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Picture This! Photo Etching on Metal


#1

Learn Photo Etching on Metal with Karen Christians at MetalWerx,
Apr 3-4 2004, 9am-5pm, 2 days Tuition: $295 Materials: $55

http://www.metalwerx.com/o/wk-etching.html

Etching metal is very simple. Basically you have a mordant (acid)
and a resist to that acid. The resist can take many forms, plastic,
vinyl, Sharpie Marking Pen, duct tape, nail polish, etc. As long as
it resists water, you are fine. With current photocopy technology
and computer laser printer technology, you have more flexibility in
your designs. These are basically the same techniques as
printmakers use with zinc, but with brass, copper or bronze and
silver, you have options for additional fabrication choices
involving solder or cold connections.

Nitric/Hydrochloric Acid vs. Ferric Chloride/Nitrate

Ferric Chloride and Ferric Nitrate are slower etches and have extra
safety features. Nitric or Hydrochloric acid etching goes

While safer than nitric, these are still considered hazardous, so
close attention to the process is important. I have outlined safety
issues when necessary.

One great feature of the acid etch is the incredible textures you
can achieve by the action of the acid playing on the surface of the
metal. Somewhere between repouse,

It is important for anyone to use good quality Safety Glasses when
handling etching liquids. Also, a pair of household, well fitting
gloves is a good idea.

Ventilation is also a good idea. Tips on disposing the etching
solutions and the Material Safety Data Sheets (MSDS) are at the end
of the protocol.

The Supplies

  1. A small Rubbermaid or other plastic tub, the size of a shoe box,
    with a tight fitting lid

  2. Ferric Chloride (for bronze, copper and brass); Ferric Nitrate
    (for silver)

  3. Duct tape and two sided sticky tape

  4. Styrofoam

  5. Red Staedler ink pen (available at Office Depot, Staples,
    Charette) or any drafting supply store

  6. Cheap air pump from a pet store

  7. Metal - 20-16 ga

  8. Iron

  9. 3M PP 2200 Overhead Transparency Film

  10. Paper towels

  11. Tweezers

  12. Curved burnisher or spoon

  13. Mix of water and denatured alcohol, 2 parts alcohol, 1 part
    water in a tight fitting jar

  14. 3M Scotchbrite pads, and a degreasing cleanser such as Comet or
    Ajax or Penny Brite (the best)

  15. Cheap pancake griddle. A new one will run about $35, but
    finding an old one in a thrift store is perfect

  16. Baking soda

  17. Safety glasses, rubber gloves

  18. Household ammonia

Process: Image onto Metal

  1. Select your metal. Start with a piece no larger than 3 x 3 to
    begin. File any corners or rough edges until they are smooth.
    Clean your metal with Scotchbrite and cleanser or Penny Brite until
    water runs off your metal in a sheet. If you see the water beading,
    then clean again. Scrubbing with Scotchbrite will serve to give the
    metal a “tooth” and will clean it well. Dry with a towel and handle
    by the edges.

  2. Select your image and photocopy onto the PP 2200 overhead
    transparency film. Images should be high contrast with visible
    distinction between dark and light. The grey parts in between can
    make it difficult for the acid to bite. Trim your picture so there
    are no overlaps from the film over the metal. It’s best that you
    leave a little extra metal around the edges.

Laser Printers vs. Inkjet Printers: Laser printers are basically
small photocopiers. They use the same kind of toner and scanning
technology. Inkjets use water soluble ink which will NOT work for
this process.

  1. Heat your iron to “cotton” and your griddle to 250 degrees F.
    Depending on the kind of iron you have, you may have to adjust the
    heat. Overhead transparency film is designed for very high heat,
    but some irons are extremely hot. I suggest some tests first.

  2. Put one piece of your paper towel on the griddle. This is meant
    to protect the griddle face, and also keeps the metal from skating
    around. Many griddles have Teflon coatings these days. Don’t worry
    about the paper burning. If you remember your Ray Bradbury book,
    Fahrenheit 451, paper doesn’t burn until 451 degrees F.

  3. Lay out all your supplies, the burnisher, tweezers, alcohol and
    paper towel next to you for easy access.

  4. First take a small wad of paper towel and saturate it with the
    alcohol mixture. Clean one side of the metal and the TONER side of
    your image. IMPORTANT!! And this is the trick to making the whole
    process work for you. Make sure when you place the image side down
    to the metal, that it is still wet. Squeegee out the excess
    moisture and any air bubbles by rubbing your hand across the metal
    and film. It doesn’t need to be dripping wet, but it does need to
    be wet.

  5. Immediately place the metal with the film side up onto the paper
    towel already warmed on the heated griddle. Immediately place
    another paper towel over your piece and your iron on top of that.
    Let the iron sit for about one minute. Carefully iron the piece for
    about 20 more seconds and lift the iron. Remove the paper towel.
    Place the burnisher in one hand and a tweezer in the other.
    Carefully lift one corner of the film and see if the image has
    transferred to the metal. If it hasn’t, replace the film and keep
    heating. Sometimes, using the burnisher will help. Burnish the
    image onto the metal. If it has transferred, remove the film, WHILE
    HOT in one smooth stroke. Voila, you have your image. If it
    smudges, then the iron is too hot, and takes it down a bit. The
    nice thing about this process is that you can scrub the image off
    and try again.

This will take a bit of practice, but in the end, you should get it
to work very well. Transfer the metal to a heat proof surface. A
metal block or anvil works nicely. Once the toner is on the metal,
it is very stable. I have had sample pieces that have been sitting
around for years that are as good as the day I ironed the images
down.

  1. Troubleshooting. Sometimes the image does not transfer
    completely. This is where your red pen can help out. You can fill
    in some areas before the etching. Thicker gauge metal takes longer
    to transfer than thinner. Large metal pieces can work, but you must
    raise the griddle heat and spend more time ironing. As a rule, I
    don’t try to use multiple pieces of film on one piece. If the metal
    cools too much, the film will pull back the image. You can however,
    do multiple images in stages. Silver heats up faster, so watch your
    temperatures carefully. Remember, hot metal looks just like cold
    metal.

Process: Etching

Now that you have your image, you are ready to etch. Lay out your
supplies, acid, tub, duct tape, Styrofoam, two sided sticky tape,
safety glasses and rubber gloves, and the air pump.

  1. Your metal should be clean. Use Penny Brite (citric cleanser)
    or regular cleanser. Don’t scrub this time, rather mix a solution
    in water or sprinkle the cleanser over the metal and rinse with
    water. You can GENTLY move it around, but don’t use any pressure.
    Dry in a clean paper towel and leave covered.

  2. Tape the back with duct tape. Place two strips of double sided
    sticky tape onto the duct tape. Cut a piece of Styrofoam to fit the
    size of your metal. Compress the two together until it sticks.

  3. Strap the air pump onto the side of your plastic tub. I actually
    like to make this fixture, but using Velcro adhesive tabs. This is
    very helpful and the gentle vibration won’t dislodge it. Why an air
    pump? These cheap pumps are made to vibrate for long periods of
    time. This vibration facilitates the etched residue to fall to the
    bottom of the tub and keeps the exposed area of metal etching
    continuously.

  4. Donning your safety glasses and gloves, pour the ferric chloride
    into the tub, about 1/3 full. Try not to create bubbles, but a few
    are ok. This should be performed in a well ventilated area.

  5. Write down the time that you began the etch on the Styrofoam.
    Strap the pump onto the side of the tub. Carefully lower the metal
    into the solution. The Styrofoam act like little pontoons and make
    sure that the metal is submerged correctly. Close the lid and plug
    in the pump. Etching should take about 45 min to 1.5 hours,
    depending on the depth of the etch you desire.

  6. Check the etch every 30 minutes. Have a separate empty
    container nearby. Pull the metal out and take it to a sink. Rinse
    thoroughly. The small amount of ferric chloride isn’t enough to
    harm the sink. Flush with water and rub your finger along the metal
    to see how the bite is taken. If you need more, drop it back into
    the tub.

  7. Etch done? Pull your piece out of the acid, drain well and bring
    it to the sink. Fill your container with water and about a handful
    of baking soda. This will neutralize the acid. Wait a minute after
    it stops foaming. Rinse well. Refill the tub with a little more
    water. Add about 1/8 c of ammonia. This acts as a stop bath for
    the acid and completely arrests any leftover or trapped acid. Under
    running water, or submersed, pull the tape off your metal. Clean
    the metal again with the Penny Brite or cleanser and Scotchbrite.
    This will scrub off the last of the toner. Now you are ready to use
    your etched piece.


#2

Hi, Karen,

It was great to meet you at SNAG. What a great time!

Thanks for the etching tutorial. It is close to the technique I have
been using for years, with some interesting additions, like the
two-sided heat, and the alcohol between the metal and the acetate.
Did you come up with that? I look forward to trying it.
The only thing that contradicts my experience is your instruction to
pull the acetate off hot. I’ve found the exact opposite-- that doing
it hot tends to leave ink behind on the acetate, but cold less so.
Hmmm. Well, one more thing to test out.

–Noel


#3

Is there any advantage in using your system over pnp film (press n
peel)? I am getting excellent results with pnp, lazerjet printed
halftones and simple pan etching with ferric chloride baume 36 for
copper and ferric nitrate 36 baume for silver We are also using this
method at Tyler School of Art, Temple University for patterns in
coloring metals. The best images are produced by taking them directly
from the computer and lazer etching the pnp film.

Frank Johnston


#4

Hi Frank:

If you are getting good results with PnP then by all means use it.
I find that the acetate is just easier for me. One feature is
expense. The acetate is really cheap. If you have a laser printer
and a computer than text is easy to do. If you don’t have a
computer handy, then making internegs for text reversal is simple.
Not everyone has a laser printer, but access to a photocopier is
everywhere.

What is an interneg? Printmakers use reverse images to print from.
In using a photocopier, your text would etch in reverse. If you
want the text to etch readable text, you must make a second copy of
the text in reverse so the toner will read correct. Basically copy
the text onto acetate as usual, flip it over on the photocopier and
copy again on the acetate. Your letters will now read right side
up.

I have a couple of etching examples on my website.
http://www.metalwerx.com/o/st-christians.html Go to my gallery.

Yours in art,

-k

Karen Christians
M E T A L W E R X
50 Guinan St.
Waltham, MA 02451
Ph. 781/891-3854 Fax 3857
http://www.metalwerx.com/
Jewelry/Metalarts School & Cooperative Studio


#5

Karen, I love your gallery! The pieces are wonderful. Thanks for
posting the URL. (http://www.metalwerx.com/o/st-christians.html, for
those who missed it.)

–No=EBl


#6
What model laser printer do you recommend?
Some previous emails on this subject mentioned that some laser
printer don't put down enough ink to work well. 

Thanks for writing! It is my belief that technique should always be
shared. Give 10 people a 1 x 3 inch piece of 18 ga metal, show them
all the technique of measuring, cutting, filing, sanding, forming
and soldering, and you will get 10 different rings.

Laser printers and photocoiers share the same technology. The toner
ink and how it is distributed depends on the internal machine.
High performance photocopiers at places like Kinkos, are built for
speed. Smaller desk top photocopiers are slower and distribute more
toner. I purchased a small Canon photocopier for this purpose which
cost me $500. It is in its’ 10th year of operation.

Like all protocols, experimentation is the rule. There is no
perfect standard, only try and try again until you find the right
combination.

Namaste,

Karen Christians
M E T A L W E R X
50 Guinan St.
Waltham, MA 02451
Ph. 781/891-3854 Fax 3857
http://www.metalwerx.com/
Jewelry/Metalarts School & Cooperative Studio