Zebrawood cracking

Hhhmmm. I dont have an answer for you but you have me worried now. I use a lot of Zebra in my CB’s. I hope someone has more info on this.

-- “There is nothing like looking, if you want to find something. You certainly usually find something, if you look, but it is not always quite the something you were after.” ~ JRR Tolkien

I also do not know the answer, though I would pose the following question in hopes of helping folks find the correct answer:

QUESTION:
Where can someone find the shrink/swell rate of various wood species when exposed to moisture/water?

-- HorizontalMike -- "Woodpeckers understand..."

My guess is that the zebra wood was at higher moisture content than the surrounding woods when you built it and now that all of the woods are reaching equilibrium the zebrawood is shrinking and because the edges are “captured” by the surrounding wood it is giving in the only place it can, by forming the cracks you see.

-- Bondo Gaposis

HM: One online source for shrinkage rates is http://www.wood-database.com/wood-identification/ I’ve seen tables in a number of other locations, too.

Bruce Hoadley’s Understanding Wood, should you have a copy of it, also has a table (p.74 of my copy). He primarily lists North American species, but does have a small section on “Imported” species.

-- Mark Kornell, Kornell Wood Design

HM,
Another possibility: http://www.woodbin.com/calcs/shrinkulator.htm

or maybe: http://www.woodweb.com/cgi-bin/calculators/calc.pl?calculator=shrinkage

-- If Carmen San Diego and Waldo ever got together, their offspring would be completely invisible.

I know of one way to repair the crack. Check this video by the Wood Whisperer for more information.

Basically you use a gap-filling epoxy. Make sure it’s food-grade.

-- -=Pride is not a sin=-

Bondo, that was my first thought as well, but then I thought about the drying and storage conditions and ruled it out. Perhaps, I was premature in that and need to get a moisture meter to avoid any future issues.

gr, that is a good suggestion for something to try. Unlike the CB in the video, these cracks are all internal to the board and I am not certain that I will be able to compress it enough. It is definitely worth trying however.

Maybe I can make a slurry of sawdust and TB3 and pack that into the voids.

-- Art

I don’t think it’s the Zebra wood that’s the problem, just the type of cut, joinery and placement (all the stars alined in other words)
I noticed in the picture you posted that both the Maple and the Walnut are almost all flat cut pieces and the Zebra wood is all quarter cut.
That and the Zebra wood is actually ‘locked’ together with the Maple and Walnut due to the joinery that you chose.
My bet is that the Maple and Walnut is actually pulling the Zebra wood apart, cracking it, with the large changes in moisture content that cutting boards are exposed to.
The flat cut material would easily expand and contract 3 to 4 times the width of the quartered material.(and in opposite directions)
If you build another one, try to keep the Zebra wood on the outside(or close to) of the board.
JMO..

-- Come to the dark side....we have cookies...

Tony, that is an interesting hypothesis that would never have occurred to me. I checked Shrinkulator and there is about a 1% differential between radial and tangential for maple and walnut, unfortunately, zebrawood isn’t listed. On the flip side, I have made a number of boards with qswo and flat sawn woods without incident so far, maybe the time bomb is ticking…......

-- Art

Hi Art,
Well, I really don’t know for sure either, but here is my guess. ...
I believe it is wood shrinkage noteing the angle of the cracks or checks accross the grain.
Just like the checks on the end grain of a log going from the center to the sapwood.
I have heard of guys cutting their parts, checking with a moisture meter (in the center of the cut), if it is a bit high they stick the parts in the microwave to dry them … I have never tried this, so it’s third hand hear say.
Please let us know what you find out.

-- Grumpy old guy, and lookin' good Doin' it.

HM, sorry that I didn’t answer your question earlier. I use the Shrinkulator as Darin mentioned.

GM, thanks for the reply. I don’t think I will ever have a conclusive answer unless the boards I made using qswo start to crack. If I ever make another board with zebrawood, I will be certain to use qs only woods in the board.

-- Art