Photoetching

Ok, I know this subject has had a good wookout some time previously,
but I’ll be darned if I can locate much in the archives.

I am looking for more on photoetching. I want to
"electro-chemical machine" component parts for items of jewelry. I am
looking for chemical or electro-chemical methods of doing simulated
pierce-work. Laser and waterjet cutting have already been explored
unsuccessfully. The pattern is too complex, I believe, for stamping,
or at least my skills at cutting the dies necessary.

In using PnP Blue, or similar, on sterling silver, can the etchant be
a more aggressive chemical than ferric chloride? How about nitric
acid?

Has anyone experienced patterns not adhering to the metal when using
copying services such as Kinko’s? (Apparently they are using custom
toners.)

Any help you can offer would be greatly appreciated.

Thanks … Marrin Fleet

Hi Marrin,

Haven’t talked to you in a while! :slight_smile:

I was just digging in Oppi Untract’s “encyclopedia” (Jewelry
Concepts and Technologies
) for this last night around
midnight! Hydrochloric acid for copper and nitric for silver. The
concentration of the acid solution and the temperature can both be
used to control the aggressiveness of the “bite”.

I bought the Rio etch press a couple years ago and have not used it,
but just pulled it out. It comes with one kind of resist, but I bought
the asphaltum for silver work. It apparently holds up better to the
nitric.

The etch press product essentially uses a silk screening process to
apply the resist to the chemically clean sheet in a controlled manner.

Now… where to get these acids…

By the way, since we’re talking about using acid, remember “AAA”.
That’s Always Add Acid - meaning you always add acid to water, not the
other way around. :wink:

Dave

Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)
dave@sebaste.com mailto:dave@sebaste.com
http://www.CarolinaArtisans.com http://www.CarolinaArtisans.com

Marrin-- I have done a lot of work with (and teaching of) what I
call “low-tech photo-etching”. I don’t use pnp blue–I photo-copy
onto acetate & iron the image onto metal. Some copiers just don’t
work, and I’ve found no way to predict which ones. It is always a bit
of a crap-shoot with silver, but with care, great results can be had.
Ferric chloride is the mordant of choice for copper and brass, but
nitric acid is just the ticket for silver. The action is so fast and
"vicious", with a lot of bubbling (especially when the mordant is
new), that the hard part is to get the image to stay on the silver. I
have, however, used this technic to “pierce”, etching all the way
through. I believe that there are companies that will do this service
for you, probably better, but it can be done, at least on fairly thin
material. I recently spent a half-hour on the phone explaining the
ins and outs and details to a student–and it would take a lot longer
to type a tutorial, as I am not a typist. However, if there is
interest, I guess I’d be willing. I have merely added by
experimentation and experience to instructions I got for $.50 from
Reactive Metals. Hope this is of some help! --Noel

Marrin-- I have done a lot of work with (and teaching of) what I
call “low-tech photo-etching”. I don’t use pnp blue–I photo-copy
onto acetate & iron the image onto metal. Some copiers just don’t
work, and I’ve found no way to predict which ones. It is always a bit
of a crap-shoot with silver, but with care, great results can be had.
Ferric chloride is the mordant of choice for copper and brass, but
nitric acid is just the ticket for silver. The action is so fast and
"vicious", with a lot of bubbling (especially when the mordant is
new), that the hard part is to get the image to stay on the silver. I
have, however, used this technic to “pierce”, etching all the way
through. I believe that there are companies that will do this service
for you, probably better, but it can be done, at least on fairly thin
material. I recently spent a half-hour on the phone explaining the
ins and outs and details to a student–and it would take a lot longer
to type a tutorial, as I am not a typist. However, if there is
interest, I guess I’d be willing. I have merely added by
experimentation and experience to instructions I got for $.50 from
Reactive Metals. Hope this is of some help! --Noel

    I am looking for chemical or electro-chemical methods of doing
simulated pierce-work. Laser and waterjet cutting have already been
explored unsuccessfully. 

Etching can accomplish this, but you need to use either very thin
stock with a backing sheet, such as another metal laminated or a
resist. If you want to use a thicker sheet, it’s best to etch from
both sides at once. Refer to Oppi Untrect’s book, Jewelry: Concepts
and Technology, for this process. You may find this method preferable
to the PnP method.

    In using PnP Blue, or similar, on sterling silver, can the
etchant be a more aggressive chemical than ferric chloride?  How
about nitric acid? 

Nitric acid destroys PnP acetate. Ferric chloride etches copper based
metals, not sterling silver. Ferric nitrate will etch silver and does
well with the PnP. The nice thing about the ferrics is there is less
chance of undercutting than with the nitric.

    Has anyone experienced patterns not adhering to the metal when
using copying services such as Kinko's? (Apparently they are using
custom toners.) 

Resists, and therefore toners, must be carbon based, such as with
laser printers. The newer “laser” printers don’t use carbon based
toners, and are therefore ineffective as resists. Most photocopiers
still use carbon base toner and are compatible with PnP.

Hope this helps. K.P. in WY

I don’t want to sound to trite but, what about piercing – with
a saw. There is almost no pattern to complex for a saw with the
exception of severely curved surfaces like rings and bracelets. While
photoetching has its place and is a great direction to explore, do
not so quickly pass by the extremely gratifying endeavor of hand
piercing. It is to photoetching as drawing is to photography. Both
exciting art forms, yet they will evoke different responses using the
same images. Just putting in my 2 cents worth --(although you
only get a penny for your thoughts) . That’s the way it works in the
arts – you almost never get what its worth. AH- a good reason not
to put the time into hand piercing. Sorry, I’m rambling now ----
by—Marty

Marty,

Piercing is an excellent way to treat a surface. While you can get
great results from using the weight of a line with piercing,
photoetching simply adds another dimension. With my work in
photoetching, I use both etching and piercing together. Email me off
line, and I will send you the pix. Photoetching gives me the ability
to have a literal use of text and photography. Piercing gives me
line, photoetching gives me texture and shadow.

-k