When a nail is hammered into an oak tree, it sends a blue vein up the wood.Submitted by Kwiercyski t3_127ss0a in mildlyinteresting
Kwiercyski OP t1_jefovus wrote
Reply to comment by dragon1n68 in When a nail is hammered into an oak tree, it sends a blue vein up the wood. by Kwiercyski
Apparently, the tannins in the oak react with the iron to make iron tannate (or tannic acid). This gives it the blue color. Pretty cool.
Substantial-Pie1758 t1_jegl9h7 wrote
People in the past used a similar reaction to make iron gall ink. They would take the tannins from oak galls and mix with iron to make black ink.
Kwiercyski OP t1_jegnl77 wrote
Interesting, I find Oak Galls all the time. I might try this just for the sake of it
Viewing a single comment thread. View all comments