Solar kiln

[Greasemonkey]

Hi all, I was wondering if anyone has attempted or made a solar kiln out of a 1000L pod?
Do you think it would work?

[Nubsnstubs]

I don't see why it wouldn't work. If I was going to do that, I would cut it near the bottom, attach some alignment staves, cut some air holes, load it and cover it. If it didn't work, then find some other container to use.
When I bought my house back in '92, there was an 8 foot OD satellite dish with a fiberglass cover on it. Finally, in 2010, when I started turning for real, I loaded it up with Mesquite. When I do turn any of the wood from the dish, it comes off my tool as a fine powder. That tells me it's dryer that the desert I live in. ........... Jerry (in Tucson)USA

[Greasemonkey]

That's a neat idea Jerry, I'm in Brisbane Australia, so heat is not really an issue at the moment but humidity

[DaveTTC]

There was a guy on another forum who used to sell plans to kilns. I cant recall if they were solar or not. Bascially you could make anything from a chest freezer to shipoimg a container i to a kiln and he would walk you thru anything you cohld not manage from the plans.

I never did it but it did interest me. This is goimg back about 5 years ago.

DaveTTC
The Turning Cowboy
Turning Wood Into Art

[BobL]

As long as you realise you can't just pack wet timber inside a sealed container and heat it, as doing this will cook the wood,

It depends how quickly you want the wood and how sure you want to be that the wood won't go mouldy.
To reduce the chances of mould and for optimum drying times the kiln will required internal circulation and external venting and you have to allow for enough room for the recirculation.

If you just operate it in a an entirely passive manner you will be looking at many months to a year, and risk it going mould especially in Brissie.

Many years ago CSIRO worked out that you need a minimum of about 50W per cubic metre of 1) internal circulation, and somewhat less for 2) external venting.
This applies to sea container sized kilns, for smaller sizes you will probably need more

Recirculation is essential or you could end up with mould and/or differential drying with more drying of the wood near external vents and less in the middle of the stack.

The venting needs to be adjustable because too much venting in winter and it won't get warm enough, and too much in summer and it may dry too quickly and split.
On about a 1000L setup "passive venting" (slots in the sides down low and on top) will probably suffice.
Ideally these are adjustable so that the venting is reduced at night time when its colder.

For internal recirculation you could use something like a 50W bath room fan. You'd need to arrange a plenum space to diffuse the fan air flow because the full force of the fan direct on wood will dry that bit out too quickly.
To avoid losing space to a plenum inside the pod you can use external ducting to hold the fan and partially recirculates the air around the outside of the pod.

A programmable microcontroller like an Arduino could be a low cost way of monitoring humidity and temperature inside and outside the pod and even make most of the adjustments needed to fan speed and venting requirements