small holes near the top of the screen that will accept two thin titanium stakes that are used as pot supports when burning solid-fuel tablets or wood (coat hanger rods work just as well here too).

The single ventilation hole is 1 inch high and 1½ inches wide. Both this opening and the pot handle opening were cut into the flashing using ordinary household scissors. 

Jim's favorite Fire Bucket
key dimensions (+)

A similar unit built for the MSR Titan Kettle, is permanently assembled using aluminum pop rivets and incorporates a burn platform constructed from picture hanging wire (the technique is described below). It weighs 1.7 ounces. A slightly larger version of the same design built for the Snow Peak Trek 1400 weighs 2.0 ounces.

Materials

WINDSCREEN PORTION

Aluminum Flashing
As noted above, aluminum roof flashing is a good all-around material for Fire Bucket screen construction. In most cases, the 6" wide version of the widely available Amerimax product called "Economy Aluminum" (product #68306) should suit your needs. 

It's about 9 mils thick when new and about 8 mils thick—according to my vintage micrometer—after the coatings have been removed (coatings are discussed below). Amerimax also offers similar flashing products in other thicknesses, widths and metals. See the Amerimax website for more information.

While aluminum flashing generally offers a good mix of properties for use in Fire Buckets, there are a couple of issues.

The first is that both sides of the aluminum (at least with the Amerimax product) are coated with a polymer that's intended to protect the bare metal from weathering when installed in a roofing environment. The first few times you subject the windscreen to the heat of a stove or the flame of a wood fire, this coating will begin to burn away. 

Because of the smoke and toxic smell, you'll want to make sure your first few burns are conducted outdoors and not inside your home. I learned this fact the hard way by filling my basement with acrid fumes and activating a smoke detector during an early burn.

Though it's possible to sand this coating off before initial use, doing so is difficult. So instead, I'd recommend subjecting the flashing to a couple of pilot burns, after which you'll note the coating will probably have turned brown or black and will also have cracked or flaked in spots. At this point, it will be fairly easy to remove using a steel wool soap pad, such as Brillo or SOS.

The photo below is of a sample of aluminum flashing that's been subjected to such heat exposures. The left side shows the burned coating, while the right shows the result of a brief cleaning with a steel wool pad.

Heated aluminum flashing (+)
Left side shows burned coating, 
right side cleaned with steel wool.

The second issue is that 9 mil thick aluminum is pretty heat resistant, but is not completely immune to melting or warping. In exchange for the weight savings, you'll need to be somewhat careful with this material, especially when building wood fires. In my experience, small-to-moderate wood fires are fine and will easily boil a couple of cups of water without causing damage to the aluminum.

If you're inclined to make bonfires, however, or if you intend to use the unit primarily as a wood burner, you'll probably want to skip aluminum and build your Fire Bucket from a more heat resistant material such as steel or perhaps even titanium.

Steel Cans, Rolls and Sheets
Steel is a great material for Fire Buckets, though it can be a little heavy, especially when building for larger pot sizes. The steel that's used in many food cans, however, is often thin enough that you may find its weight acceptable.

Coffee or large fruit juice cans are a good way to start and were the basis for my early prototypes. Because a can is already assembled into a cylindrical shape, it makes construction somewhat easier if you're OK with a non-collapsible design. The metal used in most cans with which I've experimented ranges from 8 to 12 mils thick, which makes it pretty much melt-proof with normal use.

With a pre-formed can, of course, you'll not be able to adjust the Fire Bucket's diameter to fit around a particular cook pot with the precision that's possible with flashing or sheets cut to an exact length. On the other hand, it's usually possible to find cans that are sized close enough for the purpose.

For example, my local Safeway grocery store stocks steel coffee cans that are available in a 13 ounce size that fits the Snow Peak 600 titanium mug well, a 26 ounce size that fits the MSR Titan Kettle, and a 34.5 ounce size that works with the Snow Peak Trek 1400 pot. 

The finished weights of Fire Buckets constructed from these cans will probably vary from about 3 ounces for the smaller sizes to over 9 ounces for the largest, depending on construction techniques and other materials used. The large model shown above retains the bottom and is the heaviest of my prototypes at 9.6 ounces and though somewhat hefty, makes a great full-time wood stove.

Compared with weights of 1½ to 2½ ounces for aluminum models, these numbers may seem high, but compared with the 8+ ounce base weight of a typical top-mounted canister stove system*, they don't seem so bad considering that you get a windscreen and a wood-burning stove included in the deal.

Steel is also available as flashing in rolls and as galvanized sheets for use in HVAC ductwork. It's usually about 12 mils thick in these forms, which would yield Fire Buckets of about the same weights as those made from large coffee cans. 

One advantage of starting with rolls or sheets, however, is that the material can be cut to precisely the desired dimensions and be used to create either permanently assembled or collapsible Fire Buckets. One such prototype, made from galvanized sheet steel, and built again for the Snow Peak Trek 1400 pot is shown below and weighs 6.5 ounces, complete with burn platform.

Large galvanized steel model
for Snow Peak 1400 weighs 6.5 oz (+)

* Assuming 3 ounces for the stove and 5 ounces for an empty 8 ounce fuel cartridge, without a windscreen.

Titanium Sheets and Pots
Titanium is also an excellent material for Fire Buckets, since it can be as light as aluminum, but as strong and heat resistant (or more so) than steel. In sheet form, however, it's hard to buy in small quantities and is very expensive. 

Nonetheless, if the combination of durability and light weight were really important, one approach could be to purchase an existing titanium cook pot that was large enough to serve as a Fire Bucket for a smaller pot that fit inside, and modify it accordingly. Note, however, that titanium can sometimes be difficult to cut and drill.

Other Metals
Brass and copper sheet metal are also options, but both are fairly expensive and don't seem to offer any compelling advantages over the other materials discussed above, so I'd probably bypass them unless cosmetics are important to you.

MATERIALS:  BURN PLATFORM PORTION

As used in Jim's Favorite Fire Bucket that's described above, a burn platform can be constructed by cutting an appropriately-sized section of steel mesh from a drip grate that's used on top of paint roller trays, widely available for $2.00 to $3.00 from sources such as Wal-Mart or Home Depot. 

Paint roller drip grate from Wal-Mart (+)

One alternative is to use what's called "hardware cloth", which is really just another type of wire mesh that's available in a range of sizes and material types. The downside of hardware cloth is that you'll probably to purchase a larger quantity than you'd ever need for one (or even a few) Fire Bucket projects. I did find one online vendor, however, that sells sample-sized quantities of many its wire mesh products in 6" x 6" swatches.

Welded mesh from TWP, Inc. (+)

Another option I like for permanently assembled models is to create a burn platform using picture hanging wire. I'd suggest 22 gauge solid steel wire (rather than stranded, which is heavier and more difficult to work with) that's available in 100 foot reels from sources such as Home Depot for about $2.50. The process for installing this wire to create a burn platform is described below.

Steel picture hanging wire (+)

Tools

The tools required to build a Fire Bucket will depend upon the design and materials you elect to use, but are mostly pretty simple. 

Basic Tools
Aluminum flashing models are the easiest to build since the metal can be cut with a sturdy pair of household scissors. Also helpful are an awl for making holes, needle-nosed pliers, a felt-tipped pen for marking hole and cut positions, and a ruler for measuring.

Basic tools for aluminum flashing models (+)

Other Tools
If you cut the burn platform from a section of paint roller grate, or if you build you Fire Bucket from steel or titanium, you'll need a pair of tin snips and/or sturdy wire cutters. 

Likewise, besides an awl, holes can also be made with an electric drill or a with handheld sheet metal punch. If you don't already own one, an inexpensive sheet metal punch is a great investment for avid do-it-yourselfers. Also known as "Whitney" punches, they can be purchased for as little as $20 plus shipping from online sources such as Harbor Freight, that offers both standard and deep throated models. I'll note too that these punches are very handy for building Super Cat alcohol stoves.

If you build a permanently assembled Fire Bucket, a good way to join the ends is with short pop rivets (also known as "blind rivets"). You can use aluminum, steel or copper rivets but aluminum rivets are the easiest to hammer flat to reduce their profile as described below. Handheld rivet installers are also inexpensive, available from a wide range of sources (such as Harbor Freight) and are a great addition to any tool box.

Other useful tools might include an electric drill,
 a handheld sheet metal ("Whitney") punch, 
a pop riveter, a metal file, and a pair of tin snips (+)

And finally, in instances where you're cutting a ventilation hole in a steel can where the bottom has been left in place (more below on this option), it may be necessary to make the cut using a handheld jigsaw equipped with a metal cutting blade (not shown).

Build Instructions

Note:  There are so many ways to build Fire Buckets that it's not practical to discuss each in detail. So instead, I'll describe a few basic materials and techniques, then allow you to exercise your creativity and fill in the gaps. You can skip directly to the desired subsection using the links below.

Building the Screen (Flashing or Sheet Method)

Building the Screen (Steel Can Method)

Cutting the Pot Handle Opening

Building the Burn Platform

Building Pot Supports

BUILDING THE SCREEN  (Flashing or Sheet Method)

Material Width
If you construct your Fire Bucket from aluminum flashing, you'll probably find that the 6" width will adequately protect your cook pot while also allowing sufficient room for an elevated burn platform. 

If you need more width, however, flashing is also available in 8", 10", 12" and 14" (or greater) sizes with, of course, correspondingly greater weights. Alternatively, you could join two pieces of 6" wide flashing lengthwise with machine screws or pop rivets to create (assuming about ½" overlap) a screen that's up to 11½" high.

Another choice, if you'd like more height only some of the time (perhaps only in very windy conditions), you might want to build an optional height extender, as discussed in the Accessories section below.

Fitting and Measuring
While it's possible to build a single Fire Bucket that can be used with pots of multiple sizes, it's usually most efficient to optimize the fit for a single vessel. 

The easiest way to measure the length of the material you'll need is to cut a section slightly longer than necessary, then wrap it around the target pot to tune the fit. Normally, you'll want ¼ to ½ inch clearance between the pot and the screen, though in practice what usually happens (especially with aluminum flashing) is that the heat from the flame will distort the screen so that there will be little or no clearance in some spots and extra clearance in others.

Another factor to consider is how you'll transport your Fire Bucket when not in use. If you use a pot cozy, for example, you may want to allow for its width if you intend to nest your cook pot inside the cozy which will in turn, nest inside the Fire Bucket for carry purposes.

This unit has been sized to allow room
for a pot cozy nested inside during transport (+)

Once you've established a diameter, you'll want to add approximately 5/8" to your total cut length for overlapping the two ends to make a cylinder. Once cut, you can then join the ends in several ways, depending upon whether you want to build a collapsible or a permanently assembled screen.

Joining the Ends
For collapsible models, I'd suggest bypassing most of the techniques you may have either read about or employed in the past for joining aluminum windscreen ends, such as using paper clips, office binder clips, and the like. The problem is that most traditional windscreens are not weight bearing, so if they pop apart during use, no big deal.

Most implementations of the Fire Bucket, on the other hand, will be weight bearing since they'll need to support your stove (or wood fire) and a pot full of water while in operation. You will most definitely NOT want the unit to disassemble itself when subjected to heat and wind stresses during operation, possibly spilling burning fuel, scalding water or your dinner-in-progress on you and your surroundings.

Accordingly, I'd suggest a more robust approach and join the ends of collapsible models by first drilling or punching three small holes in the overlap zone (one in the middle and one near each end as shown below), then using three small machine screws with either standard nuts or wing nuts to complete the union.

The nuts need only be hand tightened when assembling and the use of additional hardware such as flat or lock washers is probably unnecessary. Even if the nuts happen to loosen a bit during operation, it's highly unlikely that the entire screen would ever pop open with this approach.

For permanently assembled models, either 3 or 5 small machine screws (this time well tightened perhaps installed with flat and lock washers) or pop rivets work well. 

If you'll be storing a pot cozy inside the Fire Bucket for transport, you'll want to minimize the profile of your chosen fasteners inside the screen to reduce the chance of snagging the side of the cozy when it's inserted. You'll therefore want to position the heads of small machine screws on the inside (rather than outside) of the screen. To further reduce their profile, you can also file the heads down, if desired.

If you use pop rivets as fasteners, one trick is to position the head on the outside surface, install the rivet, then flatten the inside portion using a hammer on the inside and a hard surface (such as the anvil portion of a bench vise) on the other. 

Inside shows rivets flattened with a hammer
prior to installing the burn platform (+)

If you flatten the rivets (easiest with aluminum rivets, more difficult with copper or steel), you probably won't need backing washers. If you'd prefer not bothering with flattening the rivets, then you'll probably want to install the heads on the inside of the screen with backing washers on the outside surface (especially with aluminum flashing). In any case, I'd suggest testing your rivet technique on metal scraps before proceeding with your build.

BUILDING THE SCREEN  (Steel Can Method)

Removing the Bottom (or Not)
Constructing your Fire Bucket from an empty steel can involves some of the same techniques as used for a screen made from flashing. One difference, however, is that you'll have to decide whether or not to remove the bottom from the can.

While doing so can save a bit of weight (perhaps ½ to 1 ounce), leaving the bottom in place has some advantages. The bottom joins the can walls with an hermetic seal that can improve control over airflow inside the screen compared with open-bottom models. It can also serve as a heat reflector, bouncing much of the radiant energy that would otherwise be directed towards the ground back up towards the cook pot. Further, it can protect the surface under the Fire Bucket and serve as an ash collector for wood fires. 

When the Fire Bucket is used with some types of alcohol stoves (like the Super Cat), the metal bottom can serve as a priming pan, which also allows stove ignition without having to reach over the top edge of the screen and into the interior with a lighted match. The technique, which is described in greater detail below, involves a dribbling a little of alcohol down one side of the stove and onto the bottom, where it can be ignited through the large ventilation opening. The alcohol that burns briefly on the bottom surface will warm the aluminum stove above, helping to accelerate the priming process.

I will note that some of these same advantages can be realized with open-bottom models simply by placing a a few folded sheets of aluminum foil, or a lightweight aluminum disk (see the Accessories section below) under the Fire Bucket. In any case, should you elect to remove the can's bottom, you can usually do so with an ordinary household can opener. With cans that are sealed with foil tops, it may also be necessary to remove the inner ring (usually about ½" wide) using the same opener.

Cutting the Walls
As noted under the Tools section above, regular scissors probably won't be able to cut the pot handle and ventilation openings in a steel can, so you'll need either tin snips or a handheld electric jigsaw equipped with a metal cutting blade. Tin snips alone will probably suffice if you elect to remove the bottom, but if you decide to leave the can bottom intact, you'll likely need a jigsaw to create the ventilation opening. 

For this case, I'd suggest proceeding as follows: First, mark the desired position of the ventilation opening at the bottom of the can using a felt-tipped pen, then drill near each of the four corners of the rectangle with a bit large enough to accommodate the width of your jigsaw blade (see photo below).

Once the holes have been drilled, it should be fairly easy to cut the opening, moving from hole-to-hole with the jigsaw. While cutting, take care to keep the blade clear of the inside bottom surface, or you could accidentally cut through it. 

Also, be sure to wear safety glasses and probably hearing protection, since cutting sheet metal with an electric saw can be rather noisy. When the cut is complete, rough edges can be smoothed with a metal file.

CUTTING THE POT HANDLE OPENING

Whether your screen is constructed from flashing, metal sheet or a steel can, you'll need to cut an opening to accommodate your pot handles. If you're building for a pot that doesn't use handles, such as the FireLite SUL-1100 titanium cook pot from backpackinglight.com, then congratulations, you're finished with the screen. Otherwise, you'll need to figure out how to size and position this opening.

I'm going to skip ahead here, because in order to determine the best dimensions and placement for this opening, you'll first need to decide what heating method you intend to use most of the time, and will also to need to have completed both the burn platform and pot supports as described below.

To describe this simple process, I'll assume that you'll be using an alcohol stove as your primary heater. If you plan to Esbit tablets or wood, then you'll need to adjust accordingly.

1. First place the stove in the center of the burn platform. If you'll be using an optional stove holder (see below), you'll probably want to include it as well, though its effect on pot height will likely be minimal.

2. Next, position your cook pot on top of the stove (or pot supports if appropriate) with the handles collapsed and observe where the pot handles, when extended, will intersect the Fire Bucket walls.

3. Using a ruler and felt-tipped marker, measure and mark an appropriately size opening and make the cut. If working with flashing, the bottom corners should be easy to manage with scissors. If working with steel, however, it may help to drill holes in the bottom corners and to use the other steel-cutting techniques that are described above in connection with the ventilation opening.

4. Finally, snip off or file sharp corners and edges as necessary.

BUILDING THE BURN PLATFORM

Collapsible Models
For collapsible Fire Bucket designs, the elevated burn platform will need to be removable. Such platforms can either be attached to the Fire Bucket via some form of removable support (perhaps as shown below) or can be "free floating" and supported independently of the surrounding screen. 

One example of a attached (but removable) platform is shown in connection with Jim's Favorite Fire Bucket discussed above. It uses a section of wire grate that's been cut from a paint roller drip grate purchased from Wal-Mart.

Paint roller grate section cut to size using tin snips (+)

For creating a free-floating platform, one option would be to plant three thin stakes into the ground as shown below, then simply rest the burn grate on top. This option might be appealing if you'd like to convert an existing windscreen into a Fire Bucket-like model. 

"Free floating" burn platform 
supported by 3 titanium tent stakes (+)

The stake approach obviously wouldn't work on a hard surface like a picnic table or rock slab, so some other type of stand would be needed for these situations. If using a stove like the Super Cat, that burn platform stand would also need to be fairly sturdy since it would have to support the weight of a pot full of water during operation.

Another option is to suspend the burn platform inside the screen using a sling that's constructed from stranded picture hanging wire. This technique is the same as that discussed below in connection with building a sling-type pot support.

Permanently Assembled Models
If you're building a permanently assembled model, you can position a mesh grate on top of permanently installed support rods, perhaps attached to the rods by twisting small lengths of picture hanging wire around the two components in 3 or 4 locations. Permanently installed support rods can look just like the temporary rods shown above, except with the straight ends bent so that they can't slip back through the bucket.

Another lightweight approach is to construct the burn platform entirely from the 22 gauge, solid steel picture hanging wire that's described above. To do so, you can drill or punch tiny holes at 1 inch intervals around the perimeter of the screen at a distance of about 1½ inches above the ground, then run a length of wire from one hole to another, much like stringing a tennis racket.

The burn platform in the unit below was constructed in such a way by creating two independent grids: the first by running the wire in the vertical and horizontal directions; the second by adding an overlay of wire running at right and left diagonals.

Burn platform created by stringing
22 gauge steel picture hanging wire 
among tiny holes punched 1" apart (+)

A hybrid method would be to first construct a minimal grid from picture hanging wire, then layer a paint-roller grate onto top of it, again perhaps securing it in place by twisting small lengths of picture hanging wire around the two components in three or four locations to keep them together. You'll just want to make sure that your minimal grid is sturdy enough to safely support the weight of a pot full of water when subjected to the heat of operation.

BUILDING POT SUPPORTS

If you use your Fire Bucket only as a windscreen for a Super Cat alcohol stove, then you won't need separate pot supports. However, if you'd like to use it either with stoves that require separate supports, or as a standalone stove for burning solid-fuel tablets or wood, then you'll need some type of support positioned at an appropriate height above the flame.

Fixed Position Pot Supports
Probably the easiest way to create pot supports is by using either a pair thin titanium tent stakes such as those shown in the photos below (which are about 7 inches long and that weigh ¼ ounce each), or heavy-duty coat hanger wires cut to size and with one of the ends bent at about 90 degrees to prevent slippage through the holes in the screen wall.

The supports can be installed through small holes drilled or punched in the walls of the Fire Bucket. It's best to orient these holes on the sides of the screen (relative to wind direction) so that when they're not in use, a minimum of air is forced through these openings. If you'd like to have the option of positioning your pot at more than one distance above the flame, then you'll need to create a set of four holes for each position when using this method.

I'd recommend locating the holes that are used to support the cook pot in wood burning mode near the top of the screen at a height that allows your pot handles to be oriented away from the normal handle opening. 

That's because flames from a wood fire will normally exit the bucket through this opening, which would otherwise cause your pot handles, if positioned normally, to become extremely hot. Keeping this opening clear while burning wood also creates a convenient feed hole for additional fuel.

During this test burn, flames from a wood fire exit the top opening  directly onto the pot handles (+)	Supports located at a height that allows pot handles  to face away from the normal opening  when burning wood (+)

If you'd prefer to support your cook pot using a method that allows for continuous up and down height adjustments without having to drill a lot of extra holes in the Fire Bucket walls, two such methods are discussed below.

Continuously Adjustable Pot Supports (Stake Method)
Rather than using 2 thin titanium tent stakes running horizontally through holes in the Fire Bucket walls, you can use 3 such stakes positioned inside the screen, oriented vertically in a tripod formation, planted into the ground through the burn grate.

This method, of course, requires ground under the Fire Bucket that's firm enough to support the weight of a pot full of water on top of the three stakes, but assuming that condition is met, allows for continuous pot height adjustment through a range of about 3 inches without having to drill any additional holes in the bucket walls.

If your Fire Bucket has a floor of some type, you'd need to drill, punch, or poke 3 small holes in that floor at the appropriate positions to allow the stakes to pass through in order to use this technique. 

Continuously Adjustable Pot Supports (Sling Method)

Another way to position the cook pot at multiple heights above the flame is to suspend it inside the screen on a sling that's constructed from picture hanging wire. This method has the advantage of being usable anywhere since it's indifferent to the type of surface that's beneath the Fire Bucket.

To use this method, you'll need small four holes punched or drilled near the top edge of the screen in the same positions as those described above for use with the fixed supports positioned for wood burning. If these holes already exist, then the only other requirement is a piece of picture hanging wire 24" to 30" long. 

For this purpose, I'd suggest using stranded wire, rather than the 22 gauge solid wire that's discussed above in connection building a burn platform. Because there will be only two segments of this wire supporting your pot full of water, and because this wire will be located above the flame (where it will be subjected to higher temperatures) rather than below it, you'll want the extra strength.

Sling pot support (red line above)
made from stranded picture hanging wire

When threading the wire through the holes as shown below, be sure to cross the wires in the center of the screen. If you don't, and the wires run in parallel to each other, the wires can (and probably will) slip from beneath the bottom of the pot to one side, allowing the pot to fall inside the bucket onto the flame.

To increase the depth of the sling, feed additional wire into the holes from the "working ends" of the wire (i.e., the loose ends shown at the bottom of the left diagram). You'll want to feed roughly equal amounts through each hole in order to keep the pot level inside. To decrease sling depth, just reverse the process.

Once the desired depth is reached, twist the loose ends of the wire together 2 or 3 times on the outside wall of the screen.

One issue with this type of support is that when a full pot is positioned near the top of the screen on the sling, the weight will tend to cause the sides of most aluminum flashing screens to bow inwards towards the pot. If the screen contacts the pot at too many points, very hot air can be trapped between the pot wall and screen, possibly causing the screen to warp or melt. The good news is that as the pot depth is increased, the weight forces become less horizontal and more vertical, which tends to mitigate this problem.

A more direct approach to the solving problem, which also improves the general stability of the sling support, is to layer a second grate of the same material used for the burn platform on top of the sling. The second grate should be large enough in diameter that it just fits inside the screen (as the burn platform probably already is). The uneven edges of this second grate will "lock into" the sling wires in a way that will both increase stability of this pot platform while also serving as a barrier to help keep the screen walls from bending inwards far enough to contact the walls of pot.

Optional grate positioned
on top of sling to improve stability (+)

The sling wire used in the examples above weighs about ¼ ounce, while the second grate adds another ½ ounce. Since I mostly use a Super Cat alcohol stove (with perhaps some wood burning) I don't need additional supports very often. Even so, for the negligible weight, I usually carry the just the wire (and not the second grate) for those occasions where I might want to burn Esbit tablets and wish to support the pot at an optimal height.

Usage Notes

ALCOHOL STOVES

Filling and Lighting the Stove
It's probably easiest to fill most alcohol stoves outside of the Fire Bucket before lowering them into place inside the screen. I'll note here that a good way to keep the stove centered inside the screen is by using the optional stove holder that's discussed below.  

After the filling operation is complete, you'll want to move your alcohol storage bottle and other flammables well away from the bucket before lighting the stove. Likewise, you'll want to use a safe ignition method (see below) that allows you to keep your face, hands and clothing well clear of any potential flare-ups.

One such method is to dribble a little alcohol down one side of the stove, allowing it to drip onto the bottom of the bucket. Having a piece of aluminum foil or an optional floor under open-bottom models, or the original bottom in place with steel can models is obviously desirable here. The stove can then be started through the ventilation opening by lighting the alcohol that's accumulated at the bottom of the bucket.

An alternative is to fill the stove, lower it into place inside the screen, then position a little tinder in the lower chamber of the bucket which can be ignited through the vent port. The flame from the tinder will rise to the stove, prime it, and in most cases, ignite the alcohol fuel (may not work for all stove types, but works well with the Super Cat).

Another choice is to use a long dry twig as a fireplace match. First light one end of the twig, then lower that end towards the stove through the pot handle opening or over the top edge of the bucket, keeping your hand outside of the screen wall at all times.

Finally, if you're using wooden matches, you might also want to try Jim's simple wine cork extender that's described in the "Accessories" section below. Likewise, for additional information about Fire Bucket ignition techniques in general, please refer to the "Lighters and Matches" discussion.

Lowering the Cook Pot
If you're using a Super Cat alcohol stove, you can lower your cook pot onto the lighted stove as soon as priming is complete and you can see bubbling on the surface of the hot fuel (usually 15 to 30 seconds after ignition). If you lower the pot straight down onto the stove, however, the flames may, for a moment, tend to be "squeezed" out through the pot handle opening directly toward your hand.

To avoid burns, simply tilt the handle side of the pot downward a bit as it's lowered. Doing so will cause the bottom of the pot to deflect the flames away from the handle opening and safely towards the back of the Fire Bucket during pot descent.

Tilting the pot slightly while lowering it onto the Super Cat
will direct the flames away from the handle opening

If you're using an alcohol stove (or a wood / fuel-tablet fire) that requires separate pots supports, then you probably won't need to use this "tilt technique" and can probably lower the pot vertically into place.

Stopping the Stove
Most of the time, you'll just need to allow any alcohol remaining inside the stove after a cooking operation to burn itself out. In an emergency, however, you can use plain water to safely douse alcohol flames (unlike with petroleum-based fires, water won't just spread the flames around).

Because of the Fire Bucket's mesh burn platform, the use of a device like the snuffer cup (discussed in the Super Cat article) to smother the flames won't work without modifying the design. If stopping the stove by depriving it of oxygen is important to you, however, one solution would be to add a base around the stove holder that's wide enough to serve as a "smother platform" for the snuffer cup. See the Accessories section below for more discussion and construction details.

SOLID FUEL TABLETS

This one's pretty easy. Most of the time, you can just drop your Esbit or Hexamine tablet onto the center of the burn platform, make sure that your pot supports are securely in place, and then set the tablet ablaze.

You can light the tablet in several ways, but ignition from the bottom through the ventilation opening is probably easiest. If necessary, you can add a bit a kindling (such as a few dry pine needles or a little paper from your trash bag) to the lower chamber under the tablet to help get things going.

Pot Height
Esbit tablets seem to work most efficiently when the bottom of the pot is positioned only about an inch or so above the top of the burning tablet, so you may need to create a special set of support rod holes to accommodate this height if you regularly burn this fuel.

Alternatively, you can use one of  the continuously adjustable pot support methods described above to position your stove at the optimal height above the tablet.

The Shrinking Tablet
Another issue is that, depending on the coarseness of your burn grate and the precise positioning of the tablet upon it, you may find that the tablet eventually falls through the grate and onto the ground beneath since it will shrink in size as it burns. 

If this occurs, you can try placing the tablet on a second small piece of grate material turned sidewise relative to the first (effectively creating a less coarse grate) or on a piece of hardware cloth with a finer mesh. You don't want to use a solid platform made, for example, from aluminum foil or flashing, because the tablet will probably be much harder to light from the bottom. In addition, a solid platform, if cut too large, can also interfere with the supply of oxygen to the tablet.

A section of finer mesh hardware cloth
placed under an Esbit tablet will prevent it
from dropping through the main grate
as it shrinks while burning (+)

Other Burn Platforms
While there are many ways to burn solid fuel tablets, I would specifically not recommend using a Super Cat alcohol stove, or the optional stove holder discussed below, as a tablet burn platform. The tablet will deposit a gummy reside on the stove or the holder and probably also melt a portion of the aluminum wall.

WOOD STOVE MODE

Using wood as a stove fuel has a lot of appeal for some folks, especially if hiking mostly below tree line. Though campfires have generally fallen into high disregard among leave-no-tracers (and are prohibited in many places) the tiny fires built in ultralight wood stoves are a different animal.

It turns out that very little wood is required to boil a couple of cups of water, a task that can often be accomplished within 10 minutes of lighting a fire if using dry fuel. The Fire Bucket is a very efficient wood stove, primarily because the incoming oxygen flows easily through the large ventilation port, then is drawn upwards, directly through the burning fuel.

The small amount of wood fuel shown above is 
usually sufficient to boil 2 to 4 cups of water (+)

On the downside, the Fire Bucket, like most wood burners, has a couple of notable disadvantages: (1) it can deposit soot on the inside of the stove as well as on cook pots; and (2) it can infuse your hair and clothing with smoke odors if you linger near the fire for too long. Neither is a big deal for most backpackers, however, who often use simple techniques to work around these issues.

For example, it's not very difficult to remove loose soot from pots and stoves simply by wiping with a damp cloth or sponge. While the more persistent pot blackening that often occurs is more difficult to clean, it's also said to help cooking vessels absorb heat energy, so most hikers just leave it in place.

Regarding smoke, the amount that's produced by the Fire Bucket is partly a function of the species and moisture content of the wood used (hard, dry woods usually smoke the least), and partly a function of the phase of the burn. 

As wood first starts burning, it tends to produce more smoke, but as the temperature of the fire increases, smoke production generally drops off significantly. In any event, if using the fire primarily to boil water rather than doing the kind of cooking that requires frequent pot tending, it's usually easy to maintain enough distance between you and the stove to minimize your exposure to smoke.

As a point of clarification, I will also note that the Fire Bucket is not what's known as a wood gas or "inverted down-draft gassifier" stove. That type of stove, which may burn with even greater efficiency, is also more complex (requiring a double-skinned burn chamber) and is generally heavier. On the flip side, these stoves tend to produce less soot and smoke than do non-gassifier types.

If you're seriously interested in using wood as a fuel, you might want to construct a wood gas stove using instructions found on any number of Internet sites (they're fun to build and operate). For occasional use as a backcountry wood stove, however, I think you'll find that the Fire Bucket is an excellent, lightweight alternative.

Fueling and Lighting the Stove
To begin, remove your pot supports (if appropriate, depending on type), then load the burn chamber with pieces of small branches, perhaps pencil-sized in diameter and broken into lengths of 3 to 5 inches, until you have a pile about two inches high. 

That modest amount of fuel may only burn for ten or fifteen minutes, but will probably produce enough heat for most cooking chores. If you need more fuel, you can always add wood either by removing the pot and dropping it in through the top, or by feeding it in through the pot handle opening.

Next, insert a charge of tinder into the bottom chamber under the burn platform. A little crumpled paper or a small pile of dry pine needles should be sufficient to get things rolling as long as your wood is dry. 

Alternatively, a bit of alcohol fuel dripped over the fuel supply and allowed to pool at the bottom of the bucket should also work. I'll note that I actually prefer this method because it's cleaner and faster. Paper and similar tinder materials tend to produce more smoke while also creating a fair bit of ash that can fly about in a breeze.

And speaking of breezes, I'll further note that wood fires, unlike alcohol stoves or solid fuel tablets, are usually assisted, rather than disrupted, by a little air movement, so you needn't be quite as concerned about sheltering the stove from the wind when burning wood. In other words, you probably won't need to use your optional wind shade.

Anyway, you can now replace your pot supports and light the tinder or the alcohol pool through the ventilation port. 

Be advised again (see the Safety Note above) that if using alcohol fuel to help start a wood fire, its vapors will be circulating inside the Fire Bucket, which means that ignition will likely happen with a "whoosh" (in other words, a potentially startling flare-up). There should be no problem, however, as long as your face, hands, clothing, and shelter are kept well clear of the stove during this ignition process.

I'd suggest that you wait a couple of minutes after ignition to allow the fire to come up to speed, then place your cook pot on the supports. The use of a lid will accelerate the heating process and will also help keep particulates generated by the fire out of your pot.

One tip I'll mention here is that if the flame begins to falter, it may help to lift the pot from the Fire Bucket for a few moments to help infuse it with oxygen. With more air, the fire should begin to burn hotter, which will in turn stoke the chimney effect by drawing more air through the ventilation port. This effect should persist, at least for a while, after the pot is placed back on the stove.

The video below demonstrates the use of a Fire Bucket in wood burning mode. If you're not able to stream Internet video, or if you'd just like to keep a local copy, you can also download an MPG version of the video (2 min, 5 sec length, 30mb file size).

Fuel Strategies
Finally, as you consider fuel strategies for any given trip, I'll note that even if you prefer to use primarily wood, you'll probably also want to have a backup such as alcohol or solid-fuel tablets available for those times when you make camp in the pouring rain, you're bone cold, and the prospect of having to search around for dry wood is really unappealing.

LIGHTERS and MATCHES

There are, of course, many ways to ignite backcountry stoves and most experienced hikers will usually have already settled upon a personal favorite. Nonetheless, I thought it might be useful to weigh in with a few Fire Bucket-specific comments. I'll also note that there's a good bit of useful information available at the Backpack Gear Test website.

Lighters
One of the more popular methods of lighting stoves is with butane lighters such as those made by Bic, Ronson, Tokai, Calico and others. Aside from being inexpensive, these lighters are also lightweight and durable, but there are at least a couple of issues, especially when used with the Fire Bucket.

The first, of course, is that these lighters are designed primarily for use with tobacco products, so your hand ends up very close to the flame. That's perhaps OK for a cigarette, but not so good for starting a stove where accumulated flammable vapors can sometimes cause brief flare-ups during ignition. This design can also present a burn hazard when the lighter needs to be held horizontally, rather than vertically, in order to start a stove.

A second problem is that most of these lighters don't work very well, or perhaps at all, in cold weather. Most inexpensive lighters are fueled with regular butane (also known as n-butane), which has a boiling point of 31°F (-0.5°C). As soon as the air temperature drops much below freezing, the butane will simply refuse to vaporize and the lighter will cease to function. I've found this to be the case even if the lighter is stored in a warm jacket pocket because the moment the butane gas is exposed to the cold air, it immediately becomes uncooperative.

A few lighters, such as those made by Ronson, are fueled with isobutane, which has the same molecular formula (C₄H₁₀) as n-butane, but a different structural formula (i.e., it's a butane "isomer"). The boiling point of isobutane is 11°F (-11.7°C), which makes its cold weather performance better than n-butane, but even so, vaporization at temperatures below freezing can still be a bit sluggish. And when temperatures drop below isobutane's boiling point, these lighters will likewise cease to work at all.

An alternative is a butane candle-style lighter, where the flame port is moved away from the hand via a metal extension tube. This design solves the hand-to-flame proximity problem, but not the cold weather performance issue. And at weights of 2 to 3 ounces, these kinds of lighters are also significantly heavier than the ½ ounce or less of standard models. They are, however, very handy for testing alcohol stoves in home or laboratory settings.

Most candle-style lighters use piezoelectric ignition where a small spark is generated at the end of the extension tube in order to ignite the butane gas. It turns out that even if the lighter's butane gas won't ignite, this spark alone is sufficient to start some kinds of stoves, most notably butane/propane canister models. 

Interestingly, I've discovered that the spark alone from some candle-style lighters can also be used to start an alcohol stove like the Super Cat. For this ignition method to work, however, the lighter's spark point must be located near the tip of the extension tube (rather than at some distance up the barrel) and the the lighter's tube must usually be dipped into the alcohol pool for ignition to occur. When lighting the Super Cat inside the Fire Bucket, this spark-only method still requires that the hand usually be placed directly above the stove during the starting process (which makes the user susceptible to burns) and thus is not recommended.

If you perform a quick search on the web, you'll find that butane lighters are offered in a huge variety of styles and prices, with some supposedly "hardened" for use in outdoor survival situations. All told, however, I'd suggest passing on such products and s