451. Who are some of the magnet suppliers?
I often get called and asked where do you get your magnets. Well, I use various venders for many types of magnets that we use. To find a magnet supplier or fabricator it is best to look a source book called “The Thomas Register” and you can find them usually in libraries. In the books you will find a great source of many products and supplies. Look for a supplier of magnets in your area and you can usually visit them or get samples. There are less and less mills that manufacture the actual rod and bar magnet and you can find fabricators that will cut and grind a magnet to your specification.
452. Why are bar magnets used?
Bar magnets are usually used for humbucking pickups and it eliminates 6 separate poles. Bar magnets have always been used for Gibson style pickups and occasionally Gibson used rod magnets in some of their pickup/pickguard assemblies and P-90 style single coil pickups. Bar magnets have been used in many of Seymour Duncan pickups and have been used in Gibson Melody Maker, Firebird, Thunderbird Bass and several other models as pole pieces rather than adjustable screw pole pieces.
453. Why are older Fender magnets chamfered on one of the ends?
Basically the magnets are chamfered on one end to allow the magnet to be pressed into the flatwork without tearing or cutting material away from the inside wall of the punched flatwork. If the magnets are inserted without a chamfer, the magnet can tear away enough material that the flatwork is loose and the ends of the top flatwork can lift or the bobbin can widen at the ends.
454. Why do old Fender magnets have dark rough pits as compared to the new magnets?
The pits are formed into the rod and bar magnets when the molten magnet material is poured into sand cavities and the pits are from the actual sand mold. The older magnets had a larger diameter and the magnets were molded close to tolerance and cut to the desired length. The newer magnets are center-less ground to .187” diameter as compared to the older .197” diameter.
455. Why do some pickups have two, three or more magnets?
Having many magnets will increase the output of a pickup if properly used. The increased magnetic field will also make the output louder, brighter and also dampen string vibration if the pickup is adjusted close to the strings. The increased magnetic field to the strings can make the tone loud and distorted even at lower volumes.
456. Why do some pole pieces have stronger magnetic strength and others have weaker poles?
The strength of a magnetic field depends on several factors. The grade of material and quality, how it is magnetized and type of magnetizer used, outside elements that can demagnetize or how random the magnetic domains are within the magnets. The magnetic path to the strings and through the coil. Alnico rod magnets used in Fender style pickups can become weaker with time, being close to alternating currents, high temperatures when grinding and striking with a ferrous object.
457. Will rust on the magnets effect the pickup?
Rust on magnets can eventually cause the insulation on the magnet wire to break down and cause the exposed copper wire to oxidize and break. I call this ICPC for Inner Coil Pole Corrosion. It is caused by humidity, sweat from playing and not wiping the guitar down before it is put in the case and the moisture is trapped inside the guitar case. Prolonged exposure to this moisture can rust the pole pieces and cause extreme damage to the pickup. Typically single coil pickups with fibre bobbins have the biggest problem with ICPC. Moisture can be absorbed into the flatwork and sweat can soak down inside the bobbins causing the eventual rusting of the magnet rod pole pieces.
458. Will steel wool effect the pickup?
I would never use steel wool around pickups. Small bits of the steel wool can cling to all areas of the pickups including the strings, pole pieces, inside the bobbin and anywhere you have magnetic field to attract the small filings. If any repairman work on any type of guitar with pickups, please remove the pickups or assembly. I’ve seen steel wool inside the cavities of the instrument and stuck all over the place. I often have to completely de-magnetize the magnet or magnets to remove the steel wool. You can use a fine brush or masking tape to remove the steel wool but it can become a mess. I’ve even seen it inside the volume and tone controls. If a repairman uses steel wool on his work bench and puts a pickup or assembly on it, the pickups will be full of unwanted steel wool. It can even vibrate and cause feedback as the loose material can vibrate when you play. Please just stay away from it.
459. How can you remove in the insulation on the magnet wire for better soldering?
You can use a chemical stripper for magnet wire insulation’s but they can be very messy and caustic. You could use a high temperature soldering iron but that can also melt or break the magnet wire. I prefer using fine 600 grit sandpaper to physically strip the insulation. I carefully stroke the fine magnet wire with the folded sandpaper and gently remove the insulation.
460. How do you remove the insulation on humbucking pickups?
As mentioned in question # 196, I used a fine 600 grit sandpaper and carefully remove the insulation. I then use tweezers to wrap the bare magnet wire around the stranded 29 gauge hookup wire. I carefully hold the 700 degree soldering iron tip on the connection and flow a small amount of rosin core solder. Do not use acid core solder that’s used for plumbing connections because it will eventually eat away at the magnet wire.
461. How is magnet wire made?
Magnet wire starts out in the manufacturing mill as a ingot usually 4 inches square and drawn through many stages using a series of dies that reduce the diameter of the 99.9% pure copper till the desired wire gauge is obtained. The mills have pretty unique equipment for making many types of magnet wire. The wire can be round, square, flat, bi-stranded, tri-stranded etc., and many insulation can be used for the desired temperature range and color. This is a very basic description of how the fine gauges of magnet wire are made and the equipment and procedures can get highly technical.
462. I had an old "Mighty Mite" single coil that was damaged and the coil was very hard to remove, how come?
Mighty Mite pickups were made at a Southern California company called Turbo-Jet and the bobbins were wound using a bondable wire. After the bobbins were wound, the coils were heated in ovens and the special insulation would bond to each other making a solid coil. The coils were difficult to remove if the bobbin needed rewinding or turns needed to be removed. There are other bondable wire’s that are activated by chemicals but can get very messy when working with them. I prefer a hot wax solution used with a vacuum to draw the air bubbles out and this allows the pickup to be repaired easier and potting with epoxy also makes the pickup almost impossible to repair.
463. My single coil Fender pickup didn't work after I took it out of the guitar. The coil reads before the eyelet’s but not at hookup wire?
On earlier Fender pickups the beginning and finish magnet wire from the coil is often wrapped through the evelet several times before soldering the eyelet. At times the hot solder doesn’t heat the insulation enough to make a solid contact with the hookup wires and eyelet. It is often called a cold solder joint and if the strands of magnet wire that are wrapped around the edge are broken, the pickup can become inoperative. Usually heating the eyelet’s and applying a small amount of new solder will usually do the trick. I can measure pickups using an Xacto blade connected to each end of my multi-meter probe and by carefully scraping the insulation off the magnet wire and exposing the bare copper wire to be tested, I can determine if the coil is good or bad.
464. The magnet wire is broken before the eyelet, can this be fixed?
Fender single coil pickups:
A. If the beginning magnet wire is still extended from the beginning of the coil you can splice an extension by carefully soldering a new chemically stripped magnet wire to the existing piece.
B. If the beginning magnet wire is not extended from the beginning of the coil, then connecting a new beginning wire will be difficult or impossible.
C. If the finish magnet wire is broken before the eyelet, then it’s possible to unwrap a turn to give enough length to wrap through the clean eyelet and resolder.
D. If the finish magnet wire is not available and is broken somewhere in the outer part of the coil, than again you need to use a fine tooth brush to gently unwrap the outer turns to find the break. At times, single coil pickups need to have the wax removed as it’s hard and difficult to remove turns without breaking the wire again.
465. The magnet wire is missing from the beginning/finish of the coils. can this be fixed?
I would read through question # 201 for some basic information. It’s really difficult to impossible to repair Fender style pickups when the beginning wire is broken off at the beginning of the coil.
A. You need to have a qualified repairman attempt to do this kind of work and often ends up to having the coil rewound and at times unnecessary. At times the beginning hookup wires are pulled out of humbucking pickups or the pickups stop working because of cold solder joints.
B. On older humbucking (Patent Applied For) models the beginning hookup wire extended from the square hole on the bottom of the molded bobbin. If the beginning wire gets pulled out, the coil will have to be unwound. After removing the magnet wire and reconnecting the beginning wire the coil can be rewound using the same wire.
C. If the outer wire in the humbucking pickup gets broken or pulled out, it is easy to remove the insulation tape and resolder the beginning hookup wire. It may be necessary to remove a turn or two but this will not effect the tone of the pickup.
D. On later model humbucking pickups the beginning wire is connected to the hookup wire after the bobbin is wound. The broken beginning wire can be fixed if you have enough beginning magnet wire to connect to, if not then the coil will have to be unwound.
466. What are other types of magnet wire?
Magnet wire commonly used in guitar pickups is made from 99.9% pure copper and drawn to the desired diameter and annealed to make softer. There are many custom shapes available and magnet wire can be half sizes, bondable and can be made to be 2-20 conductor, parallel bonded and color coded. Specialty magnet wire can be made from Aluminum, Silver and very expensive Gold and Platinum magnet wire. Using Gold or Platinum would be way too expensive to used for guitar pickups and also the DC resistance would change.
Here are some specification on various materials used for magnet wire.
Material Ohms per circular mil/ft.
Copper 10.3
Aluminum 15.97
Gold 14.14
Silver 9.56
Platinum 63.82
Titanium 252.00
Tungsten 33.22
467. What are other types of wire insulation’s?
Magnet wire:
There are many types of insulation’s used and many companies have their own brand name and insulation types. Some of the most common and thermal rating.
Plain enamel 105?C
Polyurethane 105?C
Polyurethane Bond 105?C
Formvar 105?C
Formvar Bond 105?C
Poly-Nylon 105?C
Polyurethane-Nylon 130?C
Poly H.T. 130?C
Polyester 130?C
Polyester Epoxy 130?C
Polyester Isomid 180?C
Polyester Nylon 180?C
Armored Polyester Teflon 200?C
Hookup wire:
Typical hookup wire is Teflon, PVC and cloth braid. Using Teflon wire is the best for higher temperatures and soldering close to the ends without having it shrink or pull back. PVC wire works well but again is not good for higher temperatures and shrinking or pull back is common with this type of wire. Cloth braid is a great hookup wire and works great under heat and looks great when used properly.
468. What are the specs on magnet wire?
A typical magnet wire chart includes the following as a reference and guidelines for designs and applications:
Diameter: Bare wire diameter is Minimal, Nominal and Maximum.
Single Build Insulation: Minimum increase in film diameter.
Overall Diameter in Insulation: Minimal, Nominal and Maximum.
Nominal Ohms per 1000 feet at 20?C
Nominal Ohms per pound at 20?C
Pounds per 1000 feet.
Feet per pound.
Heavy Build Insulation is usually double build and other applications use triple build etc.
469. What is bondable wire?
A bondable wire can be a single or combination of magnet wires that when thermally or chemically treated bond together making a coil a solid component. When bondable wires are used for guitar pickups, it makes it very difficult to repair or rewind. Bondable wires are used in transformers and other electrical components where a rigid coil is necessary.
470. What are insulation’s used in guitar pickups?
An insulation is a material that keeps conductors isolated from each other such as plain enamel or formvar on magnet wire to keep the turns from shorting out, or rubber insulation on extension cords to keep the electricity from shorting out with each other. Insulation can be copper shielding in an instrument to help keep unwanted electrical interference from causing problems in your instrument and all insulators have dielectric properties or any medium through or across which electric induction takes place between two conductors.
471. What is the chemical "strip X" used for?
It is a popular chemical stripper that can remove the insulation on magnet wires instead of applying high heat that could anneal or fatigue the copper conductor. Chemical strippers can be messy and takes longer time to strip and clean the wire than my old fashioned mechanical stripping using 600 grit sandpaper. Sandpaper is less messy and faster to do. I first saw Gibson doing this back in 1968 when I visited their factory in Kalamazoo, Michigan now the home of Heritage Guitars.
472. What is the magnet wire gauge (AWG)?
AWG stands for The American Wire Gauge, which is the standard in the United States for measuring various gauges of wire. Magnet wire is not the only wire that is gauged and many other countries have adapted their own way of testing and measurements. The majority of time I use measurements in the American Wire Gauge and often convert my data to millimeters because of a few winding machines I use made in Europe. The pitch controls on winding machines determine how fast the automatic traverse will travel from right to left and back. The pitch controls the number of turns per layer and the American Wire Gauge is important because it will give you data on the dimensions and physical resistance per given length. The American Wire Gauge specifications help when trying to determine the number of turns needed for a given area and the DC resistance requirements for a given coil.
473. What magnet wire gauge is used on popular pickups?
Probably the most used gauge of magnet wire is 42 AWG with plain enamel, formvar or polyurethane insulation’s. 43 and 44 gauges are often used by the various pickup builders and they come in a variety of colors. It’s important to find a quality supplier as the magnet wire can be hardened or annealed and both play an important factor on the winding quality of the coil. Wire that is too hard cannot wind tightly around the bobbin and wire that is too soft can stretch, changing the diameter of the material and affects the DC resistance from coil to coil.
474. What types of insulation’s are used on magnet wire?
Pickup coils never get hot and the thermal rating is helpful when soldering hook up wires to the magnet wire or eyelet’s. Standard insulation’s are in the 105?C area and are usually the most economical.
475. Who are some of the magnet wire suppliers?
The best way to find suppliers is go to your local library and ask to look at a source book called “The Thomas Register”. There you will find a source of all kinds of suppliers and materials. I find it interesting just looking through the volumes of information and supplies the books contain.
