Koa questions

[JGarrison Knives]

So a friend of the family that lives on the big island and has property there was kind enough to send me a couple pieces of koa. I cut the first piece off today and sanded it up to see what I got. These are sanded to 240 and I thought I was cutting it with the grain but looks like I was wrong? Ill take a pic of the before piece but I have after shots first. It measures about 2x2x6 with a nice crack that runs diagonally across the corner. I saw these cracks when I received it and wasn't sure how deep they would run. What do you guys think of this piece and is there anything else I should know before I cut the rest of the wood into blocks?

 

[JGarrison Knives]

Here it is pre-cut, there is a smaller piece that is the same thickness but grayer.

 

[Burl Source]

Everything in the first post is cross cut and end grain.
Not something you want with Koa. All of those will turn dark and featureless when finished.
The second post looks like a cross cut piece as well.
With Koa you want the wood to be cut the length of the log, not across the log.

 

[A.McPherson]

Mark, correct me if I'm wrong, but if you are trying to cut a log with the grain, you are basically trying to cut the log along its vertical axis right? From the roots to the top, or vise versa?

Oops, I just read your post more carefully, and that's exactly what you said! Lol!

 

[JGarrison Knives]

Well the first post is all of the same piece but I understand what you're saying.

 

[Burl Source]

Mark, correct me if I'm wrong, but if you are trying to cut a log with the grain, you are basically trying to cut the log along its vertical axis right? From the roots to the top, or vise versa?

Oops, I just read your post more carefully, and that's exactly what you said! Lol!

Here is what I meant. The 5th image shows how Koa should be cut if it has curly figure.

 

[A.McPherson]

Yeah, that's what I thought... can you tell if something is going to have interesting figure before you start cutting? I know some species are more likely than others, but say two curly maple logs of similar size.

 

[Jesse Latham]

The 5th image shows how Koa should be cut if it has curly figure.

Mark, Does this hold true for other woods like curly maple? Sorry for the highjack. Jess

 

[Burl Source]

For any curly wood you want to cut quartersawn.

 

[Burl Source]

Yeah, that's what I thought... can you tell if something is going to have interesting figure before you start cutting? I know some species are more likely than others, but say two curly maple logs of similar size.

You don't always have much of an indicator on the outside of the log whether it will be curly before cutting. There are some hints sometimes but not always.
This is some curly Koa.

When you look at the ends the ones with vertical growth rings are the quartersawn pieces.

Looking at these slabs you can see that the figure gets better on the pieces that are exactly quartersawn.

 

[JGarrison Knives]

Is it a bad idea to use wood that is not cut correctly or are we just talking about how it is going to look?

 

[Burl Source]

Cross cut and end grain pieces are a lot weaker than properly cut pieces.
This makes them more prone to cracking and breaking.