Damascus finishing question

R

Riley White

Joined
Feb 14, 2004
Messages
84
I have hammered ground and hardened a damascus knife of 5160 and 1095. I would like to know what acid is best and how to administer the treatment to the blade. This is my first damascus knife. Any info would help.
Thank you, Riley
 
Some folks use ferric chloride which can be bought at places like Radio Shack. It's used to etch circuit boards. Some folks use muratic acid which can be bought at places like Lowes or Home Depot. It's used for cleaning drive ways and such. Which ever one you choose, have some water with baking soda ready to dip the blade in after etching to neutralize the acid or it will continue eating the steel.
 
As a general rule, slower is better. I would use the ferric and if you want you can use vinegar instead. I would stay away from the stronger acids until you know the look you are after.
 
I have some muratic acid. Could I water it down or something like that to lessen it's rate of effect.
Riley (Gadget)
 
There's several techniques and opinions on this subject, but here's what I do.
After heat treating, sand the blade to at least 600 grit( I sand mine to 1500, but this is just my technique), wash blade really good using soap and water and don't touch it anywhere to be etched. Get some ferric chloride from radio shack and mix it 4 parts water to 1 part ferric chloride ( if your on city water with chlorine added use distilled water from the store) submerge the blade into the mixture and allow it to sit for 10 minutes, remove blade and lightly sand off the oxidation with some 2000 grit paper, place the blade back into the solution for another 10 minutes, do this until you get the contrast and depth your wanting ( I usually do 3 times) after the last time, sand lightly under running water, I then spray the blade down with windex that has ammonia added and lightly scrub with 0000 steel wool. rinse good with water , dry and then buff lightly with green chrome compound.

Hope this helps some,

Bill
 
The more dilute you make the acid the slower it will work. This is a good thing. Do you have any idea of the initial strength of the muriatic you have? Without knowing I would dilute it 10 to 1 and see if that etches. You can then add more muriatic if neccessary. Be carefull not to splash when pouring.
 
as I'm a manufacturing jeweler and use various acids almost daily. First of all, muratic acid is a diluted form of "hydrochloric acid" from a pure state and strength. I'd guess at least four parts water to one part hyrochloric would sound about right. Hydrochloric acid is not a very strong acid to start with and I doubt it comes in different "degrees" as some stronger acids do, such as the chemistry grade sulfuric and nitric I use occasionally which are "60o" acids; quite strong. However, if I mix hydrochloric and nitric acid in a four to one ratio, I've made what the Spanish (hundreds of years ago...) came to call "aqua regia", litterally "royal water". I'd would disolve just about anything but pure gold and of course, that's what it came to be rather famous for: testing gold. I use it every day in my store.
Now on to damascus etching. Like Buxton said above; a four to one of Ferric Chloride will do a nice etch for sure but it works best where a steel with a goodly amount of nickel is used say, L-6 or 15N20. When you've used two steel close in composition as you have I have had better results with a more aggressive acid combo such as "aqua regia" I've described above. Remember these "hotter" acids can be a pain so use gloves and do the work outside for starters where ventillation is not an issue. As someone else noted I believe, ( but if not...) baking soda will neutralize acid immediantly so have some handy.
A knifemaker from many years ago "Boye"?? was his name I believe, (somewhat famous for his 'dendrtic steel'??) made beautiful kitchen knives which had beautiful fanciful etchings on their broad blades. He even wrote a book on knife making back in the 70's.... Anyway, that's the formulae he used.

Go to my homepage for a look at two blades etched with ferric if you like. Lastly I'll tell you that your blade finish must be as perfect as you would normally do on a non-etched blade before you etch or else it will show up like a sore thumb. Also I'll tell you that both the blades on my page were finished with 4 ought steel wool then cold blued as a final finish was a little "Hapich Semichrome polish which removed a little more of the blue while imparting some polish.

regards, mitch

my page:
http://www.flex.net/~mitchwilkins/homepage/page5.htm
 
Hydrochloric acid is NOT a weak acid. Acid is defined by the concentration of Hydrogen ions in solution (pH). The lower the pH number is, the stronger the acid. HCl is the strongest acid in these terms. Others, like Hydrofloric and Nitric are close, but do not have the same rate of activity.

Muriatic acid is 0.375N Hydrochloric, that is it is diluted to 3/8 of full strength.

When diluting any strong acid, make sure that you add the acid to the water. If you add water to acid, it is liable to boil and splash on you with bad results.
 
I have been under the impression that damascus knives are great users....but they are etched with acid? How is anything you cut( food in this case) not affected by the acid? Even though it is sanded/buffed is there not residual acidity in the blade? Sorry to sound stupid but it just does not jive in my wee brain. Thanks. Take Care!!!
 
CKE2 said:
I have been under the impression that damascus knives are great users....but they are etched with acid? How is anything you cut( food in this case) not affected by the acid? Even though it is sanded/buffed is there not residual acidity in the blade? Sorry to sound stupid but it just does not jive in my wee brain. Thanks. Take Care!!!
Click to expand...

The acid is neutralized after the etch, otherwise it would continue to corrode the blade.
 
I like the sound of Bruce BUXTONS metod.

The only thing I will ad is copper sulphate. It is a blue crystal or powder that is used in gardens and is readily available.

Mix it with water 2 to 4 table spoons full to a pint of water. Worm warter seems to work best. Dip the blade in for 5 to 15 min works the same as acid.
It will make the blade grow an black and red fury mess around it but it washes of with a brush. Be acrefull not to rub the blade before it is black and fury because you can get it to coat with copper when the blade has been in for a short time.
The 2 benifits to comensate for the negatives is less fumes eating at your lungs some strong acids are very dangerous fumes and spills.

The second is if you put a small shaped logo cut from electrical insulating tap or similar material the copper sulphate soluton will not lift it of. So when your etch is finished your logo sits up above the blade. I like the look of that.

Acid always lifted it of for me. I have not tried feric.
 
You must log in or register to reply here.
Back
Top