The Scourge of Ebonized Fretboards

I might have vented on this in the past but ebonized (wood that has been dyed to look black) woods are an absolute pain to work with so I figured I'd write about my discoveries.

Real ebony fretboard from a 1968 Hagstrom Viking II

Real Rosewood fretboard from a 1990s Yamaha Acoustic

Ebonized fretboard from a 1950s Harmony "Roy Smeck"

Ebonized and lacquered fretboard from a 1954 Silvertone

Ebonized fretboard from a generic fiddle
The black patches are whats left of the dye

 The How

This is going to be incredibly simplified as I'm piecing together what I'm reading and haven't actually tried this myself, I'll include sources. The process of Ebonizing wood involves soaking the lighter-colored wood with ferrous acetate, a chemical which you can make by soaking fine steel wool in a solution of vinegar. The ferrous acetate reacts with the tannins in wood and as a result turns the wood dark.

https://chemistry.stackexchange.com/questions/35351/iron-chemistry-acetates-for-ebonizing-wood

https://www.wwgoa.com/article/ebonizing-wood/

https://umgf.com/ebonized-wood-t176440.html

https://www.woodtalkonline.com/topic/20527-force-aging-wood/

Alternatively

M. Konick, in the British Journal of Photography, suggests the following method of blackening wood, which has the advantage of resisting acids and alkalies:
A
Cuprice cloride, 75 parts
Sodium chlorate, 67 parts
Water, 1000 parts
B
Aniline hydrochlorate, 150 parts
Water, 1000 parts
Paint the wood with A and a short time after with B, and remove with a damp cloth the yellow powder that forms. Repeat this operation every day till the desired color is obtained, and then rub the wood with vaselin or linseed oil. By using potassium bichromate instead of the soda salt, a good black color is obtained at once.

http://www.mugwumps.com/blacken.html 

The Why

Dyed domestic woods were not uncommon during the mid century, they were a cost effective replacement to more expensive "genuine" woods. "Pearwood" is a term used often to refer to the fingerboards made of the wood from fruit trees which was common in Europe. In the US, though, you see a lot of birch, sycamore, and other cheaper woods. I've heard faint mentions of maple fretboards that were dyed though I can only imagine they react the same way due, again, to the dying process. 

Most student model Kay and Harmony guitars from the 50s and 60s are built with these dyed fretboards to keep costs low. More expensive models and some earlier student models will have fretboards made of a solid hardwood. For example, my Kay-built Custom Kraft archtop from the 1940s has a Brazilian Rosewood fretboard but my Kay N-3 archtop from the 1960s has a domestic wood fretboard that has been dyed an almost reddish tint. I don't have a terribly large sample size to choose from but I do wonder about the scope of dyed fretboards

Painted fretboards were also commonly used and in my experience those have held up better structurally. That process is more simple and involves taking a hardwood (again usually light-colored) and painting it black then fretting the guitar. Typically these guitars don't wear through the paint unless they were loved and played regularly, but even then the wood is generally in better condition and easier to be patched. 

My Experience

The dye unfortunately has the effect of rotting the wood and making it extremely brittle and prone to chipping. So when working on these fretboards they will tend to fracture very easily even after intensely working to moisturize the wood (though it does help a little) and will likely already have cracks in them. I've found that taking out the 13th fret (on 12 frets to the body guitars) will lead to a lot of chipping and frustrating moments trying to repair the breaks.

The trick of using a like-wood dust and water-thin super glue to patch the fretboard does not work well with ebonized wood as the colors will never truly match and sanding the patch level does more damage to the soft, original wood. The Harmony Roy Smeck flat top acoustic, pictured above, was one guitar where I used real ebony dust and super glue to try and make the cracks invisible. I figured it would work since ebony is very tight grained and in my experience patching cracks in ebony comes with great results. I did not find such results as the original fingerboard chipped away as I was sanding my super glue patch and eventually I have to leave the guitar at "good enough" because I was afraid I'd do more damage. 

In the future I'll probably try to stray away from these fretboards and if a guitar has one that I am really fond of, I might pull it off and replace it with an actual hardwood that matches the color. Also Stewmac and LMII sell fingerboard dyes that I believe have a less harsh formula which will increase the lifespan of the wood but of course that all depends on what wood you use underneath it.

Conclusion

Ebony and rosewood are still valuable woods today and with environmental protections and trade bans to stop the species' from becoming extinct, they will likely rise in price. But there is a growing market for alternative woods like Pau Ferro; which Fender has substituted in for rosewood in their Mexican line of guitars. 

I wouldn't doubt that dyed fretboards are still used but personally I have not encountered them in any recently made guitars. I've run across articles where people dye their rosewood board to look like ebony but that isn't quite the same as ebonizing a much cheaper wood.

Further questions

I've stumbled across a fair amount of student guitars from the 70s until present day and I have yet to encounter another dyed fingerboard. This is all anecdotal but I haven't found them commonly used past the 1960s and I've seen them used even less in the Japanese import guitars. 

So why? Maybe the practice fell out of fashion? Maybe the wood industry changed? Maybe costs in Asia allowed for more expensive woods than the USA?