Testing trees for shrapnel

[skookum]

Hi,
Got a call from a friend on the weekend, who needs my help.
Turns out that he got ahold of some 80year old oak trees to saw into slabs on his homebuilt sawmill.
Now Germany has seen a lot of action in two world wars and many old trees over here are literally salted with shrapnel from bombs, grenades or bullets.
I figure that this will be a good time to use the 1270 with the 8" coil in all metal mode when I head out there next sunday.
I am just wondering if detection depth in wood is equal to that in the ground or not.
hh
skookum

 

[BarberBill]

I can't tell you with any certainty whether signal penetration in wood is equal to ground or not, but you should get good enough results to be helpful for what you're trying to do. On larger logs you might have to check them several times as slabs are removed to see if metal is in the remaining piece(s) that was too deep for the first check. You should be able to put some targets under several or more boards to get an idea of just how much depth you can expect.
BB

 

[Ed in SoDak]

If the logs aren't dry yet, I would imagine the moisture in the wood will help. Otherwise I'd expect something similar to air-test depths. Small steel frags might be an issue, while lead is too soft to hurt much. Bullet slugs may have had a clad covering of copper, which might dull the blade. Technically you only need to scan to the center of the log if you can get at all sides. If not, you may need to recheck as he saws into it, which may be a challenge due to the saw's carriage and everything else about it is all made of metal and large.

I used to edit a newspaper about logging and visited many local mills in the 1970's. Towards the end of the period, most major sawmills had added metal detectors, but they were specialized types. The technology was simpler back then, but maybe depth and sensitivity were comparable to your 1270, The detectors were not recognizable as such, they were just another doodad attached to the debarking/infeed portion of the mill and I never learned much about how they worked.

I'll guess it will be a challenge, as you might be dealing with rather small and unusually-shaped shards that may be at some depth. Even a small piece can wreak havoc with an expensive blade, as all the teeth will rub and burn on any piece of metal that gets in the path, perhaps cycling through the cut several times before it's noticed and the blade stopped.

While logging firewood, I've exposed buried .22 slugs from shooting squirrels. They were sometimes around 4 inches deep or more. Usually, the projectile left a "trail" into the wood that was darkened, making them easier to locate once the log is cleaned of bark and the first slabs removed. Often there might be some pitch or sap evident on the exterior, but we're talking fairly recent hits, compared to WWII or prior.

It's worth a try, but don't get too cocky about how helpful it might be. If one sneaks by you and dulls his blade, he needs to understand how uncertain the detection process might be with using a handheld machine not specifically designed for the task.

You might want to seek out any forums for small mill owners, as I'm sure other mill owners will have tried it.

-Ed.

 

[skookum]

Hi,
@ Ed,
I have already told my bud that I would bring my deepest seeking detector - but no guarantees.
Actually shrapnel probes/detectors are quite common over here in Germany.
Ebinger is one company that produces them somewhere in Cologne(K

 

[mudpuppy]

I was way out in Idaho once...I mean waaaay out. Driving down a logging road, had the detector of course, stopped and got out to look around, saw a really big old tree about 100 yards away. I said to my friend, "I bet theres a lot of bullets in that old tree" We went over there and sure enough, there were all sorts of bullets on one side of the tree, so I started detecting the ground heading off in the direction the shots most likely came from, about 50 yards from the tree, I started finding old 30-30 brass shells, then I noticed a group of old trees nearby and said, "I bet people would camp right there" Sure enough, there was all sorts of old cans and stuff one signal was an old silver ring and another a wheat penny. There were also nails hidden in those trees up about 6' where somebody evidently hung up a tarp. Thats all I can say..these detectors will find iron or metal in wood.
Mud

 

[BarberBill]

Mudpuppy, I'm in Idaho all the time and I can tell you bullets are a very common find. I've found lots of them just leaving the detector on as I cross meadows or logged areas to return to my truck. When not hitting trees or deer or elk they have to come to earth somewhere. Camp and picnic sites are always worth a check with the detector as well.
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