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View Full Version : The quest for metal in logs before sawing



Todd Burch
07-24-2015, 6:58 PM
Most of the trees I will probably be sawing will be trees local to my area. Some might be yard trees, others will be from pasture / woods / creek banks. None will really be formal woodlot or forest trees (whatever that means!!)

Do you look for metal? Do you use a metal detector? Do you only do either of these if you have been warned that metal might exist? Do you just cross your fingers you won't hit any?

What are some of the tell-tale signs that metal might be captured within the tree? I know what overgrown barbed wire fencing looks like.

I know what metal can do to a bandsaw blade. What about a swing mill blade?

Thanks, Todd

George Bokros
07-24-2015, 7:47 PM
I use a metal detector on all stock unless it is purchased as S4S. Need to cautious, blades and knives are to expensive and not fun to replace.

Scott T Smith
07-24-2015, 10:27 PM
Yes use a good metal detector and also look for tell-tale signs of metal. Oak will have a dark stain that runs slightly up and primarily down through the trunk. Look for scores in the trunk that may indicate fence wire too.

ryan paulsen
07-25-2015, 8:01 AM
Both times I've had yard logs killed the Sawyer made me sign a waiver making me responsible for any damage due to hitting metal (swing blade) on a per tooth basis. They both used metal detectors. I was clean, but he showed me the log from the guy after me with a pad lock in it...not pretty.

Danny Hamsley
07-26-2015, 9:12 AM
In my experience, ALL yard trees have metal in them, usually nails. I almost never encounter metal in forest grown trees. On yard trees, I usually scan with one of those treasure hunting metal detectors. Here is a nice yard red oak that I suspected had some metal in (only because it was in the front yard of a residence). I found 13 nails with the metal detector, and dug them out. Turns out, that once I began sawing the log, there were 14 nails :eek:.

Unless it is a high value log, fooling with yard trees is very risky, and generally not worth the issues. I spent almost 2 hours de-nailing this log. Most homeowners do not understand this and believe that their yard trees should be worth a lot of $. In reality, they are a liability. However, just like trying to explain to people that 1 year of drying per 1" of thickness for air drying lumber is a poor rule of thumb and is almost always wrong, I just don't bother anymore. When I get the calls from homeowners (and I get 1 or 2 per week) about buying their yard tree log that the tree service cut down or about the yard tree hanging over their house that they want me to cut down and remove free for the wood, I just say no.

In this pic, you can see the black stains from the nails that Scott referenced in his post.

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Dennis Ford
07-27-2015, 8:28 PM
I cut with a band type mill and ordinary nails are not too dramatic although the band needs resharpening afterwards. Hardened steel will usually ruin a band ($25 - $40). I do cut yard trees but only if they are free and look like they contain nice material.

John TenEyck
08-06-2015, 9:42 PM
I cut mostly yard trees. I get them for free. Some are really nice, white oak, black walnut, usually nice and clear. I don't have a metal detector but should have one because I've hit all kinds of stuff. Sometimes the log will tell you metal is in it. Oaks will be black below wherever the metal is. Here's an example:

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And here's what I hit in that log, the most I ever hit in one cut:

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I use a chainsaw mill and, surprisingly, nails don't usually do much damage beyond dulling a few teeth. This cut broke off a couple of teeth though. But with a chain break I can remove those cutters and replace them.

Here's an interesting find from a forest tree I milled last Fall.

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Yep, a bullet. Someone shot that tree about 40 years ago. Didn't even feel it during the cut since it was lead.

The worst thing I ever hit was a big hardened steel bolt from an electrical insulator. Never saw any sign it was there. Wiped out a whole bunch of cutters. Yep, a metal detector would sure help.

John

Cody Colston
08-07-2015, 6:33 AM
I don't use a metal detector but don't generally saw yard trees, either. I would saw them if they were nice logs.

The only time I have hit metal was when sawing a Walnut that I took down off a fence row for a friend. I knew there was fence wire in the tree but thought I had cut above it with the chainsaw. Nope, I found some more with the band mill.

BTW, Oak isn't the only species that will show a black stain from metal. Most all trees will, even Walnut.

Kevin Beitz
09-03-2018, 6:13 PM
You wont need to buy an expensive metal detector.
Your band blade will find the metal for you most of
the time on the first cut....

John K Jordan
09-03-2018, 10:50 PM
I use a Lumber Wizard metal detector on my bandsaw mill. It's a wand you swing back and forth close to the wood. Some times I don't take the time and occasionally I'm sorry. The last time I sawed through a 1/2" steel rod someone had driven into a cedar tree.

After cutting into a log, any dark spots or dark streaks are warning signs. I've found them in oak but also a variety of other wood, poplar, cedar, pine, walnut... Once you find and remove a nail look harder since people tend to put more than one nail into a tree.

One undetectable thing is a ceramic electric fence insulator. I hit one of those once - zzzzzssttt. Worse than steel I think.

The first 5 ft or so from the ground is the most likely to have nails, staples, and embedded barbed wire. If there are plenty of trees, consider discarding the first 5 ft from those off the edge of a pasture or anywhere around and old farmstead. I found lots of old fences at odd places on my property, some with nothing visible but some pieces of barbed wire on the ground, perhaps under the leaves or even buried a little.

Knowing something about the area helps. A smaller chance of metal if the tree comes from the "deep" woods or steep land that was never farmed, but even that is no guarantee. Yard trees and trees near the edge of an old field are always suspect.

I once cut down a yard tree for a friend. The inside of the tree was hollow and looked like an inverted porcupine with more nails than I would have ever imagined pointing towards the center. Then they told me it had been a tree house tree for three brothers. Nothing was visible from the outside.

JKJ


Most of the trees I will probably be sawing will be trees local to my area. Some might be yard trees, others will be from pasture / woods / creek banks. None will really be formal woodlot or forest trees (whatever that means!!)

Do you look for metal? Do you use a metal detector? Do you only do either of these if you have been warned that metal might exist? Do you just cross your fingers you won't hit any?

What are some of the tell-tale signs that metal might be captured within the tree? I know what overgrown barbed wire fencing looks like.

I know what metal can do to a bandsaw blade. What about a swing mill blade?

Thanks, Todd

david privett
09-05-2018, 9:32 AM
I use a harbor freight metal detector(cause I had it before I bought a mill) around 40 bucks works good enough when I remember to use it, but like John said porcelain is a blade killer . And nothing except maybe radar will see that. I sawed threw a 45 acp bullet and did not even know I had hit it.

Tom Hogard
09-06-2018, 4:41 PM
I've hit insulators, smoked the blade. Something else that'll do one in is an armor piercing bullet. And no, the log didn't come from a military firing range - it was from an old commercial apple orchard.
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