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Firewood Moisture Content

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A great demonstration, Billhook, and thank you.  I am trying to replicate this bubble test with three pieces of wood of differing measured moisture content  -  and one grandchild to do the blowing!  Just for the fun of it and a bit of photography!

 

Seriously, though. you don't actually say what you think is the highest moisture content acceptable in your stove, but you are clearly indicating that 21 - 22% is too high.

 

A kiln-dried supplier I purchased from recently promised all logs in the range 15 - 20% moisture content.  I had difficulty getting the delivered logs to burn in my stove, however, and when they did burn the combustion chamber of the stove only reached half the usual temperature level.

 

I tested the moisture level of these logs by various methods, including the oven-drying method.  I found that all the sample logs were between 17 - 20% moisture content on a dry basis measure, so that fits with the supplier's spec. But from your video I think I understand that this was most probably still too moist.

 

I have noticed that few kiln-dried suppliers promise the 5 - 12% level that you mention.  What would you say is the ideal range to use (or the highest acceptable for most stoves)?

 

Many thanks from Logburner.

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On 20/03/2021 at 19:14, Logburner said:

A great demonstration, Billhook, and thank you.  I am trying to replicate this bubble test with three pieces of wood of differing measured moisture content  -  and one grandchild to do the blowing!  Just for the fun of it and a bit of photography!

 

Seriously, though. you don't actually say what you think is the highest moisture content acceptable in your stove, but you are clearly indicating that 21 - 22% is too high.

 

A kiln-dried supplier I purchased from recently promised all logs in the range 15 - 20% moisture content.  I had difficulty getting the delivered logs to burn in my stove, however, and when they did burn the combustion chamber of the stove only reached half the usual temperature level.

 

I tested the moisture level of these logs by various methods, including the oven-drying method.  I found that all the sample logs were between 17 - 20% moisture content on a dry basis measure, so that fits with the supplier's spec. But from your video I think I understand that this was most probably still too moist.

 

I have noticed that few kiln-dried suppliers promise the 5 - 12% level that you mention.  What would you say is the ideal range to use (or the highest acceptable for most stoves)?

 

Many thanks from Logburner.

I do not sell firewood but burn a lot and the stove is on all day every day and night throughout the Winter.  When we have some sun the hot water is heated by solar tubes.

i burn Ash , Oak, Elm and Sycamore.  Mainly Ash and am not fanatical about checking moisture with a meter.  All the wood is kept loose filled in 2 cubic meter wooden boxes which have open slats and are stored in an open fronted lean-to.

I can tell by looking them whether they are fit to burn, colour ,cracking, settling in the box and also weight of each log and sound it makes when clacked against another.

Out of interest ,  I will try the Fairy Liquid method on some different pieces using our air compressor maybe attached to a rubber loo plunger and do a video on the result (if there is one!)

 

Proof is in the pudding and the stove has a  temperature gauge both on the door and on the heating pipe which operate in a narrow band if everything is ok with the wood.  Added to this there is no smoke out of the insulated flue when running and I have put the chimney brush up the flue only once in years and there was honestly nothing there but a little dust.

So because my supply is fairly constant and uniform, I have reached a stable situation after a time

I have the luxury of not having to deal with the general public and therefore not having to deal with the new rules.  When we did try and sell wood years ago it was painful.  They wanted different lengths, different splits, pine to make it smell good, and some wanted it stacking in their woodshed which was through a gate across the lawn, down some steps, well many here know the story. 

One customer we found sprinkling the wood with a garden hose because he said it makes it last longer!!!!  They walk amongst us!

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On 20/03/2021 at 19:14, Logburner said:

I had difficulty getting the delivered logs to burn in my stove, however, and when they did burn the combustion chamber of the stove only reached half the usual temperature level.

If the logs are ash, as you mention in an earlier post, I wonder if they were from die-back timber. I don't think the wood burns the same. They seem to just sit without doing much in the fire before catching and then burning quite quickly without lots of heat. Must be to do with the destroyed cell structure or something.

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2 hours ago, woodwizzard said:

If the logs are ash, as you mention in an earlier post, I wonder if they were from die-back timber. I don't think the wood burns the same. They seem to just sit without doing much in the fire before catching and then burning quite quickly without lots of heat. Must be to do with the destroyed cell structure or something.

 

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Interesting thought , Woodwizzard, and that would be why the bubble blowing dryness test didn't work either.  I looked it up re cell structure.

Chalara fungal spores attack the leaves first, before the disease moves up the leaf stems and into the branches and trunk, eventually blocking the water-carrying xylem vessels, starving them of moisture and killing the tree.

The biology behind 'ash dieback' (saps.org.uk)

 

Thanks from Logburner.

 

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