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Photoetch


#1

I used International Etching in Providence for a progam of designs this
past fall. They will etch their metal or yours in 4x12, 6x12, and 12x12
inch sheets. The pieces we did were oval (5 sizes, 5/8 to 1 1/4 long axis)
and cost roughly $3 each after initial art charges, but including metal
(16 g sterling). They redid the tool once because they were not happy with
the result- before they shipped anything to us. We were happy with the
results.

Rick Hamilton
Richard D. Hamilton, Jr
http://www.rick-hamilton.com
@rick_hamilton


#2

Hi Mark,

I had read a vague description of this process a little while back. Since
magnesium burns really hot and violently, I assume you don’t just invest
and burn out. Do you make a vulcanized or RTV mold then? Followed by
injecting wax and then traditional lost wax methods?

You referred to a 1mm sheet. Seems a little thin to me. Do you affix this
to some other substrate? I can’t quite visualize this from your
description… I’d like to hear more.

Dave Sebaste


#3
Would you enlighten us on the process you used to get the image from
CorelDraw to a resist pattern on the sheet of metal?  I've been looking
into this a bit, and I haven't yet found a process that seems both
cost-effective for the small artist and reliable enough to provide
consistent results.

I have always stayed away from acids because of the kids… However, maybe
I can help. You need to get a negative produced first. Either print out
your graphic at about 400% or 500% and take it to your local print shop
and have them reduce it to a negative of the appropriate size, or upload
your graphic to a service bureau and have them print it on on their
Linotronic at 2400 dpi or higher. The print shop method is less expensive
generally, but if you have multiple images, the service bureau method may
cost less.

Once you have the negative in hand, it is used as the mask in the exposure
process. Now I used that system you mention Rio Grand sells, and that
system uses photopolymer sheet. But I used to do art work and produce
negatives for other artists that used acid resist etching. I don’t know
the resist they used, but I know it was relatively inexpensive and easily
applied. The negative is applied to the sheet metal to be etched (in a
manner that presses it very close to the metal, I built a vacuum unit to
do this, and also built a glass top unit that held the negative to the
piece being exposed with spring pressure on top of the glass) and exposed
to some kind of light. In the case of The Model Master ultraviolet light is
used (I built my own exposure unit, modeled after professional units), and
in the case of resists, I believe simple bright light is used, though I
have to admit to being ignorant on the subject. After the exposure is
complete, I think you know what to do next… :slight_smile:

    Rio offers a small system; I've heard mixed reviews and even the
detail of the images in the catalog looks questionable to me.  Most of
the approaches I've seen are silk screen based... although I did hear an
interesting technique of using the heat from an iron to transfer toner,
as a resist, from a laser printed page. I've produce amazing pieces using
the Model Master, although it was many years ago, when the system was
just introduced. Some background; the process is one actually used in
the printing industry. Flexible photopolymer sheets (which are a semi-gel
state of the photopolymer liquid used in stereo-lithography) which are
hardenable in ultraviolet light, are used to produce flexible printing
plates and are used to print onto difficult materials such as certain
cloths and plastics. Silicon rubber is sometimes poured onto the
photopolymer to create rubber printing plates used for printing onto
grain sacks etc and also for *rubber stamps* (I'm sure you've seen the
masses of light pinkish orange stamps sold in stores, that's how they're
made). I use the photographic negative method (or the Lino print method)
exclusively, having long ago given up on any other method because of the
very rough edges produced due to the lack of effective resolution. You
can get very good detail with the Model Master, it's all in the
technique.
I looked into subcontracting the work out.  I think Anne (thanks!) gave me
a refence to a commercial etching house in the northeast who might be able
to do the job.  They can definitely take camera-ready art and return to you
an etched sheet.  The problem developed in trying to estimate costs on a
sterling sheet.  My mindset works on a cost of materials, plus labor. They
tend to think in some other pricing paradigm, so I was not able to really
get an estimate.  It seemed more like, "send us the job, and we'll let you
know how much it cost after we're done."  Made me a little uncomfortable.

The cost of etching is nominal. You can get a sheet of magnesium etched
for about $14, and that sheet can contain many images that can be cut out
and molded. the problem with magnesium lies in injecting the pattern.
Unless you have a vacuum wax injector or a high pressure vacuum wax
injector, or a plastic injector… the patterns are difficult to get all
the detail present. Regarding etching sterling sheet, the cost is in the
sterling sheet, not the etching process. The etching process is very
straight forward. One close friend of mine had a very neat set-up. He used
the acid etch technique to produce American Indian (he is Indian) images,
and then punched out the images using a kick press. Of course he was doing
production and could afford the tooling for the kick press… His jewelry
was then blackened and sold all over the U.S.

Anyway, I'd like to hear what has worked for you!

I eventually switched to milling my patterns. I became unsatisfied with
the limitations with the etch process.

Hope this all helps, there’s a lot more where this all came from! I did
work like this for years.

Good Luck

Jeffrey Everett


#4
Dave and Jeffery I may be a little off base. But when we need to
reproduce a logo for a customer, we use a local engraving company
who makes magnesium dyes for printers who foil stamp (I'm sure
most larger cities have one).

You’re not off base at all Mark. This method was my introduction to
etching, back around 1982… The reason I switched away from it was the
shoulders (edges) have such a large draft that fine details get lost or
become extremely shallow, but it’s great for simple images. Jeffrey Everett


#5

Dave, You cannot solder a sprue onto the magnesium plate its true, we
usually glue one on or lay it near the plate when making the mold (if you
do this you may have to do a little hunting when cutting the mold but it
won’t go far). We use regular gold label rubber (and vulcanize at regular
temp) to mold the magnesium without any trouble. We have never ignited the
magnesium, although it would probably be fun. You can have the engraving
company use whatever guage sheet you want, we use thinner to keep the
weight after casting down. What is nice is you can trim and file the
photoetched magnesium piece prior to molding and get it just how you want,
we will occasionally need to engrave more detail and it is soft enough to
work. It is not perfect but its quick and cheap and all our customers have
been happy. By not perfect I mean the really tiny detail may not turn out
after molding, like the tiny little R in the registered trademark symbol.
But if you need a company logo on the top of a ring or a tie tack, it works
great.

Mark P.


#6

I have been doing some simple photoetching experiments this past week, and
getting caught up on this mailing list I realized the group’s been
discussing it!

I’ve been using photocopies (I don’t have a laser printer) ironed on to
metal to transfer the toner to the metal. The toner becomes the resist. I
needed a way of transferring words to metal, and I have now tried it with
bronze and silver bracelets with some success. See the last three images
on my page of new work and experiments in progress at:
http://www.makersgallery.com/goss/new-a.html .

This is similar to the method described in The Complete Metalsmith, Tim
McCreight, published in 1991 by Davis Publications. A local printmaker I
know uses acetone to release the toner from the paper, but I found I lose
too much detail with that method. Things I’ve learned over the past few
days with the ironing method:

-get a very good, dense photocopy or laser print. You want lots of toner.

-make sure the metal is flat. Warps and curves stop the paper from
contacting the metal.

-make sure the metal is clean and grease free. I use a very fine abrasive
(600 paper) under running water

-use the highest setting on the iron, that’s usually “linen”.

-put the metal on a flat piece of wood. You want the metal to get hot. If
you put the metal on a steel block the block sucks the heat away.

-use a thin, low quality paper for the photocopies. Better quality papers
absorb too much toner when they are ironed.

-soak the paper in water for a few minutes and then lay it on the metal
like a transfer. The wet paper is more flexible and stays exactly where
you want it. Lay a thin paper towel on top of that and iron. When you iron
it you can tell from the steam that the temperature is almost there. Heat
a few moments longer, usually until the paper begins to scorch.

-don’t iron the paper too long, or the ink gets absorbed instead of
transferred.

-before the metal cools, peel the paper back slowly. The ink should still
be partly melted. If part of the ink has not transferred, iron those spots
now before you remove all the paper.

-it takes a lot of practice to get it right. Remove your mistakes with
acetone and try again. Photocopies are cheap!

-some minor flaws can be touched up with a waterproof fine tip marker.

For these experiments I used a nitric acid etch (1:4 acid to water ratio)
for a couple of hours. For anyone not familiar with etching, please read
all the necessary cautions in the books: mixing instructions, gloves, eye
protection, fume extraction etc.

Andrew Goss
http://www.makersgallery.com/goss/
Owen Sound, Ontario, Canada


#7

Hi everyone,

I have reproduced logos, especially for heraldic rings and class signet
rings using camera ready artwork. I take it to my local engraver/printer
who makes rubber stamps and they can reproduce the artwork on rubber stamp
rubber ( in positive instead of negative) which burns out & casts
beautifully. I carve the ring seperatly from the top and file and solder
them together. This has worked really well for me. Even better for pins
or pendants.

Wendy Newman @Wendy_Newman


#8

Andrew, Your work is impressive (no pun intended). And it looks like a lot
of fun. Have you looked into the vast variety of clip art books? I never
tried the ironing technique, it’s neat. Keep it up… and thanks for the
look at your work.

Jeffrey Everett