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With the cost of electricity going up all the time, I'm thinking about solar drying.
I have been known to dry papier mache articles in the front seat of my car in summer. I just roll down the windows a couple of inches to let out the excess moisture. But this is a nuisance when someone goes with me, and completely out of the question when the dog goes for a ride. And here in the wet NW, out of the question for winter.
I have the materials for a solar dryer that should work on sunny days. Here's my plan for a wood, plastic and brick dryer that would be 30x30x48" tall, but the size would certainly be adaptable to your needs:
A base 30x30" (76x76cm) of wood, with crosspieces all across the bottom with 1" or 2" (2.5 or 5cm) spaces between. Four corner posts 48" tall, and four 30" (76cm) pieces to form a square top.
Set bricks (whatever kind you've got) on the slotted base (these will help keep it from blowing over, as it will be quite light, plus they will absorb heat from the sun to heat up the dryer.
Wrap the sides with heavy plastic. One end should be able to open and close, but I'm not sure how to do this yet.
I'm also not sure if the top should be left open, or covered with plastic with multiple slits or holes to release moisture.
If you happen to find a large, heavy clear plastic bag, you could just make a frame that would fit inside.
I'm thinking that if the back wall was covered with aluminum foil, it would reflect even more heat.
This is on my ToDo list, so heaven knows when I'll get it done.
Sue
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Hi Sue
Don't you need a black background so the heat it absorbed ? The bricks are a good idea as they like soaking up that heat. Somewhere I have got plans for a solar drier for fruit and veg I could look it up if your interested.
I know it uses a black backed thin box with a glass front with a small vent at the bottom to allow air up then it's attatched at the top to a box with slats inside and a vent to regulate the warm air flow.
Sue.
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Hi:
My husband and I have made a electrical homemade dryer that worked almost well because of little details that we need to correct.
Here on the beach, where we live, is much easier to dry pieces, even in winter, because it's not so cold as in USA or Europe but we have a lot of humidity.
We were talking about solar dryer CatPerson plans and our homemade dryer and thought:
1- It's necessary to let the condensate water goes out because if not it will remais inside and wet the pieces again through the steam. It's good to plan a drainner. This is one of things we need to make in our homemade dryer. Maybe a good and easy way is to bend the box a little. This things will also avoid the "rain" inside.
2- We used a cardboard box with aluminium foil inside and put the pieces in the bottom but the water was accumulate there so they didn't dry well because it. So we are planning to put a metalic rail (like the barbecue one) far away from the bottom to put the pieces on.
3- If you want you can use little stones instead of bricks but we were thinking of using lava rocks as used in charbroiler that stores more heat.
To solve the open and close box problem we suggest to use accrilic pieces instead of plastic around the box because you will have more rigidity. You can fix them with hinges as used at doors.
A good site to take a look is:
www.sociedadedosol.org.br
If I have more information about our expiriences at home I can let you know and, please, let me also know yours, ok?
Good luck for us!!!!
Shali
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Shali, did you find it effective to just leave the top open?
Sue, Have you ever been in a greenhouse in summer? I don't think the black is totally necessary, although in some areas it might help. This is also the technique I use to get young tomatoes started early.
Sue
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Sue (Catperson),
All sides, including the top, should be covered or shut because if not the heat is lost.
Shali
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Hi Catperson:
I have used my homemade dryer again. This time I've put 2 pieces of wood between the pieces and the bottom and I have had no problem with water. It has worked very well.
What did you think about the things I have wrote above?
Shali
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Shali, the acrylic pieces would be nice to use to build a dryer, but they are too expensive for me. I was just planning on using cheap plastic. Maybe I can close the 'door' with tacks.
Since heat rises (and can take moisture out with it), I am thinking there should be some kind of opening in the top, holes or slits in the plastic or something. If water is condensing inside the dryer, it needs to evaporate out, not just run down.
Sue
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Ok Sue. Please tell me about the results when you make and use it.
Shali
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Great topic! We've been testing out solar oven cooking and plan to move to using one more full time once the house is built. Will be watching this thread!!
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Catperson: I think a solar dryer is a great idea. I am in Canada so it isn't as practical here with our weather.
I use the same dryer that Shali is using since it was so super cheap to make. (I posted the link for directions on the forums here.) But, I don't have the same problem with water build up as she does. I think it is because I am drying much smaller pieces.
Please keep me updated on how your solar dryer goes Catperson. I'd love to see some of the pieces that you make in the future. 
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Hi:
Butterbee: "But, I don't have the same problem with water build up as she does. I think it is because I am drying much smaller pieces".
Thinking about that my pieces were small either but I've put many of them at once(about 20). Later, when I've put only 2 I have not had the same problem even these 2 pieces were bigger than the others. I think that why, maybe, the water build up.
Shali
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