# Cuban mahogany characteristis (got a chunk from Bluegrass)



## phinds (Apr 19, 2014)

Among the sample chunks that Les sent was a piece of Cuban mahogany (and now Les, I'm assuming that you got in your rowboat, rowed to Cuba, cut off a big tree limb and rowed back, right? ).

The main way you can tell American mahoganies (genus Swietenia) from African mahoganies (genus Khaya) is in the marginal parenchyma lines (See my new wood anatomy article for the details). You can't see these in the end grain with the naked eye but they stand our really clearly in a cleaned up end grain when you look through a 10X loupe. Also very rare is being able to see them on the face grain (even with a 10X loupe ... they're usually just too thin and weak). I only had one piece where that happened until I got this piece from Les and on this one there happens to be a marginal parenchyma line in an area that has a dark stain, which makes it really stand out. On the face grain shot shown here you can't see it but that's because the photo reduction down from the original messed up the pixels just enough to make it too fuzzy, but on the wood itself you can see it clearly if you know what to look for. I've included a face grain closeup that shows both the ray flakes and the parenchyma line and I've indicated with a blue arrow the same line in several shots.




face grain showing the parenchyma line at the bottom of the stain area (you can't really see it here, but it is very visible in the wood itself, just with the naked eye)





end grain





closeup of a very cleaned-up end grain (sanded to 1200 grit) showing lots of marginal parenchyma lines with the one under discussion flagged with a blue arrow. This is shown here at about 4X (depending on your monitor) and the line so as you can probably imagine, these lines aren't visible to the naked eye (well, not to my old eyes anyway) but with a 10X loupe they are very clear.





face grain closeup showing ray flakes and the marginal parenchyma line. This is upside down from the face grain shot but it's the same surface.

These ray flakes puzzle me, as have similar ones on other pieces every now and then. The reason I'm puzzled is that the flake lines are exactly perpendicular to the rays and the rays are almost exactly parallel to the surface. Think of this face surface as a sheet of paper. The rays are lots and lots of other pieces of paper that are almost exactly the same orientation as this face, just lower and lower into the wood. Now if you tilt the ray sheets a bit from front to back or from back to front, you would get ray flakes that run left to right. The only way I can see to get the ray flakes that are actually there would be to tilt the ray surfaces down a bit on the left and up on the right, or vice-verse. BUT, given how close together these flake are, that tilt would have to be pretty severe and as far as I can tell, that just isn't happening in the wood. SO ... how the hell does it end up with all those little flake lines running up and down???

Reactions: Like 3 | Informative 1


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## Blueglass (Apr 19, 2014)

I grew up in the FL Keys which is part of Cuban Mahoganies natural range. There are a few small sawyers down there that get storm fall, permitted removal and trimmings. That was from a crotch piece if that helps you any.
I must admit it is pretty cool seeing pieces of wood I've had in my hands blown up like that. Very different perspective.

Oh and it was an inner tube raft.

Reactions: Like 2


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## DKMD (Apr 19, 2014)

I find myself becoming more and more interested in the micro anatomy of wood... Who knew it was so cool on a small scale?

Paul, I think I follow the paper analogy you gave... If the sheets were very, very thin, wouldn't that decrease the amount of tilt needed to generate those ray flakes?


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## phinds (Apr 19, 2014)

DKMD said:


> I find myself becoming more and more interested in the micro anatomy of wood... Who knew it was so cool on a small scale?
> 
> Paul, I think I follow the paper analogy you gave... If the sheets were very, very thin, wouldn't that decrease the amount of tilt needed to generate those ray flakes?


 
Yes, you make a good point and in fact they ARE very thin. Also very numerous, which would also be needed to get what we are seeing. But they are still oriented in a way that confuses me. Now, I AM easily confused  but I'm really stumped by this one. So much so that I went back and looked and found numerous other examples of the same thing, which just confuses me more. Since THREE of the pieces that Les sent me have that same characteristic, I though for a while that maybe he had some kind of magical attachment on his planer that caused this, but it's all the same situation ... numerous thin rays, almost parallel to the flat cut surface, and then ray flakes (or what I can't see as being anything BUT ray flakes) that have an orientation that I just can't make sense of. They are not exactly straight as you would get from a planer, but they are close to perfectly perpendicular to the direction I think they should be going in. Again, these are not the only woods that I find this happening on. I've got cherry and others that do the same thing.

Here's the same thing on a piece of jucaro that Les sent. I has an almost identical configuration of numerous thin rays almost parallel to the face grain and then flakes that are perpendicular to where I think they ought to be.


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## Blueglass (Apr 19, 2014)

First of all very strange things happen everyday in the Keys! IDK proximity to the Triangle? I agree with the Doc I think it would be cool to have framed blown up posters as art in my man cave (if I ever have one).

Are most of the examples you have seen of this phenomenom tropical? Different angle of sunlight and different hours?


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## phinds (Apr 19, 2014)

Blueglass said:


> First of all very strange things happen everyday in the Keys! IDK proximity to the Triangle? I agree with the Doc I think it would be cool to have framed blown up posters as art in my man cave (if I ever have one).
> 
> Are most of the examples you have seen of this phenomenom tropical? Different angle of sunlight and different hours?


 
Hm ... no I don't think so, particularly. The first one that came to mind to check out when I noticed it on the jucaro the other day was good old American black cherry and it definitely has the same thing.

Speaking of posters, do you have the wood poster that I sponsor?


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## Blueglass (Apr 19, 2014)

No I do not have it. I do love working with Cherry and I have noticed that behavior from it as well.


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