How does one keep logs at 20% at this time of year ?????

cessna · January 21, 2021

11 hours ago, sandspider said:

I try and bring mine in a day or two before I use them, and also try and sit them in front of the burner for an hour or so before I put them on, just to get rid of any lingering moisture before they go in the stove. Even logs that I've dried for 9 months in a polytunnel before burning can still seep a bit of moisture when stood in front of the fire. I presume that's moisture they've reabsorbed in the damper winter months as I'm pretty sure they were fully dry at the end of summer. I do live in a damp Welsh valley though.

Thats exactly what I suggest to my customers, just common sense really .

openspaceman · January 21, 2021

On 20/01/2021 at 20:37, difflock said:

They were all end grain readings without splitting afresh.

That by implication answers my question that you use a probe of some sort. I've never owned a moisture meter so use oven drying until I see a comparison I'll not know which basis the moisture meter uses.

Doobop · January 21, 2021

You can't.

My 2 year split and seasoned (1 year stacked outside, 1 year stacked in a wel ventilated, completely protected from rain shed) ash, which came originally from dry windblown trees, is sat at 21.5%.

Sub 20 is impossible in Devon in winter as the equilibrium moisture content is higher than 20%.

The regulation needs to change to sub 25%, rather than 20%. 20% is fine and doable on the continent, with the drier and colder winters, but it doesn't take account of our maritime climate.

Most things are impossible in Devon![emoji23]

Woodworks · January 22, 2021

On 20/01/2021 at 11:48, openspaceman said:

Now if the example of 21% moisture content being in equilibrium with air at 90%RH is based on moisture as a percentage of dry weight then that equates to 17.4% wet weight basis. Also look down the chart for cities in america, are they all seriously dryer than UK as not one of them shows an EMC of higher than 18%. I'd like to see a real experiment of a log of moisture content determined by oven drying suspended in free air under cover outside.

Hi Andrew. I spilt some ash that was reading between 20%-22% with little difference from inside to outside so I am presuming its in equilibrium with the outside RH. The split piece weighs 383g and then 315g when fully oven dried. By your wet weight bases what do you make that as I dont really understand how to do the calculation? Thanks

openspaceman · January 22, 2021

1 hour ago, Woodworks said:

Hi Andrew. I spilt some ash that was reading between 20%-22% with little difference from inside to outside so I am presuming its in equilibrium with the outside RH. The split piece weighs 383g and then 315g when fully oven dried. By your wet weight bases what do you make that as I dont really understand how to do the calculation? Thanks

See corrected calculation further down the posts

wet weight 383 minus oven dry weight 313 gives water content 70. Water content 70 divided by wet weight 383 gives fraction of wet weight that is water 0.182767624 which is 18.28% Moisture Content Wet Weight Basis (mc wwb)

Water content 70 divided by oven dry weight 313 give the moisture content expressed as a fraction of the dry weight which is 0.2236421725 or 22.36% Moisture Content Dry Weight Basis (mc dwb)

Edited January 22, 2021 by openspaceman
Misread dry weight figure correction added in later post

Stere · January 22, 2021

Quote

I'm beginning to notice this game is the same as window cleaning. To make good consistent money then you need a good expensive system in place. I just thought you would need a big barren with open ends. Store the logs in it and let the wind dry them out naturally. Once money comes in then you build another barn and do the same and the cycle continues until sales begin to fall.

I season logs in a polytunnel can gets over 45C in there in summer even with both end doors open.

Look up about solar kilns if your interested....

openspaceman · January 22, 2021

30 minutes ago, openspaceman said:

wet weight 383 minus oven dry weight 313 gives water content 70. Water content 70 divided by wet weight 383 gives fraction of wet weight that is water 0.182767624 which is 18.28% Moisture Content Wet Weight Basis (mc wwb)

Water content 70 divided by oven dry weight 313 give the moisture content expressed as a fraction of the dry weight which is 0.2236421725 or 22.36% Moisture Content Dry Weight Basis (mc dwb)

Sorry I misread your dry weight as 313 rather than 315

383-315=68

68/383=17.75% mc wwb

68/315=21.59% mc dwb

So your moisture meter looks accurate for this sample and seems to measure mc dwb

Woodworks · January 22, 2021

15 minutes ago, openspaceman said:

Sorry I misread your dry weight as 313 rather than 315

383-315=68

68/383=17.75% mc wwb

68/315=21.59% mc dwb

So your moisture meter looks accurate for this sample and seems to measure mc dwb

Many thanks. Might give Woodsure a call next week and find out if the do it by wet or dry basis.

Edited January 22, 2021 by Woodworks

Woodworks · January 25, 2021

On 22/01/2021 at 21:27, openspaceman said:

See corrected calculation further down the posts

wet weight 383 minus oven dry weight 313 gives water content 70. Water content 70 divided by wet weight 383 gives fraction of wet weight that is water 0.182767624 which is 18.28% Moisture Content Wet Weight Basis (mc wwb)

Water content 70 divided by oven dry weight 313 give the moisture content expressed as a fraction of the dry weight which is 0.2236421725 or 22.36% Moisture Content Dry Weight Basis (mc dwb)

Andrew you are spot on as they do calculate moisture content on a wet weight basis so our logs would comply. Very happy about this and have suggested to Woodsure that they make this clear.