Vinegar etch question

[Nick Schreiber]

Hey all! I have used vinegar to achieve a nice dark etch on a few knives and have been happy with the results. I bought a gallon about six months ago and use a clean water bottle that I’ve cut the top off of to soak the blade in the vinegar. After I’m done I toss the vinegar out and the next time I etch a blade I start with new vinegar from the same one gallon container I purchased. What I have been seeing lately is the blades have been taking a lot longer to achieve the dark etch than it used to. Does vinegar lose its potency once it’s opened? I bought a bottle of ferric chloride to use for the next blade I etch but I’m wondering if anyone else has had the vinegar issue? Thoughts? Questions? Suggestions?

 

[EdCaffreyMS]

Any etchatnt will "wear out" with use. It's more that the etachant becomes contaminated with various things from what you put in it to etch. Normally a freshly made tank of ferric will last me approx a year. Unless I do something stupid, and contaminate before then.

If you're going to use Ferric, dilute it 3 to 1 or 4 to 1 with DISTILLED WATER. As it comes out of the bottle ferric is too harsh, and etches everything equally. Diluted the etch takes longer, but the rule of thumb with etching any blade/damascus...... the slower the etch, the better the end results.

 

[Nick Schreiber]

Thank you! Just to make sure I am understanding you correctly, you mean 3 or 4 parts distilled water to 1 part Ferric, correct?

 

[EdCaffreyMS]

Yes..... 1 part ferric, and either 3 or 4 parts distilled water. If you have the quart bottle of ferric, just get and old plastic milk jug, rinse it out well, then pour the bottle of ferric into the jug..... then use the ferric bottle as a measuring tool...... fill with distilled water and pour into the jug with the ferric...... either 3 or 4 times.

 

[KenH]

After I’m done I toss the vinegar out and the next time I etch a blade I start with new vinegar from the same one gallon container I purchased.

Using new vinegar each time prevents the contaminants from entering the picture. acetic acid should not go bad and vinegar is said to last over 5 yrs. Not sure why your etch is taking longer with the vinegar since it's unused vinegar and should be able to be considered as new.

Ed's right on the money with Ferric for etching - dilute that stuff. I etched with 1:1 mix and the resulting etch looked sorta "muddy". With Ed's usual great advice a good 4:1 dilute with distilled water and the result was MUCH better.