Which Wood?

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slowworm

Native
May 8, 2008
1,143
188
Devon
There's a fair bit of Alder down here in Devon. In the woodland next to my house there's some good sized trees where it's very wet - next to our stream. There's also a fair bit planted in new woodlands where the soil is fairly wet.

I find it a good, if quick burning, firewood if dry and it doesn't take long to dry.
 

Robson Valley

Full Member
Nov 24, 2014
8,674
1,629
McBride, BC
Moisture content has a direct effect on flame temperature.
You are vaporizing wood water at a cost of 540 calories per gram.
That energy goes up the chimney as invisible steam.
One result is that lots of wood organics don't vaporize easily until heated.
Just above condensation, they present as tars and soot. Unoxidized carbon compounds.

I have burned at least 100,000 lbs compressed and ultra dry wood pellets to heat my home in winter.
About 10,000lbs (5 tons) per winter. Buy them as 50 x 40 lb bags triple wrapped.
Any bags at all left over in April are nearly useless in October, stored indoors and dry.
That stuff sucks moisture out of the air through the pin holes in the bags.
It is SPF (spruce/pine/fir) because we have lots of it cheap. Salvage grade stumpage royalty, if that.
Because of the resin content, the fuel heat value is excellent.

Last winter, I brought a wheel barrow into my kitchen where the pellet stove is.
Mixed old and new bags. Clearly did burn much hotter. Damn nuisance to load the stove with a bucket
but I did burn off 8-10 old bags from the previous late winter.
 

Broch

Full Member
Jan 18, 2009
3,789
2,960
Mid Wales
If, for some reason, you do go the Alder route remember to split it green; it's dreadful to split by hand once seasoned.
 

TLM

Native
Nov 16, 2019
1,061
419
Vantaa, Finland
To clarify things a bit, there are very few tree species in Finland in comparison to the Misty Isles. Birch, norway spruce and scotts pine form the forests. If I wanted to to use rowan for fire wood I would have to gather it here and there. Alder forms thickets where it is easy to cut and gather but normally birch is used for heating, alder is used for some special purposes like smoking fish and meat and smoke sauna heating.

Soooo, I would think that there exists a better or as good special fire wood in Britain and I certainly would like to here more about the different woods. Broch's list is an interesting collection of experiences.

There are of course areal differences, in Lapland I have used dead rowan dead juniper dead willow for fires when nothing else is found.
 

Erbswurst

Native
Mar 5, 2018
1,714
637
Berlin
I think we can't put experiences from ovens in the house to campfires 1:1.

The campfire dries the wood that I put on top, even if I don't dry it in a circle around the fire as usual in whet conditions.

And a well build pagoda fire gets far more air than such a closed oven.


In the oven one simply doesn't get the fire going. And because the whet wood doesn't produce enough heat it smokes and soots until the tube is full and closed, and the smoke enters the living room.

Latest if the tar is dripping out of the tube connections you know that you use whet stuff.

:eek2:
 

Broch

Full Member
Jan 18, 2009
3,789
2,960
Mid Wales
I think we can't put experiences from ovens in the house to campfires 1:1.

The campfire dries the wood that I put on top, even if I don't dry it in a circle around the fire as usual in whet conditions.

And a well build pagoda fire gets far more air than such a closed oven.


In the oven one simply doesn't get the fire going. And because the whet wood doesn't produce enough heat it smokes and soots until the tube is full and closed, and the smoke enters the living room.

Latest if the tar is dripping out of the tube connections you know that you use whet stuff.

:eek2:
Quite the contrary really. A modern woodburning stove has to meet very strict regulations about burning efficiency and soot generation. A lot of the gases and soot leaves the campfire too quickly to get burnt properly; in a modern woodburner the gasses are circulated to ensure they burn.

I installed a new woodburner this time last year replacing a 26 year old one - the difference in efficiency and cleanliness of burn is very noticeable.
 

C_Claycomb

Mod
Mod
Oct 6, 2003
5,833
910
Bedfordshire
I think we can't put experiences from ovens in the house to campfires 1:1.

The campfire dries the wood that I put on top, even if I don't dry it in a circle around the fire as usual in whet conditions.

And a well build pagoda fire gets far more air than such a closed oven.


In the oven one simply doesn't get the fire going. And because the whet wood doesn't produce enough heat it smokes and soots until the tube is full and closed, and the smoke enters the living room.

Latest if the tar is dripping out of the tube connections you know that you use whet stuff.

:eek2:
I agree that a camp fire can be used to dry wood to help reduce smoke, using the tops of the flames, where most of whatever combustion is going to happen has happened, or using radiant heat that is thrown in all directions.

I disagree with you though that one can't make use of experience with a wood stove. If you want to know the mechanism of how wood burns you will find more scientific based information from wood stoves than camp fires. Burning wood requires the same things whether in the open or in a stove, and the stove helps control some of the variables, which makes it easier to study. There is also money involved in getting complete, clean, combustion in stoves, not so much from open fires.

An open fire might be surrounded by air, but unless there is a wind, it can only pull in air based on how much up-draft it creates. Open fires are much less efficient in this regard than anything with a chimney, using more fuel for any given effect.

Granted, an indoor open fire might be the best place to see the effect of damp wood vs dry wood of the same type, but a stove works well enough.
 
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Robson Valley

Full Member
Nov 24, 2014
8,674
1,629
McBride, BC
Modern pellet stoves are marvels of efficiency and electronics. Mine makes no smoke. Zero. The fire box might hold no more than 350ml pellets at any time. It burns like a blacksmith's forge. Harman P38++ model to heat 2 x 1,200 sq ft.

Motor #1 is an exhaust fan which pulls intake air up through the burning pellet mass and pumps the exhaust gases out through the insulated stainless steel chimney.
Motor #2 intermittently drives the supply auger that pushes unit volumes of pellets up into the burning pellet mass.
Sitting above that is the steel mesh of the heat exchanger.
Once heated, motor #3 starts to push reheated room air through the heat exchanger.

Every 12-15 bags (480 - 600 lbs) I shut the stove off to cool for 60 minutes.
The flame is no longer torch-like, just gets sort of waving lazy.
Open it up to clean maybe 2 lbs fine light brown particulate ash out of the ash bin, etc.
Never any white ash. Never any unburnt charcoal-looking lumps at all. Finish with the Shop Vac.
30 minutes later, I prime the cleaned stove and light it. Everything else is electronically automatic.
The feed hopper on the stove holds about 100 lbs.
Coldest -30C outside and I might burn 1.5 - 2 bags per 24 hours.

Elsewhere, dry corn cobs are used, some places even Esparto grass, all compressed as pellets.
Harman stoves are designed to eat those. too.
Specialty pellets are pre-carbonized and sold to the Japanese steel industry.
British Columbia exports mile-long freight trains of pellets to Scandinavia. They know a good deal.
 
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Nice65

Full Member
Apr 16, 2009
4,834
1,449
55
W.Sussex
@C_Claycomb

Cheers. I see Midhurst has quite a bit of water around. I usually see alder when I am walking near rivers, but even so, it hasn't been a common sight in the places I visit.
It does, there’s an iron pan a couple of metres down in places and it makes for boggy ground, perfect for Alder. I’m in Singleton on chalk and notice the difference in plant species just by driving up the road a few miles. Suddenly the woodland is predominantly Oak, Birch and Pine. To the north of Midhurst, at Fernhurst you’ll see a place called Iron Hill. The area around Fernhurst has both iron ore and much wood to burn so another thing that travelled up to the Scottish Armouries were cannon balls. I know a few people who’ve found them in the woods at disused and disappeared foundries.
 

Robson Valley

Full Member
Nov 24, 2014
8,674
1,629
McBride, BC
In every level of commercial forestry here, Alder is classified as a "weed species" to be ignored.
As mentioned above, Alder goes from cheese to bone when it dries.
I keep looking for the right branch crook to use as a handle for an elbow adze.
Maybe not in this lifetime of searching.
Further, I don't feel like whacking the entire tree for the sake of a single branch point.

Alder here is the Pacific Northwest First Nations' choice for salmon smoke wood.
Hundreds upon hundreds of fish are smoke cured for winter.

The result is that even as Alder is the #1 prize species for detailed carvings and masks,
it is common to keep the carving in a barrel of water between sessions until finished.
By then, the carving is so thin that cracking is rarely encountered.
 

C_Claycomb

Mod
Mod
Oct 6, 2003
5,833
910
Bedfordshire
It is interesting how woods and their qualities vary by latitude, and altitude. Cold winters do seem to make for harder timber.

Birch and birch bark are the easy example, where the wood is denser and harder from Scandinavia where the winters are harsher than the UK, and that the bark is much thicker. Birch from southern England isn't good for knife handles the way the northern birch is.

I have a piece of pine branch from mid-Norway and a cut with a sharp knife leaves a hard polished surface, the rings are very tight. Different from any pine or spruce I have encountered in England, barely takes a dent.
 

TLM

Native
Nov 16, 2019
1,061
419
Vantaa, Finland
It is interesting how woods and their qualities vary by latitude, and altitude. Cold winters do seem to make for harder timber.
Properties do vary but I am not certain if cold winter is the main driver, were it so birch from Lapland would be a different wood from the southern variant. I don't think any meaningful differences have been measured. I know that people in times gone by chose carefully the place they took the wood, wood from marshy or overly wet area was considered inferior and wood grown on dry rocky places was also not prime material. Of course there are also beliefs about the phase of the moon when certain trees should be felled. :wacky:

I think that for knife handles a slow growth tree would be first choice.

But I do know that a kuksa factory has some problems acquiring proper birch and they import some from northern parts of Russia but I have understood that again the requirement is for tight grain meaning slow growth.
 

C_Claycomb

Mod
Mod
Oct 6, 2003
5,833
910
Bedfordshire
Slow growth causes a measurable difference in wood. Short days, short growing seasons and cold winters all come together with higher latitudes and cause slow growth. Maybe you mean the south of Finland vs north of Finland? I wouldn't know, but perhaps there isn't enough difference in day light and temperature to make a difference.
 

TLM

Native
Nov 16, 2019
1,061
419
Vantaa, Finland
Yes, sorry, difference between south/north Finland. Difference in mean yearly temp and growth season length is quite large. The growth day in summer is actually quite long because of long daylight hours. Strengthwise slow growth is not necessarily better, in fact on many trees there is an optimum somewhere in between. Depends really what property is desirable.
 

Broch

Full Member
Jan 18, 2009
3,789
2,960
Mid Wales
Slow growth causes a measurable difference in wood. Short days, short growing seasons and cold winters all come together with higher latitudes and cause slow growth. Maybe you mean the south of Finland vs north of Finland? I wouldn't know, but perhaps there isn't enough difference in day light and temperature to make a difference.
To be honest it doesn't need to be a big difference in latitude or daylight hours; just the difference between a south facing and a north facing slope will change the growth rate. I have two pieces of woodland, one on the south facing slope and the other on the other side of the same hill - north facing. Both ash and oak are 20 to 25% larger in diameter for the same age trees on the south facing slope.

The other interesting thing is that growth has been slower for the last 20 to 30 years, despite warming, on both sides of the hill.