the village idiot

Hi Woodworks, I only use the small diameter wood for charcoal that has no other obvious use. This thread probably gives the impression I do nothing but churn out charcoal, but the vast majority of the wood I harvest goes for firewood. My main interest is the overall management of the ancient woodland. Making charcoal means I am wasting less of the woodland resource and it keeps me out of trouble in the summer when I can't bear to pull on the chainsaw trousers.

Once again, very interesting comments. I have definately observed a greater volume of charcoal from more thoroughly seasoned wood. I sell by weight so it is not too relevant, although you would think that the dryer and more 'carbon dense' the charge the better. More end product and a quicker burn. The designers of the exeter retort have had the char tested for volatiles and it was found to be surprisingly pure.I would be over the moon if I could achieve a 40% yield but charcoal quality is very important to me. I know a lot of the imported charcoals are heaving with un burnt off volatiles as the poor sods who make it are paid by weight and have to produce it 'under charred' to try to earn any kind of living. Interesting that you mention the benefit of retort charcoal being easy to light. I am working on a new easy lighting British charcoal product called Barbecube with my partner's sister. She has got it into the co-op and possibly soon Waitrose. Amy is actively searching for UK charcoal suppliers and she pays much better than bioregional who should have been ashamed of themselves! I believe the embryonic website is up and running. http://www.barbecube.co.uk

A few pics from today's unload and re-load. Uploaded them all by myself! This is the same kiln load as the previous pictures, you will note how much volume is lost. This is partly down to the fact that the Ash wood I am using is not fully seasoned. At the moment I am averaging 3 very full barrow bags per burn, each weighing 50kg. I sell them like this- ungraded- for £1.10 per kg. There is a huge market for British charcoal and if you were less lazy than me and decided to grade and bag you can get around £1.50 to £1.70 per kg. As stated before, charcoal won't make you rich on it's own but the nature of the process allows you to do other work simultaneously. Whilst the pictured charcoal was cooking I was in the mini digger clearing the old concrete bomb pads in the wood (relics from the war).

No worries. Is that near the Dengie Marshes? Had a cousin from those parts- webbed feet but a real heart of gold. He's now my wife:thumbup:

Pop up to Hadleigh Mr. Logchopper and you can have your own personal viewing in the wood. ... I do have a beard, but I don't play the banjo!

The big limitation of this sort of retort is the small heat exchange surface the walls of the retort provides plus the reliance on natural convection and conduction to move heat around inside the charge chamber. The Exeter retort seems to manage OK in this department. I always get full conversion of the charge material and as long as I use relatively well seasoned charge wood and very well seasoned fuel wood the 'heating up' stage only takes a couple of hours and uses the amount of wood it takes to make 4 or 5 standard pallets. Once retorting no further fuel is added. If I could find an affordable way to prevent the warping over time it would be the perfect machine.

This is all great stuff, thanks guys. I'm learning more in one evening than I have got out of the manufacturers of these things in two years!

I'll try and remember to take some pictures next week. I am right in the Chalara heartland and although it is not massively obvious while you are just out and about, head into the woods and it really hits you. Lots of healthy ash too though so I'm staying optimistic for the time being.

I aim to keep the temperature between 470 and 520 degrees C, certainly keep below 600. I think if I went to 700 degrees my kiln look soon look rather Dali-esque. Could you elaborate on the Delta T reference, I'm afraid you lost me there. My charge chamber is heated directly from underneath. The temperature is taken from the flue gas emitted from the charge. Presumably I would need to take the temperature of the firebox itself to see what heat strain the base of the inner chamber was coming under?

Excellent! A bit of cold hard chemistry. It's taken two years of asking the question to finally have an intelligable scientifically sound answer to the stainless steel retort conundrum. Thank you openspaceman!

That's very interesting. I have had a lot of trouble nailing down whether stainless would be a good option or not. Some engineers swear it is the only option for long term durability, others maintain it would be little or no better (or worse) than mild steel, and considerably more expensive. I imagine you will get metal fatigue with whatever material is used. I have not yet seen a kiln that hasn't warped over time. I guess the trick is to design a machine that is easy to work on and bash back into shape. Cracking would obviously be a real headache!

Riddled I'm afraid!

My partner runs an ice cream business and gets all her flyers etc done by a company called 'a local printer'. I believe they are eco-minded and they are always lightning fast and excellent quality. Not sure how they compare cost wise.

I think it probably would be possible to make something similar yourself if you were very good at metal work, which I am not. There are several things to take into account. You need to be sure you can seal the inner chamber. You need retorting pipes to channel the wood gasses. You would also need to install chimneys and the whole outer shell including the doors needs to be well insulated. You would also need to ensure that the temperature was easy to manage. It could get a bit disconcerting if the temperature rockets up and there's nothing you can do about it. All that being said, you could bodge one up but be prepared for weeks of fiddling about to make it work properly. I am not an overly practical person and prefer to get things 'ready to go'. I'd be interested to know if anybody does decide to have a go. A good starting point would be a stainless steel vessel of some description with a flanged door/lid.

Central chamber volume is 1.7 cubic mtrs not accounting for air space. I did think about putting faces on the end doors, would look particularly effective for when you get flames shooting out of the 'mouth'! Bizzarely, when the kiln came back from the engineers in Exeter a picture of Mr Greedy had appeared on the side.

Many thanks Goaty (my IT guru). Should be a couple more pictures on the way.

The multitek we have starts at £28,000 but it is the baby of the range- a 1610.

Take some yourself you lazy bugger:001_tt2:

Interesting stuff! Could you elaborate on 'hectares of useless rubbish' that the FC are planting?

The estate I do woodland management for owns the company which imports the Multitek machines. We have one of the smaller models which we plan to use as a demo machine. If anyone is interested I could try and set up a viewing day this autumn/winter? It is road towable so may be available to hire with operator. Apologies for the slight de-rail.

Interesting that you point to the lime as your Satanic Stem of Significance Arch Mage get the strap on. I have always opted for an old Oak stump for my dabblings in human sacrifice. Nice large flat surface for easy maiden application.

Being an idiot has it's drawbacks sometimes..... I am struggling to upload my photos onto the forum from my phone. Perhaps if anyone is particularly keen to see some shots of the Exeter in action they could send me their email address and I can send them that way. Your most humble servant, TVI

I had my first go in something similar the other day. Had a Logset in to remove the last of the conifers from the ancient woodland. They are an amazing contradiction of brutality and technical finesse! Took me 10 miutes to fell and crosscut one spruce so I think I'll leave it to the professionals! The operator was concerned that the amount of work available for these machines is dwindling, and it won't be too many years before they are all fighting over the last conifer standing. Be interesting to hear your thoughts on the future in store for these big harvesters.

Yes, nature can be pretty awe inspiring at times. I still can't get my head around a single genetically distinct broadleaf surviving in the same location for 10, 000 years though! That is one heck of a long time.

If that's true it's a real mind bender- phenomenal