Working with ebony woods

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Sheumais

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Joined
Feb 17, 2010
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Location
South Mills, NC
Question for those more skilled than myself (which should be plenty of you).

I have tried doing pens using Macasser ebony (twice), black&white ebony (once), and gaboon ebony (three times). In EVERY case, the wood has CRACKED. It always happens between a day and 2 days AFTER turning out the pen and putting it in my portfolio. It's outright embarrassing when a potential customer is checking out your wares and finds a cracked pen that you didn't know was cracked.
In all but one case, I turned the blanks out using freshly sharpened or honed tools. I do my turning with the ebony at about 1080 RPM, and all my cuts are fairly light, especially the finishing cuts. I used the Hut PPP wax for the finish in every case (I like how it buffs to a glorious shine, so I keep using it).
Can anyone give me some pointers on how to turn ebony and have it survive? I'm currently sitting on a Civil War kit for a commissioned job. The client wanted an ebony body; I chose Macasser to lower the final price slightly, and because I love the lines I get from it. I'd like to do this pen before I deploy in 2 weeks, WITHOUT it cracking on me... as it has already done once, with b&w ebony.
 
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Get a Black Knight acrylic blank from Exotic Blanks and get the job done. I gave up on trying to turn ebony.
 
Ebony is very sensitive to heat, whether from turning, sanding, or polishing. Sometimes it will not crack until later, after you are finished with the pen. A very difficult family of woods to work with.
 
I have never turned Ebony so I may be WAAAAY off but all this cracking makes me think wet wood. Do you measure with a moisture meter or weigh your blanks? I have a cheapo HF scale and I wrap my new blanks in blue tape at the end and weigh them for a few days. If they stay the same I know it is dry. If it changes I put it on the shelf to dry for a week then weigh it again. I go until I get the same weight for several days before turning. Also, are you allowing the blanks to acclimate to your shop? They could have been in a warehouse and dry but your shop could be drier then the warehouse.

Just some thoughts......I have only had one cup o' coffee today.
 
So far, I have only turned one ebony blank for a pen (cigar). I just used the HUTS friction polish on it. For some dumb@$$ reason, I forgot the pen and left it in my truck. Needless to say, it cracked. I don't know if I had a good CA finish on it if it would have cracked or not. I may give it a try at some point.
 
Use African Blackwood. You can't tell the difference between it and ebony and it doesn't crack as much.It's also easier to finish.
 
Extremely dense woods like ebony and snakewood do not tolerate heat well. They are very prone to cracking when thin and any temperature or humidity change occurs. Humidity like going from desk top to sweaty shirt pocket.
I have had some that were Ok if I kept them from being too thin when turned.

I suggest that you drill them under size and let them sit for a week. There can be internal stresses in the wood that drilling exposes and the rapid drill, glue and turning did not allow the stresses to even out. Go back a week later and drill to final size. I do know from personal experience that fancy walnut woods have these type of internal stresses and if you do not allow them to release by waiting they will cause warping later. Wood aged and dried ten years will still need time to stabilize. A gunstock warps, it moves away from the metal, a pen just cracks. It, the gunstock, did make a nice lamp but it was a very expensive mistake.

Other tricks that I have tried include using a solvent to remve the oil from the hole and then flooding it with thin CA. Trying to make the wood more stable. Consider a CA finish also. You are trying to seal the wood so moisture does not move in and out of it. CA finish on oily woods can be splotchy if all the oils in the surface are not removed. No mater what you try you are going to have to let the pen sit a few days to a few weeks to see if it cracks or the finish gets cloudy. Ebony is a go slow and keep your fingers crossed kind of wood.
 
Ebony has let me down too many times. I've resolved to only use it for inlays, laminations, and tiny teacher pen barrels. If someone requests a pen out of ebony, I steer them to a dark African Blackwood.
 
I have turned Euros, Wall Street IIs, slims, Elite 2, comfort, letter openers and magnifying glasses and eggs using Macassar and Gaboon with good success (no cracks). The wood MUST be dry and acclimated. I try to avoid any heat drilling slowly with light bit pressure and backing out frequently, turning at 850 with light passes and sharp tools, sanding at 450 with very light pressure from 400 through 1,200. For a finish I use 3 coats shellac sealer followed by 3-4 or more coats of water based gloss polyurethane.
 
Another thought.....how are you glueing the tubes in? CA? Try apoxy or another type of adheasive that has some play/give in it so that the ebony has some wiggle room. If it's locked tight to the brass tube.....it has no where to go, except to 'Crack'....


Barney
 
Hmmmm - don't want to jinx myself but I have turned probably a dozen ebony blanks over several months and have not had one crack yet - I finish mine with CA.
 
Ebony cracks with heat. Every time that I've had an ebony pen crack it has been at an outdoor show where I was negligent in keeping the pen out of the sun. Given that I cannot guarantee that a buyer will keep the item out of the sun (or out of a hot car), I've stopped selling them.

It should be noted, that if I had been more careful about these pens in teh sun, I likely would never had one crack. I would post as such in threads like this, but that doesn't mean that every one of these pens didn't crack the first time that buyers left them in the car on a hot summer's day.
 
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