Ferric Chloride-n-Damascus...

R

razorhunter

Joined
Jan 27, 2002
Messages
470
Guys,
Reese Weiland sent me a few unground blades to practice grinding on, with my new BaderIII.
Last night, I noticed that in between passes on the platen, the dang blade was already starting to rust from dipping in and out of my damn quench bucket.
Well, it turns out, Reese said he must have sent me some Damascus, as it will have a tendency to rust really quickly while grinding it, if it is a little wet.
Well, I got the blade finished, and would like to bring out the damascus.
I have heard that ferric chloride can be used for this. Is this the norm procedure for damascus blades?
I just bought some FC at Radio Shack. What is the procedure for doing this? Do I need rubber gloves? Will latex gloves work, or will this crap eat through them? LOL! Should I just put this blade in a bowl, and "Pour out a little liquor to my homies"??? I ask, because I've had guys say to dilute this crap, and others say NOT to dilute. It's been 50/50.
I searched, and have read tons and tons of threads about etching names and logos in blades...
I kind of felt I should ask, before I mess with this crap for the first time...
 
Interesting, I can grind and dunk my damascus all day and never have rust problems. Heck I even let freshly ground blades sit out for weeks with out any rust.

Anyway, to aswer your question about ferric, I dilute mine 7 to 1. Pour out one pint from a gallon jug of distilled water and then add you one pint of ferric. Finish the blade upto at least 600 grit (after HT), degrease the blade, etch in the ferric for 30 minutes, neutralize the blade (I use white vinegar), bake at 200 °F for 20 minutes to set the black, hit it lightly with you last highest grit before etch to brighten everything up.

Thats how I do it anyway, hope that helps.
 
I use a 50/50 mix of ferric cloride to water and etch for 10 min, neutralize in tri sodium phosphate. I shoot for the temp of the acid/water solution to be about 70f. The warmer the acid the faster the etch. If the acid is cold it will take forever to etch the blade, if the acid is hot it will eat the steel up quickly. There have been a few times I forgot an entire bar in the etch over night and in the morning didn't have much left to work with.
 
Wow,
Didn't know it was that much work. I'm not even heat treating yet. I know, I should be!
I don't really even want to heat treat this blade. It's just a practice grind I used to help teach myself to grind. It looks ok, but it isn't going to be a finished knife or anything. I've got a lot of grinding practice to do.
Thanks for all the info bud, I will definitely use that in the future. Right now, I was just trying to focus on grinding a nice blade, and then doing the HT thing, etc.
Can I just do the FECL procedure to bring out the damascus, or do I HAVE to heat treat to make this process work? Thanks.
P.S. Keep in mind, this a fairly small folder blade, so it's not like I'm wasting a nice large blade that I'll want to use in the future...
 
I have hard water where I live and it will rust a blade pretty quickly also. If you put some baking soda in the water it will help keep the rust from forming so quickly.

Craig
 
Wise people have told me that using a more diluted solution of acid and etching the blade multiple times(with paper towel clean up between etchings) will result in a better looking, cleaner etched damascus blade.
 
I am definitely not the expert here but I thought ferric chloride was acidic? Isnt vinegar also acidic and therefore would not neutralize the etch? I though you were supposed to use something like baking soda in water to neutralize. Also, Im pretty sure you dont have to do the heat treat. I think he was just telling you the process to finish the blade. I think if you put it in the diluted ferric chloride it will bring out the pattern for you to see. If I am wrong please someone correct me but I was just curious about the vinegar.

Ryan
 
No, you don't have to heat treat to see the pattern, it just makes the contrast better.

There was a discussion quite a while ago either here or CKD/TKN about me using vinegar to neutralize the etch. I tried to go back and find it but I had no luck. The jist of the story is that the ferric makes some funky stuff when it attacks the iron, and the ones that would promote oxidation are neutralized by the vinegar.

I use vinegar because that is how I learned from Dr. Hrisoulas' video. Seems to work good so far, but I suppose TSP, baking soda, etc. are fine also.

The one thing I am a firm believer in is a slow etch. I think a slow etch is a prettier etch. When I etch cable damascus I use the same 7 to 1, but I only etch for 10 minutes and then hit it with 1200 grit paper and repeat that until I get the look I want (sometimes etching upto 60 minutes total).
 
I don’t think you have to worry about the rust that forms so quickly, I was asking the same thing to an old knife maker (30 years knife making )and he said that it is the small iron particles that is in the quench water that dries out quickly and shows the rusty color and I have made a point to regularly change my quench water.

Cheers "VAN"
 
I have gallons of Nitric Acid in my shop. I'am using it to etch my name on the blades. Can I use it to etch damascus or do I have to buy Ferric ? I know both can etch, does the ferric's etching result different ? :confused:
 
FlaMtnBkr - You are right,vinigar will not stop the etch on feric.Some guys etch in vinigar.TSP and baking soda are the usual etch stops.Rinsing and washing will remove most of the acid,and a bake at 200 will dry up the rest,but it can come back to haunt you later if you don't neutralize it totaly.
 
TSP=Tri Sodium Phosphate.

Your etch is going to depend upon the effect you want to have on the blade. It is also going to depend upon the composition of the differant steels in the mix. The instructions I gave are for most of the steels made by Devin Thomas. I worked for Devin for quite some time and this method produces the cleanest etch possible for these steels. Cable damascus is a whole differant animal and the etch I use would probably destroy the blade since you are not dealing with two differant steels to make the pattern.

The mix of steels is also going to dictate what type of etching medium you will use. With Devins 302/Aebl mix ferric attacks the AEBL but not the 302. I do have a double high carbon stainless mix that muratic acid is the medium used to etch. Muratic is used because one of the steels is resistant to the acid. If you etch this steel in ferric cloride the whole blade is attacked.

Lastly if you want the cleanest etch possible the blade needs to be heat treated.

Take a look at the knives on my site. They were etched using the above instructions.
 
The most efficient and easy to find neutralizing agent is baking soda [sodium bicarbonate]. Make sure you neutralize thoroughly . Many acids will etch damascus ; muriatic [hydrogen chloride] ,nitric acid, sulphuric acid etc. Each acid will act a little differently and of course are dependant on concentration , temperature and time.
 
BeowulftheGeat said:
I use a 50/50 mix of ferric cloride to water and etch for 10 min, neutralize in tri sodium phosphate. I shoot for the temp of the acid/water solution to be about 70f. The warmer the acid the faster the etch. If the acid is cold it will take forever to etch the blade, if the acid is hot it will eat the steel up quickly. There have been a few times I forgot an entire bar in the etch over night and in the morning didn't have much left to work with.
Click to expand...

I once etched a blade with a solution of ferric chloride that was too hot. I stupidly assumed that warmer is better, and put the solution in the microwave until it was bubbling. Etched the blade like normal, only the finished product looked like a freshly forged blade! Whatever finish I etched onto that blade was NOT coming off! I tried to grind it off with a fine belt; no way. I tried a coarser belt, but got little results. I ended up throwing the blade away.
 
I might as well throw my $.02 in here.
My experience has been that etch times vary drastically depending on the metals involved and the solution mix. Too much FC and your etch just eats away the entire blade uniformly. Too little FC and the etch takes forever. Bottom line is you've got to watch the etch and see what's going on in order to achieve the effect you are looking for.
The solution I use is 3 or 4 parts distilled water to one part FC. The etch can easily take an hour or more to achieve a nice deep contrast. Flip the blade over periodically if it is lying flat in a plastic tray. When finished, rinse with warm water and wash the blade with dish soap to neutralize the acid and remove the dissolved metal. It also doesn't hurt to scrub the blade with a rag while you are washing it off. Spray with WD40 and buff lightly with course steel wool to even things out. Oil the blade with 3-in-1 oil when finished.

Oh, and latex gloves work fine. You should also not breathe the fumes, as the stuff is actually quite caustic to tissue (i.e. your lungs) too.
 
O.K. guys, I went back and found the other post I was talking about. To see the explanation of why vinegar works and why Ferric Chloride is NOT and acid, take a look at this link:

Ferric Explanation

See, I told you so. ;) :D
 
I still think there are better ways to neutralize ferric chloride. So there. :p :)
 
Laredo,Ferric is indeed a base,and vinegar would stop the etch from to ferric,and start an etch itself.Ammonia or TSP are the simplest stops.My guess is that baking soda works by recombining the ions to create NaCl and some sort of carbonate.It's been too many years since my research days to do the formula in my head.
I use TSP and get a total stop.There is one other use for the soda,using it as a dry scrub to clean up the black crud after etch.Rinse the blade after stopping the etch,shake off the extra water,lay it down on an old towel and dump a handful of washing soda or baking soda on it.Scrub with a vegetable or nail brush .This is how silver and some other metals are brightened at the factory.
 
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