View Full Version : etching cable damascus


Diamond G Knives
12-30-2001, 12:38 PM
Hello everyone, I just finished my first piece of cable damascus! I forged to shape and ground the blade, triple normilzed it then triple tempered it at 375 for 1 hour each.
Im etching in feric cloride(thanks Max, he gave it to me)
but the etch didnt take as well as I wanted, the pattern is there, just not very pronounced. I finished the blade to roughly a 400 to 600 grit finish first. How long in the etch is long enough? Is temeprature of the echant a factor?I cleaned the blade first with asetone.

Bob Warner
12-30-2001, 03:44 PM
Temperature definately affects etching time. The colder it is the longer it takes. However, this can be a good thing, to me a slow etch is a much nocer etch. If you etch to fast you can get pitts in the metal and they don't look good on the finished product. I mix my ferric Chloride 1:4, one part FC and three parts distilled water. You can etch deep enough that the welds of the cable are raised out of the blade if you want, just etch it longer. I etch about five minutes at a time and check it between until I get what I want, then throw it in a bath of water and baking soda to neutralize the acid. Sometimes the etch takes thirty minutes to get what I want. It really does vary so you just have to keep checking it. Run it across a buffer after the etch and you will see the welds raise if you etched it long enough.

Diamond G Knives
12-30-2001, 07:30 PM
Thanks Bob
What compuond do you use on it to buff?

Bob Warner
12-30-2001, 07:46 PM
I normally go after it with green chrome compound, that will clean it up real well and get all the black off. Some people want the black to stay on but I like it off so I can see the veins against clean steel. Then I hand rub to 1500 grit (just to clean up the tops of the veins). It looks good to me.

foxcreek
12-30-2001, 08:25 PM
Of course, if a slow etch is not looking right to you, you might try a nasty quick etch of short duration, and then follow up with longer gentler etch. I etched a small blade in HOT muriatic one time. worked great, took about three minutes! Muriatic was all I had, and I wasnt sure it would touch an all high-carbon pattern weld at all. (It wasnt mine, I had made a little knife off a scrap from a Bud. )

Bob Warner
12-30-2001, 08:48 PM
I have used Muratic acid before and don't mind using it. I like to use it on very tight patterns to get a lot of depth so I can hit the highs on my grinder with a 600 grit belt (worn out) to clean them up. But I always use Ferric Chloride when I have larger areas that need to etch evenly, and to me it works best on cable damascus. But like you said, if it doesn't look right to you, do something different.

prizzim
12-30-2001, 09:06 PM
A question, gentlemen... What is the advantage of watering down one's FeCl at a 4:1 ratio? I haven't tried etching in FeCl yet, but have used Apple Cider Vinegar straight out of the bottle. What's going on with the water?

Bob Warner
12-30-2001, 09:32 PM
Watering down the FeCl will just make it weaker and etch slower. Fast etching can result in pitting so I prefer to water it down so I get a slow, even etch. I use 4:1 mix but others use different mixes and many use it straight. It is all personal preference.

I tend to get distracted because I do more than one thing at a time (etch while forging and running back and forth) and the watered down FeCl will help me avoid eating an entire blade away while I am welding some damascus or showing my kid (Kevin 11yrs) how to forge a part of his knife (don't you wish you were forging at 11?).

MaxTheKnife
12-31-2001, 09:05 AM
Hey Bob, here's something else that watering down the fecl does. It adds oxygen and actually speeds up the etching by causing faster oxidation (hence, the oxygen). But, since the acid is weaker it is a more controlled etch. I've found that room temp is the best temp for etching for a nice, even etch. That's just what I've noticed since I started playing with fecl.

If you have an old aquarium pump with a bubble stone you can put that in your etch tank to increase the oxygen content and speed up the etching process as well. I've been looking for that stuff but so far haven't found it. I guess Wal-Mart would have it. ACK!!!

Bob Warner
12-31-2001, 09:19 AM
That makes sense Max.

I have learned over the years that slower is usually better. You are less likely to mess up. I have been doing this long enough that I don't get so excited about finishing something that I take unnecessary risks to get done faster. I have seen a lot of blades all pitted up from fast etching and I just am not in that big of a hurry. Maybe because I am old now or maybe because I don't depend on the income from knives so I can take my time. As I said earlier, I seem to always have more than one thing going on at a time and if I get distracted too long, the damage can be bad enoough that It will cause me to have to redo something and that can take a lot longer than a slow etch. If I were to do nothing else (at the same time) but etch and could do it faster without pitting, I would jump on it. The oxygen idea makes sense to me and would probably work great. I may have to play with that idea.


Walmart would have the pump and stones as well as the air hose. About $15 and you are in business.

MaxTheKnife
12-31-2001, 11:11 AM
Thanks Bob. And I totally forgot to address Mike's question. He he.

Hey Mike, one thing to try is instead of using that nasty acetone just use hot, soapy water and a stiff scrub brush to clean the blade bofore etching. Dishwashing liquid like Dawn or Palmolive is best. Add some baking soda into it as well for a little abrasive action to get all the crap out that you can. Then rinse the blade very well and don't touch it with your bare hands. Handle it with a clean paper towel. Do the same treatment when you remove and check the blade each time so each time you start with a clean blade with no oxidation on it. The steel doesn't oxidize very fast with that slime on it. And it also makes it spotty and unattractive. Am I clear as mud? Hard to splain this in writing. Call me when you get the chance and I'll yak your ear off about it :)

Dana Acker
12-31-2001, 02:24 PM
After normalizing 3 times and before tempering 3 times, in what did you quench your blade? Did you check for hardness with a file after quenching? Also, did you spark test your cable before hand to make sure it was hardenable steel? I'm no metalurgist by any stretch, but I'm wondering if steel hardness could effect the etch? Also alloy content might effect it. Maybe maybe not. The Flaming Blade or Bog Iron, I hope will add their expertise here and perhaps clear some of this up. They would have definitive answers.

I use a ratio of 1 part ferric chloride to 3 parts of water. I hold my cable damascus in the acid (checking it frequently) until it turns black, then wipe it off, spray it with Windex, then wash it with warm water and baking soda to neutralize any residual acid. Then I gently go over the blade with very fine steel wool just to lighten it a bit and show the pattern. The blade will still be inbetween light black and gray, but the "lizzard skin" pattern shows up real well.

MaxTheKnife
12-31-2001, 11:46 PM
Oh yeah, after forging, annealing, normalizing X 3, quenching and tempering there's lots of nasty scale to deal with. Soak the blade overnight in regular white vinegar. That will kill almost all the scale. Of course, you still need to wash it good with hot soapy water and a scrub brush before you soak it in the vinegar. You'll get better results from the vinegar that way. Try it, you'll like it!

Diamond G Knives
01-01-2002, 12:35 PM
Dana
I didnt spark test it, If the truth be known, I was just fooling around, and was just so #### tickled that it worked this time
I wasn't too concerned if it made a good blade or not! I made my first damascus! But I guess luck is with me, It hardened very well in my quench medium. I use diesl fuel that has been slightly warmed. I checked it with a file, and it wont touch it! bounced off it like water on hot steel!! I re eched it for about 45 min and the etch was MUCH better raised the grain noticably, and then I hit it with the green compund on the buffer. I am ver pleased with the outcome!
Another question, I only fluxed then twisted the cable tight, then lightly hammered it around itself. should I have tried to fold it, and weld back into itself?

Thanks for all your help

Mike

Dana Acker
01-02-2002, 10:52 AM
There are different methods of welding cable. Some actually do a twist weld by fluxing then bringing it up to welding temp, then putting one end in a vise and twisting it tight at welding heat. Those who do it that way seem to like it,

I bring my cable to an orange heat (continually rotating the piece in the fire in the same direction of the twist--to keep the heat even and to keep from burning up strands,) then I flux, heat again and flux again prior to welding. After fluxing, I bring the cable up to a yellow heat and make my 1st weld about an inch and a half back from the tip end. I weld by hammering with a number of medium blows, then rotating the piece 1 quarter turn and giving it an equal number of blows. I continue this sequence until I feel the place where I'm hammering go hard (solid.) Then I weld again for insurance.

Once my initial weld is established I weld the tip (if you try to weld the tip first it can unravel on you--of course you can spot weld the tip before forging or tie it with wire--but that's a lot of trouble.)

I have heard that folding cable damascus and welding it back onto itself will diminish the pattern. Again, it's a case of some do and some don't--finding the way that works for you is always the best bet.

Bob Warner
01-02-2002, 01:40 PM
For welding cable, I made a littledie to help hold the cable together during the welding process. I do not arc weld it together or anything. Just make this tool and try it out.

Take two pieces of angle iron (Very heavy duty) and place them point up on a piece of flat plate. Weld them in place. They should look like the picture. Place your hot cable in it and hit it with the hammer. There is pressure on the cable from three sides, two angle iron and one hammer, working to compress it. It will not unravel if you do this. It will also not smash and spread either. It works well for me and maybe it will work for you. Excuse the bad drawing but I am not at home and have to draw with a poor program.

http://www.warnerknives.com/CKD/die.jpg

Diamond G Knives
01-02-2002, 07:40 PM
Thanks guysDana, I agree with you on "what works for you" is good view. I have found that trial and error is usually the best way, but sometimes it sure is a bitch! Ha Ha!
Thanks for the drawing, it sure does make a lot of sense with equal pressure on all sides. I wonder if this would work with moutiple strands of cable??

Thanks again for the ideas

Mike

Bob Warner
01-03-2002, 06:02 AM
I use post tentioning cable, it has six strands around 1 center strand. I have taken seven of thes cables and wrapped six around a center cable and welded them all together in a big die like the one in the drawing. It works great. Since I have a press, I made the tops of the angle iron at the right height so that when I get to where I am hitting the tops of the die, I have definately reduced the billet enough to not have any welding flaws. It really works great.

Diamond G Knives
01-04-2002, 01:51 PM
Bob
Thanks for all the great advise and input. It is really awsome to have this forum and the seemingly endless pool of knowledge!!!
Another question I had was this. I have a source for cable that came from an old historic bridge where I live, the problem is, that even though it is still solid, its quite rusty. Can I use this as is with the rust?> Will fluxing it take away any harmful non welding traits? I would really like to use this for sentimental and historic reasons. Its about 1 1/2 inch round stock and I feel that high tention bridge cable would be fairly good stuff to begin with. Any thoughts?

Thanks
Mike

Bob Warner
01-04-2002, 07:08 PM
Mike,

Rust is not a problem.

All you have to do ( and I do this a lot with the cable I use), is to get it hot and flux it, put it back into the forge, when you reach welding temp, take it out and SWING it towards the ground agressively and then on up to the anvil (or press) and forge together. When you swing it, all the garbage (rust, dirt) fly out and when you get to the anvil, you have clean steel. You have to do this fast as you only have a second or two to get on the anvil and start welding. Some people do the swing to clean and immediately reflux and go back to the forge, then get to welding temp and weld as usual. Be carefull where you swing it, most of the stuff that comes out is molten scale, it is really hot and will burn through your shoes and clothes. Make sure it goes where you want it to. Keep visitors away also.

Diamond G Knives
01-04-2002, 10:56 PM
Will do Bob, Thanks!
Mike