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...