Ebony Question
#11
LOML bought me a large piece of ebony (1” x 6.5” x 57”) covered in wax - she’s a keeper! I’m about to use some of it for a set of segmented turnings with koa. Once I cut what I need, is there a reason to re-coat the cut side or is it okay to leave it raw. Never worked with ebony, so not sure - though I alway see it with wax coating when I see it.
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#12
I never reseal after cutting. I bought a log of gabon ebony a few years ago. it was sealed at the all over; paint at the ends and shellac or something along the length, but the interior had lots of voids or large checks. I cut it up and didn't reseal and no new checks had formed, but it was quite dry by the time I cut it.
Cellulose runs through my veins!
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#13
i never reseal it either
jerry
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#14
You might want to check the moisture content of the ebony before you use it. I ordered some 8/4 ebony from a reputable dealer a couple of years ago for some saw handles. It was represented to have been air dried for 15 years. I checked it and found it was at 18% MC - yikes! I set up a finishing kiln, a trick I learned from Ron Brese, the planemaker, dried it gently for about 2 1/2 months and got it down to 7%. I'm afraid if I'd used it at 18%, I would have wasted the ebony, not to mention the time and effort to make the saw handles.

A finishing kiln is easy to make. It's basically a chimney with a single bulb incandescent light fixture at the bottom. I made mine from four sticks for uprights and sheathed it with 1/4" plywood. The wood rests on a rack in the middle of the chimney. The light bulb generates a little heat and creates a gentle updraft which rises through the chimney, past the wood and dries it. I used 60W and 100W bulbs. The 100W produces more heat, so I backed off to 60W just to be on the safe side. My ebony dried perfectly with no warping or checking. Here's a photo of the kiln.

[Image: 39930878505_047130ae3e_c.jpg]IMG_0136 by Hank Knight, on Flickr
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#15
Thanks all. Now I just have to get over the fear of cutting this thing wrong.
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#16
Hank, your comment about AD lumber having 18% MC highlights that there is no reference point for air drying, like there is for most KD lumber.  Most kiln dried lumber is 6 - 8% moisture.  Air dried could be anything; in coastal regions it could easily be 18%, or more, while in the desert SW it might be 6%, while where I live it's 12 - 14%.  And time has almost nothing to do with it.  Once lumber gets down to the EMC for where it's being stored it's not going to go lower regardless of how long it sits there.  So the lumber you bought that had air dried for 15 years might have been clever salesmanship, but offered no true benefit.  

There's certainly no reason not to buy AD lumber (other than bugs) as long as you know that in most areas of the country it likely will need additional drying before it can be used.  As you said, check everything with moisture mieter.  

John
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#17
(09-10-2019, 11:49 AM)jteneyck Wrote: Hank, your comment about AD lumber having 18% MC highlights that there is no reference point for air drying, like there is for most KD lumber.  Most kiln dried lumber is 6 - 8% moisture.  Air dried could be anything; in coastal regions it could easily be 18%, or more, while in the desert SW it might be 6%, while where I live it's 12 - 14%.  And time has almost nothing to do with it.  Once lumber gets down to the EMC for where it's being stored it's not going to go lower regardless of how long it sits there.  So the lumber you bought that had air dried for 15 years might have been clever salesmanship, but offered no true benefit.  

There's certainly no reason not to buy AD lumber (other than bugs) as long as you know that in most areas of the country it likely will need additional drying before it can be used.  As you said, check everything with moisture mieter.  

John

Hi, John,

I learned a lesson from my ebony experience. Around here (South Carolina), AD lumber typically runs 12% - 14%, like your area in New York. I naively expected the air dried ebony to arrive in that ballpark. The ebony, however, came from the Pacific Northwest, so I should have expected it to have a high MC. I didn't give the source any thought and was surprised to discover the MC so high. I'm glad I checked with my moisture meter. You're right, "air drying" means very little without reference to where the air drying takes place.

By the way, I have been impressed with your solar kiln; so much so that I posted a link to your build on another forum for the benefit of a friend there who is considering a similar project. I think you did a great job.

Hank
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#18
(09-10-2019, 01:03 PM)Hank Knight Wrote: Hi, John,

I learned a lesson from my ebony experience. Around here (South Carolina), AD lumber typically runs 12% - 14%, like your area in New York. I naively expected the air dried ebony to arrive in that ballpark. The ebony, however, came from the Pacific Northwest, so I should have expected it to have a high MC. I didn't give the source any thought and was surprised to discover the MC so high. I'm glad I checked with my moisture meter. You're right, "air drying" means very little without reference to where the air drying takes place.

By the way, I have been impressed with your solar kiln; so much so that I posted a link to your build on another forum for the benefit of a friend there who is considering  a similar project. I think you did a great job.

Hank

Your conclusion that because wood came from the PNW it must have high MC is erroneous. The relative humidity here is far lower than it is on the East coast. I air dry a lot of wood in my garage. Currently I have several hundred pounds of figured BLM that was up to 25% MC three months ago. The pieces I have cut to about 3" are now down to around 11% and stuff I have had drying for more than a year is down to 8-9%.
Cellulose runs through my veins!
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#19
(09-10-2019, 01:03 PM)Hank Knight Wrote: Hi, John,

I learned a lesson from my ebony experience. Around here (South Carolina), AD lumber typically runs 12% - 14%, like your area in New York. I naively expected the air dried ebony to arrive in that ballpark. The ebony, however, came from the Pacific Northwest, so I should have expected it to have a high MC. I didn't give the source any thought and was surprised to discover the MC so high. I'm glad I checked with my moisture meter. You're right, "air drying" means very little without reference to where the air drying takes place.

By the way, I have been impressed with your solar kiln; so much so that I posted a link to your build on another forum for the benefit of a friend there who is considering  a similar project. I think you did a great job.

Hank

Thanks very much Hank.  Sorry to the OP for this tangent, but I got the drier painted and it now looks like this:

[Image: KI6Oqm3KD7O8dRdebiflv3wTT_ByJzHPhTrTx-Wu...13-h626-no]

Actually, the vent covers are painted now, too, but that's a small point.  Anyway, I have run about 900 BF of 4/4 and 6/4 AD ash (14% mc) through the kiln now.  It took 2 weeks to dry to 7.2% mc.  I added a dehumidifier to the kiln for the last 3 days to keep the RH at 40% at night and that made a huge difference in speeding up removal of the last 2% to get down under 8%.  After I got the kiln unloaded I installed 4 mil plastic to the inside of the S. wall rafters to smooth the airflow from the fans and to decrease night time heat losses.  I also installed seals around the two doors.  I have a small load of 250 bf of 4/4 black walnut in the kiln now.  It's hard to quantify the effect of those upgrades because the load is much smaller, but the sample board went from a starting 17.8% mc to 11.8% in one day.  I'm interested to see if I still need to add the dehumidifier to remove the last couple of percent, but am prepared to do so.  In any case, I think this load will be dry in a week; maybe 4 days to get down to around 8% and 3 days hold to make sure the middle is dry.  

So far I'm impressed with how easy the kiln is to operate.  Basically, just load lumber, keep track of the MC to make sure it doesn't dry too fast, and let it go.  And I'm hoping that by adding the dehumidifier I will be able to operate later into the Fall than otherwise would be capable and maybe get another load dry before Winter.  I don't think your friend will be disappointed should he choose to build one.  

John
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#20
(09-10-2019, 02:03 PM)SteveS Wrote: Your conclusion that because wood came from the PNW it must have high MC is erroneous. The relative humidity here is far lower than it is on the East coast. I air dry a lot of wood in my garage. Currently I have several hundred pounds of figured BLM that was up to 25% MC three months ago. The pieces I have cut to about 3" are now down to around 11% and stuff I have had drying for more than a year is down to 8-9%.

Steve, you may be right. My assumption is based on my experience. I spent 6 months at Fort Lewis (Tacoma) back in the mid 1960s. I'm still drying out from the experience.
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