Thread: Lightening Struck timber - is it any good?

Originally Posted by Exador

Interesting discussion.I've milled several eucs that have been struck, including ironbark, spotty and tallow and none of them have been noticeably affected in terms of timber quality. In terms of firewood, I reckon people are fooling themselves if they think it makes much difference. I can think of a few ways in which the combustible material may be slightly altered by a strike, but none of them would significantly change the total amount of energy released when burning, except the bits that are charred, of course.

Does anyone have a theory as to what the mechanism for the firewood being ruined might be?

Yes my theory is that the cell destruction due to rupture slows the timbers ability to give up moisture to the air and therefore dries at a slower rate than the rest of the tree or similar trees giving the impression that it does not burn as well. I think it is just wetter that what it has been compared to hence the urban ledgend and as you said Cellulose is Cellulose .

Ross

I often wondered why some trees out here on the flats (Nth Victoria) appear to have grown with a twist and was told by several sources (including Don Burke) that a tree will twist after being hit by lightning and, although the trees looks relatively healthy, is doomed . About 3 months ago I milled a big Redgum that was dropped about 20 years ago after being hit by lightning 10 years earlier (pictured below). the timber was fine coming of the saw but within a month had cracked along the twist to eventually become of little value. It didn't burn with heat of "normal" seasoned Redgum either. I don't know about theories but I do know that struck trees don't burn very well, at least round here anyway.

Hope this sheds some light for you theorists out there.

Total urban/ rural myth with no scientific basis (unless you count 'a friend of mine told me . . .' or 'people around here reckon . . .' science). But as the saying goes don't let the facts get in the way of a good story . . .

That is not to say that lightning damage will not affect the growth of the tree in a particular way that could have an affect on its later use - whether as timber or for burning.

Trees are frequent conductors of lightning to the ground and since sap is a poor conductor, its electrical resistance and the fact that it is encapsulated can cause it to be heated explosively into steam, which blows off the bark outside the lightning's path. The trees commonly overgrow the damaged area and may cover it completely, leaving only a vertical scar - but possible fault lines can disappear where re-growth is over damaged wood (as can happen with any scar whether caused by lightning or other physical damage). If the damage is severe, the tree may not be able to recover, and decay sets in, eventually killing the tree.

That damage can cause a particular tree to grow in odd ways and cause weaknesses and faults is hardly unusual - and damage caused by lightning is explicable by consideration of the forces involved. For the most part the stories tend to exaggeration as there is wide spread awe and fear about lightning strikes and humans are good at using storytelling to assuage those fears (or to just get attention).

Originally Posted by Bloss

Total urban/ rural myth with no scientific basis (unless you count 'a friend of mine told me . . .' or 'people around here reckon . . .' science). But as the saying goes don't let the facts get in the way of a good story . . .


For the most part the stories tend to exaggeration as there is wide spread awe and fear about lightning strikes and humans are good at using storytelling to assuage those fears (or to just get attention).

Ah...........I'm not exaggerating Bloss. As for your "scientific basis" .... scientist once told us the earth was flat, the universe span around the earth and life as we know it would cease because of the Y2K bug. Now they were good stories...Hmmm?

Originally Posted by WillBrook

Ah...........I'm not exaggerating Bloss. As for your "scientific basis" .... scientist once told us the earth was flat,

Well actually no, scientists didn't tell us that . . . it was a common belief amongst the uninformed, but the notion of the Earth being a spere was understood (if unable to be proved by the technology of the time - we really only knew for sure when we sent spaceships into orbit, but we all know that was faked don't we: http://www.ufos-aliens.co.uk/cosmicapollo.html AND http://en.wikipedia.org/wiki/Apollo_...ax_accusations ) from very ancient times - at least from the 4th century BC: http://en.wikipedia.org/wiki/Flat_Earth "Recent scholarship has argued that "with extraordinarily few exceptions no educated person in the history of Western Civilization from the third century B.C. onward believed that the earth was flat" and that the prevailing view was of a spherical earth. Jeffrey Russell states that the modern view that people of the Middle Ages believed that the Earth was flat is said to have entered the popular imagination in the 19th century, thanks largely to the publication of Washington Irving's fantasy The Life and Voyages of Christopher Columbus in 1828. Although these writers reject the idea of a flat earth, others such as the Flat Earth Society accept or promote the hypothesis."

Originally Posted by WillBrook

the universe span around the earth

Well actually no, scientists didn't tell us that . . . but many religions did: http://en.wikipedia.org/wiki/Universe . Scientists can tell only what the evidence appears to show, and have to be content with not knowing if they are unable to find evidence. Others are happy to let imagination provide the answers (or create them for their own purposes - well-intended or not).

Originally Posted by WillBrook

and life as we know it would cease because of the Y2K bug.

Well actually no, scientists and experts in the field didn't tell us that . . . see: http://en.wikipedia.org/wiki/Y2K ,but much of the media did and no doubt many carpetbaggers and others in for quick quid exaggerated to take advantage of fear and ignorance, but for the most part the problem was real, a technical one, identified very early (at least in the early 1980s), was worked on and fixed.

In any case the simple facts about damage to trees easily explain what you and others have seen - my initial post made that clear - but there is no consistent pattern or evidence to support the notion suggested in the original post that started the thread

Originally Posted by Zoot

Someone told me that once a tree is struck by lightening and dies, then the timber is no good for anything. Can anyone shed some light (not lightening!) on this or is it just an old SWMBO tale?

(and in some of the other posts)

As I said - no need to let the facts get in the way of a good story - or to let evidence supplant belief.

BTW - WillBrook (Neale) - the timber items and pieces on your website are pretty spectacular - not much beats good aussie eucalypts for colour & patterning. I assume you do most of your work locally? Do you make the furniture or have someone do it for you?

I'll be on me bike now . . .

I say make a baseball bat out of it. Saw an old movie once where a down and out baseball player made a bat out of a tree struck by lightning. You guessed it he hit a home run, won the game, and became a hero.

Here's your chance Zoot.

Bloss, you've gotta get out more mate.

In answer to your question regarding the furniture maker.....it's my multi-talented wife. She built the house too. Check out the current Grass Roots magazine.

Seems I may have stirred up a hornets nest! But the discussion is very interesting and have decided that I am going to have a go at milling my lightening struck tree and no Kev i will not be producing baseball bats ... I think it is a silly game anyway!! Almost as silly as Gridiron.

Cheers,
Alan

Originally Posted by WillBrook

Bloss, you've gotta get out more mate.

Funny, that's what SWMBO says!

Originally Posted by WillBrook

In answer to your question regarding the furniture maker.....it's my multi-talented wife. She built the house too. Check out the current Grass Roots magazine.

I will get the mag and have a read - I have a multi-talented wife too, but on the furniture and house renovations front her talent is list-making & supervision . . .

I can't help with the veracity of lightning-struck trees being no good for firewood, but I speculated on a possible mechanism. Thought perhaps the resins may have evaporated. Just speculation, though.

Originally Posted by Mr Brush

As an aside, I've heard a theory to explain why some cows standing near a lightning strike are killed while some are not. An animal facing the point the strike goes to ground will have a substantial voltage between front legs and back legs, current flows, cow dies. Another animal standing roughly sideways-on (i.e. front and back legs about the same distance from the grounding point) will survive, as there is only a very small voltage difference across the animal......might be another urban myth in the making!

This one isn't an urban myth. Measured resistances across soil show that the potential difference with a lightning strike nearby would be enough to kill a person or a cow, and burn tracks between the legs are often recorded on humans and animals. As the PD varies directly with the distance, theoretically more would be killed if they were facing directly to or away from the strike.
Interestingly, whether you die from a direct hit seems to be a matter of luck. Some people come out of it with burn tracks on their skin but no serious damage, others are killed instantly.

Yeah, I thought about the volatile compounds being evaporated or oxidised, but I figured it would only be a small amount, not enough to change the bulk combustibilty of the wood. It may be quite large in some cases, I guess.

The recommended drill in a lightning storm is to squat with your feet together, to present both a low target for a direct strike and a low potential difference between the feet, thereby reducing the likelihood of injury from a strike nearby. The biggest potential difference is when people are standing at 90 degrees to a strike, because their feet are further apart.

Each lightning strike and tree are different.

Some trees are hit and get no noticable damage, they just carry on growing.

Others are hit so hard that the sap boils and the tree literally explodes.When I was a kid we had a big Rimu tree on our farm hit, the biggest bit that was left was the size of a fence post and 100m away.

So you cant be sure, although if the log is intact then the signs are good. If the current has flown down the wetter sapwood and killed the tree without boiling the internal sap and exploding the whole log, then it may be fine. Or it could be a mess of internal cracks... Who knows untill you cut into it.

Ian

i dont know about any of these tails.

when i was small maby 4 or 5. my father ran a dairy up here there sed to be a huge grey gum tree growing about 20 feet from the milking shed.

one evening we'd jsut got the cows into the yard and the first lot were in teh bails ready for milking. when a lightning strike hit this tree. i was inside the shed there was a bright blue flash followed by a almighty explosion.

the tree had shatterd into god knows how many peices. they were scatterd al over the padock. one of the naibours said some smal peces had landed on his roof over 500m away. one peice about 8' long and 9" square smashed threw 2 panels of the post and rail fence that made up the holding yard and lnded about 6 foot from my father.

the next morning when we wet back to servey the damage ll that was left of the tree was a peice about 10' high and half round. i remember my father standing inside the stump wile the nabour took a photo.

we ended up with heaps of pre split fire wood.

of the 50 cows in the yards not one was injured surprisingly

A couple of interesting reports of lightning strikes on humans on this thread:
Lightning strikes