Colorado Bob's Solar Oven

The Sendai Airport During the Great Quake & Tsunami

2011-03-13T10:30:00.002-05:00

The Sendai, Japan Airport as the Tsunami waters flood the runways . Notice the survivors on the roof , what you don't see, is people running from the solar panels. After this terrible disaster, those solar panels are ready to make electricity again, once the system has been inspected for damage. No one will be spending time and money pumping sea water on them, so they don't explode.

How to Assemble the Maria Telkes

2010-07-14T06:27:00.006-05:00

The Maria Telkes with out her "Bonnet", or reflectors.

Directions on putting Maria together
Hello whoever you are , I'm going to walk you through getting this solar oven unpacked, and set-up to cook with. First off there are parts inside the oven you will need to assemble the "Bonnet", so get everything out of her, once you have removed the packing wrap and tape. In addition, I have included a couple of tools on the skid help you do the step-up. A hammer to take the skid apart, and a pair of adjustable pliers to get the wheels back on. Start by getting all the parts off the skid , don't over look to the two bundles of support rods that are taped on each side of the skid.

This what she looks like with the that step done -

Be sure that the oven is up off the ground at least 14 inches in the rear, so you can get the wheels back on. Remove the nuts off the axles , and the small steel spacer on the axles, and slide the 2 wooden skid rails off the axle. You can now mount the wheels on the axle in this order :
2 flat washers, the wheel, 1 flat washer, the lock washer, and the nut.
The red object between the wheels is the brake, it looks like this :

With the brake on the wheel, and the tow bar all the way down on the ground, you can now begin to install the "Bonnet" parts.
There are 4 main reflector parts, and 8 support rods. These rods will allow 1 person to assemble the "Bonnet" alone, but having 2 people makes it much easier.

There 4 four flanges around the glass seen here :

These flanges can be removed, in order to take the glass out for cleaning, when necessary.
Each reflector has a flange that slips into the space between the glass flanges, and the oven case. This picture shows that using a sheet of paper :

Notice the small "R" on the case, each side is marked , so the right side reflector, and the left side reflector get installed correctly.
Here are the 2 side reflectors they are taped over the glass during shipping :
Note the flanges running along the top, these side into the slot where the paper was in the picture above:

Here are the top, and bottom reflectors, the top one has a black flange riveted along it's bottom at a right angle. This flange rests on the case of the oven when it's installed, it is the one on the right in this picture. Note the flanges running along the top, these side into the slot where the paper was in the picture above:

Next install the "Bonnet" rods for the bottom . They are the set that doesn't have a "hooked" pair. There are 2 holes drilled in the bottom frame on each side for the long ones, and "loops" for the shorter set. Note the "loops" at the bottom of the oven case, and that the bends point to the center :

The "loops" on the "Bonnet" :

You are now ready install the bottom reflector on to the oven case.
Center the reflector flange on the case with the 2 sides folded in. Once you locate it , start one corner down into the slot, (Remember the paper from above ?) This can be worked down , but be patient it's a tight fit. Once the whole flange is seated, swing up the two center rods, and slip them into their "loops". This will support the bottom reflector, this what you're going for :

Next install the top reflector, (the one with the black flange) , using the 2 short rods that have "hooked" ends, these hooked ends clip onto the "Bonnet" , with "loop" ends just above the oven door . Again center the reflector left and right on the glass slot, and work one corner into the slot. The 2 long rods have wing nuts that thread into holes drilled the the side frames.

Next install the "Target" in the bottom right corner of the glass. It is inside the oven with the pins used to fasten the reflectors in a plastic sack, it just slips under the glass flanges. This target tells you when the oven is pointing directly at the sun, the idea is not have any shadows at the base of the target :

You are now ready to install the sides. Right side in the right side, left in the left. Again center the reflector flange left and right in relation to the glass, and work one corner into the slot between the glass flange, and the oven case. There are 6 hinges on each side that pin the sides to the top and bottom , but only pin the top sets together as you mount each side.
This done so that if the parts aren't "centered" on each side, you can adjust their positions left and right. If every thing lines up, install the other 8 pins in the hinges. The "Bonnet" will now support itself, and the rods can be adjusted if need be. The 4 long rods stick into pockets on each triangle section of the "Bonnet".

(These pins are inside the oven in a plastic sack.)

You'er just about done, now install the "bonnet clips". There 8 of them in that sack with the target, and pins. These just press down around the lip of the "Bonnet" where each section meets the next. The top "hooked" rods go over these clips.

With the the clips and rods installed , the "Bonnet" will stand-up to wind pretty good, it can wheeled around from one location to the next, and it can be pointed way over without fear of it losing it's shape.

Odds and ends
I have included a roll of reflective tape for repairs to the reflector. There's a couple of cooking pots inside along with the oven furniture & some thermometers. There are several racks and shelves that can be moved to various areas in the oven depending on what one is cooking. Remember the cleaner one keeps the glass, and reflector, the higher the temperature.

The site has my email address, so if you need help, just tell me know.

Maria on the Skids

2010-07-09T01:05:00.003-05:00

Broke Maria down and put her on the skids for shipping . Writing up the instructions for how to assemble her, and will post it here, with pictures. Have that up in a day or two.

Maria with one of her new friends, Colton Carthel at the Breedlove Foods dock -

Donating Maria

2010-06-30T09:36:00.000-05:00

The " Maria Telkes " June 2010

When I started this project 13 months ago, my goal was always to pass her long to some group that could put her to good use. I have found that group , the good folks at Breedlove Foods
I have no idea exactly where she may go from here, but in the next week , I will spend getting her ready to ride in a shipping container . Like the rest of this site , I'll post the process of that here, as well as some background about Breedlove.

Gumbo & Apples

2009-08-03T16:43:00.000-05:00

Sourdough Bread

2009-08-02T09:34:00.002-05:00

I baked a test loaf at home in a regular electric oven . 50 min. at 375 F degrees It was slightly under cooked. I then baked a smaller loaf in the Maria. for 2 hrs. 10 min. It was done. Next up, peppers in the sourdough.

Cooking Vegtable Beef Stew & Brown Rice

2009-07-30T16:48:00.001-05:00

The clouds thickened up from 1:30 to about 4:00 pm. So the rice was under cooked just a bit.

Sourdough & Better Oven Furniture

2009-07-27T22:41:00.003-05:00

I have started some Sourdough Starter
And a short clip tweeking the oven furniture.

I like looking into the bonnets of these things.

Saturday July 25th Tweeking & Cooking.

2009-07-26T15:54:00.002-05:00

Tweeking

Cooking

This was the largest amount of food by far that I have tried to cook. Our brisket was 14 lbs.
In all, nearly 30 lbs. of food and the associated water that goes with it. ( I had a gallon of water to cook the corn. That's 8.6 lbs, plus 10 apples, 18 ears of corn , plus maybe 2 lbs of peas with their water. )

Tomorrow's menu at The Maria Telkes :

2009-07-25T01:47:00.002-05:00

10 lb. brisket
Boiled corn on the cob
Purple eye peas with peppers, garlic, and onions.
Super thin corn bread with peppers
Baked apples with brown sugar & cinnamon
And iced spearmint lime aid.

And here's the logo , it's going on the back of the bonnet. Along with the screen names, or first names of all the people who helped me build is " red pepper " .

Cooking

2009-07-21T17:29:00.001-05:00

Back to Back Days of 400 Plus Temps

2009-07-20T18:45:00.002-05:00

415 F yesterday, 405 F today .

The first firing was 305 F , these improvements from that number are all due to me fixing bad design work and poor craftsmanship. There's another 70 degrees there in that puzzle pile, yet to capture.
Lots of clips of all this, but life has been hard lately , and I've been away from my Mac.

Remember one thing, Maria Telkes took her oven to 437 F 50 years ago.

Everything else has just been making pizza boxes into something useful.

This thing is like owning a Double A Fuel Dragster.
A couple of " tweeks " , and this thing stands up, and runs like a bat out of hell.

Tony & Larry Take " The Maria Telkes " to 335

2009-07-09T22:47:00.003-05:00

Sorry no clip , I cleaned up my mess today, and made most of my " corn pan ".
It's a 16 X 24 X 6 inch box. With a fancy lid.
You'll see it tomorrow. We're cooking tomorrow. Ceremonial corn bread all day long.
I have chosen a name for my oven . The Maria Telkes. I decided on a ship name. Not a machine name.
I love to give machines names. So from now on, she's called " The Maria Telkes ".
There's a bit of "seamanship" in running her.

RECORD EVENT REPORT
NATIONAL WEATHER SERVICE LUBBOCK, TX
212 PM CDT THU JUL 9 2009

...RECORD HIGH TEMPERATURE TIED AT LUBBOCK...

AT 159 PM CDT...THE TEMPERATURE REACHED 107 DEGREES AT LUBBOCK/S
PRESTON SMITH INTERNATIONAL AIRPORT. THIS TIES THE DAILY RECORD HIGH
TEMPERATURE ORIGINALLY SET IN 1940.

My friends, running much better instruments, made 335 in the Maria Telkes today .

First Sun Shot - 305 for 4 Hours

2009-07-09T12:47:00.003-05:00

305 , that number is about to go up by another 100 degrees . There are several adjustments yet to be made. Bringing the reflector bonnet into it's correct angles. I did this with one side yesterday during the first sun shot, and saw a 20 degree jump. There is a door gasket leak , to fix, lot's of dialing it in so to speak. Baking the first ceremonial corn bread tomorrow.

It was 106 here yesterday , a new record for the date.

It Is Done, Tomorow We Point It At The Sun

2009-07-08T00:50:00.002-05:00

The taping of the reflector edges, the glass install , final assembly. To all the friends who made this possible , many thanks.

Now the forecast at Lubbock for tomorrow, er a today -

" Wednesday: Sunny and hot, with a high near 103. South southwest wind between 10 and 15 mph. "

I'll be at 500 degrees by 11 A. M. folks.

Application of the Reflective Film

2009-07-07T11:43:00.002-05:00

I got 3 of the 4 reflector panels coated . Challenging work. Not hard , but challenging.

The glass comes in today. If that happens, we'll point it at the sun for the first time tomorrow morning.
I feel like a little kid waiting for the " Solar Santa " to arrive.

Door Install & Prep for Film Application

2009-07-06T11:30:00.002-05:00

Building the Door

2009-07-05T00:38:00.002-05:00

9 1/2 hours today. But the door is ready to hang.
And it is pretty clean. All my mistakes in fabrication came together in the door, and the hole it fits into. But it will be tight, and it will close. That was a big leap. And I think I cleared it.

New Goggles & Gasket Install

2009-07-03T22:46:00.002-05:00

This the 39th clip in the series. Wow, I can't believe I'm nearly done.

Nearly Finished Making the Bonnet

2009-07-03T14:55:00.002-05:00

I hope to apply the film to the inside of the Bonnet this weekend.

July 1st Putting Bows on the Bonnet

2009-07-01T23:21:00.006-05:00

I bought some goggles to cook with :

I also ordered the glass 2 - 3/16 clear tempered 24 /12" X 27 1/2". And a snafu this morning, I learned, the door gasket was only shipped today.

Day 30

2009-07-01T02:40:00.004-05:00

Just about solved the problem of how to keep an 8-ft. high "Bonnet" on the oven in the wind.
No small problem the past 2 days. This thing is huge. I really like standing next to it , it's what I call "man sized". 1 guy can manage it. It's been a design rule of mine for a very long time.

Still waiting on the oven gasket to finish out the door.

Reflector Mock - Up.

2009-06-29T14:24:00.002-05:00

Making Reflector Parts & Some Numbers

2009-06-27T22:46:00.003-05:00

The total surface area of my glass is 700 sq. in. or 4.86 sq feet. That's 25 X 28 inches.
The reflectors are going to be 6,129 sq in. or 42.56 sq feet .
That's 8.82 to 1

That's 47.42 sq feet of total collecting power going into a box that is 10.89 cu. feet. of space.
This also means that I have enough ReFlectec film left over for 2 more ovens. So the $491.00 bill
divided by 3 equals $163.66 in film for the reflector. I bought 3 more sheets of 26 ga. steel.
That's 6 sheets total , of which 5 and a half will go in the oven. They were $33.00 per sheet.

$163.66 in film for the reflector.
$198.00 in sheet steel.
$80.00 in Prodex foil insulation.
$82.00 in rockboard mineral insulation
$23.00 in hinges.
$90.00 for wheels.
$77.00 for steel for frame and axle.
$60.00 for hardware & bits.
$36.00 for tape.
-----------------------
$809.66
I've sure there's a couple of things I've missed but , that number is where I am right now.

Door Fabrication & Flanges for the Glass/ Reflectors

2009-06-27T14:30:00.002-05:00

On to the Door

2009-06-25T02:29:00.002-05:00

The "can" is done , not finished, but done. I still have dozens of pop rivets to run.

Boxing the Back & Thinking About Glazing

2009-06-24T00:35:00.002-05:00

I ordered the door gasket today , another $45 . I keep saying I'm about to stop spending money .

Rounding the Club House Turn 6-22-09

2009-06-23T01:26:00.002-05:00

Lot's of parts coming together now. Ordering the glass tomorrow.

June 21st The Sun Dagger

2009-06-23T00:02:00.003-05:00

Well yesterday was the solstice, and all eyes were on Stonehenge. But I was thinking of The Sun Dagger, and Fajada Butte in Chaco Canyon. It was a very good day. Let's go to the clips.

1st Insulation and Axle Install.

2009-06-20T11:23:00.000-05:00

Moving on to the Outer Shell

2009-06-17T22:40:00.000-05:00

New Wheels & 5 Gimbals.

2009-06-17T00:47:00.002-05:00

Finished installing the all the gimbal pins, .... 5 sets. I can cook 8 , 8 quart pots, with plenty of room for more, all at once. This was one of my main goals. Maybe the central one.
Installed the new wheels and axle. Big difference. It looks like my minds eye now.

Kick Stands & Gimaling Racks.

2009-06-15T19:20:00.002-05:00

I bought a pair of aluminum crutches for the front "Kick Stands" today, and some scrap wire racks for the gimbal racks.

A Gimbal Moment

2009-06-14T20:29:00.002-05:00

Tomorrow is one month since I put up this site. I managed to run 12 days of production on the oven before a break for our monthly Art Market here. But I was back at it today. Not hard at it, but working on it. I was making another set of struts to support the next gimbal pins, and it occurred to me that the pots are what really needs to gimbal.

Pop Rivet Party

2009-06-12T17:50:00.003-05:00

Running the pop rivet gun , riveting the inner shell together. Will have another clip up later tonight.

Gimbal mounts go in -

Completing the Frame

2009-06-12T00:07:00.004-05:00

Painted the frame with 4 coats of paint . Moving on to making the inner shell. Making the floor supports, & rack gimbals.

The Fundables Site

2009-06-11T01:32:00.004-05:00

The fundraiser I set-up will close in 21 hours. The response was more than I hoped for. As of now, we raised $650.00 on the web, of which Fundables gets a 10% commission,
That's $585.00 I will receive in the next few days. In addition, I received another $20.00 in person. That's $605.00 .
I am about to order the glazing for the oven, when that is behind me, I can give an accounting of just what I've spent.

To everyone who stood up and helped with this crazy idea, I will not disappoint you. There is a larger purpose behind the mere building of this oven. It's going to cook a lot of friendships, and we won't release one carbon atom doing it. And this thing will be around awhile, the only moving parts are the wheels.

So to everyone, and many thanks ........

Colorado Bob

Changing Wheels

2009-06-10T13:04:00.005-05:00

I bought some new wheels , from the same outfit, Northern Tool. ( Best Price )
I had gotten 16 inch ones for $17 bucks a piece. These new ones are 26 inch ones at $35 bucks a piece. This will raise the height of the oven by 5 inches, it also means getting a new axel. This larger wheel has a 3/4 " bearing.

I did this for several reasons .
The most important being , that it will add to the summer angle of the oven. By raising the rear end of the oven with larger wheels, the oven will tip even farther back. The next one is it will add in the comfort of working the oven. And thirdly , it will just look better.

Update -

Made a new axel carrier, added another 5 inches to the height of the oven frame. Much better setup.

Sorry, my batteries die at the end. 60 or so more seconds.

I'm Buying New Wheels

2009-06-10T00:05:00.002-05:00

I knew my wheels were too small when I bought them, now that steel is setting on steel, I have a better idea of just how big they should be. I'm buying new heels. It other news, the shells look look supriseingly like my Sketch-Up Drawings. If you attempt such a project, learn Sketch - Up first. It's worth the effort. It's a free drafting box. And it makes you think of every part before you ever make it.

Oven Graphics

2009-06-09T12:14:00.003-05:00

The oven will have a red paint job , another beautiful design from our friend Randy Fisher.

Today's Clips

2009-06-08T21:36:00.002-05:00

1 of 5

2 of 5

3 of 5

4 of 5

5 of 5

Never Forget your "Johnson Bar"

2009-06-07T23:17:00.003-05:00

We moved the sheet metal brake, and installed it.
Made the first bends in the shell parts.
It's time to Roll N' Roll. This thing will go fast now.
I've never had as much fun in my life, ..... with my clothes on.
Also figuring out the camera set-up so I can have a stills page of all the parts, with easy to see numbers arrows etc.

Billy Thorpe - Children of the Sun

2009-06-06T23:39:00.001-05:00

A very nice comment from solarcookingnut

WHAOOOOO, THAT IS GOING TO BE A BIG OVEN! Will be great to cook at family reunions and cookouts! Looking forward to seeing this one cooking! Keep up the videos, can't wait to see this!

He offers more sage advice for me.

I built several large ovens, not as big as this, but still big enough to cook a whole meal in ONE oven. I always tell newbies to BUILD A BIG oven, this way, they won't be disappointed with having to build another one that is larger than the first. In my slantfaced oven, I can cook a meat, casserole, veggies, bread and dessert in ONE oven. i start with the meat first, then add the other pots in the order they will be done by dinner I stack them on top of the other pots using racks.

Good work song -

D-Day Sheet Metal.

2009-06-06T21:59:00.003-05:00

My vologging is getting a little better on this ...... I think I have the thread in hand. This oven has 2 parts, the building of it, but as important to me as that is ,
it's the keeping of this diary, that means nearly as much to me. Any sheet metal guy in American can use this site to make one wherever they are.

The Sheet Metal Guys Show Up :

2009-06-04T23:53:00.007-05:00

Welding Steel

2009-06-03T23:08:00.004-05:00

I have not welded steel in 30 years. And I never have had any time on a wire welder. I learned welding in the shop at O.L. Slaton Jr. High in 1963. That gave me enough courage, to be a hippie welder years later. But finally it was in the oilfield I practiced enough to be just O.K. But that was all stick welding. This frame is being made with a wire welder. I like it. I'm not any good as a welder, but I like it.

Made a $31.00 trip to Home Depot for fastners. Axel nuts, screws to mount the oven shell on the frame, a 1/4 - 20 tap and drill, to tap the frame. And $11.30 for 4 bolts, they're in the clip. Dropped another $10.00 for grinding wheels at Harbor Freight.

I am about to start the sheet metal work tomorrow. I spent time in a sheet metal shop. The rest of this fabrication work is sheet metal.

The Frame Construction

2009-06-03T00:56:00.004-05:00

We made our first cuts today starting at 3:30 this afternoon . As you can see in the clip we made good progress.

June 1st - We Begin

2009-06-02T02:04:00.004-05:00

If my stuff is confusing please make a comment , and let me know. If I'm doing something stupid, tell me that as well. I'm still pulling parts of this larger project together in my head. Here's an example :
I plan to approach the Boy Scouts with this oven when it is done, after I do a shake down on it.
When this happens I will send them to the newest Walmart here. And there on a Saturday afternoon this summer, they will sell Walmart's corn on the cob , solar roasted for $ 3.00 an ear. I don't care what they do with the money, the rental for that Saturday will be small. The Walmart manager is going to send an email to Bentonville late that same Saturday telling the corporate office of the world's largest corporation , that they just sold a shit load of ears of corn one at a time , cooked by the sun, and the Scouts are going camping with the proceeds. Then, I can finally get a shout out on Boing Boing.

The FF Focuser 5-31-09

2009-06-01T11:40:00.002-05:00

Mária Telkes (1900 - 1995)

2009-05-30T01:33:00.004-05:00

Frome Wiki -

Mária Telkes was a Hungarian-American scientist and inventor who worked on solar energy technologies. Her work on solar cooking starting in 1959 made her probably the first person to create a practical oven for serious daily use. Reflectors popularly known as the Telkes design which was one of the best in the series and could develop a temperature of 225° C. , 437° F. The box was a rectangular double-walled insulated box with a door on each side. The box had double glazing fixed at the top, and the there were four main reflectors set at an angle of 60° to the horizontal. The corner spaces between these main reflectors were fitted with four triangular mirrors. The insulated box had a cradle frame to hold the cooking vessel and to assist in tilting. The whole cooker was mounted on to an "A" type frame.

More Drawings

2009-05-29T18:08:00.005-05:00

Interior shell with 5" insulation space.

There will be two of these folding side panels with triangles mounted with piano hinges.
The long tab running along the bottom fits into a slot running around the glass cover.

The crossing lines in the rectangles , are slight bends that sheet metal workers put to flat panels to make them stiff. Again, the flanges running along one edge are inserted into a slot running around the outside edge of the glass cover.

Detail of the slot to accept the reflector flanges. Crude drawing.

A gimble rack for the bottom of the oven.

The Forkner Fresnel Focuser Moves to the Garden

2009-05-28T23:43:00.007-05:00

I finished the fork today. This will always be outside :

There are 2 other parts that can be taken inside and stored when not in use, here they are , mounted on the fork :

We are going to have a lot of fun with this device. If I can figure out how to not blind people who stand near it. But that is why I built it , control rods are the next step with the Sun shining . Then a small copper boiler to make steam , and a whistle that goes off at noon. Remember, it's 650 degrees somewhere on the top of that little aluminium table. It ain't Farrington Daniels , but it sure is fun. My mother's garden is the coolest place in West Texas right now, That spot has always rolled around , and we won't have it long, but right now, right here, we got our hands around it.

Shop painting almost done -

A Clean Shop & the FF Focuser

2009-05-26T21:39:00.004-05:00

I helped the " Twisters " clean the shop this weekend. It was a busy spring with long hours for all, and the place was a wreck. But this weekend marked a change, we added a "Wood Wing" , and we made room for Tony's Sheet Metal Break, to be brought over from the old neon shop. We set it up so we can paint the ole girl, without much trouble. All the metal tools have room to work around them now. I made a classic out feed bench for a great old cast iron saw we have. One more bench for the wood miter saw to finish, and we can start this project in a greatly expanded shop with far more capabilities than we had last week. I will be setting up a fixed camera position of these 2 benches, Hoping to make a time lapse of this oven.

The Forkner Fresnel Focuser

2009-05-26T00:32:00.006-05:00

The Forkner Fresnel Focuser ....... My other Solar Project, the one I'm not begging for on the internnet.

This thing has no point whatsoever, except to show people how hot a little sunshine can get.

Lot's of big changes on Buddy Holly Ave. I stood my focuser out in the garden tonight . And damn it I forgot my camera. Where I have it now, is the wrong spot . We will move it's 09' location farther to the east, right next to the cement foot print. A little bond-dough work and some paint, & field testing can begin. We have a lead "pipe part" off a big ass organ , I want to make steam in a small copper boiler on the focuser, and see if we can make the old organ part " whistle".

As a life long student of just what the Sun can do. When the chance came to buy a 22" Fresnel Lenses on eBay at 2 A.M. , I bite hard. This lenses takes just the sun light from a 22" inch circle, and focuses it into a 1/2 inch rectangle. That rectangle is nearly 700 degrees.

We need a sundial.

The Outer Shell

2009-05-23T00:58:00.001-05:00

WOW

2009-05-22T00:37:00.003-05:00

I am at a loss for words, a rare event folks , enjoy it while you can. As things stand today, after we get the shop cleaned up , we can make a start on the oven this coming week. I set a goal of raising $500 online to defray the cost of this oven. Today that fund has $610 in it.

And that's a good thing, because the $491 roll of reflective film is on a UPS truck coming from Colorado. Still hashing out the steel materials list for the frame, but that is about the last major expense left, everything else has been bought, and paid for. When that is complete , I'll post the whole list and costs here.

To everyone who has helped me with this project, my sincere thanks.

Up Date Sat. Morning
Got the steel list done, and fiddled with the size of the oven to use my materials more efficiently when we start doing the layout. I also forgot to mention the glazing, I will order that when the oven shell nears completion.

In an effort to hold down the number of posts , and to try and make this site more useful, I am adding comments, drawings, and pictures to older posts . I have added drawings and measurements to the post on the frame for example. As the shell construction moves along I will be adding to that post, and so on.

Once again , to all who got in this canoe, and took up a paddle, many thanks.

Colorado Bob

The Under Carriage

2009-05-21T04:07:00.003-05:00

Steel for frame :
1 - 20 ft 3/4 square tube
1 - 20 ft 3/4 - 1/8 angle
1 - 48 in 1/2 round rod - axel

Sketch - Up doodles -

Gathering the Materials

2009-05-20T23:37:00.002-05:00

As I said in the side bar, I read "Direct Use of the Sun's Energy " a while ago. So this hunt for materials on the net was pretty fun. I bought a couple of real solar age products for it. My first was the reflector film , still hard to find small amounts from these guys who make and sell it. But the upside I bought it at $3.00 a foot, 94% reflective from a company who has just run a series of tests with the National Renewable Lab in Colorado. This outfit is called : ReflecTech, Inc. ( Warning their site is under attack! )
They mail out samples free, and their minimum is 150 sq. ft. As it stands now my machine will need roughly 60 sq feet of that . So the 150 sq. ft. buy breaks roughly into 3 machines. This is good news. Because , I have just ordered the rest of the stuff I need online. That being the wheels.

The other solar age material I bought was this stuff :
ProDex

The Prodex and steel sheet.

The outer shell of the oven will have this next to it. Then a dead air space, then 4 inches of some old insulation; rockwool board insulation.

I'm building a pizza oven, that weighs like a box kite.

These two materials will give me something like an R - 40 wall under 6 inches thick. And it won't weigh anything. I will be getting the piano hinges from ebay when the time comes. I've got a feel for that cost. Taking in all the research to date. This oven isn't going to cost more than $700.00 in materials.

So here is my latest projection tonight -

A 15 cu. foot oven on wheels , that works when the sun shines. That 2 guys can pick-up , and load into a pickup.

The Drawings

2009-05-15T22:22:00.000-05:00

I'm using Google Sketch - Up to do these , it's my first real foray into Sketch - Up.

This image shows part of the Reflector Shroud missing. The total area of reflector surface on this oven will be around 49 3/4 sq. ft.

I'm using a design called the 60/40 that Ken in Canada has supplied to me. My plan is double the size of Ken's oven, and construct it from 26 ga sheet metal. Here's Ken setting up his oven on a winter's day :

What This Is

2009-05-15T04:30:00.000-05:00

For 40 years the concept of solar ovens has rotated around the idea of bringing relief to a charcoal starved 3rd world. I read "Direct Use of the Sun's Energy" by Farrington Daniels in 1973. And it was 10 years old when I found it. It's the bible of solar power. Nothing has changed about the things Daniels laid out. Nothing. Materials science developed since 1964, but the things Daniels states about the sun, and the problems of capturing, and using that stored energy, it haven't changed a bit.

But back to the ovens. This spring I planted a lot of sweet corn with the idea I would cook it , and sell it on a stick. Always with the idea of using solar power to do it. So, I went looking for the state of the art in solar ovens. It's still stuck on all those charcoal burners in the 3rd world.

Which is to say , " How do we make a solar oven from cardboard, and tin foil, and heat a 3 qt pot ? "

I'm serious, a fellow perfected that oven . It's called the Global Sun Oven . You can buy one for $289 bucks. Your purchase sends one somewhere into the 3rd world as well. And they're great, but I can't cook 100 ears of corn on one, all at one time. Which made me think , neither can someone in the 3rd world. No one has designed , and built a small solar oven like a backyard grill. With wheels on one end, and handles on the other, about 4 feet long.

So, that's what this is, this is the building of that oven, with that goal in mind. All the designs, plans and clips will be free to anyone who can use them. Whether, it's tamales in Mexico, lamb in Mecca, or corn on Buddy Holly Ave.