Tag: DIY Chronicles

16 brick rocket stove

In our middle school ecojustice class, one of the things we’re doing is experimenting with alternative low-cost, low-impact cooking methods, such as a solar oven made out of cardboard. Now we’re experimenting with rocket stoves, designed originally by Dr. Larry Winiarski and colleagues at the Aprovecho Research Center. Rocket stoves use biomass to cook, but are much more efficient than traditional cooking fires, and because they’re more efficient produce fewer pollutants such as smoke and harmful gasses. Not really something we need in the first world, except in disaster situations, but a huge advance for the developing world.

Last week in class, we put together a simple brick rocket stove but couldn’t get it to light. So I spent some time this week building and using a simple rocket stove made of 16 bricks. This stove is based on Larry Winiarski’s 16 brick stove, but instead of using adobe bricks I used clay bricks commonly available at masonry supply houses and building supply centers. Specifically, I used nominal fifteen 8 x 2-1/4 x 4 inch clay bricks, and one 8 x 1 x 4 inch clay brick, as shown in the sketch below:

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For fuel, I split an 18 inch long 2 x 10 into finger-sized pieces. To light the stove, I balled up a piece of paper and dropped it down the center hole, dropped some shavings, small scraps of wood, and slightly larger scraps of wood on top, then dropped a lighted match in. When the fire was burning well, I began feeding 3 to 4 pieces of fuel in from the bottom, adjusting the air intake gap as needed to get a hot flame.

The rocket stove needs you to pay attention to it. The fuel burns pretty quickly, and you have to keep pushing it into the combustion chamber, adding new fuel as needed. Once the fire was going strong — which took seven or eight minutes — I got ready to cook.

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Continue reading “16 brick rocket stove”

Winter melon

What would you do with a half a winter melon? I’ve gotten friendly with a farmstand that specializes in Asian vegetables at the San Mateo Farmer’s Market. The woman who runs the farmstand knows I love bitter melon, and has told me about its health benefits. She probably figured this white guy needed to expand his Asian melon repertoire, so today she gave me half a winter melon, and said, “Try it in soup.”

There are lots of winter melon soup recipes online, and I’m leaning towards a simple one with dried black mushrooms, chicken broth, a little bit of chopped meat, and some slices of ginger.* But — what would you do if someone gave you half a winter melon?

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*Two weeks later: And here’s the recipe I have been using for winter melon soup:

Half of a five pound winter melon, cut into 2 inch pieces (about 2 pounds of melon)
1 quart of chicken broth
1 knockwurst, cut into 1/2 inch circles
8-10 dried black Chinese mushrooms, soaked in hot water for 20 minutes
half a dozen slices of ginger root, peeled, and slivered
salt to taste

Bring the winter melon to a boil in water to cover, then simmer covered for 20 minutes.
Drain the water off.
Add chicken broth, mushrooms, ginger, and knockwurst to the cooked winter melon. Simmer for 20 minutes.

Adventures in solar cooking

Yesterday in Sunday school, two groups of kids started making solar ovens. While they were working, we had solar s’mores cooking in the solar oven I made on Saturday. However, it took a long time for the solar s’mores to cook. First problem: the morning clouds didn’t begin to clear until halfway through Sunday school. Second problem: thin clouds persisted most of the morning, and even the thinnest of clouds caused the temperature to drop at least ten degrees inside the oven. We started cooking the s’mores at about 10:00, and they weren’t really done until just before noon — after most of the kids had already gone home.

The clouds finally cleared away completely, and I left the solar oven outside my office for several hours in the early afternoon. The inside temperature rose to over 200 degrees Fahrenheit (200 degrees is as high as the meat thermometer goes), with outside air temperature in the high 70s. I heated up a mug of water, to over 170 degrees, and made a nice cup of tea. While I was making tea, Fred Z., from the Green Sanctuary Committee, stopped by and suggested trying cast iron cookware in the oven — it’s dark and absorbs heat well, plus it provides a good thermal mass to even out cooking temperature.

So this morning I dug out a small cast iron frying pan, and decided to try cooking a fried egg in the solar oven. The air temperature was about 65 degrees, but in spite of clear skies I couldn’t get the inside temperature over 190 degrees — which suggests I need better insulation in the oven. I cooked a fried egg, over easy:

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It took about twenty minutes, and was really more of an egg baked in butter than it was a fried egg (it tasted good, though); obviously there is a lot more to be done to improve the efficiency of the oven.

Solar oven prototype

Tomorrow, the middle school ecojustice class in Sunday school is going to make solar ovens. So of course I had to make a prototype:

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I started with a basic design made out of carboard boxes, a design that is sometimes called the “Minimum Solar Box Cooker.” But instead of just nesting one smaller box inside another box, I took the smaller box, cut out the ends, and turned it 45 degrees:

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While this reduces the amount of cooking space inside the oven, it also reduces the amount of air that has to be heated. And then, too, it’s easy to run a couple of dowels through the inner box to make a support for a cooking pot.

In preliminary tests, the oven worked reasonably well. I set the oven out at 2:45 p.m., stuck a meat thermometer in one end of the oven, and within twenty minutes, the thermometer was reading between 190 and 200 degrees F. (the thermometer only goes up to 200). At about 3:10, I put in a cup of water in a glass container. By 3:40, the water temperature was 155 degrees F., and the glass container was more like 190 degrees F. (Air temperature is 75 degrees F. this afternoon.)

Tomorrow comes the real test: we’ll set the oven out at the beginning of Sunday school and see how quickly we can make solar s’mores.

Update, one year on: This solar oven prototype proved to be only marginally effective. After using it fairly extensively, it has one big problem: when you open the lid, much of the hot air escapes; there is very little thermal mass, aside from the heated air. At the very least, I need to provide a significant thermal mass (preferably black in color, to better absorb heat). In addition, it would make sense to place the door low on one side of the oven, to minimize the loss of heated air.

Better easy bubble juice recipe

Back in 2012, I posted an easy bubble juice recipe for making soap bubbles 9-12″ in diameter. Here’s a better easy bubble juice recipe, which uses easily obtainable ingredients, and features a superior mixing procedure for the lubricating jelly. With this mixture, I’ve made bubbles that start out at 4-5 feet long tubes, then stabilize into two or more spheroids up to 30 inches in diameter. The glycerin isn’t absolutely necessary, but it does seem to make the bubbles last a bit longer, an important point in our dry Bay area climate.

Ingredients:
4 oz. tube of personal lubricating jelly (store brand is fine)
2 oz. container of glycerin
12 oz. of Dawn Ultra dishwashing liquid (do not substitute another brand)
water to make up about 1 gallon
Total cost: $12-15

Method:

Put 3 quarts of water in a gallon container. Continue reading “Better easy bubble juice recipe”

What I did on my vacation, pt. 2

Ms. M and Mr. O, old friends of ours, are adopting two girls. I’m supposed to make two shelf units for them by this weekend. So far, one is completed and ready for finishing. Here’s the completed unit (the fish-eye lens makes it look out of square, but it’s not):

DIY shelves

I’m supposed to have both shelf units completed by this weekend. I don’t think I’m going to make the deadline. The sad truth is that it’s been something like eighteen or nineteen years since I worked for the cabinetmaker, and I’ve gotten out of shape — I can’t put in an eight hour day in the shop any more.

(The details: 28 x 33 inches, 9-1/4 inches deep. Adjustable middle shelf. Solid pine construction throughout.)

Maker Faire and lobsters

Carol and I went to Maker Faire today. It was held just a couple of miles away in San Mateo, so we were able to walk there — which was good, because so many people attended that some of the parking lots were four miles away from the event. If you’ve never heard of it, Maker Faire is kind of like a state or county agricultural fair for geeks and engineers.

We saw the gee-whiz showy things you’d expect to see at Maker Faire: strange metal constructions that belched fire; all kinds of robots; people riding around inside giant self-propelled cupcakes; a Rube Goldberg-style giant mousetrap powered by simple machines and a bowling ball; the CO2 eruptions that happen when you drop Mentos into carbonated beverages. My favorite gee-whiz showy thing was the Sashimi Tabernacle Choir, an art car covered with fish and lobsters that danced in carefully choreographed movements:

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And we saw the geeky technical things you’d expect to see at Maker Faire: conventional automobiles converted to electric power; too many projects made with Arduino microcontrollers; robots; drones; giant soap bubbles; a blacksmith; ham radio operators.

We also saw things that you might not expect at Maker faire: goats; chickens; beekeepers; a guy selling New-Agey devices to protect you from EMF radiation; a steam-powered scale-model train; lessons on how to walk on stilts; a really good drummer who used plastic trash barrels and other found objects for his drum set.

It was very satisfying, if for no other reason than being able to spend time hanging out with thousands of other geeky people who like to make things instead of consuming things.

Update: Because a commenter asked, here’s a video (taken by Carol) of the Sashimi Tabernacle Choir:

Keyboard table

I spend too much time typing, and have been getting little twinges in my hands and fingers. It was past time to pay attention to my typing position. So I made a keyboard table out of salvaged and scrap wood, to hold my keyboard at the correct height for typing:

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The top is salvaged Douglas fir that Carol got from one of the building material exchanges in the Bay area. The two side pieces are scraps of #2 common Western pine left over from bookcases I made fifteen years ago, which we have carted across the country two or three times. The spreader bar in the back is a short piece of moulding that I found in the basement of our building.

This is not a fine piece of furniture, nor did I want to hide the fact that it’s made by hand of salvaged materials. So I left nail holes, chips, dents, and rough patches visible on the salvaged Douglas fir top; and the top is screwed onto the base, with the black drywall screws left exposed. All cutting and joinery was done with hand tools, and I didn’t bother eradicating scribe marks or tool marks. I even left the grade marking on one of the uprights — it reads “212 STERLING WWP S-DRY IWP” — as well as a fluorescent orange lumber crayon mark.

This keyboard table might not be suitable for polite company. But it makes a good surface to work on and write on: imperfect, scarred, comfortable, with a wealth of associations you don’t get with something bought at a big-box store.

Below: a closer look:

Continue reading “Keyboard table”

Kraut

A gloomy, rainy, chilly, enervating, soul-sucking December afternoon. Carol and I were sick of being stuck in the house doing chores, sick of short days and long dark nights. We went to Wisnom’s Hardware across the street and spent a long time buying five dollars worth of hardware, just so we could get out of the house. But eventually we had to go back home, and watch the world outside the windows turn ever grayer and darker.

So we decided to make sauerkraut. I chopped a two-pound head of cabbage into thin strips, grated some carrots into the cabbage, and dumped everything into a glass bowl. We grabbed big handfuls of cabbage and carrots and squeezed hard to bruise them and begin to release their liquids (this was the best part; very satisfying):

I added five teaspoons of salt (two for each pound of cabbage plus one far the carrots), and mixed it in. We smushed the mixture down with a plate until the liquid rose up over the vegetables: Continue reading “Kraut”

Making labels

Yesterday, my friend Lewis came over to our apartment. Lewis is a luthier who makes (among other things) Celtic bouzoukis, and he wanted me to make some labels for them.

He brought a bouzouki to show me where the labels would go. I talked to him about light-fast pigments and archival papers, while for his part he told me about the instruments he makes:— His Celtic bouzoukis are beautiful instruments, and each one differs slightly in small details from the others — a slightly different bracing pattern, an inlaid piece of ebony inside the sound box with the number of the instrument. When you look at one of his bouzoukis, he wants you to know that it was made by hand, not by a machine. And he wanted each label to look hand-made, beautiful but with small imperfections.

So we sat at the kitchen table, eating home-made soup Lewis brought, and we made labels. I had some 100% rag vellum which I cut into 1-1/2 by 2-1/2 inch rectangles. Lewis signed each one using a magic marker with light-fat archival ink. I carefully wrote the serial number and “CELTIC BOUZOUKI / Oak. CA” under his signature, and then put a band of red watercolor paint along the top edge of the label. I don’t make many things like this any more; most of the things I make are text or photos or videos meant to go on Web sites, things you cannot touch. Real papers have different textures; they feel good under your fingers and hands, the pen moves over them in different ways, the ink soaks in or adheres to the surface differently. Paints are incredibly sensuous: the pigments finely ground into some luscious medium — linseed oil, gum arabic, casein, beeswax, whatever — and you dip a brush or knife into that vivid blob of color, and as you spread it the color changes as it interacts with whatever you’re painting, and you can smell it, and feel it when you use your fingers to smooth or blend.

The tools you use to make things have their own sensuality. To put the paint on the labels, I used a red sable watercolor brush, a gorgeous tiny little cluster of perfect animal hairs at the end of a delightfully balanced wooden handle. I remember one painting teacher, years ago, who used to insist a good watercolor brush should be as firm as a partially tumescent penis (yes, he was a man). The subject of art is always love or sex or death, but making things is all about sex, all about the act of creation. Creating things to be viewed on a screen is very satisfying — I love the way the completed image or text glows with that faintly blue light that comes out of your screen — but you can’t touch it or smell it while you’re making it. If making things is like sex, then making things for the screen is like reading about sex; it all happens in your mind and eyes, not in your body.

But the metaphor has overwhelmed the subject, because all I was doing was making labels. What amazes me is that the labels I made yesterday — cutting out a rectangle of paper, adding some lettering and a spot of color — will wind up inside musical instruments which are works of art and which may well outlive me. Far fewer people will see the labels I made than will see this blog post, but making the labels was far more satisfying.