Guitar Fretboard Radius
When we talk about a radius on the guitar fretboard, it pertains only to the electric guitar or acoustic guitar fretboards. Classical Guitar fretboards are almost always flat or have a bit of a taper at the bass end of the fretboard to minimize buzzing.
Why Use A Radius?
The radius adds comfort for the guitar player. Our fingers are naturally curved or arched, especially when playing bar chords and therefore making a fretboard arched or with a radius makes sense to take advantage of the physical attribute.
You will see exceptions for providing a fretboard radius, especially with acoustic guitars. I, for one, do not like a radius on my personal acoustic guitars. This is rooted in my classical guitar background and I like the consistent feel of the flat fretboard when I switch between acoustic and classical guitars.
How To Radius A Fretboard:
By far, the easiest way to provide a consistent and accurate radius from the nut to the sound hole end of the fretboard is with a fretboard radius sanding block. You can attempt to sand a radius with a flat sanding block, but you will find that you will produce less than satisfactory results. The fretboard can be lopsided, inconsistent or just plain uneven.
There are commercially made radius block available from such luthier supply houses as Stewart MacDonald, and they are very well made. However, if you possess some woodworking skills and have the proper equipment, you can make a set of them for yourself and save about $100.00.
We have free PDF plans available at the Plan Shop for a set of (6) fretboard radius sanding blocks. Just scroll down to the bottom of the page in the Free Plan Section.
The plans for the radius blocks are 7.5″, 10″, 12″, 14″, 16″ and 20″. (190, 254, 305, 355, 406 and 508 mm). To find the instructions for building the radius blocks simply and easily, go to our article How To Build Guitar Fretboard Radius Blocks.
How To Use The Blocks:
The blocks are very simple to use. Just start with a flat fretboard, adhere some 120 grit sandpaper to the underside of the block and make long, consistent strokes along the length of the fretboard. Check your progress and when there is no longer a flat spot showing up at the center of the fretboard, you have completed your radius.
Ultimate Guitar Building Tip: Be sure to make your strokes the full length of the fretboard to minimize the likelihood of humps or waves in the fretboard. These blocks are 6″ long and should minimize this condition, but you should make a conscious effort to make all the stroke with the same pressure and length.
Double check the fretboard by holding it up to a light and sighting down the length of the fretboard. If you see imperfections, lightly sand them out.
Final Steps:
The final preparation for the radius is to change out the 120 grit sandpaper for 220 grit. Now very lightly sand the length of the fretboard until all of the scratches of 120 paper have been removed.
Tags: fretboard curve, fretboard radius tool, guitar fretboard radius, how to make a guitar fretboard, how to round a fretboard
