Wednesday, 28 March 2012

Etching pattern welded steel (Damascus)



Etching pattern welded steel (sometimes called Damascus) was a rather tricky process. The first time I tried it, it took 5 attempts before I was happy with the results. I have just finished 2 more Damascus sided planes and am pretty confident that I know what I am doing now.

The above photo shows the set-up.

A) Acetone
B) Ferric Chloride (the etching acid)
C) Hot water rinse bucket
D) Neutralizing solution bucket
E) Baking Soda
F) measuring cup
G) brushes
H) glass 9"x9" cake pan

The steel sides of the plane are sanded to 600 grit. This is way finer than I typically go, but if the surface is not really smooth, the serrations in the steel left by a more coarse paper will be visible - even after etching (learned this after round 1:)

The challenge with etching a plane is the fact that you have infill material (in this case, Ebony) touching the steel that is to be etched. Normally, a knife blade can be dipped in to the various solutions - which happens very quickly and more importantly - the coverage is consistent. On a plane, the various solutions need to be brushed on which makes it difficult to get an even etch. As the solution runs down the sides of the plane - the etch rate changes accordingly. I could not think up a way to cover the bronze lever cap or protect the Ebony sufficiently to dip the plane.

Here is the process.

Use the Acetone to clean the steel surface to remove any wax, oil or fingerprints. This is pretty critical as anything on the surface of the steel will retard the etching process and it will be visible!

I mix the Ferric Chloride with distilled water - 50/50 - one full measuring cup of each. I dump this into the glass pan.

I boil a kettle of water and put 1/2 of it into the rinsing bucket and the rest into the neutralizing rinse bucket - along with a bunch of baking soda. I don’t have a measurement for how much... just a little pile at the bottom of the bucket.









The three photos above show the etching process. This took about 20 minutes to do each plane. I was brushing the Ferric Chloride solution onto the sides being as careful as I could not to get too much on the blue tape or the bronze lever cap. I did not worry about getting any on the sole as this would lap out after the mouth was filed. The 01 tool steel (the sole and the cross pins) are affected by the etchant as well - but they turn a pleasant dull grey. After about 10 minutes of constantly bathing the sides in etchant, I take a piece of 2000 grit wet/dry paper and wet sand the surface of the sides. This removes the black crud (my scientific name for it) and exposes fresh steel to be etched. You have to be very careful to sand evenly - right up to the edge of the tape - or the etch will not be consistent. Then re-apply the etchant for another 10 minutes or so until it looks like what you are after.

At this stage, you will feel like a hero because the sides will look amazing. This next step is often where the wheels fall off and you will want to chuck the plane out the window.

Once you are happy with the amount of etching - you have to rinse off as much of the etchant as you can and then neutralize it. And fast. I use a second clean brush and warm/hot water to rinse off the etchant and then immediately rinse that with the baking soda solution. This sounds easy, but as the water recedes off the sides - rust usually appears. The best solution I found to keep this at bay was to use a hair dryer (not the one on used for the bandsaw) and remove the water as quickly as possible.

NOTE: If you do not pre-rinse the etchant off, there is a rather foamy reaction between the full strength etchant and the baking soda solution.



Here is a shot of the neutralized and dry plane. Note how grey everything is. This will darken as soon as you put something on the steel to protect it from rusting. I used WD40 and then a coat of paste wax.



The finished XSNo.4D



The finished SNo.4D and a few shots of the pair.









I need to re-thank my friend Brian Buckner who was a huge help last time I did this. I had a print out of his email instructions with me which were once again a great help. And if anyone else out there has any suggestions about how I might improve this process - I would love to hear from you.

19 Comments:

Blogger Kim said...

Have you considered asphaltum ( bitumen ) as a resist?

28 March 2012 at 16:00  
Blogger Jim Shaver said...

Wow...... I had no idea, that is a beautiful result!

28 March 2012 at 17:30  
Blogger Richard Wile said...

Good insight into this process Konrad, was not aware this step was the real effect one sees with "damascus" steel.

Thanks for sharing.

28 March 2012 at 18:25  
Blogger Jameel Abraham said...

That is workmanship of risk at its finest (whatever that means!) About the only improvement I can come up with is the next logical step after after askinging Brian for advice: ask Brian to etch the plane. ;-)

28 March 2012 at 19:43  
Blogger raney said...

Beautiful planes - and impressive consistency between the two planes given the process.

I found myself whether it might be easier to use acetone to evaporate the water after the rinse rather than the hairdryer. (besides - you never know when you may need that hairdryer for some new piece of machinery)

28 March 2012 at 20:25  
Blogger Konrad said...

Hi Kim,

Thanks for the suggestion. I am not even aware of asphaltum but will look into it.

Cheers,
Konrad

28 March 2012 at 21:00  
Blogger Konrad said...

Thanks Jim. It is a pretty intense process and can bite you in the butt when you least expect it:)

Cheers,
Konrad

28 March 2012 at 21:01  
Blogger Konrad said...

Hi Richard,

yeah - it is pretty cool watching the pattern emerge. Reminds me of watching a print come to life in the darkroom.

Cheers,
Konrad

28 March 2012 at 21:02  
Blogger Konrad said...

Hey Jameel - that is pretty funny... and a darn good idea. The good thing about etching is if you screw it up, you can start over again. It is a lot of work to start over - but nothing is ruined... or at least I have not ruined anything thus far:)

Cheers,
Konrad

28 March 2012 at 21:03  
Blogger Konrad said...

Thanks Raney. The two planes came from the same piece of steel... but I was careful about timing the applications in the hopes that they would come out the same.

A great suggestion to try Acetone. I will look into it further.

Yeah - hairdryers have a whole new lease on life around here... or maybe Tartarus better describes it from the hairdryers perspective.

Cheers,
Konrad

28 March 2012 at 21:08  
Anonymous Anonymous said...

That is sick!! It looks like woodgrain. You really do amazing work, and I love to read your blog....keep up the great work.

28 March 2012 at 21:32  
Blogger FredW said...

Konrad, as always you do truly amazing work. Imagine now a trio of those with your number 4d. :o)Fred

29 March 2012 at 10:42  
Anonymous Chris Bame said...

Those are subtle yet striking Konrad. Great choice on the Ebony. I think anything else would have competed with the Damascus steel.
Didn't know you where a part time Chemist also !!

29 March 2012 at 11:32  
Blogger Craig D said...

I wonder if phosphoric acid (aka Metal Prep, active ingredient in Navel Jelly and it's in Coke) would work? I've used it as an etch to show stainless steel weld lines. The nice thing about it is it really doesn't like rust and you can use alcohol as a rinse. Same nice gray color to the etched steel.

29 March 2012 at 13:13  
Blogger Jamie said...

Just great, the picture of the pair look wonderful, thanks for sharing the process. Does it only have that effect on 01 tool steel? and have you tried it on other metals?

It will be a long time before I try anything like that

all the best

Jamie

29 March 2012 at 15:46  
Blogger Unknown said...

Konrad,

I love the Damascus effect on your planes. Amazing job keeping the etch consistent. Certainly not the time to day dream, huh?

Best,

Lee Laird

29 March 2012 at 23:39  
Blogger Carl Jara said...

seriously bad-ass planes!
thank you for sharing the process, I take with it a greater appreciation of the art.

31 March 2012 at 18:25  
Anonymous Dan Unrau said...

Beautiful work.

8 April 2012 at 08:55  
Blogger Rollo said...

thanks for documenting and posting the process Konrad! u rock

5 May 2012 at 15:37  

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