Introduction: Re-Magnetize a Tool
This is a magnetic grabber. Its magnet has lost most of its strength so that it will hardly pick up a screw without the screw shaking off of the magnet.
This Instructable will show how to make the magnet stronger while maintaining the original magnetic polarity.
- Small gauge insulated wire
- Electrical tape
- Round shank screwdriver
- Magnetic compass
- Old flashlight batteries
- Wire cutter
Step 1: Wind a Coil
The magnet is in the smooth end of the grabber. I want to wind a coil of small gauge insulated wire around the smooth end. The wire is plastic coated, but enameled wire would work as well. I wound a coil almost the full length of the smooth end, although less would have been fine, since the magnet is surely shorter than the smooth end. I did not count the turns of wire, but wound three layers.
Step 2: Check Magnetic Polarity
I want to strengthen what magnetism remains in the magnet. I do not want to reverse its polarity so that I must take it down to zero and then build it up in the reverse polarity.
I am using a magnetic compass to determine the polarity of the magnet in the grabber. I turned the compass so it is not on the earth's North - South axis and brought the magnet near to the compass. The indicator swung so that the magnet attracted the South pole of the magnet in the compass.
Step 3: Determine the Electrical Polarity Needed
I taped my coil of wire so it would not unravel. It is wound loosely enough that I was able to slip it off of the grabber and onto a screwdriver with a slightly smaller diameter.
I energized the coil with an old flashlight battery. One lead on my coil is shorter than the other and I found if I connect the shorter lead to the positive (+) tip of the battery, the screwdriver temporarily becomes a magnet that attracts the South pole of the magnet in the compass. Now I know how to connect the batteries to strengthen the magnet in the grabber.
Step 4: Magnetize
I slipped the coil off of the screwdriver and back onto the end of the grabber so the shorter lead is nearer to the forward end as on the screwdriver in the last step. I used two old flashlight batteries to energize the coil, and I held the leads from the coil by hand for a couple of minutes. I could actually feel some warmth at the negative (-) connection held by my thumb.
3 volts was enough to do what I needed. If I had connected the coil to a car battery, the results would have been faster to achieve, but I may have melted the insulation on my coil, too.
I stopped to check the strength of the magnetism in the grabber. When it seemed strong enough to do what I want to do, I disconnected the batteries and removed the coil.
Step 5: Test
I am holding the magnetized end of the grabber so the photo will be more understandable. Of course, I would normally hold the other end when retrieving a screw from some recess into which it had fallen.
My newly re-magnetized grabber can now lift a 3 inch lag screw 5/16 inch in diameter. That is far better than it could do before.