http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

On 10/26/2011 10:54 PM, wrote:
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC


Looks like your etch found some weak spots to exploit.

Is it like that all over? Or just along the bottom?

On Wed, 26 Oct 2011 20:54:22 -0700, wrote:

http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

Was the original metal some type of casting? In that case, it could be
porosity in the original casting uncovered/opened up by the etching
process.

BTW: The sun dials you make are way cool. Do you sell them on a web
site?
Dave

wrote in message
...
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

What I remember from chemistry lectures long ago is that the components of
an alloy separate as the cast ingot cools, giving crystals of the more
stable composition surrounded by a less organized mass of somewhat different
proportions. Rolling the metal into sheets spreads out the crystals and
depending on their size (cooling rate) may make the alloy vary with location
at visible scales, like granite rock.

The junction of two different alloys has an electrical potential that is the
difference between their attraction for electrons, like a thermocouple or
battery. In a corrosive environment these slightly different alloys act like
weak batteries, so the more active material will dissolve faster than the
less active one. This is part of why rust forms isolated deep pits instead
of cutting in evenly.

Notice the uncertainty:
http://en.wikipedia.org/wiki/Pitting_corrosion

Another part:
http://en.wikipedia.org/wiki/Crevice_corrosion

HTH
JSW

On Thu, 27 Oct 2011 01:24:12 -0400, lid wrote:

On Wed, 26 Oct 2011 20:54:22 -0700, wrote:

http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

Was the original metal some type of casting? In that case, it could be
porosity in the original casting uncovered/opened up by the etching
process.

BTW: The sun dials you make are way cool. Do you sell them on a web
site?
Dave

Thank you.

I have a few on Etsy:

http://www.etsy.com/shop/crquack?ref=pr_shop_more

The original metal is a 2" washer!

I have a stack of pictures of this phenomenon but in all other
instances there was an intervening resist. I thought I solved the
problem at one point by having the cathode on top so the hydrogen
bubbles would not have to go past the work piece (anode). I am now
wondering if the distance between the electrodes is critical. I did
another piece on the same day which I did not photograph. Because of
the shape of it the distance between the electrodes was very small
(1/8"). The piece was full of holes such as those shown in the
picture. This however, was a negative etch so the holes were all under
the resist. In fact you could tell the result was going to be bad when
I spray-washed the piece after it came out of the bath - the resist
starting coming off in spots exactly where the holes appeared
underneath.

Previously I attributed it to foul biting but seeing it without an
intervening resist makes me re-evaluate.

FWIW I never see this when doing brass which is a gasless process.

I am going to run a trial with several electrode distances to see if I
am right.

I have read a lot about cavitation but it is still black magic to
me:-)

Michael Koblic,
Campbell River, BC

On 2011-10-27, wrote:
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Are those truly pits, or are they projections? I could imagine
air bubbles (or hydrogen) forming on the surface which would prevent as
much access from the etchant.

Either tapping the edge every so often, or applying ultrasonics
from a cleaner might break them up fairly quickly.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 10/27/2011 8:00 PM, wrote:
On Thu, 27 Oct 2011 01:24:12 -0400, lid wrote:

On Wed, 26 Oct 2011 20:54:22 -0700, wrote:

http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

Was the original metal some type of casting? In that case, it could be
porosity in the original casting uncovered/opened up by the etching
process.

BTW: The sun dials you make are way cool. Do you sell them on a web
site?
Dave

Thank you.

I have a few on Etsy:

http://www.etsy.com/shop/crquack?ref=pr_shop_more

The original metal is a 2" washer!

I have a stack of pictures of this phenomenon but in all other
instances there was an intervening resist. I thought I solved the
problem at one point by having the cathode on top so the hydrogen
bubbles would not have to go past the work piece (anode). I am now
wondering if the distance between the electrodes is critical. I did
another piece on the same day which I did not photograph. Because of
the shape of it the distance between the electrodes was very small
(1/8"). The piece was full of holes such as those shown in the
picture. This however, was a negative etch so the holes were all under
the resist. In fact you could tell the result was going to be bad when
I spray-washed the piece after it came out of the bath - the resist
starting coming off in spots exactly where the holes appeared
underneath.

Previously I attributed it to foul biting but seeing it without an
intervening resist makes me re-evaluate.

FWIW I never see this when doing brass which is a gasless process.

I am going to run a trial with several electrode distances to see if I
am right.

I have read a lot about cavitation but it is still black magic to
me:-)

Michael Koblic,
Campbell River, BC



Are you agitating the solution?

On Thu, 27 Oct 2011 07:51:16 -0400, "Jim Wilkins"
wrote:


wrote in message
.. .
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

What I remember from chemistry lectures long ago is that the components of
an alloy separate as the cast ingot cools, giving crystals of the more
stable composition surrounded by a less organized mass of somewhat different
proportions. Rolling the metal into sheets spreads out the crystals and
depending on their size (cooling rate) may make the alloy vary with location
at visible scales, like granite rock.

The junction of two different alloys has an electrical potential that is the
difference between their attraction for electrons, like a thermocouple or
battery. In a corrosive environment these slightly different alloys act like
weak batteries, so the more active material will dissolve faster than the
less active one. This is part of why rust forms isolated deep pits instead
of cutting in evenly.

Notice the uncertainty:
http://en.wikipedia.org/wiki/Pitting_corrosion

Another part:
http://en.wikipedia.org/wiki/Crevice_corrosion


I read both several times. Interesting. I can sort of see the pitting
type of corrosion more than the crevice type. I am not sure that it is
the whole explanation. Some of the considerations that puzzle me a

1) Why would a weak local battery not be swamped by a 2.5A current
passing through the whole system?
2) Why are the pits, if they develop as described in the article, so
deep and apparently so uniform in shape (I enlarged the photo - most
of them seem comma shaped)?
3) Why does one not see similar phenomenon with brass? There I am
removing copper from zinc. One would have thought that local batteries
would if anything be "stronger".

There are other considerations derived from the previous experience of
similar pits developing under a resist. However, I am not even sure
this is the same phenomenon. The pits sure look similar.

I am going to run a few test and see what gives.

Michael Koblic,
Campbell River, BC

wrote in message
...
On Thu, 27 Oct 2011 07:51:16 -0400, "Jim Wilkins"
wrote:
....

I read both several times. Interesting. I can sort of see the pitting
type of corrosion more than the crevice type. I am not sure that it is
the whole explanation. Some of the considerations that puzzle me a

1) Why would a weak local battery not be swamped by a 2.5A current
passing through the whole system?
2) Why are the pits, if they develop as described in the article, so
deep and apparently so uniform in shape (I enlarged the photo - most
of them seem comma shaped)?
3) Why does one not see similar phenomenon with brass? There I am
removing copper from zinc. One would have thought that local batteries
would if anything be "stronger".

There are other considerations derived from the previous experience of
similar pits developing under a resist. However, I am not even sure
this is the same phenomenon. The pits sure look similar.

I am going to run a few test and see what gives.

Michael Koblic,
Campbell River, BC

The undergrad chemistry courses skimmed lightly over a very wide field of
industrial applications. They told us we weren't really chemists yet, but
when (if) we got a job in industry we knew enough theory to understand the
explanations, many of which were proprietary trade secrets. Electrochemistry
is particularly secretive about the details that make one battery better
than another. It's still black art, or FM as we say in electronics.

I did check other references. Do you really want to dive into the theory of
redox potential?

jsw

On Oct 26, 10:54*pm, wrote:
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

Non-uniform alloy, just like the other poster said. You can also get
this with higher carbon steels when removing rust with phosphoric acid
or the like. Preferential etching at certain grain boundaries. Get
some lower carbon material and more uniform. Non-metallic inclusions
can also get etched out and leave pits, too. Without polishing,
etching and viewing a sample under a microscope, it's just
speculation, though.

Stan

On Thu, 27 Oct 2011 21:35:27 -0500, Richard
wrote:
[...]

Are you agitating the solution?


No, I am not.

On Fri, 28 Oct 2011 08:18:53 -0400, "Jim Wilkins"
wrote:

[...]

The undergrad chemistry courses skimmed lightly over a very wide field of
industrial applications. They told us we weren't really chemists yet, but
when (if) we got a job in industry we knew enough theory to understand the
explanations, many of which were proprietary trade secrets. Electrochemistry
is particularly secretive about the details that make one battery better
than another. It's still black art, or FM as we say in electronics.

I did check other references. Do you really want to dive into the theory of
redox potential?

Not especially. Not beyond what I read in the books I have.

I spent this PM making components for a test set up (time I should
really be spending otherwise, but until I have this sorted it is hard
to move forward). I hope this will provide some insight and
confirm/refute my theory.

I should mention that I have never seen similar pitting on steel when
using a non-electrolytic process (e.g. Ferric Chloride).

Michael Koblic,
Campbell River, BC

On 28 Oct 2011 01:42:54 GMT, "DoN. Nichols"
wrote:

On 2011-10-27, wrote:
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Are those truly pits, or are they projections? I could imagine
air bubbles (or hydrogen) forming on the surface which would prevent as
much access from the etchant.

Either tapping the edge every so often, or applying ultrasonics
from a cleaner might break them up fairly quickly.


They are pits and quite deep at that. The main reason I have the
cathode on top now is to allow for the hydrogen to escape without
coming into contact with the work-piece.

I am going to try a few things tomorrow and see what pans out.

Michael Koblic,
Campbell River, BC

On Fri, 28 Oct 2011 09:08:12 -0700 (PDT), wrote:

On Oct 26, 10:54*pm, wrote:
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

Non-uniform alloy, just like the other poster said. You can also get
this with higher carbon steels when removing rust with phosphoric acid
or the like. Preferential etching at certain grain boundaries. Get
some lower carbon material and more uniform. Non-metallic inclusions
can also get etched out and leave pits, too. Without polishing,
etching and viewing a sample under a microscope, it's just
speculation, though.

I would buy that if I ever saw similar pits using Ferric Chloride. I
never do.

I would go back to using FeCl3 but the depth of etch is so much better
with this process. As often as not I get a clean etch. It is the
unpredictability that irks me.

Michael Koblic,
Campbell River, BC

On 2011-10-29, wrote:
On Fri, 28 Oct 2011 09:08:12 -0700 (PDT), wrote:

On Oct 26, 10:54*pm, wrote:
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Michael Koblic,
Campbell River, BC

Non-uniform alloy, just like the other poster said. You can also get
this with higher carbon steels when removing rust with phosphoric acid
or the like. Preferential etching at certain grain boundaries. Get
some lower carbon material and more uniform. Non-metallic inclusions
can also get etched out and leave pits, too. Without polishing,
etching and viewing a sample under a microscope, it's just
speculation, though.

I would buy that if I ever saw similar pits using Ferric Chloride. I
never do.

I would go back to using FeCl3 but the depth of etch is so much better
with this process. As often as not I get a clean etch. It is the
unpredictability that irks me.

How consistent is your metal supply? If you buy mild
(low-carbon) steel and process it, you will probably get fairly
consitant results. If you use a lot of "found" or "mystery" metal, then
you don't know what alloy you have, and have to expect variable results.

And buying large washers from the local hardware store leaves
you open for almost any flavor of alloy -- often from the same bin. :-)

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote in message
...
...
And buying large washers from the local hardware store leaves
you open for almost any flavor of alloy -- often from the same bin. :-
DoN.

I don't know about their alloy but the thicknesses can vary considerably
within the bin.

Half a foot of snow in October???
Support Global Warming!

On 28 Oct 2011 01:42:54 GMT, "DoN. Nichols"
wrote:

On 2011-10-27, wrote:
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Are those truly pits, or are they projections? I could imagine
air bubbles (or hydrogen) forming on the surface which would prevent as
much access from the etchant.

Either tapping the edge every so often, or applying ultrasonics
from a cleaner might break them up fairly quickly.

Good Luck,
DoN.

I think DoN has the answer.

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

You could also try mechanical stirring (try a paint mixer in a drill just to
see if it helps), or maybe bubbling with compressed air (mixes ok but
evaporates lots of your solution). Helps keep surfaces uniform when
electropolishing stainless steel, and that's basically what you are doing.
Do you use just vinegar or do you add some table salt for better
conductivity? What strength vinegar? Very nice pieces, BTW.

-----
Regards,
Carl Ijames
"Gunner Asch" wrote in message
...

On 28 Oct 2011 01:42:54 GMT, "DoN. Nichols"
wrote:

On 2011-10-27, wrote:
http://www.flickr.com/photos/2768312...in/photostream

Previously when I saw pits like these I thought it was caused by pin
holes in the resist. There was some discussion about its here. I
firmly believed that it was the hydrogen bubbles cavitating causing
this. However, in this case there is *no* resist!

Are those truly pits, or are they projections? I could imagine
air bubbles (or hydrogen) forming on the surface which would prevent as
much access from the etchant.

Either tapping the edge every so often, or applying ultrasonics
from a cleaner might break them up fairly quickly.

Good Luck,
DoN.

I think DoN has the answer.

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

On Sat, 29 Oct 2011 07:25:38 -0400, "Jim Wilkins"
wrote:

"DoN. Nichols" wrote in message
...
...
And buying large washers from the local hardware store leaves
you open for almost any flavor of alloy -- often from the same bin. :-
DoN.

I don't know about their alloy but the thicknesses can vary considerably
within the bin.

Half a foot of snow in October???
Support Global Warming!

In truth everyone has a valid point although I am not sure that it
explains the problem entirely.

I am about to give up using washers, at least the 2" variety for the
very reason you state: The thickness varies quite a bit, the quality
varies also. Their availability has decreased: I used to be able to go
to Fastenal and rummage in their bin and pick the ones that were
useful. Fastenal no longer stock them. You can order them but then you
have to take what they send you.

Anyway, to confuse matters further: Here is the first trial I did
today:

http://www.flickr.com/photos/2768312...7627882701769/

Make of it what you will. The next thing is to try increase the
distance between the plates and/or try to run the whole assembly on
its side so the bubbles have a free exit.

I included a picture of a piece that ended up like pig's breakfast
just to show that whatever it is that causes the pits it blasts its
way through 4 coats of resist if the conditions are right.

That is always assuming that the cause of the pitting in the different
pieces is the same.

Michael Koblic,
Campbell River, BC

Our temperatures have been sub-normal practically whole year. Either
it is not warming or it is not global:-)

On Sat, 29 Oct 2011 18:24:31 -0700, wrote:

On Sat, 29 Oct 2011 07:25:38 -0400, "Jim Wilkins"
wrote:

"DoN. Nichols" wrote in message
...
...
And buying large washers from the local hardware store leaves
you open for almost any flavor of alloy -- often from the same bin. :-
DoN.

I don't know about their alloy but the thicknesses can vary considerably
within the bin.

Half a foot of snow in October???
Support Global Warming!

In truth everyone has a valid point although I am not sure that it
explains the problem entirely.

I am about to give up using washers, at least the 2" variety for the
very reason you state: The thickness varies quite a bit, the quality
varies also. Their availability has decreased: I used to be able to go
to Fastenal and rummage in their bin and pick the ones that were
useful. Fastenal no longer stock them. You can order them but then you
have to take what they send you.

Anyway, to confuse matters further: Here is the first trial I did
today:

http://www.flickr.com/photos/2768312...7627882701769/

Make of it what you will. The next thing is to try increase the
distance between the plates and/or try to run the whole assembly on
its side so the bubbles have a free exit.

I included a picture of a piece that ended up like pig's breakfast
just to show that whatever it is that causes the pits it blasts its
way through 4 coats of resist if the conditions are right.

That is always assuming that the cause of the pitting in the different
pieces is the same.


One thing is for su Putting coffee filter between the electrodes
does not work!

http://www.flickr.com/photos/2768312...in/photostream

Michael Koblic,
Campbell River, BC

On Sun, 30 Oct 2011 17:22:55 -0700, wrote:

On Sat, 29 Oct 2011 18:24:31 -0700, wrote:

That is always assuming that the cause of the pitting in the different
pieces is the same.


One thing is for su Putting coffee filter between the electrodes
does not work!

http://www.flickr.com/photos/2768312...in/photostream

Um, Mikey, try using one -without- the old grounds in it next time.
snort

--
Inside every older person is a younger person wondering WTF happened.

On Sun, 30 Oct 2011 18:11:53 -0700, Larry Jaques
wrote:

On Sun, 30 Oct 2011 17:22:55 -0700, wrote:

On Sat, 29 Oct 2011 18:24:31 -0700, wrote:

That is always assuming that the cause of the pitting in the different
pieces is the same.


One thing is for su Putting coffee filter between the electrodes
does not work!

http://www.flickr.com/photos/2768312...in/photostream

Um, Mikey, try using one -without- the old grounds in it next time.
snort

You are probably right. This would make my original idea of using
toilet paper even less acceptable...

On Mon, 31 Oct 2011 20:21:48 -0700, wrote:

On Sun, 30 Oct 2011 18:11:53 -0700, Larry Jaques
wrote:

On Sun, 30 Oct 2011 17:22:55 -0700, wrote:

On Sat, 29 Oct 2011 18:24:31 -0700, wrote:

That is always assuming that the cause of the pitting in the different
pieces is the same.


One thing is for su Putting coffee filter between the electrodes
does not work!

http://www.flickr.com/photos/2768312...in/photostream

Um, Mikey, try using one -without- the old grounds in it next time.
snort

You are probably right. This would make my original idea of using
toilet paper even less acceptable...

Indeed. Even if you used the Advanced Polish toilet paper, where you
take a square of TP and fold it into quarters, then tear off the tip
where the 4 squares meet. The piece is unfolded and then placed over
your bird finger to the second knuckle, used for its purpose, folded
over the finger and pulled off to clean off the finger, and the small
piece used to clean your fingernail.

(This is a real hoot to show to people.)

--
Inside every older person is a younger person wondering WTF happened.

On Mon, 31 Oct 2011 21:03:16 -0700, Larry Jaques

[...]

Um, Mikey, try using one -without- the old grounds in it next time.
snort

You are probably right. This would make my original idea of using
toilet paper even less acceptable...

Indeed. Even if you used the Advanced Polish toilet paper, where you
take a square of TP and fold it into quarters, then tear off the tip
where the 4 squares meet. The piece is unfolded and then placed over
your bird finger to the second knuckle, used for its purpose, folded
over the finger and pulled off to clean off the finger, and the small
piece used to clean your fingernail.

(This is a real hoot to show to people.)

Aren't we fortunate this place isn't moderated!

But back to the original problem - I think I found the solution. The
bubbles *are* a problem and if one keeps the electrodes 1" apart and
vertical the etch is pit-free.

http://www.flickr.com/photos/2768312...in/photostream

Michael Koblic,
Campbell River, BC

On Tue, 01 Nov 2011 17:41:46 -0700, wrote:

On Mon, 31 Oct 2011 21:03:16 -0700, Larry Jaques

[...]

Um, Mikey, try using one -without- the old grounds in it next time.
snort

You are probably right. This would make my original idea of using
toilet paper even less acceptable...

Indeed. Even if you used the Advanced Polish toilet paper, where you
take a square of TP and fold it into quarters, then tear off the tip
where the 4 squares meet. The piece is unfolded and then placed over
your bird finger to the second knuckle, used for its purpose, folded
over the finger and pulled off to clean off the finger, and the small
piece used to clean your fingernail.

(This is a real hoot to show to people.)

Aren't we fortunate this place isn't moderated!

You betcha!


But back to the original problem - I think I found the solution. The
bubbles *are* a problem and if one keeps the electrodes 1" apart and
vertical the etch is pit-free.

http://www.flickr.com/photos/2768312...in/photostream

Cool! Now to figure out why 1 inch is the key to pitless etching of
that material with that solution and power supply. Maybe a perfect
multiple of the bubble width?

--
When you are kind to someone in trouble, you hope they'll remember
and be kind to someone else. And it'll become like a wildfire.
-- Whoopi Goldberg

On Tue, 01 Nov 2011 20:43:38 -0700, Larry Jaques
wrote:

On Tue, 01 Nov 2011 17:41:46 -0700, wrote:

On Mon, 31 Oct 2011 21:03:16 -0700, Larry Jaques

[...]

Um, Mikey, try using one -without- the old grounds in it next time.
snort

You are probably right. This would make my original idea of using
toilet paper even less acceptable...

Indeed. Even if you used the Advanced Polish toilet paper, where you
take a square of TP and fold it into quarters, then tear off the tip
where the 4 squares meet. The piece is unfolded and then placed over
your bird finger to the second knuckle, used for its purpose, folded
over the finger and pulled off to clean off the finger, and the small
piece used to clean your fingernail.

(This is a real hoot to show to people.)

Aren't we fortunate this place isn't moderated!

You betcha!


But back to the original problem - I think I found the solution. The
bubbles *are* a problem and if one keeps the electrodes 1" apart and
vertical the etch is pit-free.

http://www.flickr.com/photos/2768312...in/photostream

Cool! Now to figure out why 1 inch is the key to pitless etching of
that material with that solution and power supply. Maybe a perfect
multiple of the bubble width?

Nah, the bubbles just don't go near the anode. I suspect the poor
result on Plate 5 was because the precipitate was holding the bubbles
in the electrolyte and they got closer to the anode. Although plate 4
was closer to the cathode the electrolyte was clear and the bubbles
were free to escape.

Tomorrow I am going to look at a container big enough and narrow
enough to do some of the bigger pieces side-by-side so there is enough
space between the electrodes yet I do not have to use a gallon of
electrolyte every time.

Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Michael Koblic,
Campbell River, BC

On Wed, 02 Nov 2011 20:46:05 -0700, wrote:

On Tue, 01 Nov 2011 20:43:38 -0700, Larry Jaques
wrote:

On Tue, 01 Nov 2011 17:41:46 -0700, wrote:

But back to the original problem - I think I found the solution. The
bubbles *are* a problem and if one keeps the electrodes 1" apart and
vertical the etch is pit-free.

http://www.flickr.com/photos/2768312...in/photostream

Cool! Now to figure out why 1 inch is the key to pitless etching of
that material with that solution and power supply. Maybe a perfect
multiple of the bubble width?

Nah, the bubbles just don't go near the anode. I suspect the poor

I think I was referring to any electrical characteristics of the
electrolyte may have, wondering if it equated to bubble (or potential
bubble) size. I know that there are shadings in solution, so parts not
directly in line will have different etch characteristics. Jeeeze, I
haven't done any etching in a couple dozen years, and even then, it
was plating. g


result on Plate 5 was because the precipitate was holding the bubbles
in the electrolyte and they got closer to the anode. Although plate 4
was closer to the cathode the electrolyte was clear and the bubbles
were free to escape.

What precipitate? The etched material?


Tomorrow I am going to look at a container big enough and narrow
enough to do some of the bigger pieces side-by-side so there is enough
space between the electrodes yet I do not have to use a gallon of
electrolyte every time.

Is this entirely sacrificial, or can you reuse electrolyte?


Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

--
Knowledge speaks, but wisdom listens.
-- Jimi Hendrix

On Thu, 03 Nov 2011 03:20:34 -0700, Larry Jaques
wrote:

[...]

Nah, the bubbles just don't go near the anode. I suspect the poor

I think I was referring to any electrical characteristics of the
electrolyte may have, wondering if it equated to bubble (or potential
bubble) size. I know that there are shadings in solution, so parts not
directly in line will have different etch characteristics. Jeeeze, I
haven't done any etching in a couple dozen years, and even then, it
was plating. g

From my careful scientific observation: Mo' current, mo' bubbles.


result on Plate 5 was because the precipitate was holding the bubbles
in the electrolyte and they got closer to the anode. Although plate 4
was closer to the cathode the electrolyte was clear and the bubbles
were free to escape.

What precipitate? The etched material?

Ferric Hydroxide. Some ferrous too I think. When the acetate is used
up the iron begins to precipitate. If you omit the vinegar it happens
right at the start.


Tomorrow I am going to look at a container big enough and narrow
enough to do some of the bigger pieces side-by-side so there is enough
space between the electrodes yet I do not have to use a gallon of
electrolyte every time.

Is this entirely sacrificial, or can you reuse electrolyte?

CuSO4 I re-use all the time. Just top up the wastage and evaporation.
Salt and vinegar needs to be fresh for the reasons above.


Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

Michael Koblic,
Campbell River, BC

On 11/3/2011 10:56 PM, wrote:
On Thu, 03 Nov 2011 03:20:34 -0700, Larry Jaques
wrote:

[...]

Nah, the bubbles just don't go near the anode. I suspect the poor

I think I was referring to any electrical characteristics of the
electrolyte may have, wondering if it equated to bubble (or potential
bubble) size. I know that there are shadings in solution, so parts not
directly in line will have different etch characteristics. Jeeeze, I
haven't done any etching in a couple dozen years, and even then, it
was plating.g

From my careful scientific observation: Mo' current, mo' bubbles.


result on Plate 5 was because the precipitate was holding the bubbles
in the electrolyte and they got closer to the anode. Although plate 4
was closer to the cathode the electrolyte was clear and the bubbles
were free to escape.

What precipitate? The etched material?

Ferric Hydroxide. Some ferrous too I think. When the acetate is used
up the iron begins to precipitate. If you omit the vinegar it happens
right at the start.


Tomorrow I am going to look at a container big enough and narrow
enough to do some of the bigger pieces side-by-side so there is enough
space between the electrodes yet I do not have to use a gallon of
electrolyte every time.

Is this entirely sacrificial, or can you reuse electrolyte?

CuSO4 I re-use all the time. Just top up the wastage and evaporation.
Salt and vinegar needs to be fresh for the reasons above.


Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

Michael Koblic,
Campbell River, BC


LOL, No. Arlo Guthry - from Alice's Resturant

On Thu, 03 Nov 2011 20:56:23 -0700, wrote:

On Thu, 03 Nov 2011 03:20:34 -0700, Larry Jaques
wrote:

[...]

Nah, the bubbles just don't go near the anode. I suspect the poor

I think I was referring to any electrical characteristics of the
electrolyte may have, wondering if it equated to bubble (or potential
bubble) size. I know that there are shadings in solution, so parts not
directly in line will have different etch characteristics. Jeeeze, I
haven't done any etching in a couple dozen years, and even then, it
was plating. g

From my careful scientific observation: Mo' current, mo' bubbles.

A truly "Duh!" moment, was it?


result on Plate 5 was because the precipitate was holding the bubbles
in the electrolyte and they got closer to the anode. Although plate 4
was closer to the cathode the electrolyte was clear and the bubbles
were free to escape.

What precipitate? The etched material?

Ferric Hydroxide. Some ferrous too I think. When the acetate is used
up the iron begins to precipitate. If you omit the vinegar it happens
right at the start.

OK.


Tomorrow I am going to look at a container big enough and narrow
enough to do some of the bigger pieces side-by-side so there is enough
space between the electrodes yet I do not have to use a gallon of
electrolyte every time.

Is this entirely sacrificial, or can you reuse electrolyte?

CuSO4 I re-use all the time. Just top up the wastage and evaporation.
Salt and vinegar needs to be fresh for the reasons above.

Cool. That's an inexpensive bath.

Those pretty blue crystals are good for poison oak/ivy, too. Make a
solution and pad it on the affected area. It'll make your skin crawl
for a few minutes but it removes the oil, the itch, and the spread.
I haven't noted any toxic feeling afterward, but it's a 1-time bath.


Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

Newp, I don't have anything to do with the Jacksons, ever.

We must have hit the cultural divide between our countries.
Arlo Guthrie's song "Alice's Restaurant" is a cult classic here in the
States. Listen to it and weep: http://goo.gl/qsb8K

Another cultured fave is "The Motorcycle Song" http://goo.gl/Scw2p
"I don't want a pickle. Just wanna ride on my motorsickle."

OBTW, this is folk culture, not opera or symphony or sumpin'.

--
The unexamined life is not worth living.
--Socrates

On Fri, 04 Nov 2011 05:26:43 -0700, Larry Jaques
wrote:

On Thu, 03 Nov 2011 20:56:23 -0700, wrote:

On Thu, 03 Nov 2011 03:20:34 -0700, Larry Jaques
wrote:

[...]

From my careful scientific observation: Mo' current, mo' bubbles.

A truly "Duh!" moment, was it?

Ah, but I wish it was all that simple. I just rigged up my new set-up:

http://www.flickr.com/photos/2768312...in/photostream

(and the next two pics)

The results are beautiful, but then I could do the small pieces with
negative etching quite well before. The thing that was interesting was
the unidirectional movement of the hydrogen bubbles *away* from the
anode.

The proof of the pudding will happen in a day or so when I shall
repeat the etch that sparked the OP.


[...]

Is this entirely sacrificial, or can you reuse electrolyte?

CuSO4 I re-use all the time. Just top up the wastage and evaporation.
Salt and vinegar needs to be fresh for the reasons above.

Cool. That's an inexpensive bath.

Those pretty blue crystals are good for poison oak/ivy, too. Make a
solution and pad it on the affected area. It'll make your skin crawl
for a few minutes but it removes the oil, the itch, and the spread.
I haven't noted any toxic feeling afterward, but it's a 1-time bath.

Here they use them to kill roots in septic tanks. Actually I am using
a commercial solution sold by jewelers' supply company for copper
plating. I do have a bunch of CuSO4 crystals which I will go to next
when I run out of the current solution.


Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

Newp, I don't have anything to do with the Jacksons, ever.

We must have hit the cultural divide between our countries.
Arlo Guthrie's song "Alice's Restaurant" is a cult classic here in the
States. Listen to it and weep: http://goo.gl/qsb8K

I seem to remember a movie of similar name. About 1970? I was never
into the hippie thing.

Another cultured fave is "The Motorcycle Song" http://goo.gl/Scw2p
"I don't want a pickle. Just wanna ride on my motorsickle."

OBTW, this is folk culture, not opera or symphony or sumpin'.

Your culture. I shall stick to "Does your chewing gum lose its flavor
on the bedpost overnight?", "Calendar song" and other such
masterpieces.

Michael Koblic,
Campbell River, BC

On 2011-11-04, wrote:
On Thu, 03 Nov 2011 03:20:34 -0700, Larry Jaques
wrote:

[ ... ]

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

It is a popular culture reference. :-)

You never heard the full 18 minute 34 second run of Alice's
Restaurant -- a cant-fable (talking and singing mixed) by Arlo Guthrie
back in the 1960s I believe.

This will tell you about it:

http://en.wikipedia.org/wiki/Alice's_Restaurant

and here are the full lyrics, if you prefer to read it instead of to
listen to it:

http://arlo.net/resources/lyrics/alices.shtml

The first mention of the quoted text is about in the tenth
paragraph/verse, depending on how you count.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Fri, 04 Nov 2011 20:46:59 -0700, wrote:

On Fri, 04 Nov 2011 05:26:43 -0700, Larry Jaques
wrote:

On Thu, 03 Nov 2011 20:56:23 -0700, wrote:

On Thu, 03 Nov 2011 03:20:34 -0700, Larry Jaques
wrote:

[...]

From my careful scientific observation: Mo' current, mo' bubbles.

A truly "Duh!" moment, was it?

Ah, but I wish it was all that simple. I just rigged up my new set-up:

http://www.flickr.com/photos/2768312...in/photostream

(and the next two pics)

Y'know, that looks like a januwine termite barf inlaid Harbor Freight
workmutt clone that your etch tank is resting upon. I sold mine in my
garage sale a few months ago. Nice power supply, sir.


The results are beautiful, but then I could do the small pieces with
negative etching quite well before. The thing that was interesting was
the unidirectional movement of the hydrogen bubbles *away* from the
anode.

Yeah, that's fun. Now reverse the polarity and see what happens!
silly grinne


The proof of the pudding will happen in a day or so when I shall
repeat the etch that sparked the OP.

G'luck!


[...]

Is this entirely sacrificial, or can you reuse electrolyte?

CuSO4 I re-use all the time. Just top up the wastage and evaporation.
Salt and vinegar needs to be fresh for the reasons above.

Cool. That's an inexpensive bath.

Those pretty blue crystals are good for poison oak/ivy, too. Make a
solution and pad it on the affected area. It'll make your skin crawl
for a few minutes but it removes the oil, the itch, and the spread.
I haven't noted any toxic feeling afterward, but it's a 1-time bath.

Here they use them to kill roots in septic tanks. Actually I am using
a commercial solution sold by jewelers' supply company for copper
plating. I do have a bunch of CuSO4 crystals which I will go to next
when I run out of the current solution.

Doesn't it kill the beneficial bacteria, too?



Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

Newp, I don't have anything to do with the Jacksons, ever.

We must have hit the cultural divide between our countries.
Arlo Guthrie's song "Alice's Restaurant" is a cult classic here in the
States. Listen to it and weep: http://goo.gl/qsb8K

I seem to remember a movie of similar name. About 1970? I was never
into the hippie thing.

Yes, 1969, starring Arlo Guthrie his own self.


Another cultured fave is "The Motorcycle Song" http://goo.gl/Scw2p
"I don't want a pickle. Just wanna ride on my motorsickle."

OBTW, this is folk culture, not opera or symphony or sumpin'.

Your culture. I shall stick to "Does your chewing gum lose its flavor
on the bedpost overnight?", "Calendar song" and other such
masterpieces.

Um, OK. cringe

--
The unexamined life is not worth living.
--Socrates

On Fri, 04 Nov 2011 05:26:43 -0700, Larry Jaques
wrote:


Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

Newp, I don't have anything to do with the Jacksons, ever.

We must have hit the cultural divide between our countries.
Arlo Guthrie's song "Alice's Restaurant" is a cult classic here in the
States. Listen to it and weep: http://goo.gl/qsb8K

Another cultured fave is "The Motorcycle Song" http://goo.gl/Scw2p
"I don't want a pickle. Just wanna ride on my motorsickle."

OBTW, this is folk culture, not opera or symphony or sumpin'.

It IS Opera. Just not European or Italian.

Freakian Opera

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

On 5 Nov 2011 04:11:44 GMT, "DoN. Nichols"
wrote:

On 2011-11-04, wrote:
On Thu, 03 Nov 2011 03:20:34 -0700, Larry Jaques
wrote:

[ ... ]

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

It is a popular culture reference. :-)

You never heard the full 18 minute 34 second run of Alice's
Restaurant -- a cant-fable (talking and singing mixed) by Arlo Guthrie
back in the 1960s I believe.

This will tell you about it:

http://en.wikipedia.org/wiki/Alice's_Restaurant

and here are the full lyrics, if you prefer to read it instead of to
listen to it:

http://arlo.net/resources/lyrics/alices.shtml

The first mention of the quoted text is about in the tenth
paragraph/verse, depending on how you count.

Enjoy,
DoN.

"you can get anything you want...at Alllliccces Restaurant....."

Crom but those were the fun daze....


One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

On 11/5/2011 2:02 AM, Gunner Asch wrote:
On Fri, 04 Nov 2011 05:26:43 -0700, Larry Jaques
wrote:


Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

Newp, I don't have anything to do with the Jacksons, ever.

We must have hit the cultural divide between our countries.
Arlo Guthrie's song "Alice's Restaurant" is a cult classic here in the
States. Listen to it and weep: http://goo.gl/qsb8K

Another cultured fave is "The Motorcycle Song" http://goo.gl/Scw2p
"I don't want a pickle. Just wanna ride on my motorsickle."

OBTW, this is folk culture, not opera or symphony or sumpin'.

It IS Opera. Just not European or Italian.

Freakian Opera

Gunner



NOT opera. It has spoken dialog.

On 2011-11-05, wrote:
On Fri, 04 Nov 2011 05:26:43 -0700, Larry Jaques
wrote:

On Thu, 03 Nov 2011 20:56:23 -0700, wrote:

On Thu, 03 Nov 2011 03:20:34 -0700, Larry Jaques
wrote:

[ ... ]

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

Newp, I don't have anything to do with the Jacksons, ever.

We must have hit the cultural divide between our countries.
Arlo Guthrie's song "Alice's Restaurant" is a cult classic here in the
States. Listen to it and weep: http://goo.gl/qsb8K

I seem to remember a movie of similar name. About 1970? I was never
into the hippie thing.

The movie was based on the events in the song.

Another cultured fave is "The Motorcycle Song" http://goo.gl/Scw2p
"I don't want a pickle. Just wanna ride on my motorsickle."

OBTW, this is folk culture, not opera or symphony or sumpin'.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Fri, 04 Nov 2011 21:44:50 -0700, Larry Jaques
wrote:

[...]

Y'know, that looks like a januwine termite barf inlaid Harbor Freight
workmutt clone that your etch tank is resting upon. I sold mine in my
garage sale a few months ago. Nice power supply, sir.

1) Close - Crappy Tire. With a bit hacked off during the Heroic
Fence-building of 2011.
2) It *is* nice. $6 in a garage sale. It keeps constant current up to
3A. It is particularly useful when doing brass as the voltage seems to
dance around a lot doing that.


The results are beautiful, but then I could do the small pieces with
negative etching quite well before. The thing that was interesting was
the unidirectional movement of the hydrogen bubbles *away* from the
anode.

Yeah, that's fun. Now reverse the polarity and see what happens!
silly grinne

Some other time.

[...]

Those pretty blue crystals are good for poison oak/ivy, too. Make a
solution and pad it on the affected area. It'll make your skin crawl
for a few minutes but it removes the oil, the itch, and the spread.
I haven't noted any toxic feeling afterward, but it's a 1-time bath.

Here they use them to kill roots in septic tanks. Actually I am using
a commercial solution sold by jewelers' supply company for copper
plating. I do have a bunch of CuSO4 crystals which I will go to next
when I run out of the current solution.

Doesn't it kill the beneficial bacteria, too?

Who knows? Who cares? The Global Warming will kill us all anyway!

Michael Koblic,
Campbell River, BC

Gunner Asch on Sat, 05 Nov 2011 11:30:56 -0700
typed in rec.crafts.metalworking the following:
On 5 Nov 2011 04:11:44 GMT, "DoN. Nichols"
wrote:
On 2011-11-04, wrote:
On Thu, 03 Nov 2011 03:20:34 -0700, Larry Jaques
wrote:

[ ... ]

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

It is a popular culture reference. :-)

You never heard the full 18 minute 34 second run of Alice's
Restaurant -- a cant-fable (talking and singing mixed) by Arlo Guthrie
back in the 1960s I believe.

This will tell you about it:

http://en.wikipedia.org/wiki/Alice's_Restaurant

and here are the full lyrics, if you prefer to read it instead of to
listen to it:

http://arlo.net/resources/lyrics/alices.shtml

The first mention of the quoted text is about in the tenth
paragraph/verse, depending on how you count.

Enjoy,
DoN.

"you can get anything you want...at Alllliccces Restaurant....."

He redid the album, with a longer version of "The Massacree". In
which he observed, that Nixon was notorious for an 18 minute gap in
the tapes. "'Now Arlo', I said to myself, 'Can you think of anything
else which is exactly 18 minutes and 34 seconds long .."

Crom but those were the fun daze....

"Excepting Alice!"

tschus
pyotr
--
pyotr
Go not to the Net for answers, for it will tell you Yes and no. And
you are a bloody fool, only an ignorant cretin would even ask the
question, forty two, 47, the second door, and how many blonde lawyers
does it take to change a lightbulb.

Gunner Asch on Sat, 05 Nov 2011 00:02:23 -0700
typed in rec.crafts.metalworking the following:
On Fri, 04 Nov 2011 05:26:43 -0700, Larry Jaques
wrote:


Anyway, I moved onto brass today which I thought I had pretty much
worked out. I did two small plates and observed some really weird
behavior. OTOH I do not care as long as the result is OK.

Got eight-by-ten colour glossy photographs with circles and arrows and
a paragraph on the back of each one explaining what each one was to be
used as evidence against us?

You lost me there. Something to do with Mchael Jackson perhaps?

Newp, I don't have anything to do with the Jacksons, ever.

We must have hit the cultural divide between our countries.
Arlo Guthrie's song "Alice's Restaurant" is a cult classic here in the
States. Listen to it and weep: http://goo.gl/qsb8K

Another cultured fave is "The Motorcycle Song" http://goo.gl/Scw2p
"I don't want a pickle. Just wanna ride on my motorsickle."

OBTW, this is folk culture, not opera or symphony or sumpin'.

It IS Opera. Just not European or Italian.

Freakian Opera

They even made a movie of it.

"It might be a movement!"
--
pyotr
Go not to the Net for answers, for it will tell you Yes and no. And
you are a bloody fool, only an ignorant cretin would even ask the
question, forty two, 47, the second door, and how many blonde lawyers
does it take to change a lightbulb.