The treasure detector type, not to keep the nails out of my planer.
Looked on Ebay, there must be a thousand types & prices.
Not looking to find the Hope Diamond, just recreational junk hunting.
Who knows what, & who has one in the attic for sale cheap?
Joe H
Replies
There are three or four basic types. The simplest type is just a single coil that detects metal as a change in coil inductance. It can only work effectively to a depth of 6 inches or so, and is much more sensitive to iron than copper, silver, etc. But it has an advantage that it's fairly precise in what it finds.
I think most of the other systems use two coils and are a bit more like radar. They can penetrate deeper and locate non-ferrous metals better, but aren't as precise.
Your choice is based on price, depth of object, size of object, type of metal, and how accurately you want to locate it. No all-around ideal choice, even if you take money out of the equation.
(I read an article about this maybe 30 years ago, so the details are a bit fuzzy.)
Harbor Freight has one called "Little Wizard" for about $16. Other hardware stores sell this, too. I got one because after swapping my planer knives, about the fourth board I ran through had a nail in it, which I saw with 6" remaining and couldn't stop the machine in time. It works pretty well and does double duty for me when I need to find metal studs in a wall.
I assume you want a metal detector to avoid cutting wood with nails, screws and bolts that will damage your equipment, right?
"I cut this piece four times and it's still too short."
Edited 2/7/2005 10:38 pm ET by highfigh