= pop can pot + tomato paste can burner + windscreen
Faced with the task of getting 34 young Scouts backpacking stoves + pots (to only boil water), a couple hours to do it, $ones per boy not $$hundreds, BSA's alcohol fuel ban, and knowing how boys simply can't maintain or tune stuff, I combined lots of postings to create a very simple, quickly built stove consisting of:
Soda can (emptied by Scouts) as pot for boiling 1 cup water (it fits 1.5 cups but these are boys so you want less spilling and they eat smaller amounts.
6 oz tomato paste can (emptied for pizza) as the burner & 'pot' stand
10" tall aluminum flashing as windscreen
Hexamine fuel tablet (~1 Coghlans tablet boils 1 cup water)
Handkerchief, cloth, glove, pliers, etc as pot holder
Burner & Stand. Using a church key opener, punch 4 triangles on bottom of tomato paste can, plus 4-6 on top. This focuses flame upward to & around pop can and offer a bit of a standoff from the ground. The can's bottom holds the solid --> liquified fuel well. Use a long needlenose pliers to hold the can next to where you punch the hole (else can bends too much). Later, you'll burn the plastic liner outta it.
Windscreen can be many things, but aluminum flashing seems best cuz its lightweight, easily cut with scissors, leaves few sharp edges, holes punched with cheap paper hole punch, and comes in right size from Lowes, Home Depot. Foil works but tedious to maintain. Galvanized steel (HVAC duct) stronger & cheaper but edges sharp, need tin snips, and hole punched w/ a hammer & punch. Big beer cans then cut apart work, but metal is thin and not quite big enough.
On bottom of windscreen put many small holes. Roll flashing tight to fit around the pop can -- if tighter than can, then cut a 1/8" notch on top & bottom to keep it open. 10" is a bit taller than burner & can stacked, but it really keeps the heat in, protects everything when jammed into the pack, and its one less cut to make building it. (Get 10" tall flashing from Lowes, Home Depot).
Pot. No changes to pop can (pot, boiling kettle). It fits ok atop stand. Easily replaced if crushed.
Big Pot Option: A 24 Foster beer can also works fine atop the burner/stand. Leave as is to boil 2-3 cups water (with many tablets) or for more of a pot look, cut the top's inner ring (inside the lip) by scoring a knife or razor blade inside the little trough around the top ~80 times. After the top separates, press backside of knife around edge to remove sharp stuff. Wash well to remove aluminum shavings.
Light it! Put water in pop can, put fuel tab in burner, tip burner to ignite tablet with lighter, put pop can atop burner, wrap with windscreen (critical, not too tight, want flames up sides of pop can but not windscreen), watch water boil in few minutes, pour hot water into Ziploc and Cozy Cook (use a cloth or gripper to grab), blow out tab, cool, place all in plastic grocery bag for travel.
Cautions & Caveats. Despite telling boys many times, several will grab a hot can & git a bit burned. Expect to find aluminum dots from punching holes for years. Its not optimized (like many do here to eke out a few seconds less boil time or drop a gram). This is meant to be a Webelos or Boy Scout stove, simple, cheap, tough, no worries if lost, easily replaced/made by boys.