Photo 1
String nut touch-up.
Super glue is handy for making small repairs to a guitar’s finish. Here’s an example: Most guitars have a little finish at either end of the string nut to create a smooth transition between the edge of the fretboard or binding and the nut itself. But after replacing the string nut—let’s say you’ve upgraded from a plastic nut to one made of bone—there’s usually a small edge or drop off where the nut meets the fretboard (Photo 1). As you may recall from our prior column, super glue is available in a variety of thicknesses. To smooth out the transition between the nut and where it joins the fretboard, you can fill that area using a few drops of medium viscosity or gel-formula super glue.
Make sure the area around the edge of the string nut and binding is absolutely level, because you don’t want the glue to pool on one side of the nut edge and create more work for you later.
But wait, there’s more! It’s common for the binding on older guitars to turn yellow over time. Stewart-MacDonald sells an amber-tinted formula that matches this aged look nicely. (Stew-Mac also offers tinted super glues in white and black, which can come in handy for other finish touch-up projects.) If your guitar has binding, using tinted medium super glue will accomplish two goals: You’ll fill the edges around the ends of the replacement nut and help it blend in with the binding.
Assume the position.
First, place the guitar on its side so the neck is horizontal to the workbench and one end of the nut faces up, the other down. To prevent an electric guitar or bass from tipping over, I use a quick release clamp on the body to stabilize it. Because acoustics have a thicker body, they’ll typically stay in place without a clamp. Balance the guitar on its tuner keys, not the neck, and use books or small boxes to support the guitar as it rests on it side. (In our shop, we use leather bags filled with buckshot for this and other stabilizing tasks.)
Make sure the area around the edge of the string nut and binding is absolutely level, because you don’t want the glue to pool on one side of the nut edge and create more work for you later. A bubble gauge comes in handy here.
Apply the glue.
Photo 2
This is where you don your safety glasses. Once the guitar is stable, put a few drops of super glue on the end of the nut and let it dry (Photo 2). You only need to apply enough glue to cover the side of the nut and binding to build a smooth surface where they join together. A medium formula of glue, which is what we recommend, will take several minutes to dry. If you want to speed up the drying process, you can spray super glue accelerant on it. We’ve used GluBoost and NCF Quick brands in our shop, and they both work great.
Having a well-ventilated workspace will reduce accelerant fumes and minimize eye irritation. At the shop, we run a small fan to keep the air circulating when using super glues and accelerants.
Tip: Accelerants can cause what we call the “Swiss cheese effect.” This happens when you prematurely spray the accelerant on the glue. It causes a chemical reaction that results in the glue bubbling up into a white foam, which forces you to scrape away all the glue and start over. To avoid this, wait several minutes before blasting the glue with an accelerator. A little patience will save you a lot of time.
File it down.
Photo 3
When the glue is dry, use a miniature file to gently file away any excess (Photo 3). Do this carefully to avoid damaging the original finish around the nut and binding. The object of the exercise is to file the glue flush with the nut and binding without disturbing the surrounding surfaces.
Sand and buff.
Photo 4
Next, lightly sand the glue-covered area with 600 grit paper to feather it to the edge of the fretboard or binding (Photo 4). Now gently sand it with 1500 grit paper to smooth out any scratch marks.
Photo 5
Finish this job using extra-fine buffing compound and a polishing cloth (Photo 5). I use Planet Waves Restore for this last stage, but you can find other buffing compounds at auto stores or online.
Photo 6
Now step back and admire your work, which should look similar to Photo 6.
After flipping the guitar over on its opposite side, position and secure it (remember to keep the neck perfectly level), and then repeat the process for the other end of the nut.
And that’s it—another task completed, thanks to super glue.
[Updated 1/20/22]
Photo 1 — The essentials: a low-watt soldering iron, a stand, a small damp sponge, and a roll of “electronic silver solder” like this .020" 60/40 tin/lead rosin flux solder from Kester.
The tools.
You’ll want a decent soldering pencil (a small type of soldering iron) rated at least 25 watts, but no more than 60 watts. (Many guitar techs like a 30-watt soldering iron for working on guitars and amps, and a 15-watt iron for working inside stompboxes and on delicate printed circuit boards.) You’ll also want a stand to hold the hot iron when not in use, a damp sponge, and some rosin core solder made for electronic work (Photo 1).
Photo 2 — If your soldering stand doesn’t house a sponge, just put a damp household sponge in a glass or ceramic dish. Other helpful tools: a hemostat and small clamps to hold parts still as you solder them, and a “solder sucker” bulb for removing solder.
You should also have some basic hand tools, such as wire strippers, needle-nose pliers, wire cutters, and something to hold the wire in place while a solder joint cools (Photos 2 and 3).
Photo 3 — In addition to hook-up wire, you’ll want wire strippers. Alternatively, luthier suppliers offer old-school “push-back” wire with a waxed cotton jacket (center) that eliminates the need for stripping off the plastic insulation from the end of the wire. Electrical tape and heat shrink tubing come in handy when you need to protect or insulate your work.
There are tools sold specifically for holding wires and parts, available through an electronics supply house.
Step 1: Prepare the Joint
Photo 4 — Before you attempt to solder a connection, the wire and component must be secured to assure they remain absolutely motionless. Here, a spring-loaded heat-sink clamp holds the wire in place while a vice grip gently clamps the pot shaft.
For every joint, you need to find a way to hold the wire in position without using your hands (Photo 4). Wrap the wire through the solder lug once to make it hold tightly on its own, use tape to hold it in place, lay a pair of pliers on the wire to hold it firmly where you want it, or use a mechanical soldering aid to hold it. Use whatever works, except holding the wire manually. When you make a solder connection and rely on your hands to hold the soldered wire steady while the joint cools, you will fail—no human hands are steady enough to hold anything perfectly still, and you want the wire to remain absolutely motionless while it cools. If there is movement, the result will be internal fractures in the solder.
Step 2: Clean the Tip
Photo 5 — Wipe the hot tip with a damp sponge to keep it clean.
The tip must be cleaned before each and every joint—you can use the damp sponge for this (Photos 5 and 6).
Photo 6 — A clean, dross-free tip looks smooth and shiny.
Solder produces a by-product called dross very, very quickly, and the dross fouls the tip, preventing good heat conduction and introducing waste material into your solder joints.
Step 3: Tin the Tip
Photo 7 — Add a small amount of solder to a freshly cleaned tip just before you solder a connection. When you see this telltale puff of smoke, pull the strand of solder off the tip, shake off any excess, and then move quickly to the joint.
Immediately before you get on the joint with the heat, add fresh solder to the tip of the iron to “tin” it. Simply feed solder directly onto the tip so it’s completely coated (Photo 7). A tinned tip will provide much better heat conduction than a tip that’s clean but not tinned.
Step 4: Remove the Excess Solder
Shake off the excess solder after tinning—you want the tip coated, but not dripping. I have a fire-resistant container beside my soldering bench, and after tinning I tap the barrel of my iron on the edge of the container to knock excess molten solder into it. You can use any fire-resistant container for this, such as a tin can or ceramic bowl, but use care not to start a fire. Because solder melts at such a low temperature the risk of a fire is very low—molten solder is unlikely to ignite even highly flammable materials like paper—but use care anyway!
Step 5: Get on the Joint Right Away
As soon as you’ve removed the excess solder from the tip, get right on the joint. By “joint,” I mean the wire and the solder lug, or the wire and the back of the pot, or whatever it is you’re soldering. Dross will start to form on the tip very quickly, so as soon as the tip is prepared, get to work.
Step 6: Heat the Joint
Photo 8 — Gently press the iron’s hot tip against the joint to heat it before you bring the solder into the equation. The goal is to make the joint itself hot enough to melt the solder.
Heat the joint, not the solder (Photo 8). You want the joint to be hot enough to melt the solder. It’s a given that the iron is hot enough to melt it—just feed a little onto the tip and you’ll see—but you also want the joint itself to be hot enough to do the same.
Photo 9 — While holding the tip against the joint, feed the solder onto the heated joint, not the soldering iron tip. Here the emerging puff of smoke indicates the solder is melting.
If you feed solder onto the joint without it touching the iron (Photo 9), the solder will melt and be attracted right to the joint. You can watch the solder actually wick out onto the surface you’re soldering to—this is what you want.
Step 7: Get off the Joint
As soon as the solder has flowed onto the joint properly, remove the heat from the joint. Most components can stand a fair amount of heat, but some are more susceptible to damage than others, so there’s no need to push your luck. Pots are fairly durable (unless it’s a cheap pot), so it’s highly unlikely you’ll damage one by trying to solder a wire to its back. But again, there’s no need to push your luck, so as soon as you’ve completed the joint, pull the iron away and let the joint cool with the components remaining motionless.
Photo 10 — When the molten solder has flowed into the joint, pull away both the solder and iron. Keep the joint motionless as it cools and don’t blow on it—the moisture in your breath will enter the cooling connection and potentially cause it to fail.
If you’re soldering to a ring-shaped solder lug, then you’ll want to fill it completely with solder (Photo 10). This will maximize the mechanical strength of the joint.
Like most skills, soldering proficiency is acquired through practice. Employing good technique will allow you to become competent all the more quickly, so follow these steps, and you’ll be soldering like a pro in no time. You should probably practice on projects that aren’t expensive or mission critical—you might want to think twice about rewiring your only guitar before that gig with Clapton tonight. But if you keep at it, you’ll be one step closer to being a consummate DIY’er.
Two Ways to Improve Your Soldering Projects
After you master the basics, there are two more skills to add to your bag of tricks: removing old solder and installing heat shrink tubing. There are plenty of occasions where you’ll wish you could remove old solder and re-use a part. For example, you might have rescued a volume or tone pot from a previous mod or project. If it’s a high-quality pot, like those from CTS, why toss it and buy a new replacement when you can put the old one back into service? It’s easy to reverse the soldering process and remove old solder and bits of wire. You simply need a solder removal tool. There are several types, including disposable braided wire that’s designed to wick molten solder away from a joint, and various vacuum pump tools and “solder suckers.” I prefer a simple rubber bulb with a heat-resistant Teflon tip.
Photo 11
Here’s how it works: Stabilize your component, in this case, a pot (Photo 11). See how one lug is filled with solder? Let’s make that go bye-bye. Apply heat to the lug with a freshly cleaned soldering-iron tip.
Photo 12
When you see the solder turn shiny and molten, hold the bulb away from the lug, squeeze and hold the bulb, and then bring its tip to the lug and release the bulb. Fffffft! The molten solder goes up the tip and into the bulb (Photo 12).
Photo 13
Look at that—a nice clean lug ready for its next mission (Photo 13).
Tip:It’s good to recycle pots and parts, but never try to reuse old solder. Clean it off and start fresh.
In case you’re wondering what happens to the old solder, every few months you simply work the tip out of the bulb, shake the collected cold solder beads into the trash, and reinsert the tip into the bulb. Good to go.
When you’re working with wire and electronics, you’ll often encounter instances where you need to insulate a connection from other wires or components. For example, you want to install a favorite old pickup into another guitar. However, the pickup leads have been cut back over the years and now they won’t reach the intended switch or pot, which means it’s time to splice short extensions to the pickup leads. No problem, except if the exposed wires touch each other or other components, they’ll create a short and you’ll hear only silence (or an annoying hum).
Electrical tape will do the job to insulate the splices, but heat shrink tubing—aka heat shrink—offers a more elegant solution. To make this work, you’ll need a heat source. Some folks use a lighter, but I prefer a heat gun because I like to avoid open flame in my workshop. Heat guns aren’t expensive and they get the job done efficiently and safely.
Photo 14
The details: Designed to slide over wire of different gauges, heat shrink comes in various diameters. After you select the right diameter to comfortably slip over your wire, cut off a piece that will straddle the solder splice or joint you plan to cover. The pros suggest a length that’s about three times as long as the exposed section. Use hemostats or a clamp to temporarily hold the ends together while you gauge the length you’ll need to cut (Photo 14).
Photo 15
Next, remove the clamp, slide the heat shrink over one end of the wire (keep it far away from your hot iron) and solder the wires. When the solder has cooled, slip the heat shrink over the new joint, center it, and fire up the heat gun. The tubing will start to immediately contract around the joint (Photo 15). Don’t worry, air from the heat gun doesn’t get hot enough to compromise the solder joint. Once the tubing has completely closed up around the wire, you’re done. The joint now has a tough, new skin to protect it. —Andy Ellis
[Updated 1/13/22]
Fig. 1. Changes in temperature and humidity can cause checking in traditional nitrocellulose lacquer finishes.
Over time, sweat, dirt, and oils build up on the guitar's finish and slowly break it down. This causes the finish to develop a hazy film and become discolored. In addition, if your sweat has a high acid content (low PH balance), it can actually cause the finish to deteriorate, especially where you rest your arm. Sweat contains water, acids, salt, and several minerals that are corrosive to finishes and hardware. When you add in environmental issues, such as dust and pollen, it's no wonder our guitars get so filthy.
A little background. There are many different types of finishes used on stringed instruments. Vintage instruments typically sport nitrocellulose lacquer—a thin, hard finish that lets the wood resonate well. But nitro is also prone to checking and cracking over time (Fig. 1), especially when the instrument is exposed to sudden temperature and humidity changes. To combat this, many modern guitar builders and manufacturers cover their instruments with finishes that are more impervious to environmental conditions. These include urethane, acrylic, polyester, and epoxy formulations. In some cases, the switch from nitro is a way to save production costs, but builders can also be motivated by a desire to spray materials that are less harmful to the planet and workers. For example, in recent years there has been a trend toward UV-cured and water-based finishes, both of which reduce chemicals released into the atmosphere during production.
Fig. 2. A gloss finish (left) looks shiny and usually feels smooth and glass-like to the touch. Fig. 3. A satin finish (right) has a softer, less reflective sheen, allowing you to often feel the wood grain.
Modern finishes come in two styles: gloss and satin. Gloss finishes are shiny and have a glass-like look (Fig. 2), while satin finishes have a softer, hazy sheen (Fig. 3) and sometimes can actually feel "unfinished."
Cleaners and polishes. No matter what kind of finish is on your instrument, it's a good idea to keep it clean to prolong its life. There are hundreds of products on the market that claim to be the best for cleaning and polishing an instrument. The truth is many of them will cause the finish to slowly deteriorate. These cleaners contain petroleum products and solvents that can damage a nitrocellulose finish, and some polishes contain abrasives that will remove a vintage instrument's natural patina. The best guitar care products won't leave behind residue and do not contain solvents or petroleum products.
There's a debate about whether polishing a guitar is more harmful than helpful. When you polish a guitar, it creates a seal or coating that's intended to protect the finish. However, I've found that the outcome is more cosmetic than functional, and many finishes don't benefit from waxing or polishing. Polishes and waxes build up over time and can eventually dampen the sound of your guitar—almost like wrapping it in a bed sheet.
But that's not all: If your guitar has finish checking, polish will build up in the hairline cracks, and this can discolor the wood underneath or even cause the finish to flake off. Based on experience, I believe cleaning your guitar is more beneficial than polishing or waxing it. Polishing will make your guitar look better, but really doesn't benefit the finish other than making it shiny. If you feel compelled to polish your instrument, look for products that contain pure carnauba wax—it's the safest for your guitar.
Fig. 4. Professor Green's Instrument Polish (left) is a water-based "guitar soap" that cleans effectively and leaves no residue. Fig. 5. Planet Waves Hydrate (center) is formulated to condition and clean unfinished fretboards. Fig. 6. Naphtha (right)—the main ingredient in lighter fluid—is safe and effective for cleaning most finishes and hardware. However, it's toxic and flammable, so you must carefully follow the manufacturer's directions.
Three products I've found to be both safe and effective for cleaning a guitar's finish are Professor Green's Instrument Polish (Fig. 4), Planet Waves Hydrate (Fig. 5), and naphtha (Fig. 6). Though each is radically different, they can all be used with a damp cloth.
Here's the breakdown: Professor Green's Instrument Polish is a natural, water-based liquid cleaner with no harsh chemicals. I'd classify it as "guitar soap" rather than a modern polish. It does an excellent job cleaning dirt, oil, sweat, and oxidation. Being water based, it's very easy to clean up without leaving any residue.
Planet Waves Hydrate fretboard conditioner is a paraffinic hydrocarbon-based liquid. Effective for removing dirt and oils from most any finish and unfinished fretboards, it's non-toxic and non-flammable.
Which is not the case for naphtha—essentially lighter fluid. It is a gentle and high-flash solvent that's safe for most finishes. (Naphtha-saturated Q-tips do a great job cleaning rusty saddles and bridge hardware.) However, naphtha fumes and liquid are toxic to humans, so if you use it, I recommend wearing a mask and gloves. It's highly flammable, so avoid open flames!
No matter what brand or type of cleaner you choose, always avoid those that contain silicone, heavy waxes, lacquer thinner, bleach, etc. Household furniture polish and all-purpose cleaners—such as Pine Sol, Windex, and 409—will also damage your finish. The only household product that's safe to use to clean your guitar is white distilled vinegar. It will clean the finish, but do you really want a guitar that smells like a pickle?
Fig. 7. A damp paper towel (left) or microfiber cloth works well to clean a guitar's finish. Fig. 8. Use a Q-tip (right) to clean hard-to-reach nooks and crannies.
Cleaning the finish. When cleaning your guitar, I recommend using a damp paper towel or microfiber cloth. Spray or dab a little cleaner on the towel and gently wipe away the dirt (Fig. 7). Avoid saturating your guitar with water. It's okay to use a lightly damp cloth, but don't waterlog it. Use a Q-tip for those hard-to-reach areas (Fig. 8). Once the guitar is clean, go over it once more with a clean, damp cloth. That's it—quick and simple.
Polishing a gloss finish. If there are a lot of light scratches and swirl marks in a gloss finish, you need to decide if it's worth buffing them out. This really depends on how old the guitar is and what type of finish it has. If it's a fairly new guitar, it's okay to use a gentle buffing compound, such as Meguiar's M85 Mirror Glaze or Planet Waves Restore (Fig. 9), with a microfiber cloth to remove these marks. Keep in mind that every time you use any compound to buff out a finish, you are removing finish, so use polish sparingly and with great discretion.
Fig. 9. Buffing compounds can remove swirl marks and light scratches in a gloss finish,
but you should never buff or polish a satin finish.
Please note: If your guitar has a satin finish, never buff or polish it. Cleaning is fine, but buffing and polishing a satin finish will make it look blotchy.
Another cautionary note: If you have a vintage instrument with a nitro finish, be aware that as a normal part of the aging process, most nitro finishes will change color and develop a sheen or patina. When cleaning a vintage guitar, go easy—you simply want to remove the dirt, oils, and sweat. The underlying patina adds to the instrument's value, and removing it to make the finish shiny and pretty will devalue your guitar.
[Updated 7/25/21]