How do you air dry your wood down to 20% ??

[difflock]

Well I measured a scrap of firewood at 9.5%,(multiple deep probes, some were 9.6, but more 9.5's)

then weighed it a few times on small digital kitchen scales and consistent at 31g,

I gave it a few mins in the microwave(zero steam), then spent hours and hours toasting on top of the stove,

I cannot get it below 28g, and mostly giving 29g, but I picked the lower figure to use.

The scrap is only about 10mm thick by say 40mm wide, so I figgered it should be dry by now

so 3/31= 9.67% compared to my 9.5%(and sometimes 9.6%) with the moisture meter.

So near enough.(depending on the underlying accuracy of the scales)

I went back out to my log pile in the shed and a few random samples were 13.5 to 15% max.

I cannot explain this,(perhaps my shed is situated on ley lines or sommat black-magical) but those are my figures.

Cheers

Marcus

Edited February 26, 2020 by difflock

[struie]

On 22/02/2020 at 16:54, Woodworks said:

Funny you should mention them being idiots. Had 2 in 3 drops today.

 

First one needed logs urgently as he was about to run out of telegraph poles to burn. I saw these "logs" when I got there and he was not kidding they were literally chunks of wet telegraph pole out in the rain!

 

Number two had got some fresh wood off a mate that he was struggling to burn on his open fire so could he have some nice dry softwood to mix it in with.

 

Wouldn't be surprised if these two dont give off more pollution than 20 sensible users with modern wood burners with our logs. The new regs wont make the slightest difference to either case.

should get these 2 numptys together.

[Rough Hewn]

 
I'd check your moisture metre. There isn't any way the MC could be that low. Looking at the general forcast for central NI, the average relative humidity is just over 90% (and has been all winter). It's very unlikely it's below 20% and I'd guess it'd be 22-23%. The equilibrium moisture content it 22.2%, and whilst it might be carrying a bit of summer gained dryness, I'd hazard a guess that you've had plenty of 100% RH days that will have knocked it right up.
 
I'm not being pedantic, but just had to point out that in the UK that sub 20 in winter is very tough to achieve and sub 15 is impossible.

I've got a mate with a barn full of oak Elm yew etc slabs.
All below 14% mc.
Air dried.
Lots of it is around 10%.
Barsteward.
I can't check the wood mc at my yard as the moss and fungus are too deep to get the probe in.
[emoji849][emoji106]

[Big J]

Just now, Rough Hewn said:

I've got a mate with a barn full of oak Elm yew etc slabs.
All below 14% mc.
Air dried.
Lots of it is around 10%.
Barsteward.
I can't check the wood mc at my yard as the moss and fungus are too deep to get the probe in.

I think unless you've been able to protect the timber from the elements over winter, that 10% is impossible. The lowest we ever had over winter was mid 17s on beech in the airdrying barns and 12-13 in the scorching summer (2018). That's with meticulous stacking and a £350 moisture meter. 

 

You'll get a grace period going into winter from the dryness acheived over summer, but at this stage in winter, the equilibrium moisture content is fairly consistently 20%. Some years it was 23% for us near Edinburgh.

[Rough Hewn]

I think unless you've been able to protect the timber from the elements over winter, that 10% is impossible. The lowest we ever had over winter was mid 17s on beech in the airdrying barns and 12-13 in the scorching summer (2018). That's with meticulous stacking and a £350 moisture meter. 
 
You'll get a grace period going into winter from the dryness acheived over summer, but at this stage in winter, the equilibrium moisture content is fairly consistently 20%. Some years it was 23% for us near Edinburgh.

It is in a barn, tested with magnetic field meter.
And he's OCD about stacking[emoji23]

[emoji106][emoji106][emoji106]

[Big J]

21 minutes ago, Rough Hewn said:

It is in a barn, tested with magnetic field meter.
And he's OCD about stacking

It must be spectacularly well protected from the elements. That being said, I think I've moved from one very wet part of the country to another and we never saw below 17% in winter on our stacks

[Rough Hewn]

It must be spectacularly well protected from the elements. That being said, I think I've moved from one very wet part of the country to another and we never saw below 17% in winter on our stacks

Devon is pish wet.
I grew up going camping on Dartmoor.
Every camping trip since, not on the moors is so nice and easy.
50mph wind rain sleet fog and that was in summer.
[emoji106][emoji106][emoji106]

[Woodworks]

10 hours ago, Rough Hewn said:

Devon is pish wet.
I grew up going camping on Dartmoor.
Every camping trip since, not on the moors is so nice and easy.
50mph wind rain sleet fog and that was in summer.

Yes and we get bad weather in winter ?

Edited February 27, 2020 by Woodworks

[openspaceman]

3 hours ago, Big J said:

I think unless you've been able to protect the timber from the elements over winter, that 10% is impossible. The lowest we ever had over winter was mid 17s on beech in the airdrying barns and 12-13 in the scorching summer (2018). That's with meticulous stacking and a £350 moisture meter. 

I know where you're coming from and @Woodworks is saying much the same but here in Sunny Surrey I was pulling softwood from my log shed in the low teens , I've very little left to test but I'll look to do a test.

3 hours ago, Big J said:

 

You'll get a grace period going into winter from the dryness acheived over summer, but at this stage in winter, the equilibrium moisture content is fairly consistently 20%. Some years it was 23% for us near Edinburgh.

Yes but as I mentioned some posts back the equilibrium moisture content verses relative humidity is not a line but an area bounded by two ogives, one is the path  the drying takes as timber dries and the other as it readsorbs moisture, I have found an image from a research paper on mahogany as an illustration, so it is to illustrate the principal only:

 

Equilibrium moisture content of mahogany wood as a function of relative humidity at 25°C. Filled and open symbols correspond to the adsorption and desorption states, respectively. 

 

 

If you interpolate using 90% RH as the average maximum humidity a log will experience in the middle of a stack ( given that it takes time for the whole log to reach equilibrium) you will see it settles at 16% mc but the same log being dried from green settles at 19%. Again there is the problem is that the basis on which the moisture content is being measured is not stated.

 

What it means is that the water from 25% down is weakly bonded to the wood structure and energy is needed to release the water molecules from that bond hence the drying line is higher than the wetting line.

[xdcx]

Lad here on the Facebook selling dry ready to burn hardwood saying it is all "mostly below 25%". I'm pretty good with my stove but I don't relish the challenge of getting that stuff going. Life is too short.

This thread made me go for a little looksy around Facebook and Gumtree for the local and semi local area just as a wee experiment. Vast majority of what you see for sale and what is being sold/re-listed with more stock etc is all hardwoods. Birch/elm mostly. One lad selling some nice looking Ash actually and I have ended up contacting him.... bloody internet!!

 

But yeah I find it incredible that with the abundance of softwood cut sites around me right now, all of which are spruce, pine, larch! That it's almost pretty hard to find any soft in amongst the troves of h/wood. Goes to show the guys selling are appealing to the dumbing off the masses. Which I of course do not blame them for but I just don't get this mentality.