Cocobolo woe

[James Simonds]

So, i am using Cocobolo for the first time, for a full set of 3 handles and sayas.

 

 

It started as a 3x3x12 block, and it was gorgeous. then i split it on a bandsaw into 3 sayas and 4 handle blocks (just the way the material was best used) all measured up for this set of kitchen knives.

 

When i cut it, the wood was a beautiful orange-brown colour, a slight hint of dark purple in places, especially un-oiled.

 

 

here is one of the parts i split for making a saya (saya is in two halves with a bronze bar in betwee, which is why its so short)

 

i set it aside for a few days. when i came back it was bright orange. no problem i thought, it probably surface staining. It wasnt. when i came to shape the handles i found the orange stain was quite deep in places, and its ugly. i've now for the first handle down to rough shape, and one side is beautiful, and one side is marred with orange stains. its ruined, frankly. i suspect the entire set is.

 

 

above is the side of the handle block with orange staining, below is the side that for whatever reason has none.

 

 

Losing the full set of woodwork isn't the end of the world. its $50 worth of wood and a few hours etc. (i'm still sad, you all know the feeling. and this wood was nice) but, how do i stop this happening again? how do i stop the surface of cut cocobolo staining orange from the oil released from the wood by the cutting (because i think that is what it is). I cleaned all the sawdust off, because i know that can stain.

 

Any expereince with this appreciated.

Edited February 6, 2020 by James Simonds

[Joël Mercier]

This sure is a strange wood. I made two handles from the same plank and they were quite different in appearance. 

 

We can see some of that orange tint on the second one, though it's nowhere near like yours. Sorry I can't be of much help. I'm following this in case I get the same issue with the rest of the plank. 

[Dan Hertzson]

I know that Cocobolo will darken as it ages.  I believe that the mechanism is oxydation and have heard it suggested to leave it un-sealed in a sunlit spot to accelerate the process (UV and O2 exposure).  Also be careful to use a good respirator when sanding and clean up your dust.  The oils in the wood can cause a skin reaction which apparently is a cumulative effect and will sensitize you to a wide variety of the oily rosewood family (Dalbergia?).

[tsterling]

Orange and fresh-cut cocobolo just go together. Like most fancy woods, it will eventually go darker and brown. Don’t set it somewhere it will get warm, that will cause the oil to flow more easily, so I wouldn’t put it in the sun. Time and oxygen will do what you want. 

[James Simonds]

ok, so i need to leave these handles somewhere to 'ripen' essentially? darker is fine, its just this patch of orange that is a problem. on the rest of the set, I've sanded them down and as it happens all the deep orange stains are gone, so 2 of the three will end up much more consistent. 

And yup, heard about the dust so im wearing full respirator and hoovering it all up.

 

Cheers.

[tsterling]

What's wrong with the orange color? Cocobolo is a natural material, and variation is the rule of nature. Try 0000 steel wool on the surface and call it good. The handles you like will change over time as well... If it's consistency you want, then plastic or metal is the way to go. Learn to love the "happy little accidents."

[steven smith]

the orange and black is what makes it exciting but it doesnt last long, also the dust is horrible and it doesnt work well with hand tools. it also can clog sandpaper like nothing else if its not totally dry. 

 

use the knife a bit and your hand will make it darken quick. 

 

the only piece i ever had did have lighter and darker areas that were all heartwood.

 

the good news is cocobolo holds up pretty well as a kitchen knife handle, i sold one to a chef and it hasnt blown up after a year.

[James Simonds]

10 hours ago, tsterling said:

What's wrong with the orange color? Cocobolo is a natural material, and variation is the rule of nature. Try 0000 steel wool on the surface and call it good. The handles you like will change over time as well... If it's consistency you want, then plastic or metal is the way to go. Learn to love the "happy little accidents."

 

The problem is twofold. 1.the intense variation and contrast. Variation and contrast in wood is fine, in fact i like it (look at some of my previous work), but its not a nice contrast in this case. it looks like i spilled something on it or something. 2. it sometimes happens and sometimes doesn't. most of the cuts age by darkening within a few days, which is fine. so, with a carefully matched set of 3 sayas and 3 handles, to have them all colouring very differently, for an unknown reason, is quite frustrating. 

 

I've worked with wood for various thing for 20 years but a surface spontaneously turning bright, day glow orange over 3-4 days if totally new to me

[tsterling]

It looks to me like you are influenced by the Japanese art ethic, so maybe the best direction to go is with more subtle colors and enhanced textures. Maybe try something like wenge (roughish grain) with slightly sandblasted surface to enhance the grain texture. I used to carve all kinds of little  things "painted" with different colored hardwoods, and ran into your problem with most of the pretty woods, so I sympathize. The only woods that I found that had even remotely stable color were yellowheart, holly and the woods that start out dark brown. Best of luck!

[Mike Ward]

 

These handles are all from the same board of cocobolo. The one on the right is about two years old, the others are finished a couple of days ago. Turns into a nice chocolate color with some dark red mahogany coloring. I’ve found that leaving them in the sun for a bit darkens them up and just using them does it further.

I’ve never had it go brighter orange after sanding is done though. Maybe it was because it wasn’t at a higher grit?

[James Simonds]

Those handles look nice. i have zero problems with that happening!

 

So, i have been experimenting for the last few days. i sanded some of the wood to a fresh surface and left it in my shed, where i have a damp problem (the sealing failed and we have had non stop rain for 3 months so i just cant dry it out properly atm.) and left some other freshly sanded wood inside my house and also some of the 'orange' wood.

 

3 days later, the orange wood that was inside my house has darkened and is no longer orange, the freshly sanded wood inside has only darkened slightly, the wood left in the shed went bright orange and the wood that was already orange didnt darken appreciably..

 

So, the answer is fresh cut + damp. something about the damp is causing that reaction that turns the surface orange AND its preventing that orange colour from turning brown.

 

Interesting, and also now we know. dont let your Cocobolo get damp!

Edited February 9, 2020 by James Simonds

[Ross Vosloo]

this seems like a very similar problem to what i have with tambotie (Spirostachys africana). its a very hard dense wood with a very high oil content. it has so much oil that single pass with sand paper immidiately gums up. its not too alergic to water, but i have found when that if it makes contact with water that is contaminated with anything, like chlorine, it looses a lot of its colour. 

it might be a similar problem to what you are experiencing

 

just for reference, here is what tambotie looks like

 

[Garry Keown]

 

This is a cocobolo paring knife I just did. Lighter but even. 

[James Simonds]

It all worked out in the end. the areas of orange staining are darker, but no longer garish, and the handles are looking sweet and figured. pretty happy. might make a proper post about these knives later.

 

[Arthur]

Cocobolo is extremely toxic....I ended up with COPD from sanding it while using an industrial type face mask..Be Careful !

[Brian Myers]

Cocobolo is a bit like Purpleheart, it takes time to change color. Exposure to dry air and ultraviolet light help.

[Doug Lester]

If you want to see a real color change try working with fresh cut Osage Orange.  It will go from a bright yellow with just a tint of green to a deep russet brown.

 

Doug

[James Simonds]

On 4/15/2020 at 8:29 PM, Arthur said:

Cocobolo is extremely toxic....I ended up with COPD from sanding it while using an industrial type face mask..Be Careful !

 

Yeah i spent ages cleaning the workshop and all my gear afterwards, not worth the effort on multiple counts. Other woods are just as nice and far less difficult to handle. Did you recover? hope all is well.