Official Luthiers Forum!

I just sawed up a plank of Cocobolo that was bought about 30 years ago. The outside of the plank is a beautiful dark brown with cream colored sapwood along the edges. When I sawed the plank the interior is a ghastly color with pink, orange and yellow hues. I plan to use this wood for a double top guitar with laminated sides (Port Orford/Cocobolo) and double back (red cedar/nomex/Cocobolo). Do you think fuming with ammonia will darken these hideous panels? Any other ideas?

Give it time to oxidize. You could set it in the sun and see what it does.

My $.02

Best, M

Just let it sit for a little while. It should oxidize and return to its normal color in a little while, it will,also change if you sand through the outer layer but will again darken up,given a little time.

Its amazingly photosensitive. Its pretty much back to original darkness now.

_________________
My memory is so good, sometimes I remember things that never happened.

It's only 13/16" thick and has been sitting in my shop for over thirty years, after all that time the oxidation is only about a mm or so into the wood. I went through this with another piece of Cocobolo a few years ago and several months after re-sawing it had darkened only very slightly. I plan to sand this wood to about 1mm in thickness for laminating and am hoping there's a way to get it to darken rapidly and all the way through like fuming. Just wondered if anyone had tried fuming on Cocobolo or if there's another way to get it to darken (oxidize) rapidly all the way through. I don't want to have light spots when I scrape the bindings level with the sides.

The fretboards on the guitars below are made from macassar ebony, on the left, and cocobolo on the right.


This is what the cocobolo looked like freshly sanded


This is what it looked like with mineral spirits on it

_________________
Julie Moriarty
http://JulimorCreations.com

You might look into some Uv lamps, or if you know someone with a tanning bed.

_________________
My memory is so good, sometimes I remember things that never happened.

I like the colors of day old Cocobolo. I wish I knew a way to keep it from darkening. If you heat the surface with a heat gun that may bring the oils up and cause it to darken.
If it is thick enough to use as is it seems a shame to gum up the sander to take it to a mm. Some of the old veneers were cut to 1/24 inch. They might be less work and give as good a finished product.

Thanks for your thoughts. I have a bunch of old maple veneer that is 1/24", I bought a whole flitch about 50 years ago for $35 and am still using it. I generally agree with you that wasting nice woods like this by laminating it is wasteful but I really don't like Cocobolo, I hate the smell and in general don't want to work with it. It is however over 30 years old, has a nice tap tone and is very stable so I feel compelled to use it up. It's way too heavy to use on guitars for my most valued customers so laminating is really the only solution to keep the guitars weight down. This is the last piece of Cocobolo I have and I will never buy any more. I bought it from Gilmer hardwoods in Portland Oregon, at that time he had a stack planks of this wood that must have been 30' tall and 50' wide. Kind of like the big piles of Black Limba that was being used for cabinets.

Couple years ago Mamie Minch did a video using potassium permanganate to darken new spruce so it would match the original wood in a repair. I tried it to darken Indian rosewood and it worked well. It worked by chemical reaction rather than staining or dyeing, so the wood still had some life in it, as opposed to the way dyeing just kills all the character. Got mine from Home Science. Might be worth a shot.

_________________
formerly known around here as burbank
_________________

http://www.patfosterguitars.com