Metal in wood

I have read on the forum about metal in trees turning wood black or blue. While I was cutting the Red Oak I put the saw on the stump to sharpen the chain. I went back the next day and this was on the stump. Just from the shavings it turn black quick.

I also noticed that the splits have a dark edge where the maul contacted the wood. I have noticed this more with Oak than Ash or Maple.

 

You never know what your going to find in wood

 

IME Oak shows color the fastest. I've seen exactly what you are. Even the smallest amount of metal will usually give a bluish color overnight. No idea why Oak is so much more prone to this.

 

I see the blue hue often, when using wedges to split red oak.

 

Tannins in the wet oak react with iron.

It is a good indicator when cutting that something bad is about to happen to your chain.

 

supposedly it is the tannic acid
If you handle a lot of wet red oak splits and get the tannins coated on the palms of your hands pretty good and then handle some bare steel the palm of your hands can turn black

 

Much better to find with the splitter than the saw!

 

I found a piece of 1/2” round bar halfway into a huge corkscrew willow. Just glad it wasn’t my saw. Backhoe finished the stump after that

 

This I've known for a long time.

This I just learned. Thanks fellas.

 

Most of the time iron stain in wood is black/blue. This is because it is mostly Fe2+. Fe3+ oxides are orange/brown like rust, but I've never seen that yet. Must have to do with the redox contions in the wood

 

Yes, it's the tannic acid in the oak. I have seen it after 10-15 minutes when using a steel wedge to fall a tree.

 

I found this in a huge round that a tree service cut with the splitter. Lucky they didn't hit it.
This log on the trailer was a line fence tree. Had 3 strands of barb wire in it.