Identifying Black Locust

A woodturner tries to figure out if the wood he's using is Black Locust. February 15, 2009

I have been turning a log left from highway clearing. The leaves and branches have been ground so I can't use them for identification. At first glance I thought the wood was butternut, due to the deeply furrowed bark, but it quickly became apparent by the hardness that it was something else. There was not much of a distinguishing odor to the lumber, but one thing I noticed and that the forum on locust didn't mention was that the wood was even worse than walnut in the way that it stained my hands a dark black/blue. Does anyone have any ideas?

Forum Responses
(Sawing and Drying Forum)
From the original questioner:
I forgot to mention that the wood was from central Connecticut.

From contributor L:
Can you post an image? What color is it when freshly cut?

From contributor M:
Black locust has a light yellow color off the mill. The color is a deeper yellow when black locust is kiln dried.

From Gene Wengert, forum technical advisor:
Do you have a "black light" source? Locust will fluoresce when exposed to UV.

From contributor R:
Locust smells. Once you cut it you'll never forget it. Minimal sapwood on black locust. I'm in CT as well and mill it quite often. As for staining your hands it’s not as bad as walnut or butternut. Maybe you do have butternut. A butternut log would be light weight compared to black locust. There are not too many physical similarities between the two.

From the original questioner:
I turned another bowl yesterday, and am beginning to think that it is definitely black locust. When first cut it was a light yellow, with greenish tinge, and it quickly started to oxidize into a deep gold/light tan. The tree was about 18" in diameter and had a somewhat pronounced darker heart of about 6" in diameter. The odor was nothing like butternut, of which I dislike greatly. Instead, it had a sort of sweet, cut grass or fresh grain aroma. The bark was very deeply furrowed, and almost resembled cork for 1/2", although it was quite stringy. Again, I mention the staining. The white sealing wax I use almost immediately started to turn brown on contact with the wood. The wood seems to be quite stable, with minimal checking. I've roughed maybe twenty five bowls ranging in diameter from 8 to 16 inches out of the tree, and am looking forward to completing them when dry, no matter what the species.

From contributor T:
Butternut tends to have a very shallow furrow in the bark, and without the furrow, the flatter parts would resemble something like ailanthus. Black locust does have very deep furrows unless the tree is young.

It sounds like you have black locust. You seem to have described the strong smell as freshly cut grass perfectly. It is also common for black locust to get a darker heart as it rots on the interior, as this wood is best harvested when young. Very few woods have a normal double heartwood with a different tone of color. Is there any difference in density in the darker hearwood? Stay away from the bark as it is toxic to animals. The toxicity to humans seems to be unknown.

From contributor W:
If it is black locust, there will only be a few rings of sapwood, the rest will be heartwood. If that is not the case, it is not black locust. What you described sounds like it could also be mulberry.