Walnut cut today w/ pics

ohsoloco · March 24, 2008, 10:38:45 PM

Hopefully this isn't too far off topic...it's regarding walnut sapwood. I just happened to be slicing up some nice walnut crotches this weekend

Why does the sapwood sometimes turn an aqua-blue color in some spots almost immediately after cutting ???

When I went to stack the crotches on Saturday, I was looking at some of the crotches that I cut last month, and noticed quite a bit of checking on them :-\ They were logs that had been sitting for a while...don't know if that had anything to do with it or not. I decided to experiment with some anchorseal on the crotch areas this time.

Ironwood · March 25, 2008, 01:08:46 PM

Yes, that blueing/ greening does seem to occur with frequency where water can lay and penetrate (esp. crotches). Generally the sapwood can change color damatically from piece to piece right after sawing and even as it ages.

Ironwood

isawlogs · March 25, 2008, 06:40:10 PM

The stainning is caused by chemical reaction between the wood and iron . The tannin acid in the board will darken with contact with any steel other then Stainless steel .It is common in oak , helmlock and butternut , wallnut ... probably a lot more.

ohsoloco · March 25, 2008, 07:34:56 PM

I've seen woods turn that blue-black color when exposed to iron, even walnut heartwood. This doesn't seem like it would be the case with the color change I'm talking about, but perhaps it is? The color is like a teal (sp?)....like a carribean ocean almost. It seems to follow the grain somewhat as well, especially right along the sapwood/heartwood border.

Ironwood · March 25, 2008, 08:44:57 PM

Ohsoloco,

Yes, that is the color, and I must agree I think its the exposure to the air as opposed to the metal blades. Walnut is VERY air reactive and and changes dramatically immeadiately after coming off the saw, so much so, that i began to think about putting a disclaimer with all my right off the saw walnut pictures that this is a representation of the material "as it came off the saw" and it can change alot when drying no matter how much special attention you give it. Some architects and designers have problem even with subtle color variation from the pictures, which are taken in the "wettted down " mode, and I don't want to do that after it is dry.

ironwood

ohsoloco · March 25, 2008, 09:34:57 PM

Yeah, it's neat to open up a walnut log that's been sitting around for a year or more, and the ends of the boards for about a foot or so in are a different color than the rest of the board. When it's fresh cut it has olive hues to it, and then very quickly changes to a more purplish-brown color.

Husband · March 26, 2008, 03:51:53 AM

All I can say is WOW

Some VERY nice looking pieces of wood there!

Sparty · March 26, 2008, 08:46:09 PM

We were scared for a moment when we found some slight black marks on the end of one of the prime logs. We all thought that there was metal in the log. Then I remembered that the tree didn't have those marks a couple weeks ago. I then realized that I had left a chain on the end of the log for a week. A week of metal to bare walnut, in some wet weather, only left a very small black mark. My point is that I would be surprised if walnut would react to brief contact to a metal blade. Oak, maybe, but I've never known walnut to do that. If the blue stain follows grain lines, I would suspect bacterial stain. I don't have much experiance with stain in walnut, but bacteria would be my guess.