Repairing Cracks in a Fretboard
Source: Crack Repair
Tools and Materials Required:
Spatula
2-Part Epoxy
Garnet Sandpaper
Silicone Carbide Sandpaper
Sanding Sticks
Repairing Cracked Fretboards:
Cracks in a guitar fretboard are usually caused by one thing – the guitar was exposed to a very dry atmosphere for an extended period of time.
While not hard to repair, you can eliminate the problem by solving the condition and keeping wooden instruments in a climate controlled condition with the relative humidity in the mid-30′s to 50′s. For more information on humidity in your shop see the article Humidity in the Shop. For general humidity information and suggestions as to how you control the atmosphere for your guitar, see the article Guitar Humidity Control.
Also, accompanying fretboard cracking you may find that the fret ends will protrude out the side of the fretboard due to the differential expansion between the wood fretboard and the metal frets. If the frets are still in good condition you can smooth the frets and take off the sharp edges. For instructions on this, go to the article How to Repair Rough Frets.
Another reason you will see cracked fretboards is mainly due to the wood drying out over the years. You will see this condition quite often on older or vintage instruments. Not something to be overly concerned about, as the fix is very easily done.
Mix Up Your Crack Filling Glue Mixture:
Usually the cracking will not be very severe because the fret tangs keep the fretboard from pulling apart. If you intend to fix the cracks you should mix up a mixture of wood dust and epoxy glue. I start with about a 50/50 mixture of each. This will give you a pasty mixture that is very easy to work with.
As I repair and make guitars, it try to keep some of the fine sanding dust materials in small glass jars. I have one for Ebony and several for different shades of Rosewood. If you do a lot of electric guitar repairs you will want some Maple dust as well. Try to sift out any sandpaper granules before you store the material in the jars.
Mix up a batch of 2-part Epoxy Glue and mix-in the desired wood dust coloring. Keep in mind that the mixture when wet will appear much darken when dry. Ebony fretboards are not a problem and you can go ahead and mix in the ebony dust and it will match the fretboard very closely.
If you are fill-in a Rosewood fretboard for the first time you may want to do a trial run until you become acquainted with the color shifting after the glue dries.
Filling In The Crack:
Just take a small Spatula and work as much of the wood/epoxy mixture into the fretboard as you can. Leaving the crack a little over-filled is a good idea as it is easy enough to sand it down to the fretboard surface.
Sanding the Filler:
After the glue has thoroughly dried, sand it down to the fretboard surface using a sanding stick. Start with about 150 grit Garnet Sandpaper. Finish up with 220 and finally 400 Silicone Carbide Sandpaper.
Final Finishing:
If this is an Ebony fretboard you should consider giving the entire fretboard a good coat of black aniline dye. This will put a beautiful deep finish on the wood and it really soaks into the wood as well (it also soaks into your fingers so be sure to wear rubber or latex gloves.)
Tape the edges of the fretboard to prevent any spills. Also apply with a small cloth or swab to control where you apply the dye. Follow with some non-silicone based wax.
For porous fretboards, such as Rosewood I prefer to use a Fretboard Conditioner. My favorite is D’Andrea DAL2 Lemon Oil & Conditioner. It will remove all dirt and grime and leave a fretboard in better shape to resist dryness.
With this quick and easy fretboard fix the fretboard should be permanently repaired and there should be no recurrence of the cracks.
Tags: fretboard cracks, how to fix fingerboard cracks, repairing cracked fretboards, repairing guitar necks
