Log drying test

[Woodworks]

3 weeks back there was some discussion on how wood looses it's moisture so I decided to do a little test. First was to work out how big a part bark has on moisture loss and the second was to see how much different end grain is to straight grain. In this picture you can see the samples.

 

1 log with bark

2 log but with bark taken off on lathe

3 wood turned from piece to side of center of tree so all growth have been cut through

4 end grain on main face

5 straight grain on face cut from same piece as 4

 

1 2 and 3 are ash and 4 and 5 are sycamore. All the samples have been left to air dry in the house and weighed each day to access how much moisture is lost. click on the pdf file at the bottom of the page to see the results. Sorry I am unable to show the picture on the screen if you can please fell free .

 

Now I am sure the results are not a surprise to the old hands on here but personnel I did not think the log with bark would be so much slower to dry than the other samples and is still not dry.

wood drying test.pdf

Edited February 3, 2013 by Woodworks

[andrewc]

Good of you to share the results of the test.

 

Will try to minimise bark when splitting!

[TimberCutterDartmoor]

Fantastic experiment; 1st class Hons!

[oasispta]

I'd be curious to see the results to a barked split log and an unbarked split log. Mainly because I don't remove the bark when splitting as I would have thought they'd both dry evenly. Obviously with the bark all of the way round it I retaining the moisture, but if split would bark make much difference???

[Justme]

Using logs all of the same species, size & shape would have made the results of real value.

[woodyguy]

Excellent result. Really glad you posted this.

So if it was 50% moisture when cut and needed to get down to 20% to be burnt, then 30% loss, so 70% is the line we need. The end grain cut got there in 4 days and the side grain in 8 days, so twice as fast losing from end grain than side of grain. Moral - cut your logs short rather than thin.

The bark is shocking and shows why splitting logs however small makes sense. Interesting that none of the those three are down to the 70% line yet.

Nice to see a fully valid test which fully addresses the issues that we were discussing - respect!

[TimberCutterDartmoor]

Using logs all of the same species, size & shape would have made the results of real value.

 

Justify your comment please.

[farmer_ben]

I dont process much Poplar, but the few ton i have done its worth stripping all the bark when splitting. Drys so much quicker.

[woodyguy]

just for Justme's benefit.

this would be of real value if it was the same size and same species - true. That's why it is two experiments. The first 3 rounded pieces are the same species and the same size ie properly controlled experiment.

The second experiment (4+5) is the same species to the same size just one cut across the grain and one ripsawed with the grain.

So it fulfills everything you quite rightly wanted it to be.

[Woodworks]

Thanks chaps.

 

I will keep samples 1,2 and 3 until there is no more weight loss and update. I was going to just cut them in half now and measure the internal moisture content but the missus band me and said "no the experiment should run until they completely dry" (she is a scientist) In fact she wants to do some more tests along the same lines just for fun so what do you want to know?

I did cut samples 4 and 5 in half and they were both down to 10/11% moisture content.