Solar Oven

This project was an idea we received from a great group of people, New Survival Skills. (You can also find them on Face Book.)

What else?  A solar oven.  A great idea with a lot of possibilities. 

We all started the project together.  However, my oldest quickly decided she didn't mind doing the majority of the work.  So with a little bit of guidance this is what she/we did.
We started out with the 81mm Mortar box.  Here in Utah we were able to find one at about $40.00.  I know I can find them a little bit cheaper online, but had two disadvantages to that.  1) I would have had to wait for shipping, and 2) I wouldn't have been able to inspect the box before purchasing it. 

The store we found, had several mortar boxes.  That was an advantage because we were able to pick the one in the best condition. 

We is my daughters and I.  Sometimes, when he has time, my husband.  More often than not, these projects take us everywhere together.  From chasing lightning, to building hobo stoves, and camping together.  We love the challenge of a new adventure.  Now I just have to get them to remember that there are still regular chores too.  But that is a subject for another day.

Anyway, back to the solar oven. 

So we started, as I said, with the mortar box.  81 mm mortar box.  Next we needed a role of reflectix silver insulation.  It is thin and of course reflective.  The purpose is to line the interior of the box creating a surface that will hopefully redirect the sunlight toward the contents of the box, creating a heat value.  The reflectix was just under $17.00 dollars after taxes.  Not bad for 25'.  We could probably do two full ovens with just the one roll. 

This role is 25' ft. long and 16" in wide.  The box didn't need more than 13 1/2" in and 24 1/2" in long.  That gave us plenty of reflectix to use for the various parts of the solar oven.  Including, when I neglected to tell my oldest that she didn't need to wrap all of the foam. 

Oh yes, and the foam.  Our mortar box came with foam inserts.  Some were glued into the mortar box, some were loose.  The foam is strategically placed to hold the original mortar shells.  We either ended up with extra pieces, or that is what the box comes with in the first place.  In the end, we only needed two of the foam inserts that were glued in, and two that were loose. 

Like I was saying, our box came with a total of 8 foam pieces.  Two on the lid, and two in the bottom of the box.  The other four pieces were loose.  They were also thinner and wider than the four glued to the interior of the box.  All we needed to do was carefully pull or cut the foam out of the box. 

The first to foam pads we attempted to remove buy cutting.  We did our best to only cut the glue away from the metal, but achieved a much less appealing result.  Should have stuck to the tried and true, "pull on it, see if it's loose".  That's what we did for the last to pads. 

As you can see a bit of testing effort in the beginning might have given us a clue that we could muscle them out.  Oh well, live and learn.

Next, we needed to attach the silver reflectix to the interior of the mortar box, and around several of the foam pads.  For this we were going to need spray glue.  This is where knowing people who have worked in the sign and printing industry can be a great help.  (Thank you Marc).  We were able to get a hold of spray adhesive.  Now we were told that the other thing we would need to use was rubber cement.  Rather than that we purchased a roll of aluminum tape.  The kind you would use to close leaks in your air ducts. 

Aluminum or heat duct tape.  This contours to the shape you intend to cover, and is adhesive, making it easy to seal seams and gaps.

This silver colored tape allowed us to close the seams created in the reflectix when we used it to wrap the foam pads, and still keep a reflective quality to the full interior of the oven.  The spray adhesive covered in a good solid coat and didn't, at least as far as we can tell, need any extra adhesive. 

So to recap:

81mm mortar box, with original foam pads They are priced anywhere from $25.00 up to $40.00.

25' x 16" reflectix insulation.  It is rated Class A/ Class 1.  Just under $17.00 after taxes

Spray adhesive Anywhere between $11.00 and $25.00

And aluminum tape. Depending on length, anywhere between $6.50 to $15.50 a roll.

There are a couple more things we are going to need, but we will get to those in a minute.

Pull out the foam pads, and then with a flat knife or scraper, clean up any left over foam or glue.  Next measure the interior of your mortar box.  Your going to need 2 piece that are approximately 24" x 13 1/2" , one for the lid and one for the bottom. 

 

One recommendation... Don't do this in the direct sunlight.  Unless you have really good sunglasses.  Save the sunlight for cooking time.  :)

Go ahead and attach the lid and bottom first.  The spray glue works best in generous amounts.  Spraying both the mortar box and reflectix you'll be creating two contact points that making the adhesive more likely to connect your reflectix with out any problems.  (remember to do a test run with the reflectix pieces to make sure they fit before you glue them in.  Any trimming will be done at this time.) 

You can measure and pre

**Then you'll want to measure and cut the piece or pieces that are going to make up the interior sides of the box.  We chose to cover the sides with one full piece.  This was a little more challenging, but effective and left us with only one seam, which we later taped with the aluminum tape.   

Getting the length and width measured and then test fitted onto the side of the mortar box was easy.  Spraying glue and then attaching the reflectix was a bit more challenging, especially trying to keep the sides as one piece.  Dads are great helpers.  :)

Once the interior is covered you can begin working on the foam. 

We knew we were going to have seams, so we decided to cut the material specifically to deal with that issue.  Cutting this modified "T" allowed us to enclose the entire foam, with minimal bunching at the seam sights.  Then aluminum tape, and we had fully enclosed foam pads. 

Now we needed to decide which foam would work in what location.  To make the best decision we would need at least one more item.  Plexiglas.  This was another thing I already had on hand.  I wouldn't need to buy any.

Now the last two things your going to need are Plexiglas and cording.  The plexiglas can be purchased in certain sizes, but you may find that you need to buy something just a little bit larger and then cut it to size.  (The hardware of construction depot that you buy your Plexiglas from should also sell Plexiglas cutters.  This is the best way to cut your plexi.  Be patient.  It may take several passes before the cut is complete.)  Then once your done cutting you can drill two holes in each end for handles.  This is where the cording comes into play.  One loop on each side is all you need to make your handles.  This is how ours looks finished.

In both the right and left photos you can see the handles.  My husband melted the ends into a slight ball, making them large enough not to slip back through the holes.  These "loops" will allow us to pick up the plexi-glass without trying to dig our fingers underneath it.  (Just makes things a bit easier)

Optix Plexiglas For a sheet that is 36" x 30" x .093 your going to pay about $20.00.

Cording.  This all depends on what you want to use.  We had a 1/4" x 12" long piece of braided cord that worked for what we needed.  Because there are so many different types of cording, and it will be your choice, The cost can be a few pennies for the amount you need to half a dollar or so.

Most hardware stores will carry all of the items your going to need, except that is the mortar box.  For that your going to need to check in to Army/Navy surplus stores.  We found our box at one called Uncle Sam's.  There are also General Army-Navy stores.  Both physical locations and online stores.  

We only had one challenge with the plexi.  It was a standard pre-cut size.  That meant that it was just about 3/4 of an inch to short on one side.  In order to accommodate that gap we just added more foam to the front edge of the solar oven. 

And then finally with handles on each side of the plexiglas we are finished. 

Because we had a great group of people who had already done this before us, we had a good idea of where we were headed.  We didn't run into any real snags.  Just a bit more time to put in the sides because we did them as one piece. 

We hope this article will be helpful to you as well.

Staci and Kel

Corn

These are in the first plot or bed.  They were planted in June.

This year we grew some, well a few, okay more than a few corn.  Corn has a lot of great qualities, and tastes wonderful, especially right off of the stalk.  (That is when it is the sweetest.)

I know, I know so what, I grew some corn.  Well that is only part of the story.

We did two plots.  We started with the first behind a fence.  (Dogs.) In the first plot we dug in mulch.  Nothing special, just some stuff we picked up from our local dump.  The city accepts green fill and mulches it.  Then they sell it back to the public for about $30.00 a truck load.  1 truckload is about 3 cubic yards. And fish.  Not all of the fish.  We "planted" the guts, heads tails, and bones of the fish. 

After digging in the mulch to a consistency of about half mulch and half dirt, we began planting.  We didn't plant the fish until we were ready to plant the corn seeds. 

We started the bed with radishes.  They are better as an early crop.  We kept everything we planted this year in fairly uniform rows.  That made it easy to get the corn seeds started in between the radish rows.  All of the radish seeds we did this year were from last years crop.  Once the radishes were large enough to pull, we got them out of the way to make room for the quickly developing corn.  A few we left for a new seed crop this year.  Radishes loved the mulch, and fish.  Rather than the few dozen pods like last year, we have thousands of pods.  +1 for the mulch and the fish.

Now for the corn.

For the longest time we had just short little stalks of corn.  They couldn't have been more than 3 ft tall.  I was worried that the ground was to "hot".   (Mulch that is to much and to fresh.)  We had already lost several garlic starts that just couldn't take the new rich soil.  Boy was I wrong.

The corn and sunflowers are both in the same bed.  This pictures was taken a couple of weeks after we initially measured the corn and sunflowers.  By the time of this picture the sunflowers are 13 ft tall.  Unfortunately due to the weight of the flower heads, and the wind we sometimes get here, this particular stalk has since been broken.

We left on a two week trip.  Between a sprinkler system and several great people who helped to keep the yard running while we were gone, we came back to a thriving and healthy garden.  In the two weeks while we were gone our corn and sunflowers decided it was time to really show off.  (we planted our sunflowers along the fence line behind our corn.)  The tallest corn stalks were approximately 8 ft tall.  The smallest were still in the 5 ft range.  The sunflowers were just about 8 1/2 ft tall.  In just a couple of weeks we were rewarded with some very showy plants.  As far as size was concerned, +2 for the mulch and the fish.

Now the leaves of the corn, and sunflowers, was a beautiful medium shade of green,  They were large and lush.  There were no wilted spots that we could see upon inspection.  Overall a beautiful color for both plants.  +3 for mulch and fish.

Along with the beautiful colors and height of the corn, we also discovered an ample supply of corn ears.  Each stalk had two ears.  (This was much more than I expected for just a backyard garden.)  From all outside appearances the ears looked wonderful.  They were still way to early to even hope to pick, but beautiful just the same.  (When corn is close to being ready to harvest the "silk" at the top of the ear will appear to be dried out and brown.  A quick inspection underneath the husk will verify if the corn is truly ready.  Sometimes the kernel's at the top of the cob don't develop.  This is because they weren't pollinated.  This can be because the stalks are to close together, or the wind wasn't able to carry enough of the pollen between plants.)  Still we were going to have to wait until the corn was ripe. 

Now picking time.  We had a beautiful array of yellow and white in the individual kernel's.  The kernel's were large and plump.  And there was very little un-pollinated kernel at the top of the cob.  Having experienced un-pollinated corn kernel's in the past, and remembering the conditions previous stalks were subject to, I still will chalk this up to a better mulch process.  (The mulch and fish, I believe, gave the corn the needed nutrients that allowed the "flowers" to mature properly.  With the added size of the stalks, I believe, the corn was given the best chance possible at reproduction.) + 4 for the mulch and the fish. 

Now for the flavor.

Each corn ear we have pulled so far has averaged about 8 inches in length, and about 6 inches in circumference.  I wish I could remember their name, because they are a wonderful sweet corn.  A sweet, beautifully large plump kernel.  One bite an your hooked.  +5 for mulch and fish.

Now for our other corn. 

Averaging about 8 inches long and approximately 6 inches around, these ears are just as large as the ears on the first plot.

This second batch of corn was planted nearly three weeks after the first batch.  Our attempt at a late crop I guess you could say.  Rather than a mulch combination, we tried just using the fish. Why not, this is a process that has been used in ancient cultures?

We prepared the corn beds by creating rows to determine spacing, and then "planting the fish. 

Just like the first bed, not the whole fish.  The guts, heads, tails, and bones. (Of course we kept the meat for dinner ;) )  In my family we like to fish, and thanks to the generosity of certain people, You know who you are, we were able to put nearly 2 dozen fish into the ground.  Once the fish were planted into the rows, we laid seeds in the tops of those same rows.  No other fertilizer or mulch process was used in this bed.

This photograph is a bit over washed with light, but if you look closely you can see the corn in the background.  It is the first plot.  Even though it is in the background, you get the general idea of the two sizes.

Compared to the mulch and fish bed, this corn wasn't nearly as tall.  Part of that I attribute to the late start, part to the fertilizer.  However most still hit approximately the 4 ft range.  Not bad for a back yard garden.  We have a sprinkling system, and we also had plenty of rain this year.  I doubt lack of water was a factor.  On height, fish gets a -0-

The color of the stalks and leaves was the same as the batch with the mulched ground.  A beautiful medium green.  No dry spots or fungus that we could see upon inspection.  Overall a really healthy looking plot of corn.  +1 for the fish.

Again, just like with the mulch, each stalk had two beautifully large ears.  The hardest part at this stage was leaving them alone so they could finish ripening.  Each of the ears looked plump and long.  Even though the stalks were shorter than the first bed, the ears were approximately the same size as the first plot.  +2 for the fish.

Once we were finally able to check on one of these beautifully sized ears of corn, we couldn't wait to start picking them.  Carefully pulling aside the husk to reveal the corn inside, we could see again the beautiful yellows and whites that colored each kernel.  The kernel's were large and plump, and almost all had been pollinated.  (There are almost always a few kernel's toward the top that don't get pollinated.  But it is a relief to see only a few affected in this manner.)  +3 for the fish.

Each one of these looks this beautiful.  Rich color both in the husk and kernels.  You can see to the left what the silk should look like before you harvest your corn.

Now for the flavor. Just as sweet and delicious as the first bed.  The sweetness is addicting.  Large round kernels lots of rich color, and large ears all come together to create a delectable treat. + 4 for the fish.

The yellow banana peppers that we added right at the ends of some of the rows became huge plants, with huge peppers.  + 5 for the fish.

These banana peppers are the ones that we planted at the ends of some of the rows.  This is my best year for peppers.  I will do them again next year. Cucumbers loved the mulch, and so did the raspberries.  However this years raspberries are living on last years mulch.

The only detectable and obvious difference was the height of the stalks.  However in both flower beds there were other obvious differences.  Like how well other crop plants grew.  With the Zucchini we got beautiful large lush leaves, but very little fruit.  Same with the crook neck squash.  However, the radish, turnips, corn, sunflowers, carrots, peas, and peppers all thrived on the "hot" or rich soil. 

Look how big these kernels are...

We broke this cob in half.  That gave us the chance to see how big the kernels were.  Such a great flavor!

Lessons learned:  Certain crops thrive on "hot" soil while others take on an ornamental view or completely die off.  The addition of fish seemed to be the extra boost that the gardens needed.  Next time we plant corn we will for sure use the fish trick.  Next year we will allow the garden to run on what we added this year.  One of the crops that seemed to do VERY well on just mulch no fish was the mustard we planted this year.  It was all nearly 6 ft tall, and covered in pods loaded with seeds.  But that is a subject for another blog.