Drying of Doug Fir in Idaho for the first 28 days after felling. Lots of science in the paper. It can be summarized as they wanted to figure out how much moisture was lost from logs after felling since logs are sometimes sold by weight in the forest industry. They found that significant water is lost in log form within 28 days of harvest. This study contradicts one commonly said thing in the wood burning community, that is that "wood doesn't start seasoning until it is cut and split". It might not easily season to a burnable content but it certainly dries by quite a bit. Other interesting thing that they observed is that trees left whole on the ground dried out more than logs that were cut to length had limbs removed. It would be interesting to see it compared to being cut to firewood length without the ends butted. I would hazard a guess that rounds would be even drier than if left in tree form. They also found that the size (diameter) of the log matters, smaller is faster. No surprise there. My conclusion from a wood burner's perspective is that if you wait a month before processing fresh cut wood in any form it is going the be considerably lighter, in this case with Doug Fir by about 25%. No need to pick up and move about lots of water unnecessarily.
I still have a couple cords of red oak that I cut but haven't split yet, I sure hope that gets lighter by spring! That stuff is so heavy, but I won't be splitting that until July unfortunately. Pretty interesting stuff, nice post!
I'm thinking that the air is Idaho is a bit more arid than back here in the humid midwest also. But it is interesting to see how much loss there was in a month!
Yes. Definitely the species, overall climate and day to day weather will be a big factor. One of the graphs in that study shows a net weight gain (on days 16 and 26) corresponding with a rise in RH.
Ive been walking over a suspended (horizontalish) lodgepole in the bush for 3 years and plan on harvesting it this spring when the snow loosens its grip. I would expect it to be around 28% mc. Interesting read Paul bunion
I noticed that. Though the trend is most definately down, the changes in RH do cause "blips" on the graph. More so than I would have thought, for a short-term event.
Thanks PB! It made common sence to me that if I left the top on a tree, esp with leaves on it, that it would suck out some moisture from the log. But that was only a thought rolling around in my little brain and never knew (or checked) to see if it was valid.
My disadvantage is 100% lodgepole pine, goes up too fast, advantage is (if you can call it that) is that it drys fast especially in our climate. He has let 12' logs sit for a year, then bucked, and by the time he split them by hand the next summer they are tinder dry and literally crack apart from his splitting maul. Except, the only oak I have ever burned was the way too small scrap pile from new hardwood floors. (terrible job installing, story for another time).
Yeah its a double edged sword isnt it? Its better than eastern white pine by a stretch but not as good as some soft woods like doug fir and larch. It seasons fast, heats your house quickly due to its high temperature potential in the stove but is difficult for long burn times. In my PE super 27 I get around 5 hours maybe as much as 6 off of a load but dont pack the stove tight like I do with other woods like larch or birch. I feel I have a bit of an advantage since I have doug fir (in lesser amounts than lodgepole) and also an abundance of larch which as you know is the top shelf btu soft wood available outside of one other softwood species which alludes my mind at the moment. I also really like spruce when you need to handle those short in between scheduled stove loadings. Stihl, I look at cords of lodgepole in my yard as being money in the bank.
Great information. Thank you. I'm at sea level with much higher humidity. But, this matches my observations over the years. A guy gave me a Red Oak he had cut down behind his house 8 months ago in a very wet area. I got it out this last cold snap when things were frozen. I expected that wood to be waterlogged. Some of the rounds were inches into the frozen mud and had to be pried out with a peavey. It's been a shocker splitting that stuff as it's not that wet. It's in the 40-50% range.
Pretty cool info, thanks for sharing. I know when I leave logs that im going to mill setting around for a week or two, they are significantly lighter (I am actually able to pick them up with the tractor lol).
