Etching with Press-N-Peel

I’m having difficulty maintaining a solidly resistant mask when I
etch copper and brass in ferric chloride using Press-n-Peel. Even
with a slow solution, the ferric chloride eats through the resist, so
that the area that is protected has pitting, similar to an aquatint.
Some surfaces remain completely masked. I want to be able to achieve
a deep etch in brass, to make a plate I can use in the rolling mill.
I also want to do more shallow etches using copper/silver bimetal.

I’ve followed the procedures I received with the P-n-P–as follows:

Clean copper or brass (water sheets off) HP LaserJet to print design
on p-n-p Iron set on 3 (polyester/rayon setting) Air cooled or
quenched before peeling mask off Tested by etching in half-hour
increments from 30 minutes to 3 hours: Test strip A in used, nearly
spent ferric chloride and Test strip B in fresh, full-strength ferric
chloride. Both etched through the mask, though A didn’t start to etch
through until about 2 hours.

I’ll appreciate any help other Orchid members have to offer.

Joan Hammond

Hi Joan. I have been etching with PNP with no problems. However,
I wonder if the Lazer jet ink could be the problem. Perhaps it
does not hold up as well as the ink in copier machines. I have
been making the transfer with a copier machine. Although I have a
Conon copier, I don’t mine for fear of something going wrong, but
take my stuff down to the local copiers. The resist holds up just
fine. You might try the copiers and see if that makes a difference.
Hope this solves your problem. Alma

It sounds as if you’re not getting a clean transfer of the resist to
the metal. PnP is quite durable in the ferrics and even a weak
solution of nitric. I’ve responded to some of your specific problems
with some troubleshooting tips below.

    with a slow solution, the ferric chloride eats through the
resist, so that the area that is protected has pitting, similar to
an aquatint. Some surfaces remain completely masked. 

This is most probably from oil contamination, possibly dust
contamination. Be scrupulous about cleaning your metal before
applying the resist. Sand to 400 grit to provide a bit of ‘tooth’.
Wash with a good surfactant dish soap (my personal preference is Ajax
plain dish soap), wipe both the metal and the PnP with a lint free
paper towel (cheap brown ones are best) moistened with alcohol. After
you have the metal and PnP set up to transfer, and just right before
applying the heat, wipe both surfaces with alcohol again.

    a deep etch in brass, to make a plate I can use in the rolling
mill. 

Etch into tool brass (hard yellow).

    Clean copper or brass (water sheets off) HP LaserJet to print
design on p-n-p 

Make sure it is a strictly laser printer, not an ink jet. You must
have the carbon-based DRY toner. You can also photocopy with a
machine that uses heat-set dry toner (Kinkos have been going to the
liquid toners that are not carbon-based, therefore they don’t work).

    Iron set on 3 (polyester/rayon setting) 

Personally, I’ve found this isn’t hot enough. Optimum heat transfer
is around 425 degrees Farenheit. When the resist transfers, it should
be a dark blue-black in color.

   Tested by etching in half-hour increments from 30 minutes to 3
hours: Test strip A in used, nearly spent ferric chloride and Test
strip B in fresh, full-strength ferric chloride. Both etched
through the mask, though A didn't start to etch through until about
2 hours. 

I’ve had no problems etching for 8 hours or more without the resist
lifting. Undercutting is a different animal, and the strength of the
ferric can be adjusted to prevent this.

 I'll appreciate any help other Orchid members have to offer. 

You might try making the masks with a different printer/copier, or
putting in new toner. If the toner/image isn’t dark enough, it might
not be well enough adhered. Also, try cleaning the sheet with
powdered pumice, so the suface has a fine light matte finish rather
than a high polish. That will give the toner/adhesive a lot more
surface area to grab onto.

Hope that helps.
peter Rowe

  I'm having difficulty maintaining a solidly resistant mask when
I etch copper and brass in ferric chloride using Press-n-Peel. Even
with a slow solution, the ferric chloride eats through the resist,
so that the area that is protected has pitting, similar to an
aquatint. 

Joan, it’s not anything you’re doing wrongly. I was never able to
make that stuff work to produce anything other than a very poor
"hobby-level’ etch - and I’ve never seen anything that looked even
halfway decent produced using it. I would be delighted to be proved
wrong however because that would mean I could then learn how to
achieve satisfactory (to me) results, in the process saving
considerable time and money.

Any outraged proponent of the stuff should feel free to email a 300
dpi jpg to pictures@netconnect.com.au of something with delicacy and
depth that they’ve produced in this fashion. I don’t expect to be
inundated with pictures.

Al Heywood

I have also found that the PnP works great with a copier. At first
I used the self-service copiers at Kinkos. Then I tried the big
xerox machine at work which also worked great. One thing I
discovered, however, was that I needed to set the copier as if I were
copying onto a transparency otherwise the paper melted. The copies
were very crisp and clear and I had no problems with the resist
coming off of the metal. --Vicki Embrey

      I'll appreciate any help other Orchid members have to offer. 

When you photocopy onto p-n-p, hold the copy up to the light, if you
see open spaces, the toner is not dense enough so turn the darkness
up, test first on regular paper for darkness.

If you have air bubbles in the p-n-p where the resist should be, that
will leave holes . You can cover up holes with nail polish.

Make sure the metal is very clean before application of p-n-p, a
final rinse with alcohol sometimes helps.

I’ve gone through over a hundred sheets of this stuff without
problems. Donna in VA

        Hi Joan.   I have been etching with PNP  with no problems.
However, I  wonder if the Lazer jet ink could be the problem. 
Perhaps it does not hold up as well as the ink in copier machines.
I have been making the transfer with a copier machine. Although I
have a Conon copier, I don't  mine  for fear of something going
wrong, but take my stuff down to the local copiers. The resist
holds up just fine.  You might try  the copiers and see if that 
makes a difference. Hope this solves your problem. Alma 

No! InkJet printers do not work! The pigment must be applied
thermally. Black & white laser printers and most copiers use a toner
that is fused on with heat.(Feel the paper, it comes out hot.) When
applied to PNP and heated this pigment absorbs the heat and is
transferred to the metal. Nothing else will do it. Bill

Joan, I have never seen this mask used to process for that long a
period. PNP Blue was designed to etch circuit boards that have a
very thin copper coating. I have used it for normal etches to reveal
a pattern but nothing like leaving it etch for hours. I would
suggest you look to a more professional level of masking. Kodak
sells a whole line of photo resists. In general they require baking,
negatives and UV light exposure. Bill

Hi, Joan, This is Kitti DeLong in Port Townsend. Glen Paris and I
have been using PnP Blue for quite a while and have not had any
trouble with it etching away (other than with very thin lines, which
need to be made wider before transfering to the PnP). Could it be
that your iron is not hot enough to do the transfer properly? That
setting you used is not hot enough on my iron. It might help to get
a thermometer to hang on your iron. We use one that is magnetic and
sticks to our wood stove. Made quite a difference in our finished
product. Regulators inirons probably differ. It might be easier to
help more over the phone. My number is 360-379-5330 if you would
like to call. Good luck. Kitti