We are about to hit the season in which fingerboards are beginning to shrink, and many fretted instrument players can experience fret buzz. Also normally this is a case where one or two frets are mainly buzzing and most other notes seem to ring out fine, and the truss rod is adjusted where it should be for adequate relief and the buzzing notes are still present. This more than likely means you have fret ends that have become unglued or “unanchored” from their fret slot.
 
Gluing Unanchored Frets

 

First, sight the neck. Most of the time, you will notice the frets that have become unanchored very easily because they will not fall in line with the other frets. Also, play the notes throughout the fret board to isolate the buzzing frets and mark them by means of chalk or tape to identify. Once you have found the buzzing notes or fret, you can press you finger on the ends of the fret and you will see a slight movement or gap between the fret and the fingerboard.
 
Next you will need a clamp, normally I use a quick release bar clamp with rubber grips normally this type of clamp you can tighten with one hand with a squeeze trigger and has a release button, a flat wood block that is about 1” wide and about 3” long this block is used for the top side of the clamp jig and will evenly distribute the clamping pressure across the buzzing unanchored fret, and two pieces of ¼”-1/2” dowel rod, long enough to go across the unanchored fret end and the surrounding frets ends on both the fret above and the fret below the unanchored fret, the dowel rod pieces will put the pressure on the fret ends.
   
Once the unanchored frets have been marked, loosen the string tension and turn the truss rod to zero setting meaning no tension one way or the other.
 
For the re-gluing of the frets you can use thin superglue or if you don’t feel confident in the super glue, you can use premium wood glue mixed with one part white vinegar to thin out the wood glue so it can get into the fret slot. Also use a guitar string end to guide the glue onto the side of the fret and letting the glue run into the fret slot when using super glue put on drop on the string end applicator and let it drop onto the front and backside of the fret. In other words, on both sides of the fret, do a total of two drops on both sides, wipe the extra glue off of the fingerboard with a piece of tissue.  Use only one wipe on both sides. The rest of the glue squeeze out will be scraped off with a razorblade once you have the glue in the fret and the fret is ready to clamp with super glue, you will need to clamp it up quickly... about three minutes before it dries. If you are using the wood glue/vinegar mix, you can dip the string end applicator into the mix and drop a few drops on the front and backsides of the unanchored fret using the wood glue/vinegar mix. It will be a little easier to clean off and will give you more time to clamp, but will take longer to dry, compared to the superglue.
 
Now we are ready to clamp place one dowel rod under the square block while putting pressure on the block. Place the other dowel under the opposite side, keep pressure on the block to keep the dowels in place, and then grab the one-hand-squeeze clamp with your free hand and place one end of the clamp mouth on the topside of the square block and the other side of the clamp mouth on the backside of the neck, in the center of the neck and squeeze the trigger until the clamp is nice and tight.  Let it dry. Once glue is dry, perform the same procedure to the next unanchored fret, if any others are unanchored.
 
Once all unanchored frets have been re-glued, if you have glue "squeeze out" around the area of the fret, you can carefully and easily scrape the "squeeze out" off with a box knife razorblade. Scrape in the direction or the wood grain of the fingerboard.
 
Once all "squeeze out" is cleaned up, you can level and dress the frets if needed to get rid of any glue that might have dried to the tops of the frets. If you are a seasoned repair tech with fret work under your belt, just do your normal fret leveling procedure. If not, here are some helpful steps for the leveling and dressing procedure.
                                                                                                                                                      
Leveling and Dressing

 

Before you begin, protect the finish of the body by tape or a foam padding that is taped down on both sides of the fingerboard overhang, in case you slip off, it will not scratch the finish on the soundboard or top. Also adjust truss rod to make sure the neck is straight before you begin the leveling procedure.
 
To get rid of any left over glue from the tops of the frets, or to make the frets uniformed and level to each other, use 220 grit sandpaper, running the sandpaper with the grain of the wood from the first fret to the last fret,  making sure that we do not lower the frets in the lower positions without lowering the frets in the higher positions. Also, I use a small round piece of wood like a dowel rod about a ½” thick and wrap the sandpaper around the round piece of wood which will allow the frets to not become flat or so that we don’t loose the rounded crown of the topside of the fret. Also make passes with the sandpaper using the rounded wood piece as your sanding block and with the grain of the wood from the first fret to the last until I see all or most of the glue is removed or when leveling, count up to eight passes from the first fret to the last fret. At this point, I will make eight passes with the sandpaper from the second fret to the last fret, and then eight passes from the third fret to the last fret, and then eight passes from the fourth fret to the last, and fifth fret to the last fret keep moving up the fingerboard until all frets have been cleaned, and in the leveling aspect, you will find by doing this, you will have the taller frets in the lower positions, which will eliminate more fret buzz.   
 
Once the 220 grit is complete then use the rounded wood piece with a 400 grit sandpaper making passes in the same direction first fret to last fret until the scratches from the 220 grits paper have been removed from the frets and fingerboard. This part is much quicker and normally only takes about eight to ten passes to complete.
 
Once the 400 grit is complete, use the steel wool make passes in the same direction as the wood grain from the first fret to the last fret, and at this point, you will notice a shine to the frets, and scratches in the fingerboard will start to fade away. Also, this part will not take very long... about eight or ten passes.
 
Once steel wool is complete blow off dust left behind from polishing and put a small amount of lemon-oil on a rag and rub the oil-rag into the fingerboard. Avoid getting any oil on the finish of the body to eliminate further clean up.
 
This example of fret leveling and dressing is for fretted instruments with a solid Rosewood and Ebony styles of fingerboards that do not have to be taped off before sanding unlike ebonized or black paint fingerboards and electric guitars with a maple neck, which will require tapping off the fingerboard.

 

Greetings from the WoodShop!