Solder Like A Pro
by Daniel Brooks
Image Credit joebeone
A guitar requires a little maintenance now and then, just like any other fine-tuned, high-performance piece of equipment. You probably learned how to do the essential, routine tasks when you first began learning how to play the instrument, and unless you are a working musician who wisely hires a guitar tech to keep your collection stage ready, you wouldn’t dream of paying anyone to restring, tune, clean, polish, or do basic bridge and pickup adjustments on your guitar. Of course, there are those repair jobs that require the expertise of a professional. Maybe you have the proper knowledge and experience to refret your guitar or perform some major reconstructive luthiery, but if not, it is worth the time and money to seek out a professional who does. It is certainly less than the price of replacing a once-playable guitar.
Most guitar repairs, however, are relatively simple electronics fixes that are well within the reach of any practical and intelligent do-it-yourselfer. The information concerning the designs and specific parts used for all but the most obscure guitars is readily available, and often presented in a simple format that doesn’t require you to know how to read a schematic. Most of these repairs require some basic soldering tools and the skills to use them. But it is certainly worth the nominal investment in some multi-use equipment that will, from now on, save you a whole lot of money whenever you replace switches, pots, capacitors and pickups. And who knows, maybe you’ll create some brilliant new wiring modification in the process.
The basic tools are simple:
Soldering Iron: A 25 to 40 watt soldering iron with a fine pointed tip. You can spend more than $100 on an industrial strength unit, but there are plenty of good ones, with stands, that will work perfectly on any guitar project for around $20.
Flux cored solder: $3 on up, depending on quantity.
Wire Cutters: $5-$20 You can also use these to trim the excess off of the end of your new strings.
Needle-Nosed Pliers: $5-$20.
Helping Hands: $5-$15. Essentially a clip attached to the end of a stable but movable arm anchored to a weighted base. Some feature lights or magnifying lenses, but all are designed to hold your work in place.
A Solder Sucker: $5-$15. The solder sucker looks and operates like a spring loaded syringe to remove melted solder from any old connection. Push the plunger down, put the tip on the hot solder and push the release button on the side, the vacuum created by the extending plunger arm will suck all melted solder away from the site. Desoldering braid performs the same function by using the capillary action of a braided metal wire to wick away the melted, liquefied solder.
Heat Shrink: $3-$5. Rubber tubing that permanently shrinks when heated to create form-fitted insulation.
You’ll also always want to have a clean wet sponge, in a bowl or a dish, and some cloth to cover and protect your guitar’s finish.
Good soldering technique is simple. Keep everything clean, tidy, and efficient. Plug in your soldering iron and give it a minute or two to come up to its working temperature. Common electrical solder is an alloy of tin and lead that melts at a temperature of at least 360 degrees Fahrenheit, or 182 degrees Celcius. Despite this high temperature, it is reasonably safe, since it is usually applied in such a small quantity that it cools very quickly, but it can still burn skin and damage the finish on your guitar, so be careful. Then, just follow these steps for each solder joint.
Step 1) Prepare the joint. Use the soldering iron and the solder sucker to clean any old solder off of the potentiometer lug, or the back of the pot. Strip and tin the end of the wire. Remove any excess solder and let it cool.
Step 2) Depending what kind of connection you are soldering, either fit the stripped, tinned wire through the potentiometer lug far enough to bend it back over itself, or position it onto the back of the pot, using the helping hands to hold the wire in place. If you are soldering two wires together, strip and tin the ends of both wires and fit an inch-long piece of heat shrink over one of the two wires before you solder them together.
Step 3) Tin the tip of your soldering iron. Melt a small bead of solder onto the tip of the hot iron. When the entire working part is covered with a thin layer of solder, use the wet sponge to wipe off the excess, leaving a clean shiny surface. Heated solder creates a byproduct called dross, which limits the conduction of heat and introduces impurities into your solder joints. It forms fairly rapidly, so do this as often as needed to keep the tip shiny and clean. It takes half a second to do and insures good electrical connections.
Step 4) Heat the joint and feed it some solder. As soon as the tip is clean, touch it to the joint you wish to solder. It is important to understand you are heating the components you wish to join together and not just melting solder. If the joint is properly heated the solder will wick into the wire and melt onto the lug or the surface of the pot.
Step 5) Remove the heat. As soon as the solder has “glued “ the two parts together, take the soldering iron away and let the joint cool while making sure the components remain motionless. Not only do you want to avoid creating dross in your solder joint, you also want to avoid any unnecessary risk of heat damage to your components.
Step 6) Heat Shrink. If you have soldered two wire ends together, let the joint cool, then slide the heat shrink over the joint and heat, briefly, with a lighter.
Step 7) Check your work. Before you put your guitar back together, plug it in and tap the pickup. Does the pickup you just installed make a sound? Does the volume or tone control you just soldered together work as designed? If not, figure out why and fix it now before you put it all back together, and then have to take it all back apart to get to where you are right now. If it does work, put it all back together and play on, with a little pride in your smile and a few extra bucks in your pocket.