OLIVE WOOD- how to get it to not crack

[Guner Tautrim]

I have loads and loads of large, old (200 year old) olive wood.  The trees went through a fire and were cut down about 2 years ago.  I have milled a bit of it and it is incredible but it is very prone to checking and cracking.  Any one out there know how to best deal with it.  I have only air dried it.  Is straight to a kiln a better option?  Thanks.  Guner

[jueston]

are you coating the ends of the boards after you cut them or recoating it before you cut it, doing so will reduce the movement of water and slow the drying process.

cracks are ussually a sign of it drying to fast, so slowing it down might help.

[metalspinner]

Is the problem you descibe on the board ends, or on the faces of the boards?  Are the cracks huge and running through the thickness of the board or very small and just on the surface?

Do your boards contain lots of crotch areas or are they straight grained?

Olive is beatiful wood and I have only turning it.  I have not seen any boards that something large could be made.  The turning blocks that I have purchased have been completely sealed with beeswax and showed no signs of major drying defects.

Having been through a fire and cut for a couple of years, my intuition is telling me that could be part of your problem.

I'm getting hungry just thinking about that wonderful olivewood smell.

[Den Socling]

It's too much air and/or too much sun. Describe your set up.

[Guner Tautrim]

Thanks for those that responded.  I will try and post a photo or two at a later date.  However the olive I have from milling 2 years ago is what it is- some end checks but lots of cracking on the face and many defects.  Of course olive does not get that big but these were 200 year old trees so yeah, lots of crotch areas and many limb areas. On average they are 5' long logs and 18" diameter.  I guess my question is how to do it better next time since I still have loads waiting to be milled.  End sealing- sure, will do.  Stacking and stickering is standard- out of the sun with a shelter over the top with good air flow- that is my standard but maybe the "good air flow" is too much and airflow should be constricted more to allow slower drying.  Not sure.  Amazing wood with so much dark to light variation.  There is very defined black variegated lines throughout that are incredible.  Since surface checking has been pretty constant (all logs were milled through and through) we have used a technique of filling all the surface checks with an epoxy filler mixed with charcoal to get a jet black effect that matches the black variegated lines that exist in the wood.  Drying is slow in this wood.  Slabs that were milled 5/4 and have been drying for just about 2 years, still have moisture in them when I cut them now (case hardened??) Thanks for any help. ???

[jimF]

As Den said, slow drying is the answer - low air flow.  This can be achieved many ways: thinner stickers 5/8 even 1/2 inch thick initially, cover whole stack with a fabric called "shade dry" (I think is the name), keep out of the sun, increase width of stack, surround it with other stacks of lumber, imagination here could help you.

As you can tell, it is a dense wood and dense wood is slow drying and tends to check.  The burls, crotch and limb wood also tend to check.  Don't fill the checks with any material.  It would be safer to fill checks after it is thoroughly dried but you would still have further risk of checking even then because wood continually shrinks and swells, .  As the inner wood starts to dry and shrink, the filler will restrain the checks from closing and cause the check to grow further inward, acting like a wedge.

All wood becomes casehardened with drying, but casehardening is the result from drying and does not effect the rate of drying.  You say they are still wet now.  Do you know what the average moisture content is or the moisture gradient now?

[mikeb1079]

guner is there any chance that the wood was re-wetted after you milled it?  what i mean is perhaps did it get rained on or even exposed to condensate or mist? 

i've run into this with oak and it led to bad surface checking.  it seems like you're on the right path taking it slow (as evidenced by the fact that the core is still not dry) but perhaps the outer surface was re wetted.  the only other idea i have is that maybe the initial air drying was too fast, such as a windy few weeks during a dry spell. 

just some thoughts....

[GeneWengert-WoodDoc]

I have also noted the black lines and do not know what they are...maybe fungal, but maybe not.

Olive wood is very dense.  This is partly why we have problems.  It is also very branchy, so the grain is never straight and full of tension wood, so warp is common.

There are a few wood species that we can air dry slowly for a year and still find the core is soaking wet; oliveis one of them.

What is needed from drying without cracks is extremely slow drying.  Put a very thin coating of wax on the faces and then wrap the piece in paper.  Then put it in a cool, damp location for a year.  Then, check the core MC to see if it is under 30% MC so you can bring it out and dry it more normally.

[Tree Feller]

There are a few wood species that we can air dry slowly for a year and still find the core is soaking wet; oliveis one of them.

Aha!  I have a chunk of Olive Wood that a friend from Norway sent me. He got it from another friend that got it from Israel. It's about 14" long x 5" thick x 8" wide. It's been in my shop over a year and I have no idea how long it dried prior to my getting it. This weekend I cut a small piece off one end and turned a bottle stopper from it. There were really long, thin curls coming off the 3/8" gouge, similar to turning green blanks. When I went to sand it, it clogged the sandpaper immediately...almost like green wood. I guess it was still wet in the middle. I'm out-of-town right now but will check the MC when I get back home. I had assumed it was dry but I guess that's what I get for assuming.

[metalspinner]

Treefeller,

Those are characteristics of all the olive I have ever turned.  Even pen blank sized pieces that I have had for years machine in that manner.  I believe the oils in the wood keep it "feeling" green although the water content may have dropped.

WoodDoc, please feel free to correct me if my hunch is off base. ;)

[jimF]

Mikeb1079 brings up a good point.  You don't want to let the wood become rewetted.  This will cause the surfaces to become larger. 
Also, be sure once the blade leaves the log not to let any sun or breeze get to the lumber.  I have seen operations spend a good deal of money on the best kilns only to fill the kiln up with green surface checked lumber because by the time a layer of lumber has been stacked from the green chain that layer is already surface checked from the sun and breeze on a nice clear day. Once even only slight surface checked, further drying deepens the checks.

[Tree Feller]

Treefeller,

Those are characteristics of all the olive I have ever turned.  Even pen blank sized pieces that I have had for years machine in that manner.  I believe the oils in the wood keep it "feeling" green although the water content may have dropped.

WoodDoc, please feel free to correct me if my hunch is off base. ;)

I checked the moisture content yesterday and the highest reading I got was 11% on freshly cut long grain. I think you are right about the oils in the wood.

[Guner Tautrim]

Thanks all again for the input.  Still have not got photos for you all but I'll respond briefly.  No I don't think it got re-wetted.  From the sounds of it, thanks Wood Doc, it needs very very slow curing.  When done as you suggest do you not get any mold growing?  I suspect an end seal wax like product would work for the surface sealing you suggest.  I have lots of burlap at my disposal would that be good instead of paper?  As the branching, crotches are everywhere but man what an amazing grain.  It is so beautiful and smells incredible- kinda like an empty wine barrel for some reason.  I have lots to mill and want to make good use of it.  I've always envisioned end grain cutting boards- what do you think of that.  It would be very beautiful but you have to have NO cracks/checking for that huh?  This learning curve is never ending I tell you. ???

[GeneWengert-WoodDoc]

Burlap should work.  You might get some surface mold, but that is ok.  End coating, if thin, is good indeed...we do want some drying, so do not coat too thickly.  Note that 4/4 and 5/4 are easier to dry without checking than thicker stock.