When most of us think of photo etching we think of very small packages at the hobby
shop that cost a fortune for a few small pieces!
But with a very small amount of knowledge you'll soon discover making and using your
very own photo etched parts is much easier than you think.
Let's not waist any more time and get started with the tutorial
The hardest part of this whole process is designing something to etch, at a bare minimum
you can use a program like Microsoft Paint however if you use a program like Adobe Illustrator
or something similar you'll be able to get much better designs.
There's just a bit of a learning curve to using a program like this but the results
are worth the time spent learning the program.
For this tutorial I'll be using the Photo Etching kit from Micro-Mark called the Pro
Etch System, it comes with everything required however if you live overseas you'll need
to purchase the etching chemicals locally from your country.
Supplied are two clear sheets for printing on, before using them make sure they are free
from fingerprints and dirt as this will affect the quality of the print.
One side is ever so slightly duller than the other but it was very difficult to tell.
If you're struggling to figure out what side to print on just grab a high lighter
and draw a small dot in one of the corners, if the highlighter ink rubs off then you'll
need to flip the sheet over, if the highlighter ink doesn't rub away then you have the correct
side for printing. And now we're ready to print
Make sure that all the print settings are set to their highest quality and if you printer
has the option, adjust the color to ensure it prints as dark as possible.
After printing just let it sit aside for 10 minutes to ensure the ink is completely dry.
If you're tempted to try overhead projector clear sheets let me save you some time and
money!
On the left is a projector sheet and right is the micro mark clear sheet.
They both look great right… let's get a closer look.
The micromark sheet looks nice and crisp and the projector sheet in comparison looks terrible!
The ink is uneven, blotchy and more translucent compared to the smooth, sharp and even micro
mark sheet.
Any spots or imperfections can be touched up with a sharpie.
When cutting out the templates leave a fair bit of overhang in the sheets except for the
top sheet, the top sheet needs to be taped to the bottom sheet and this is much easier
if one sheet is bigger than the other.
It's easier to register the template by first taping the bottom sheet to something
white, in the pro etch kit you'll have a sheet of white styrene that does a perfect
job for this.
Just make sure the ink side is facing up on the bottom sheet, now with the top sheet make
sure the ink side of the sheet is facing down and line it up with the bottom sheet.
So the two inked surfaces of each sheet will be touching.
Take your time lining them up, the closer to perfect you can get them the better your
final etched piece will be.
Also just remember that these sheets are not waterproof and if they get any drops of water
on the inner surface they'll be ruined.
So keep them dry.
With everything lined up you can tape the top and bottom sheets together.
You only tape 3 sides so we create a pocket for our metal sheet to slot into.
Now we can remove it from the white sheet, trim away the excess and put it aside to be
used later.
The pro etch system comes with a .005 inch sheet of brass and a .005 inch sheet of stainless
steel, I'll be using brass for these etches.
Cut a piece of brass so it will fit inside the pocket and if you use scissors remember
to flatten out and kinks or bends.
Next I'll cut some photo resist to fit over the metal, It's safe to open the UV sensitive
resist under normal room lighting for a few minutes however to be on the safe side I dim
the lights to preserve the life of the roll.
You'll need one for the top and bottom of the metal.
While I continue to prepare the metal I store the two small pieces of photo resist in a
dark box until I'm ready to apply them.
The metal needs to be polished, simply use the supplied polishing pad.
As you can see at the moment when water is dripped onto the brass it beads up.
To polish dampen the polishing pad with some water and rub back and forth on the metal
in the direction of the grain until the water no longer beads ups but instead evenly spreads
across the surface.
Both sides need polishing and once done rinse the metal with water, try to avoid touching
the top surfaces.
Handle from the edges to avoid getting finger prints on the surface.
Now we can apply the photo resist.
The resist has a protective cover on both sides, one side will peel away much easier
than the other and to do this you'll just need a piece of celo tape and gently peel
revealing the corner.
If you're having trouble you can use two pieces of tape one on each side of the same
corner.
The metal is still wet from cleaning which is what we want, gently place the resist over
the metal and lightly press and rub along the resist.
This will help remove the excess water from between the metal and the photo resist.
Then do the same for the other side of the metal.
In preparation for laminating the metal is placed between two pieces of carrier sheet,
the carrier sheet has a shinny side and a dull side, the metal gets wedged between the
two shinny sides and the dull side should be facing out.
If you're like me and live in Australia you'll need a 110v power source to plug
the laminator into, now we just wait a few minutes for it to heat up.
Now that it's ready we just feed the metal in-between the two carrier sheets through
the laminator, on the second pass we just flip it over and rotate 90 degrees.
Check that you have no bubbles and we can move on…
If you have any bubbles you'll need to strip the photo resist back and start again.
To expose the metal we place it into the template pocket ensuring that it's centered, to make
sure we get nice crisp lines from the exposure we'll need to place the template and metal
in between two pieces of Perspex and clamp tightly from all for sides.
Everything here is all supplied in the kit.
The light I used for exposure is a Nelson portable security flood light and a 100 watt
Philips 100w Clear Edison Reflector Globe, its set up to be 17cm above the table and
about 15cm away from the top surface of the Perspex.
It gets pretty warm so I wouldn't set it up any closer than that.
I set my timer for twelve minutes and go drink a coffee, it will gradually turn a medium
purple color and once the time goes off I flip the plate over and cook on side two for
another 12 minutes.
If you're wondering why 12 minutes it's from doing a few test pieces.
I did one at 10 minutes and it wasn't enough another I did for 15 minutes and some of the
black areas started to become exposed so 12 it was!
To develop and remove the unexposed photo resist I simple use washing soda.
I mix a rough 1% mixture into 100ml's of water.
It doesn't have to be perfect, this stuff is pretty forgiving.
As long as it's close.
Before we dunk out metal into the washing soda we need to remove the final protective
layer.
Again with a piece of sticky tape press it on one corner and peel it back.
You should see a clear sheet being removed.
Do this on both sides.
Drop the metal into the developer bath and gently brush the surface for about 2 minutes
on each side or until all of the unexposed resist has been removed then rinse of in clean
water.
You should be able to see clear edges around your pattern, as if your design is a sticker
that has been pressed on and the metal should look clean.
It's hard to tell on camera but when you look at it and touch it with your own hands
you'll know.
The etching tank is prepared following the supplied instructions, it's pretty straight
forward.
The metal is press into the clip and test fitted into the tank.
To etch I'm using hydrogen peroxide, and I'm using hydrochloric acid.
Because the etchant we're making is highly corrosive you'll most certainly want work
in a well ventilated area and you'll need to use skin and eye protection.
To calculate exactly how much etchant I'll need to mix up I firstly fill the tank with
water up to the desired level, next I weigh the water which in this scenario was just
over 240ml, so know I know in order to mix a 2:1 ration of 2 parts hydrogen peroxide
and 1 part hydrochloric acid I'll need a total of 160ml of hydrogen peroxide and 80ml
of hydrochloric acid.
Were ready to start etching.
Insert the metal that's attached to the lid and turn the air pump on.
Leave it for a few minutes then remove it from the tank give it a quick rinse and remove
it from the clip and rotate it 180 degrees and put it back into the tank again.
I repeat this process about 3 or 4 times.
The side that is pressed into the clip tends to etch slower from that side which is why
we need to rotate it on the clip a few times during etching.
Once it's finished remove the parts from the tank and give them a thorough rinse in
water.
Some bits broke away but that ok.
You may fine some parts are fully etched but others needs just another minute, this is
easily done by removing that part that needs additional etching and placing it a small
container with some of the etching fluid in it.
Gently swish the etchant around until the part is fully etched.
It's possible to do an entire etch in a small container from scratch, I found by elevating
the piece in the container helps get a more even etch however it takes a little bit longer
over all to etch and you'll need to continuously agitate the fluid during the etch.
Just mix up the same ratios of hydrogen peroxide and hydrochloric acid and watch your design
come to life.
Remember to carefully dispose of the etchant solution once you're done, I put mine in
a spare bottle and once it's full I'll take it down to the local waste facility that
can handle these materials.
To remove the rest of the photo resist I roughly mix a heaped teaspoon of washing soda in with
water, after mixing I just place the parts into the water and leave it to soak, after
15 or 20 minutes the resist will just float away revealing the completed pieces.
Now they just need a good rinse in clean water and we have our finished pieces.
I use a good pair of scissors with a very fine tip which is perfect for cutting these
very small parts and you'll also need some small files to clean up the edges.
Here you can see the difference between a 0.015 inch thick pieces of copper and a 0.005
inch piece of brass, you'll soon discover if you have a design with very fine detail
you'll get better results using thinner metal rather than the thicker metal as you
can see from the fine tips on the fence.
The brass on the left has retained the detail while the thicker copper on the right has
rounded tops and it looks overall a lot softer around its edges.
To add these to my models and glue them to plastic I find using CA glue and a pin works
just fine.
That completes the tutorial, you should now have no trouble designing and etching your
very own metal parts to add insane amounts of details to your scenes.
If you are enjoying these video and you'd like to help support the channel feel free
to check out my patron
For more infomation >> Guardians of the Galaxy 2
No comments:
Post a Comment