Pattern Weld Etchant Question

[Meridianfrost]

Hello everyone!

i have a question that I can’t seem to find the answer to. I have done my first pattern welded knife, and I am confused by the etchant portion. I’ll attach a picture of the knife that I etched in instant coffee. 

I know that I need to get some ferric chloride to get the texture that I want, but there doesn’t seem to be specific information about how to mix the ferric chloride solution so I will get a proper etch. 

As you may know, ferric chloride is available in all sorts of forms. You can buy it dry, and mix your own solution. You can buy it from various places pre-mixed in a number of different ratios. 43%, 60%, etc. Also, I don’t know what ratio of distilled water to use with powdered ferric chloride, or if the pre-mixed solutions available need to be diluted. 

Any help you could provide would be very much appreciated. If there is a standard that people use with consistent results, or a particular brand of ferric chloride works better than others, I would love to know about it. 

Thanks very much for all of your responses.  The knife in the photo say in an instant coffee solution for about 2.5 hours. 

[Jclonts82]

I have researched quite a bit, and have found that about a 20% solution is generally as strong as you want to get. you can go lower and etch longer until you get the desired effect. its more careful that way too.

In my world of pharmaceuticals, the shortcut i use for making anything with pure powder is this:

 

1% = 1gm in 100mls.      20% = 20grams in 100mls.   expanded out to a liter: 200 grams in 1000mls = 20%

 

if starting with ~60% liquid, adding an equal volume would cut the percentage in half. ie 250mls 60% concentrate + 250mls H2O = 500 mls of 30% concentration. 

 

 

I buy the 60% and mix 100mls concentrate to 300 mls water for a final concentration of about 15%

[Meridianfrost]

This is great information. Thanks very much for the response. Powder arrived today, so I will be mixing and etching. I’m going to use this formula. Thanks again.