White vinegar etch problems

S

Shawngambrel

Joined
Dec 21, 2018
Messages
10
hey guys, I’m having a problems. I’ve etched a few blades just letting it soak in white viniger over night with success until now. This larger knife, Siberian knife etches dark super dark but I can’t keep from washing it off. What am I doing wrong? How can I keep from washing the dark etch off?

https://imgur.com/a/rDs29BU
 
You didn't say what the steel was ... that makes a difference.

You will have far better results with FC.

I would leave the edge bevel as it is and re-sand the upper bevel at a lower grit. That way the etch has something to "grab" onto. Re-etch, neutralize, and clean off the edge bevel to be white while the upper part stays dark.
 
400 grit should get a bite from the etch. I wouldn't worry about coating the bevel. At 1000 grit it will etch less dark than the 400 grit. A few passes with a piece of steel wool will make it bright again.

The biggest problem is etching 15N20. The nickel makes etching harder. Vinegar probably isn't sufficient. You can try hot vinegar at 120F and see if it helps. FC would make your life easier.

Make sure the blade is surgically clean before etching. Scrub with soap and hot water. rins with hot water. Wipe dry with a clean paper towel. Etch without touching the bevels.

Using FC:
Make sure the tank is large enough. A 18X3" piece of PVC with a closed flange on one end and a slip cap on the other works great.
Take out of the tank every 3 to 5 minutes, rinse with the garden hose, wipe off lightly with a clean paper towel ( some use 4/0 steel wool gently), rinse again, and put right back in the tank. You have to remove the black sludge from the surface or it acts as a shield against continued etching.
After 20-30 minutes of clean and etch cycles you should have a deep etch (sometimes it takes an hour or so).
Make sure you rinse well and clean the blade, then neutralize the etchant with TSP/Windex/ammonia/etc.

Remember, no matter how long you etch, the etch is only a surface oxide and doesn't really penetrate the steel. Rub hard in cleaning and you will rub it off.
 
Stacy E. Apelt - Bladesmith said:
400 grit should get a bite from the etch. I wouldn't worry about coating the bevel. At 1000 grit it will etch less dark than the 400 grit. A few passes with a piece of steel wool will make it bright again.

The biggest problem is etching 15N20. The nickel makes etching harder. Vinegar probably isn't sufficient. You can try hot vinegar at 120F and see if it helps. FC would make your life easier.

Make sure the blade is surgically clean before etching. Scrub with soap and hot water. rins with hot water. Wipe dry with a clean paper towel. Etch without touching the bevels.

Using FC:
Make sure the tank is large enough. A 18X3" piece of PVC with a closed flange on one end and a slip cap on the other works great.
Take out of the tank every 3 to 5 minutes, rinse with the garden hose, wipe off lightly with a clean paper towel ( some use 4/0 steel wool gently), rinse again, and put right back in the tank. You have to remove the black sludge from the surface or it acts as a shield against continued etching.
After 20-30 minutes of clean and etch cycles you should have a deep etch (sometimes it takes an hour or so).
Make sure you rinse well and clean the blade, then neutralize the etchant with TSP/Windex/ammonia/etc.

Remember, no matter how long you etch, the etch is only a surface oxide and doesn't really penetrate the steel. Rub hard in cleaning and you will rub it off.
Click to expand...
Do you dilute the FC with distilled water or vinegar? If so, what ratio do you recommend?
 
My tank has 3:1 distilled water to FC. For etching a hamon, I use 15:1. I use it at room temp.

I played with vinegar in the mix and didn't like it.

BTW, I mix my FC stock solution from dry powder and mix it to 42 Baume. Use the Google Custom Search Engine to do a search on my mixing instructions.
 
You must log in or register to reply here.
Back
Top