[Gary Mulkey]

I, like many, make my damascus from 1084 & 15N20 (Aldo's) and use a 4to1 ferric solution for the etch. Periodically I will get small pits(for lack of a better word) in the 1084 after etching. I sand each billet to 1000 grit before the etch and etch immediately afterwards. I have refreshed my ferric thinking that it might be old and the cause of the problem with no noticable change.

Any ideas as to what is going on? Is this simply in the steel initially or something that I am doing?

Gary

[Mike Williams]

How long do you etch each time?
How many times in the etch?
When in the process do the "pits" appear? Immediately,second, fourth cycle?
What is your layer count?
What pattern?
What is the ferric temp when etching?
How often does it happen; every time, often, sometimes?
Lots of things to think about before we can figure out any solutions.
Mike

[Gary Mulkey]

Mike,

I will etch for 10 minutes at room temperature, wipe the steel off and repeat for another 10 minutes. I make a lot of different patterns & layer counts but seems to notice the problem most with my basic 240-300 layer random. I haven't noticed the "pits" until after the final etch but if they are there earlier, I probably wouldn't be able to see them.

I don't have this problem everytime but it happens often enough to be disturbing. I'm not sure that "pits" is an appropriate term but there is definately an uneven etch there.

Thanks for the responce.

Gary

[Mike Williams]

Gary;
Lots of variables to be considered. When?; in the etch cycle that the problem starts is a big question.
A thought: The next blade that does this; sand it back clean and line it off into four parts. Etch the tip end,clean; 2nd etch one part deeper, clean; and so on for four parts. Look closely at each section after cleaning.
When you find the problem and sand it back down; does the pitting somewhat follow the flow of the pattern?
Lots of variables in damascus steel.

Definition of insanity: doing the same thing over and over and expecting different results.
Us genious knifemakers: Doing something a thousand different ways and expecting the same results.

[Gary Mulkey]

Mike Williams, on 20 June 2012 - 08:15 AM, said:

Gary;
Lots of variables to be considered. When?; in the etch cycle that the problem starts is a big question.
A thought: The next blade that does this; sand it back clean and line it off into four parts. Etch the tip end,clean; 2nd etch one part deeper, clean; and so on for four parts. Look closely at each section after cleaning.
When you find the problem and sand it back down; does the pitting somewhat follow the flow of the pattern?
Lots of variables in damascus steel.

Definition of insanity: doing the same thing over and over and expecting different results.
Us genious knifemakers: Doing something a thousand different ways and expecting the same results.

Thanks, Mike. That makes a lot of sense. I'll give it a try.

Gary

[Karl B. Andersen]

Gary, when you say wipe between etching cycles, what are you wiping with?
I will clean oxides off with NEW 0000 steel wool and rinse in clean water, before the following etch, but never wipe with anything.
Too easy to contaminate your steel.
Please don't say paper towels!! They are loaded with chemicals that will wreak havoc with etching.

[Gary Mulkey]

Karl B. Andersen, on 20 June 2012 - 07:14 PM, said:

Gary, when you say wipe between etching cycles, what are you wiping with?
I will clean oxides off with NEW 0000 steel wool and rinse in clean water, before the following etch, but never wipe with anything.
Too easy to contaminate your steel.
Please don't say paper towels!! They are loaded with chemicals that will wreak havoc with etching.

I have been using a cloth. I never thought much about it but I suppose that I could be contaminating the steel while wiping it between etches.

Gary

[Shawn McIntyre]

G'day Gary
This is a problem i also encountered years ago. What I am about to say only relates to my steel, heat treating, patterning etc. i know for a fact that other smiths use other techniqus that do not have the same trouble I did. It became apparent that if I etched for too long before scrubbing the oxides off the problem would start. It seemed that the oxides would form a nucleation site for lack of a better term. The Ferric (3to 1) would find a spot, lots of spots in fact, and drill like mad. i mean worm holes to another universe, straight into the blade. I thought at first it was the weld lines but then realised it would happen in homogenouse bands of material as well, although not as frequently. My solution was not to etch any longer than 5 minute cycles and to use more of them to get the depth. The worm holes stopped. I must also echo Carl's comment on the towels. Aside from contamination, I want the steel back to clean surface for the next etch. For me that was oooo steel wool but i have now gone over to 2500 grit paper and windex as a lubricant. Flush with clean water and then back in for another 5. I am also making sure my Ferric is about 85-90 degrees. It is counter intuitive but the I find that the warm ferric is more aggressive but i have better control because it takes less cycles to get the depth I want. Lot's and lot's of cycles in a cold etch gives me less definition than i want. I hope this helps and let us know how you go. Cheers Shawn

[Mike Williams]

In the long past I used steel wool also. Steel wool comes in the pack oiled to prevent it from rusting. That oil can be a real problem if little tiny bits,streaks,lines, blotches, etc., stick to the blade as it goes in for the next etch cycle.
M

[Gary Mulkey]

Shawn McIntyre, on 24 June 2012 - 05:22 PM, said:

G'day Gary
This is a problem i also encountered years ago. What I am about to say only relates to my steel, heat treating, patterning etc. i know for a fact that other smiths use other techniqus that do not have the same trouble I did. It became apparent that if I etched for too long before scrubbing the oxides off the problem would start. It seemed that the oxides would form a nucleation site for lack of a better term. The Ferric (3to 1) would find a spot, lots of spots in fact, and drill like mad. i mean worm holes to another universe, straight into the blade. I thought at first it was the weld lines but then realised it would happen in homogenouse bands of material as well, although not as frequently. My solution was not to etch any longer than 5 minute cycles and to use more of them to get the depth. The worm holes stopped. I must also echo Carl's comment on the towels. Aside from contamination, I want the steel back to clean surface for the next etch. For me that was oooo steel wool but i have now gone over to 2500 grit paper and windex as a lubricant. Flush with clean water and then back in for another 5. I am also making sure my Ferric is about 85-90 degrees. It is counter intuitive but the I find that the warm ferric is more aggressive but i have better control because it takes less cycles to get the depth I want. Lot's and lot's of cycles in a cold etch gives me less definition than i want. I hope this helps and let us know how you go. Cheers Shawn

Thanks, Shawn. It sounds as if my problem is the same as what yours was. I'll start 5 minutes cycles and make sure the steel is clean. I appreciate the advice.

Gary

[Tony Hughes]

Mike Williams, on 25 June 2012 - 08:04 AM, said:

In the long past I used steel wool also. Steel wool comes in the pack oiled to prevent it from rusting. That oil can be a real problem if little tiny bits,streaks,lines, blotches, etc., stick to the blade as it goes in for the next etch cycle.
M

[Tony Hughes]

Hey Mike, what do you use if not 0000 steel wool? I have been dipping
mine in acceton first, but I would love a better idea.

[Mike Williams]

Tony Hughes, on 09 July 2012 - 08:59 AM, said:

Hey Mike, what do you use if not 0000 steel wool? I have been dipping
mine in acceton first, but I would love a better idea.

Hi Tony.
I was wondering if you were around those fires or not.
I use either the white ultra-fine scotch brite or 1500 grit paper.
Acetoning the steel wool is good too, I am just getting too lazy to fool with it.
M

[Tony Hughes]

Mike Williams, on 10 July 2012 - 04:23 AM, said:

Hi Tony.
I was wondering if you were around those fires or not.
I use either the white ultra-fine scotch brite or 1500 grit paper.
Acetoning the steel wool is good too, I am just getting too lazy to fool with it.
M

[Tony Hughes]

Mike Williams, on 10 July 2012 - 04:23 AM, said:

Hi Tony.
I was wondering if you were around those fires or not.
I use either the white ultra-fine scotch brite or 1500 grit paper.
Acetoning the steel wool is good too, I am just getting too lazy to fool with it.
M

Yeah it's been exciting. Seemed like the whole state was on fire. It has been so smokey that it is like being in fog. It finally cooled off and we got some fair rain, so it is better now.
Thanks I will try the ultra fine, I have some.