Finishing hand forged knives

[David R. Pennington]

Learning to do a little smithing and knocked out three fair knife blades. After I did all the file work took them to a friend of mine who is a master and watched him harden and draw the temper. He sharpened each one afterward till it would shave arm hair and then tested the edge on a 20d nail forcing the sharpened edge to deflect. If they would deflect and then spring back without breaking he judged the temper to be good. One of the blades looks like it has a little pattern in the grain of the steel. My question is can I etch that blade and help acentuate that grain. Will aqua fortis do it?

[rich pierce]

I'm not sure there should be much grain to a simple forged knife.  There are formulas to accentuate Damascus patterns but they differentially brown or darken the softer and harder layers if I understand it correctly.

[LRB]

  Ferric acid is used by many knife makers to bring out a hamon line. radio Shack used to sell it. It is commonly used to etch circuit boards. That pattern you see may only be from heat scale, and only on the very surface.

[cmac]

I broil my blades in bleach for about 20 minutes or cold blue and then cold soak for about 30 minutes. One of these knives is on my blog:  http://cmacsflints.blogspot.com if you want to see the pattern. It may be back a ways in the posts

[cmac]

Oh and if there is a grain appearance the steel may have been rolled or folded. That is about the only time I have seen what you are describing

[nc_cooter]

What steel did you use? I have seen 1095 steel show some "grain" effect when overheated a bit. One of my students made a couple that showed that effect.
Mike

[David R. Pennington]

Two of the blades were made from discarded brake shoe clips from a railroad car and one was from an old file.

[keweenaw]

If you don't grind the teeth off of an old file before you start forging or remove a lot of surface metal after you  rough forge it the tooth lines will appear in the steel.