Replies

1. 
   Dave45 | Feb 02, 2008 04:49pm | #1

   Considering the potential for major damage if you miss something, I doubt if I would trust a "hobby" level metal detector.  I've seen a couple of woodworking shows where they (Norm Abrams & ??) used wand type metal detectors like they use in airports.

1. 
   xmike | Feb 02, 2008 06:05pm | #2

   Actually, some of the most sophisticated metal detectors available are "hobby" detectors.  Not only are they very sensitive, many contain discrimination circuitry that can determine the difference between, say a dime and an old pop-top pull tab - not an easy task for something buried in 9 -12 inches of dirt.   Some can be tuned to pick up 1/16-bb sized gold flakes out of highly mineralized soil, and tell you how deep it is.  They are also pretty expensive ($250 for one I bought 5 years ago). 

   You don't need all that circuitry - you just want to know if there's metal in that log - not what it is.  Simple wand detectors are only looking for a disturbance in their electromagnetic field as they are moved about (oh, look - something metal),  and should cost quite a bit less than a "hobby" detector.   

   Finding a nail or screw in a 3/4" plank at a woodworking show is pretty tame stuff.  Your real interest should be how reliably can the detector you are considering detect a piece of wire, nail, or screw in 8 to 25 inches of wet log.   

   I would think that you could test that by marking a spot on a log with a spray can, shooting an 18 gauge brad into it with your brad-nailer, and seeing if you can detect it from the other side with the detector you are considering.  If you can see that with the detector, then you should be able to detect the odd piece of 10 penny nail, barbed wire, or heavy staple in the log before you find it with your blade. 

   And if you can't find the brad during your test, at least the 1/2" long bit of 18 gauge wire is unlikely to damage anything, and you can always avoid it completely by avoiding your spray mark.

   Mike D

1. 
   Miko | Feb 03, 2008 11:39am | #5

   Thanks Mike_D,

   What brand and model of detector do you have and have you tried the brad nail test with your detector.  If this works I would rather spend a little extra and get a detector that I could have some fun with when I wasn't scanning logs for nails.

1. 
   xmike | Feb 03, 2008 09:08pm | #6

   Hi Miko,

   Mine are Whites.  They are in storage right now, so I can't tell you the model numbers.  One is the highest grade "discriminator" model sold about 5 - 8 years ago and the other is the highest grade "gold detector" model sold during that time frame.  We lived in Phoenix at the time and had fun coin and gold detecting.

   I have not tried the experiment that I described.  I don't have a band saw mill, so no need to ever try it.  Just thinking out loud.

   Someone suggested the forestry site for better information on all this.  You might surf there for a while and find something actually worthwhile to you on this subject.  :)

   Good luck,

   Mike D

2. 
   JeffHeath | Feb 02, 2008 06:25pm | #3

   Rather than reiterating all the info, check out this thread on the forestry forum, if you already haven't.

   http://www.forestryforum.com/board/index.php/topic,29573.0.html

   Small detectors, like the Lumber Wizard, won't penetrate the log deep enough to help you out with a band mill, unless you want to spend twice as much time checking every log.  I know, I have one.  They only detect metal at the surface.

   Jeff

1. 
   Miko | Feb 03, 2008 11:31am | #4

   Thanks for the link.  A rather discouraging discussion especially the comment about the $800 White metal detector.  It sounds like I could spend alot for a hobby metal detector and still hit a nail or spend a little for the wand style and still hit a nail.

3. 
   colebearanimals | Feb 03, 2008 10:53pm | #7

    

           Go to the source and talk to a few small mill owners and see what hardware and technique works for them.

                                                                     Paul

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   Edited 2/3/2008 3:00 pm ET by colebearanimals

   
   

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   Edited 2/3/2008 3:01 pm ET by colebearanimals

4. 
   Tinkerer3 | Feb 04, 2008 06:31am | #8

   The gas company in our town uses a detector that is supposed to be able to find metal several below the ground's surface.  I've heard they also cost several thousand dollars.  That said, I have a neighbor has a Woodmizer band sawmill and says the company does not recommend a metal detector for their mill.  I'm not sure why.

5. 
   RickL | Feb 05, 2008 09:50pm | #9

   We use the Fisher 1212X in our reclaimed timber business before the wood goes to the bandmill.

   Kellyco is the best place to buy a detector

   http://www.kellycodetectors.com/fisher/fisher1200xseries-1212x.htm

   Then we use a Zircon metalliscanner to pin point the nails in boards. It has cross hairs to locate the nail exactly.