"Self-sufficiency does not mean 'going back' to the acceptance of a lower standard of living. On the contrary, it is the striving for a higher standard of living, for food that is organically grown and good, for the good life in pleasant surroundings... and for the satisfaction that comes from doing difficult and intricate jobs well and successfully." John Seymour ~ Self Sufficiency 2003

Saturday 12 April 2014

Sun drying...

I have spent absolutely ages researching solar dehydrator designs so that I am able to dehydrate my excess garden produce for use later in the year.

I even went so far as to purchase plans so that RMan could make me one.

That presumed that RMan would (1) want to tackle the task and (2) would be able to.  The answer to both was nada - he didn't feel his woodworking skills were up to it.

So, when the kitchen shelves received doors and the flyscreens were installed I grabbed the opportunity and asked the carpenter if he would be interested.

Turns out he was... :)

So, after agreeing on his labour quote and ordering some 6mm marine plywood, plus 32 X 32mm wood, and sundry other items, the dehydrator started to become an actuality.

It took him two weeks, and finally I received the call I had been waiting for.

We collected the dehydrator from him, took it home, established the exact size of the toughened safety glass top (a definite necessity as I didn't want to chance the glass shattering into very dangerous shards if something unforeseen happened), ordered and then waited for the toughened safety glass to be delivered to a collection point in our nearby town.

A week later the glass arrived. 

(A side note - the carpenter didn't follow the copy of the written instructions he was given, and the unit wasn't square :(  Not easy to order and install glass on an unsquare unit... <sigh> )

A week earlier I had contacted a local wood preservative manufacturing company and the lady I spoke to assured me that once the product was dry it was safe to use with food.  I took her at her word and we coated the dehydrator inside and out with their product.

So, the unit was "workable".

Workable in that it was complete, even if it lacked the bottom absorber plate and the shelves.  I am still trying to souce affordable non-toxic shelving to go inside, but, I couldn't wait to try it out.  So I grabbed my cake / biscuit cooling rack from the kitchen and, balancing it on wooden dowel rods, created a drying shelf.
You can clearly see the wooden dowel rods
supporting the cooling rack
The very last of my tomato harvest went onto this rack, and the wait began.

It easily reached a temperature of 45 - 50°C (113 - 122°F).

I was ecstatic :)  Yeeeeeeeeha!  Solar dehydrating had just become a fact of life in my kitchen.

But, something kept niggling at the back of my brain.  And that kind of niggling keeps me up at night.  And, being up at night, means that if I want to research anything I need to Google via my smart phone.  Not the easiest as the screen is too small for my aging eyes (even with specs) and my fingers too big for the tiny keyboard, but I don't want to switch on the laptop in the middle of the night - that would inevitably mean that I wouldn't get to bed until the sun came up - I can get very carried away once I start investigating...

But, what I discovered gave me serious pause for thought - which I re-investigated, and confirmed the following day when I woke up.

The instructions I purchased stated that I should use plywood.  But, after contacting our local co-op and getting a certificate on the plywood I had purchased from them (it is imported from Malaysia!!!) I discovered that there is no plywood in this country that does not contain formaldehyde!  Good grief!  I'm going to poison us...

Much, much, much research later has unearthed the fact that it seems that all wood in this country has been pressure treated against beetle, mould, worm, etc by using formaldehyde or boron or arsenic, etc.

I thought I would ask the wood preserving company if they would put their "non-toxic" product safety in writing.  It turns out it is not rated food safe.

But - they were kind enough to give me a link to a site which detailed food safe techniques.

As soon as I discovered that the unit was unsafe for food, I whipped the tomatoes out of it, and shoved them into the solar oven to dehydrate.  The solar oven works OK, but, even with the lid propped open 5cms, it still attains too high a temperature, which has led to my incinerating a couple of loads of tomatoes this summer...

So - back to the drawing board I go.  Ah well, I've got at least 5 - 6 months before I will need a solar dehydrator.

But, for all those (and there are many of them out there) who make a solar dehydrator out of scraps and left over bits of wood - be warned.  Your wood may contain harmful chemicals...

23 comments:

  1. Oh, how disappointing. At the risk of using a cliche, where there is a will there is also a way. My money is on you to find it. Good luck with your research.

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    1. Vicki - I do have an option I'm busy designing (on MS Paint LOL) right now. But, I need to keep the unit as light as possible to facilitate moving it in and outdoors according to the weather...

      Will and Way are good friends of mine :)

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  2. Oh my, I'm glad you got that niggling feeling in the middle of the night.

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    1. DFW - Trust me - so am I!! It's a peculiarity of mine - my head starts working as soon as it hits the pillow. So either I lie there and sort it out mentally so that I can fall asleep, or I have to get up and write it down / do some research. It's normally productive when I get up - and it's quiet too ;)

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  3. It's a good job you have done such detailed research. I bet you were really disappointed after all your waiting. I hope you find a solution.
    Love from Mum
    xx
    PS I've replied to your comment on my blog - basically I freeze my bread until I need to use it. I normally only make 2 loaves at one sitting so the second loaf is not sitting in the freezer for a long time but this week I decided to do four.

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    1. Mum - Where food (and especially it's preservation) is concerned, research and confirmation of all aspects of that particular technique are vital to one's health and peace of mind :)

      Ah - freezing bread. Oh, for a decent sized freezer that works on our solar system... :). T'would make life easier.

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  4. What a shame Dani! You'd put so much thought into it. We would like to have a solar dehydrator one day but for me, it's more urgent that we solve our water problems. We would have had nothing to dehydrate this summer.

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    1. Linda - Spot on. Water security is right there at the very top of the list and should and must take precedence before anything else.

      Your solar dehydrator will happen I'm sure :)

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  5. Well, trial and error is not a bad way to learn. I'm trying to think who I know has a solar dehydrator that they built themselves. I know somebody did but I just can't remember who.

    Don't forget to let me know what you wanted to ask me about. I'd like to help with whatever it is if I can.

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    1. Harry - T&E is good, but can work out expensive if there is too much of it LOL

      Thanks. I did write to you - to your "other" address.
      Perhaps I'd better forward the mail to HF :)

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  6. Oh, that IS frustrating, Dani!
    I admit when I saw the title of your post, I expected to read about how you can dehydrate just by spreading things in shallow baking pans and stirring the contents every hour or so. Looks like I'm overestimating the dryness and heat of your climate!
    Good luck with the next iteration :)

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    1. Quinn - You are 100% correct - we can sun dry fruit & veg by just laying it in the sun. But, with the hordes of flies (and very cheeky field mice) we have here I would far prefer to enclose the food behind a screen of some kind ;)

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    2. P.S. the dusty wind is also a large motivating factor... :)

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  7. You can always make one from cardboard. There are some plans over here: http://solarcooking.org/plans/ And this one can be cut in an angle too if needed : http://solarcooking.wikia.com/wiki/%22Minimum%22_Solar_Box_Cooker

    I want to make a solar oven and dehydrator for ages but like you my research never ends and I honestly don't trust the abilities of "fundi"s here... I saw on amazon "all american sun oven" comes with dryer racks and everything but your experience with a solar oven being too hot to dry made me question it now. Otherwise that's a great oven if money wouldn't be the object..

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    1. nihal - Yes, a cardboard one with some protective netting would work, but I have bigger plans that spurs me on to a more substantial model.

      If you can afford the solar oven, you wont regret the purchase. They are brilliant for giving you the freedom and power saving to cook outdoors when the weather is suitable. I have even successfully canned tomatoes in mine

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  8. How about melamine-covered wood? I had a snake cage with a heater made from melamine and it stood up to the heat well.

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    1. donna Leslie - Welcome, and thank you for taking the time to leave a comment.

      My only concern with melamine is the production process - it also uses formaldahyde - and secondly, the fumes that the "plastic" will give off during heating. Repeated heating of melamine must surely encourage deterioration, and exposure to further chemicals within the product.

      I used a metal Coleman's cooler box when I first started experimenting with solar cooking, and the distortion of the internal surface stopped that habit very quickly. I knew there had to be chemicals leaching into the air with my homemade "solar oven". Given that I easily reached 70oC in the unfinished solar dehydrator, toxic chemical fumes was an immediate worry.

      For more info on melamine : http://en.wikipedia.org/wiki/Melamine

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  9. That's really disappointing Dani, I hope you find a workable solution.

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    1. dreamer - Once I get an idea in my head I worry it out and figure it out. I'm not giving up ;)

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  10. If you left the box outside in the sun for a few months would the formaldehyde leach from the wood enough to make it safe to use?

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    1. Jayne - welcome, and that you for taking the time to leave a comment.

      As I would be coating the entire unit with a foodsafe mixture, I'm not sure if leaving it out for a couple of months would suffice. I'd rather be safe than sorry...

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  11. does it have some sort of craft possibilities?
    Firing clay beads or something??

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    1. Or covering the top with wood, and making it into an owl box... :)

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Thank you for taking the time to comment - it makes my day and removes the "loneliness' of sitting at my screen blogging supposedly to myself ;) I try and reply as quickly as possible so please forgive me if sometimes my response is delayed.