You can use junk fuels and a metal oil drum to make a wood-fired water heater for laundry.
Anyone who's ever lived in the bush—or for some other reason done without electricity or running water—knows how much time and effort it takes to do the laundry under such circumstances. My wife and I have lived in the back country and regularly tackled this chore for upward of 15 years now, and I think we've streamlined the process just about as far as it will go.
When we first came to live in the Alaskan woods, Manya and I really started from scratch. Our original laundry setup consisted of a homemade wood stove, two empty five-gallon cans, and a stick. As the years went by, we added a manual wringer (no more blistered palms from squeezing diapers by hand), a plunger-type agitator, extra tubs, better cooperation, and—most important of all—a burning determination to get the wash done quickly.
But as our speed picked up, we ran into a new bottleneck: We couldn't heat our water fast enough! To solve that problem I built a simple, heavy-duty, high-capacity, energy-efficient, wood-fired water heater for laundry using materials that we had on hand.
My plan was to build a metal shell that would hold an ordinary washtub above the fire, yet allow the flames to lick both the bottom and the sides of the container. To bring my vision to reality, I cut a circular hole in the top of an old oil drum (making certain the vessel was large enough to accept a No. 2 washtub) before slicing off the lower third of the barrel, at the first rib. I then made a few smoke ports around the drum's rim, and a fuel-feed opening—as well as some draft holes—in its bottom edge. With that, the heater was complete.
Next, I dug a shallow pit, set the heater shell over it, and loaded the pit with wood. I then put the washtub in place, filled it almost to the top with river water, and lit the fire. Boy, did that heater takeoff! By the time we'd rounded up the other tubs, set out the soap, mounted the wringer on its board, and color-sorted the clothes, the water was already at 150°F and rising.
We've used the heater for a year now, and our wash day system goes something like this: We start scrubbing when the water gets hot enough. As soon as we draw off any liquid, we replace it immediately with more river water (and stoke the fire, if necessary). By the time we need more hot water for washing, what's in the tub is always right back up to laundry temperature or even higher.
I call the heater "energy efficient" because it runs well on "junk" fuels that would otherwise go to waste. I can't bring myself to use real firewood for doing laundry, so I burn driftwood that's too sandy to saw, branches, chips, bark, paper, cardboard, lumber scraps, and the like. (Long branches and willow stems are especially handy, since they can be slid into the fire a little at a time and don't have to be cut up.)
After we finish the wash, I often stew dog food over the same fire. This involves removing the washtub from the shell and replacing it with an older container, which we use only for this purpose. I can then boil up several dozen fish at once ... enough to feed our huskies for five or six days.
I've also used the heater to brew up large vats of hot dye to tint my fish nets ... and, occasionally, built a fire in it to turn spoiled fish into a soupy fertilizer for the garden. Perhaps you'll find additional uses around your place for what I sincerely believe is the world's easiest-to-make wood-fired water heater.
EDITOR'S NOTE: Ole Wik is a longtime expert on using wood fuel efficiently. His very readable publication, Wood Stoves: How to Make and Use Them is available from many bookstores.