Best Metal Detector for Embedded Nails?
JohnSprung
| Posted in Power Tools and Machinery on
What’s the best thing for finding nails in old lumber? I have a bunch of 80 year old Doug fir 2×3’s, many had lath and plaster nailed to them for a long time. In some cases, the little lath nails break off below the surface. The problem is finding out which of the hundreds of black stained little holes have a 1/4″ fragment of steel deep inside. My hope is to turn some of this into acceptable paint grade stock for making some window sash.
Thanks —
— J.S.
Replies
John, my friend, you have come to the right place!
The metal finder shown below is made of a piece of scrap (poplar, I think) and 5 1" dia. x 1/4" high rare earth disc magnets, which I got at National Imports, which has the largest supply and variety I've seen - also great customer service and technical explanations if needed.
It was tough to make ;-) - Drilled a 1/4" x 1" hole with a forstner bit, epoxied the 1st magnet into the handle, and just let the other 4 magnets cling to each other like they were hangin' on for dear life! No additional adhesive. After I made it and showed it on another thread, someone suggested I submit it to one of the mags, so I cleaned it up by making the grip with a 1" Microplane chucked into the drill press, and gave it a once-over with some combo stain-poly coating.
In most hardwoods, it'll detect metal fragmants from broken nails down to a 1'2" deep. I just pass it back and forth like a wand over each face of my rough board, and if something's there, it tugs pretty noticeably.
Hope that helps,
Mitch
"I'm always humbled by how much I DON'T know..."
Edited 3/18/2005 10:41 pm ET by mvac
Must give that a try,though the handle could stump me:-)
We use a lot of recycled timber here in NZ and to buy a dedicated jobbie is $300nz($230us)Mind you,it is a very good one,you will have seen some bad ones.
Thought I would order the magnets from the place you mentioned.
$12 for magnets $55 shipping and that was by surface mail,the cheapest method.
Will have to rethink,bugger!
"$12 for magnets $55 shipping and that was by surface mail,the cheapest method."
Unbelievable! But I can't believe there isn't a local distributor of rare-earth magnets, and if not in the Land of Kiwis, certainly in Oz... I'd do a Google or whatever kind of search you use ad see what you come up with. Good luck,Mitch
"I'm always humbled by how much I DON'T know..."
There must be some sort of scientific equipment supplier that you can purchase magnets from closer to home. If you can't find anything, try contacting a science teacher to see where they get their supplies from. They might even have a catalogue.
(Doubt that Lee Valley has gotten down there yet. Too bad.)
Good Luck.
Thank you Wooden,on your advice,went to Lee Valley,they are on the way,transport $7 by air.
All I've got to say regarding the shipping cost is WOW!!!!
Glad it worked for you. I'm a big time Lee Valley fan. Been buying from them since they came out with their first catalogue in the 70's.
If you find a Kiwi source of rare earth magnets, can you let me know please? I also use a lot of recycled timber.
MalcolmNew Zealand | New Thinking
A New Zelander posted in the Lee Valley thread above - they get stuff from LV all the time...Give them a shot.Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
Will do.
Cooooool....
I will be whipping up one of these. I've got a Little Wizard but 2 look sees are better than one!
Not too worried about other metals as the old stuff I check has steel brads and nails. Bullets and shotgun pellets haven't hurt my blades. Think the lead is softer than the wood. Now let me hit a brad that I missed and you will hear me talk very ugly.....lol
Mitch that's one thing I love about WWers they came come up with simple solutions to hard problems all the time.
Jimmy
as always I wish you enough
What does a MRI scanner cost?
Lets see....take 4 of the magnet nail finders.....so they all go around the wood you want to ck.....put a usb connector on the end of one of the handles....wire them all together.....plug the usb in to your ole trusty pc.....whoa! ...we got us a MRI!!!!!!
Should be that easy and low cost.....
Jimmy
as always I wish you enough
Our 1.5 Tesla scanner ran about $1.5 million. Included setups and programming for reconstructions, high-speed, DICOM imaging & filing.IIRC, it's a Siemens.Leon Jester
At that rate, one could buy a new set of blades for everyone in this forum for life :-)Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
I'd try that gismo with the ceramic magnets.
I use two -- the wand type is good for weeping over a board. But a few years ago I bought a cheap Wizard, which is good for zeroing in on a particular site.
I bought the wand thing for about $200, but that was before they were commonly offered in wwing catalogs. I believe they are a lot cheaper now. The Wizard, as I recall, was something under $20.
The Wizard is more like $30- $40, the Little Wizard is under $20. I have a Little Wizard and it works well. Their customer service is really good, too. When I bought mine, I installed the batteries and promptly dropped in on my garage floor, breaking the tab on the battery cover. I called the company and asked if I could buy some extras, but he said he would just send them to me. When I go out today, I'll try it on some various non-ferrous metals and post the results.
"I cut this piece four times and it's still too short."
the "little" Wizard is what I was referring to. Thanks.
Highfigh,
"The Wizard is more like $30- $40, the Little Wizard is under $20. I have a Little Wizard and it works well. Their customer service is really good, too. When I bought mine, I installed the batteries and promptly dropped in on my garage floor, breaking the tab on the battery cover. I called the company and asked if I could buy some extras, but he said he would just send them to me. When I go out today, I'll try it on some various non-ferrous metals and post the results."
That's what I like about the shopmade metal-finder - no batteries, no special plastic housing or LED's to crack or fail - Its a piece of wood with 5 very powerful magnets and some glue. Sometimes the best solutions are the simplest - IMHO, this is one of those.
See ya,Mitch
"I'm always humbled by how much I DON'T know..."
Actually, I looked at a Woodcraft catalog this AM and the Wizard is $80. The problem with a metal detector with magnets is that it only works with ferrous metals. No aluminum, brass/bronze, copper, lead(bullets included), zinc, magnesium, etc.
"I cut this piece four times and it's still too short."
Neither does a scanner. I have a 3 1/2 inch piece of titanium in my left hand and the scanner will barely pick it up -- but it will detect the rebar in my shop floor from shoulder height which makes it hard to use.
Highfigh,
"The problem with a metal detector with magnets is that it only works with ferrous metals. No aluminum, brass/bronze, copper, lead(bullets included), zinc, magnesium, etc."
I've been thinking about this for a bit now, and I keep asking myself how often one would find non-ferrous metal in wood planks. While I'm sure it happens once in a blue moon, what you're almost certain to find in most found wood suitable for woodworking preparation are nails and nail fragments - all of which are ferrous.
I guess zinc screws would be something you'd find now and again, but that, like bullets (!) and other lead objects, is soft and much less likely to ruin a blade than cold, hard steel. I don't know enough about magnesium's properties to comment, but I come back to my original question - When metal is embedded in found wood, how often is it non-ferrous?
So I thought that you might work in an industry where that's more often the case - if so, please do tell. And please give me your thoughts on the likely frequency of finding non-ferrous materials in found wood. Finally, do you know if the Wizard, or any of its metal-finding competitors, find non-ferrous metals?
Best regards,Mitch
"I'm always humbled by how much I DON'T know..."
The main reason I mentioned those metals is that they're in the Wizard's description in the Woodcraft catalog I have. Copper nails are used in gutters and flashing, although if someone was using what they had, they can be in the wood. Personally, I don't care what kind of metal is in the wood, I just don't want to cut through it. I'm not a big fan of metal hitting my safety glasses and being imbedded(which has happened). If it's there, I want to be able to find it, and an active circuit metal detector will pick up the changes due to some non-ferrous metals, magnets won't. A saw blade will go through most of these metals without much damage, but a jointer or planer knife will be toast. I changed my planer knives a few months ago and when I was checking it out, I ran a piece of oak through there was a nail in it that I didn't see when I looked at the top and bottom. It had been pounded into the edge and bent as it went in. So much for my nice, new knives. After I did this, I went out and bought a metal detector.
"I cut this piece four times and it's still too short."
> I keep asking myself how often one would find non-ferrous metal in wood planks.
This being framing lumber from an 80 year old building, one thing that comes to mind is that in a jack stud there might be the end of a brass screw from a hinge or strike that was sawzalled off during demo. In planks from a roof there might be copper nails, which are used for copper or slate.
Thanks for the lead. I'll try the idea using one of their 1" cube magnets, which seem to be the strongest they have.
-- J.S.
John,
"This being framing lumber from an 80 year old building, one thing that comes to mind is that in a jack stud there might be the end of a brass screw from a hinge or strike that was sawzalled off during demo."
OK, I confess my ignorance - What's a "jack stud"?Mitch
"I'm always humbled by how much I DON'T know..."
A jack stud is a stud that doesn't run clear to the top plate. They are often used to support headers for a door frame or window frame.
Short studs used under a heavy window are also called jack studs in today's parlance. Cripple studs used to be the term of art, but it is not PC.
Regards,
Ken
"Do as you would be done by." C.S. Lewis
This may shock you but you can cut most non-ferrous metals with ordinary wood working tools. Copper/aluminium etc. cut just like butter and don't seem to dull even sensitive blades..
Certain stainless steel's will dull the blasdes but unless you happen to have access to xray machines with really large capacity I doubt you'll find stainless steel.
On the other hand stainless steel is extremely rare imbedded in wood..
> On the other hand stainless steel is extremely rare imbedded in wood..
Oy, veh. I used stainless for my fascia, and plan to use it for the exterior sheathing and window installation. Maybe some future reclaimer will be cursing me.... ;-)
-- J.S.
It's not a shock to me, I have done it with other metals, it's just not a good idea to cut metal with a blade that doesn't have a lot of teeth, unless the feed rate is very low. I just don't have fine toothed blades and don't need to cut a lot of metals. Actually, if I needed an X-ray machine that is big enough, a friend of mine worked for a company that made X-ray scanners for the food industry. I don't need anything that costs $100K to protect a $100 saw blade, though. I also don't want to cut anything that's too hard, to keep the carbide from chipping.
"I cut this piece four times and it's still too short."
We do recycled lumber and deal with that on a daily basis. We use the Fisher 12X available from http://www.Kellyco.com Good for finding the general nails and then use a Zircon, forget the exact model number but it lists for $200 but can be bought online for $150. It has cross hairs to pinpoint those tiny nails and we use the Shark nail puller to get them out. http://www.coastaltool.com The Fisher has a lifetime warranty as stuff get pretty rough handling here. We run the stuff through a moulder so the few hundred dollars is a good investment. The cheaper Zircon doesn't go as deep or is as accurate.
Edited 3/19/2005 3:55 pm ET by rick3ddd
Edited 3/19/2005 3:56 pm ET by rick3ddd
Lee Valley has rare earth magnets too...Mark
Measure it with a micrometer, mark it with chalk, cut it with an ax.
Thanks for the info. I'll try the zircon in additon to the magnet, belt and suspenders.
-- J.S.
John, I have a couple of needle pointed tools that I can probe nail holes - easy to feel metal if there is any - - - cheap - - - leather sewing needles might be readily availible and suitable for this purpose...
Thanks, Metod,
Sometimes simpler is best, but many of us seem to like adding complexity to solutions. I understand that, as I've been guilty of that once or twice myself. :-)
Regards,
Mitch
"I'm always humbled by how much I DON'T know..."
John, careful with those powerful magnets
Especially if you have a heart implant.
Or a non-nonmagnetic watch' Also keep it far away from tv ans computer screens Else you might have to De Guasse it. Stein
Not to mention credit cards
>>What's the best thing for finding nails in old lumber?
I find that my planer and jointer blades do a really good job of finding nails, if there are any around.
hundreds of black stained little holes..
Fire wood?
If you have a Saw Stop saw be careful as any metal can trigger the emergency stop destroying the blade and holder; 175 at least
Cutting into a bit of metal like a nail will not trigger the sawstop safety tech UNLESS you are in contact with the nail when it makes contact with the sawblade. The cartridge is triggered by the electricity in your body (insert super-techy language here) and will not trigger on "dead" metal.
If the nail is scraping along the sawtable and you are touching the table the tech can trigger by reading the user/table/nail/sawblade circuit.
I triggered mine through contact with some wet glue inside a frame and panel door with a metal panel insert. The glue was dry on the outside so I trimmed the horns off the door and BANG! I was touching the metal panel and the saw read me through the wet glue. Pretty impressive.
Just to be clear, the Saw Stop triggers when it senses something that it thinks is a human based on a conservative value the manufacturers chose. I have hit embedded staples, even a piece of razor knife in plywood without issue. I check my material but, have sawn my fair share of nail parts, no problem.
I did trigger when cutting some static dissipating UHMW (duh!) and once when I cut through some scrap that had an unseen (duh, again!) stick-on metal tape strip that I, of course, had against the table causing a dead short during the operation.
This forum post is now archived. Commenting has been disabled