SO does anyone use a metal detector before breaking down timber for cutting bowl blanks with your bandsaw? What model of metal detector is your favorite? Is it mostly effective or just look the wood over and hope for the best. I've only found one surprise in about 18 months of woodturning, and no injuries, but I do have to say the blade makes a very distinctive sound when it finds that old piece of rusted masonry nail or whatever it was.
-
April 2025 Turning Challenge: Turn an Egg! (click here for details) -
Congratulations to Kelly Shaw winner of the March 2025 Turning Challenge (click here for details) -
Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.
When cutting bowl blanks....
- Thread starter Paul Durden
- Start date
I do on my sawmill, especially if I see any discoloration from iron. (iron will make dark streaks up and down the log, even in walnut)
Over the years, I’ve found these embedded in logs:
- nails
-screws
-screwdriver with handle
-barbed fencing wire
-porcelain electric fence insulator
-insulated copper wire (used to wire up a bradford pear branch)
-a 1/4” dia steel rod
-piece of rebar
and the worst:
-railroad spike
All these except for copper wire are terrible for Woodmizer blades.
Some suggestions from the pros:
- Never saw logs from a yard tree (the most likely to contain nails, screw eyes, etc). Logs from higher than a person can reach are usually OK.
- Never saw the bottom 5’ of a fence row tree.
I have some of the Lumber Wizards, large wands and the small detectors.
These are non-discriminating unlike some of the metal detectors sold for finding coins and such.
I’ve cut many hundreds of blanks (bowl, spindle, other) on my shop bandsaw and never once encountered any metal. If I saw dark streaks I’d stop and evaluate.
Here’s a tip: don’t cut a bowl blank from a tree like this!
JKJ
Over the years, I’ve found these embedded in logs:
- nails
-screws
-screwdriver with handle
-barbed fencing wire
-porcelain electric fence insulator
-insulated copper wire (used to wire up a bradford pear branch)
-a 1/4” dia steel rod
-piece of rebar
and the worst:
-railroad spike
All these except for copper wire are terrible for Woodmizer blades.
Some suggestions from the pros:
- Never saw logs from a yard tree (the most likely to contain nails, screw eyes, etc). Logs from higher than a person can reach are usually OK.
- Never saw the bottom 5’ of a fence row tree.
I have some of the Lumber Wizards, large wands and the small detectors.
These are non-discriminating unlike some of the metal detectors sold for finding coins and such.
I’ve cut many hundreds of blanks (bowl, spindle, other) on my shop bandsaw and never once encountered any metal. If I saw dark streaks I’d stop and evaluate.
Here’s a tip: don’t cut a bowl blank from a tree like this!
JKJ
What! No bullets?
I hit one once while turning a bowl. Lead cuts nearly as easy as wood, so I didn't notice it until I stopped the lathe. I also hit a rock that had grown into a crotch. I did notice that pretty quickly.
I've found shotgun pellets -- most identified by my brother-in-law as birdshot. In one case it must have been at relatively close range since there were a bunch of embedded pellets. The tree grew for decades afterward.
- Joined
- Apr 27, 2004
- Messages
- 9,139
- Likes
- 5,745
- Location
- Lakeland, Florida
- Website
- www.hockenberywoodturning.com
I’ve found shot and bullets.
One walnut crotch HF I found three .22 bullets. They were not deformed very much.
Found the first when my tool stopped cutting because it was stuck in one of the bullets.
Found two more removing shavings. This crotch was 25+ feet up as my friend, who was given the tree, got three 8’ logs out the tree below the crotch.
Must have been a lucky squirrel.
Also found much of the assortment that @John K Jordan lists.
On several occasion I’ve turned pieces with old barbed wire where the wire was so rusted and soft that it barely dulled the tools and added character to the piece.
Last edited:
Ha! I forgot to mention bullets. I was given a big (24”) walnut log from down the hill and sawed it into boards, planks, and turning blanks. One section was riddled deep with bullets on one side of the tree, fairly large caliber. From the wood growth around the bullets it was obvious that tree had been used as a target for a long time, maybe 50 years! (The lead certainly doesn’t affect a Woodmizer blade.) I cut one section into some blocks a stack of maybe 20 thin boards, each with a lot of embedded bullets. I thought someone might want to make a unique wooden box (maybe to hold cartridges). I still have that stack of thing boards somewhere.
I sanded and polished one block riddled with bullets and gave it to a gunsmith friend as a paper weight!
On the subject of bullets, I used to do a lot of underwater metal detecting in freshwater ponds and springs, especially in Florida at areas where a lot of people visited. The most common metals I found buried in the sand were bottle caps, pull tabs, coins, and bullets. My best find was a heavy gold men’s wedding ring with an inscription inside - it took some research but I finally located the owner about 60 miles from the spring. I contacted them and the wife was thrilled and came and got it. She said her husband had lost it while swimming in the spring on their honeymoon a year before. They had just replaced it, but she was glad to get the original back. She said she was going to put it through his nose - wonder what she meant about that…?
JKJ
I also hit a rock that had grown into a crotch. I did notice that pretty quickly.
Did you ever turn Manzanita root burl? I bought some once and every one had embedded rocks, not surprising since they grow underground! Fantastic wood though, hard, dense, and deep color! (I still have one if anyone in the area wants it.)
Other roots can be surprising too - some of the most unusual and complex figure I’ve ever found was in a large Rhododendron root, a big Box-elder root from Lisi Oland had the deepest red I’ve ever seen, I found unusual color streaks in Dogwood roots, and big roots from a huge cherry tree where the most dense, burled, and stable cherry wood I’ve never seen - simply refused to crack. (I always pressure wash roots.) Roots suddenly got a lot easier to get when I got an excavator!
Hint: when cutting up roots with a chain saw use a carbide chain!JKJ
Hi, I'm new to the forum. I've got a bunch of pecan logs from trees that fell over with hurricane Helene. I've wondered about finding metal in the wood, but hadn't come up with the idea of using a metal detector. Seems like I should have thought of that.
My question is, does it work? Will a run of the mill metal detector work through wood?
My question is, does it work? Will a run of the mill metal detector work through wood?
I agree, roots can have amazing grain patterns. I found that out when I turned a tiny vase from a crepe-myrtle root from the yard. I have a HUGE old pecan tree root I've cleaned up and I'm just waiting for it to dry, if I live that long.Did you ever turn Manzanita root burl? I bought some once and every one had embedded rocks, not surprising since they grow underground! Fantastic wood though, hard, dense, and deep color! (I still have one if anyone in the area wants it.)
Other roots can be surprising too - some of the most unusual and complex figure I’ve ever found was in a large Rhododendron root, a big Box-elder root from Lisi Oland had the deepest red I’ve ever seen, I found unusual color streaks in Dogwood roots, and big roots from a huge cherry tree where the most dense, burled, and stable cherry wood I’ve never seen - simply refused to crack. (I always pressure wash roots.) Roots suddenly got a lot easier to get when I got an excavator!
JKJ
er
Yes, a typical “treasure hunter’s” metal detector will certainly work through wood, but there’s another possible problem. Many such metal detectors are tuned so they reject things worthless to those looking for coins, gold rings, etc. This “discrimination” circuitry is completely adjustable on many, especially the higher-end detectors, but might not be on some. The problem is the detectors are tuned to ignore exactly what we are most concerned about in wood - ferrous meta, iron and steel! For example, I have a reasonably good $1000 metal detector I tried to use to locate steel survey pins made from rebar. I had a terrible time getting the thing set so it wouldn’t ignore iron. However, it would locate a coin at 16” down and even tell me the depth! These treasure hunter’s detectors also find a lot of aluminum pull tabs from soda cans - they are too close in response to rings!
There are metal detectors wands made and targeted towards sawmill operators. I have several Lumber Wizards wands that work well at the sawmill - have picked up nails and such before cutting through them. There are other brands too - google “metal detectors for sawmills”. I also have a couple of Lumber Wizard’s smaller detectors (named Little Wizard) for wood. They are a LOT cheaper and may be perfect for at the lathe and shop bandsaw.
I have no experience with other brands.
JKJ
Yes, a typical “treasure hunter’s” metal detector will certainly work through wood, but there’s another possible problem. Many such metal detectors are tuned so they reject things worthless to those looking for coins, gold rings, etc. This “discrimination” circuitry is completely adjustable on many, especially the higher-end detectors, but might not be on some. The problem is the detectors are tuned to ignore exactly what we are most concerned about in wood - ferrous meta, iron and steel! For example, I have a reasonably good $1000 metal detector I tried to use to locate steel survey pins made from rebar. I had a terrible time getting the thing set so it wouldn’t ignore iron. However, it would locate a coin at 16” down and even tell me the depth! These treasure hunter’s detectors also find a lot of aluminum pull tabs from soda cans - they are too close in response to rings!
There are metal detectors wands made and targeted towards sawmill operators. I have several Lumber Wizards wands that work well at the sawmill - have picked up nails and such before cutting through them. There are other brands too - google “metal detectors for sawmills”. I also have a couple of Lumber Wizard’s smaller detectors (named Little Wizard) for wood. They are a LOT cheaper and may be perfect for at the lathe and shop bandsaw.
I have no experience with other brands.
JKJ
Thanks, lots of good info there. I didn't think about the wands... kinda like they use t airport security. I'll look for one of those.
Last year, I had just under 400 linear metres (1200') of T&G cedar planks to plane, sand and refinish. They had been on the wall of my late dad's office until he retired 30 years ago, so they were moderately sprinkled with screws and nails of various sorts. I used a Little Wizard on about 5 planks laid side by side at a time. This was quicker than doing the planks one by one, but a poor choice. It meant I stopped worrying about overlapping the lines properly, making (say) two or three strokes rather than 5, if I'd done each plank on its own. I took chunks out of my planer blades at least a couple of times. I got almost all of the metalwork, but that's not really good enough. My lessons are:
• Don't skimp. If you have wide pieces of wood, use a wide enough sensor.
• Don't rush.
• If you have a lot of wood to check, get a bigger, better scanner. Being human, you will eventually get bored and start taking short cuts.
• I now have both the big and small Lumbar Wizards, and I rate them both.
• The best sensor is the one you use. Keep it somewhere right by the machine you want to protect. Lower the bar so you will just use it and not find yourself an excuse to skip the step.
• Don't skimp. If you have wide pieces of wood, use a wide enough sensor.
• Don't rush.
• If you have a lot of wood to check, get a bigger, better scanner. Being human, you will eventually get bored and start taking short cuts.
• I now have both the big and small Lumbar Wizards, and I rate them both.
• The best sensor is the one you use. Keep it somewhere right by the machine you want to protect. Lower the bar so you will just use it and not find yourself an excuse to skip the step.
I remember years ago reading a column- maybe in American Woodturners? The title was “they’s metal linnit” - heard from a sawmill operator about being wary of logs from older trees - deeply hidden metal of all sorts- bullets , nails and old hooks that the tree had totally grown around with no outside signs!
I got a "barn yard" tree once. That was more than enough. Many residential trees will have metal in them.
robo hippy
robo hippy
I cut through a nail just a couple of days ago. It was completely hidden within the log but I was using a M42 bandsaw blade and it did no discernable damage to the blade.
Carbon steel blades are a different matter....
Duncan
Carbon steel blades are a different matter....
Duncan