Guitar build CD60-5 – Repairing a broken neck – Leveling – Compound Radius


The first thing to do is to check the fret board for level without string tension. You will probably have to loosen the tension on the truss rod via the adjustment until it is level without string tension: Once you are level you can begin the job of leveling the frets themselves. Once you have finished the fret leveling job and have restrung the guitar, readjust the fret board back to a flat surface once more via the truss rod adjustment.

You can buy a tool specifically designed to do this job. Or you can take a good, straight piece of scrap pine and make a piece that will do the job easily. The main idea here is to have a uniform fret surface height with the correct radius in it that compounds from one end to the other. I started with a block of wood that was approximately 18 inches long with 120 grit oxide paper. It was flat, zeroed on my planer, and then run against a piece of sandpaper glued to the stainless top of my saw table to make it flat on all sides. I used that piece for approximately three passes and no more.

You have to be very careful how much material you take off, you can easily take the soft metal compounds of the frets down too fast ad have to re-fret the guitar. The key is to watch the board and check it after every full pass with something that will span the entire board and is level itself. I have an aluminum level I use for the purpose and it works perfectly.

Make a pass, check the frets. It will be very easy to see where they are high or low in most places, but some areas may be close enough that you will have to be a little more careful as you measure the gap.

There are tools that you can purchase to help you do the job. There are probably tools that have been invented for nearly everything you do. I prefer my eyes and my hands. This is a slow process and I am willing to take the time to do it.

Three passes leveled this fret board. You can see the metal dust, and I examined the fret board closely to make sure that there was contact with every fret: Some heavy, some very little.

As I made each pass I pushed from the nut end toward the opposite corner of the other end, and then from the other corner back to the nut on it’s opposite side with steady, but easy downward pressure. I consider that one pass. Check it and then make a second pass, then a third if needed. Examine the frets; you will see where the paper has, or has not, made contact.

Normally two passes would probably be sufficient, but this guitar neck was snapped at the headstock, the fret board itself was lifted, and so many of the frets had lost their seating. They were re-seated by me, but that is not going to be a good or proper fret job, they will still be off and need to be re-leveled.

 The other thing to remember is that although this is a Fender guitar it is a low end model, and I do not know of any low end models made by any company that receive additional fret work or set up after they leave the Asian factories and are shipped here. It is common to pick up a brand new, undamaged guitar and have the frets off anywhere from slightly to badly. So, it is not a reflection on any manufacturer, it simply comes down to affordability. In some cases a professional fret job will cost almost as much as the guitar itself. So they are left as they come from the factory where they are tapped in and left. Very often the edges of the frets are ragged or rough as well.

In the second picture I have changed to a smaller block of wood and lighter grits as I smooth the frets out. These are very light, very fast passes to reduce the scratches from the various grits. I will continue until I am at 400 grit oxide or wet and dry paper. I use wet or dry, and even though I only use it dry, it has superior anti-clogging properties and therefore lasts longer.

It is important not to skip grits of paper. Sand paper is designed to be used that way, the next higher grit removing the scratches of the grit below it. Skipping too many grits can leave scratches in the surface that you may not find until the end, then you will have to go back to work smoothing the frets all over again. The same is true when sanding wood, plastic, just about anything.
When I am finished with the grit sanding I will turn to the level and check the surface for flatness and radius by sliding the frame across the frets from side to side. I am looking to make sure that the flatness or gap stays the same from the frame to the fret tops: If it does then the radius has transferred. A set of radius gauges are fairly cheap, and they are an invaluable tool for checking your final results.

At this point the fret board is leveled. Some scratches remain, and the feel is rough. I will take care of that, but before I do that I will take one of my small flat files and re-crown the tops of the frets that were leveled.

I am looking to put a crown back on the top of the fret instead of the flatness the leveling has caused. This is another case where slow is better. Tape the fret board on either side of a fret that will be re-crowned. This will protect the fret board if your file slips. Simply run the file along the edge and round over the flattened frets.

At the same time I will remove any roughness from the edges of the frets and redress those cut ends to smooth them over.
This is fairly simple, and consists of simply rounding over the very edge of the fret wire where it was cut. On some fret boards the fret ends are bound, but with most low-end guitars the wire is simply clipped at the edge of the board, touched up with a file and left. Running your fingers along the fret board in a sliding chord position will quickly tell you. It is always a good idea to check for this and it is very easily fixed.

I am carefully removing the file scratches from the frets I re-crowned. These are very light passes along the tops of the fret to smooth them and blend the crowning back in. You can buy crown files for this job, but if you practice you can achieve the same results with a small flat file very quickly.

With the crowns reapplied and the edges smoothed I am ready to clean up the board and the frets. First I will use a scuff pad at 2000 grit to polish the frets. At this grit it will not damage the fret board, but it can embed some metal dust into the fret board finish, so it is best to re-tape between the frets for this job as well. You can buy special tape for this, but I use a good quality masking tape and it works well for me. I watch the frets as I polish them, removing the roughness, making sure to catch the edges as well, and when they are shiny I inspect each one for rough spots and check once more with the level before I remove the tape.

The scuff pad makes short work of polishing the frets, but it will not make them perfectly shiny. To do that I will take a small amount of metal polish on a soft cloth and polish them by hand until they are shiny and reflective.

One completed fret job, nice and smooth and with an excellent compound radius from the nut to the end of the fret board.

What is Compound Radius?

What is a compound radius? A compound radius is having a different radius on one end of the fret board than the other. This is usually a smaller number at the nut end, a larger number at the sound hole end. This allows the fret board to become flatter as it travels from the nut to the sound hole. This provides for better play-ability as the string spacing will be closer at the end of the scale near the sound hole. On this guitar we started with about a 12 and ended with an 18 at the bridge.

Next week we will shape the Nut and Saddle and install them…


Guitar Works Volume 5 Doing neck repairs, refretting jobs and cutting, shaping and installing your own nut or saddle: Fret board removal, truss rod installation; how to radius the new board and install new frets. #Custom #Guitar #Builds #Luthiery

Guitar Works Volume Six This will cover a snapped neck, where the neck is cracked in two. How to make a lasting repair and the order in which to do the multiple repairs you will need to perform to do that. #Guitar #CustomBuilds #Luthiery

Guitar Works Volume Seven I will show you how to take a bone blank and turn it into a saddle; how to get the shape and measurements you need to accomplish it: How to install it and set it up to your own tastes. #Custom #Guitar #Builds

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