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Picture of Fine Silver (99.9% pure) Popcorn Pendant!
Make FINE SILVER (.999 pure) Pendant with POPCORN or any other organic material as a model!

The instructable is to make a 3-D hollow-form pendant for a necklace. We make the hollow form by coating a Completely Dry organic armature (Popcorn, in this example) with 8-12 layers of Precious Metal Clay (PMC) Paste.

When fired, the popcorn will burn away, leaving only the pure (99.9%) silver from the PMC in the shape of your popcorn kernel!

Required Stuff:

Jar of PMC3 (Precious Metal Clay) paste.
1 inch piece of Fine Silver wire (dead-soft).
Popped Popcorn.
Victory Wax (or cheese wax).
Hot plate.
Shallow pan for water.
Metal measuring cup for melting wax.
Small Paintbrush.
Bamboo skewers.
Styrofoam.
A craft or ceramic kiln of some kind.
Small, smooth jawed pliers.
Pencil.
Wire cutter or scissors.
Brass brush for polishing.
A necklace, piece of ribbon, or leather cord.

...all will become clear...
 
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Step 1: What is this Magic "PMC" Stuff?

Picture of What is this Magic
In the 1990s scientists in Japan developed a combination of organic binders and metal particles to create a material with the working properties of ceramic clay. The organic binder provides elasticity while holding very tiny grains of metal in suspension.

This product became known as Precious Metal Clay (PMC).

After drying, the PMC is heated to the fusing temperature of the constituent metal. During this heating, the binder burns away, and the metal particles sinter together into solid metal.

We will be using a form of this product which is pre-prepared to a paste-like consistency.

Basic PMC Working Tips:

Its all about the moisture, PMC can dry out very quickly.

1) Plan ahead (have your tools at hand) before you open your jar of paste.
2 ) Water can be used used to moisten the clay and smooth the surface of your pendant.
3) Dried out PMC can be reconstituted with water and reused.

Step 2: Select the Popcorn Kernel for Your Masterpiece.

Picture of Select the Popcorn Kernel for Your Masterpiece.
Pop some popcorn, or buy a bag of pre-popped popcorn at the grocery.

Sort through the kernels and find an interesting shape! This is the fun part! (Eat the rejects.)

Decide how you want the shape to hang.

We will suspend the pendant using a piece of fine silver wire inserted into the popcorn. Because the pendant will hang from a wire loop, it is important to consider where the finished pendant 's center of gravity will be. If there is more weight on one side than another, the pendant will slip on the loop (forward, backward or to either side) until the weight is equally distributed (whether we want it to or not).

Ideally, the wire used to hang the kernel on the necklace will intersect the kernel's center of gravity.

Step 3: Make a Loop with Your Fine Silver Wire.

Picture of Make a Loop with Your Fine Silver Wire.
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Using smooth jaw pliers, twist your wire into a loop around a pencil tip. If you're using dead-soft fine silver wire, it won't break your pencil.

If you break your pencil, or if you're using half-hard or hard fine silver wire, you may need to bend your wire around a small nail or other small, smooth, round object.

You will attach this loop (known as a "bail") to the kernel, later in step 8.

Step 4: Skewer Your Kernel!

Picture of Skewer Your Kernel!
Note: This will leave a hole in the final piece of jewelry. Plan for it to be at the bottom or back of your pendant. Remember where you want to put your bail and plan accordingly.

Insert a small bamboo skewer halfway into the popcorn kernel.

This provides both a handle to hold the shape as we coat it. Also, when the bamboo burns away, it provides a vent hole to let any remaining moisture/steam/smoke out during firing.

Step 5: Check Your Wax for Compatiblity.

Picture of Check Your Wax for Compatiblity.
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Popcorn is a very fragile material. If you get it wet, it disintegrates.

To solve this, we are going to coat the kernel with a thin layer of wax.

However, the type of wax is important. Standard paraffin (candle) wax is too hydrophobic (water repelling) for the PMC to adhere.

I use "victory wax" which is a sticky, brown, sculptor's wax.

If you know a sculptor, odds are she/he has a few pounds of the stuff around. If not, I'm told that many PMC artists use cheese wax. That is to say, the wax used to dip cheeses in to seal them (like BabyBel cheeses). Just buy some Gouda, Edam, or BabyBel, and save the wax when you eat the cheese!

An experiment to see if your wax will work: just dip a tiny amount of the wax you have into the PMC paste. If it sticks, you're good to go!

Step 6: Heat Your Wax in a Double Boiler

Picture of Heat Your Wax in a Double Boiler
Wax is flammable!

To avoid causing a fire, we are going to melt the wax in an improvised double boiler.

1) Put a pie pan with about 1/2 inch of water on a hot plate.
2) Place a measuring cup containing your wax into the water.
3) Turn on the hot plate to medium/medium high (on my hot plate, at least).
4) Wait patiently until the wax melts.

Why use a measuring cup? It gives enough depth to dip, but doesn't require a lot of wax to fill.

Step 7: Dip the Kernel in the Wax

Dip the kernel in the wax and give a little twist with your fingers. This will ensure that all sides are coated with a thin layer.

IMPORTANT: The video below only appears to show the wax being melted directly on the hot plate.

Do not melt your wax directly on a hot plate! Use the double boiler described in the previous step!

I just didn't want to set a cup of hot wax on the counter. So I set it on the (cool) hot plate. That hot plate is not even turned on!


Step 8: Add the Bail

Picture of Add the Bail
Stick the bail made from the 1-inch piece of fine silver wire into what you want to be the top of your pendant.

The PMC paste will fuse to the bail during firing, providing a solid connector for your pendant.

Step 9: Coat the Kernel in PMC Paste!

Picture of Coat the Kernel in PMC Paste!
Apply a thick layer of slip making sure to cover all areas of the kernel evenly.

Try not to jostle the bail wire. However, do make sure you paint a little PMC where the wires cross to ensure it attaches to the finished piece.

I used a #8 flat, golden nylon bristle brush. However, any inexpensive, synthetic bristle, artist's brush would do fine.

Step 10: Dry Completely.

Picture of Dry Completely.
Stick the other end of the skewer into the styrofoam block and place out of the way so the PMC can dry without touching anything.

Let each PMC layer dry completely!

It will lose it's glossiness when completely dry. It will also be a lighter gray.

Step 11: Add Layers of PMC to Make It Stronger

Picture of Add Layers of PMC to Make It Stronger
8 layers will usually do it for me.

You've already done one layer...so...only 7 more to go!

(Remember to let it dry completely between coats.)

And after the last coat, it looks like the main picture (below).

Step 12: Shorten the Skewer.

Picture of Shorten the Skewer.
The last thing before firing is to shorten the skewer with a pair of scissors or a wire cutter. This is just to make it easy to load into the kiln for firing.

Step 13: Fire up the Kiln!

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I'm going to use a small craft kiln to fire this pendant.

Place the pendant on a small pile of vermiculite on a kiln shelf. (See pics).

Then you put the kiln shelf in the kiln. (See pics).

Since there are several types of PMC, you should follow the firing instructions in the box, but I'll summarize the firing properties here.

- PMC+: Smaller Particle sizes, firing times range from 10-30 minutes at temps from 1470-1650, Shrinks 12-14%
- PMC3: Smallest Particles, firing times range from 10-30 minutes at temps from 1110-1250, Shrinks 10-12%

The minimum times are what's required to sinter the metal particles together. However, the longer times will yield a stronger end product. You stop seeing any improvements in strength after the maximum times.

There are several inexpensive options to fire PMC without using a kiln. They require a little finesse, however, and so will be covered in their own instructables!

Step 14: Take the Pendant Out of the Kiln.

Picture of Take the Pendant Out of the Kiln.
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As long as you've held the proper temperature for the proper length of time (described in the previous step), the pendant will now be 100% fine silver.

Let the kiln cool down to 800 degrees F before removing your piece. If you take the kiln shelf out of the kiln and rest it on top, the piece will air-cool to a touchable temperature after a few minutes.

Remember: It is HOT! It will fry your fingers!

Step 15: Why is it White?

Picture of Why is it White?
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Silver is a white metal. You have to polish it to make it take on the "typical" silver shininess!

It's kind of ugly if you leave it white, so let's polish it with a fine (small wire) brass brush!

See the difference? Even while it's still being brushed!

Step 16: Hang it on a necklace!

Picture of Hang it on a necklace!
Just two steps left:

1) Hang it on a necklace, a piece of ribbon, or a leather cord.
2) Show off to your friends!

Enjoy!
Detoxiodine4 years ago
Hello!

I really like the idea of this piece. You did a great job on it. I would like to ask you something. I have a dried lizard. We found it in the ice-melting salt that you put on sidewalks. Do you think it could be turned into a medallion with this process? Will I need to wax it down?

Thanks in advance,
Adam.
Kazooie7 years ago
Well, I did it! I made this for my girlfriend for Christmas. I folded the crane with origami paper, then used the same method as the popcorn, except I didn't use wax, and I torch-fired it. Using a butane torch to fire was easier than I thought it would be.
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cinne Kazooie5 years ago
That is so cool! :) I realize it has been a while since you posted this, but you wouldn't be interested in giving a more detailed description of how you did this? :) I would love to learn!
Kazooie cinne5 years ago
From what I remember, it wasn't too difficult, just a little bit time consuming. I slightly thicker paper, can't remember where I got it. The thickness is important. If it's too thin, the wetness of the pmc will seep in and start making it bend. If it's too thick, you could get air-pockets in folds, or it could be too difficult to make something small. My paper was too thin, and it started to break down where I had the hanging loop stuck through it. It was very close to breaking off by the end. Then just lots of coats, I think I did around 7 but I was kind of running out of time. As for the torching... It would probably be better to have a kiln, but my way with the butane torch seemed to work alright. For everything else, I just followed this great instructable! The only thing I would try to change next time is the smoothness. I'm not sure how, but I'd like to find some way to make the finished product smoother and shinier. Maybe sanding or a different way of applying coats? Hope that helps. Good luck!
cinne Kazooie5 years ago
Thank you so much! :) I really want to try this, but I guess it would be best if I got access to a kiln. I don't know anyone that got one, and I think it's to expensive to buy one "just to try" ;) Maybe I'll post on some forum about borrowing one...? And I was thinking about trying the kind of PMC that comes in sheets, then I can just fold the crane out of the clay, then I don't have to make all of those layers. Hmm.. I wish the materials wasn't that expensive, then I would have no regret about trying. :)
roughtyper (author)  Kazooie7 years ago
That's beautiful! Thank you so much for pushing the limits of my instructable!

You were right in skipping the wax step, that's so the popcorn keeps its shape. It sort of "deflates" from the water in the paste. It wouldn't be needed for your origami creation.

Since you already have origami skills, you might want to try "PMC Sheet". A Google search on that will turn up many sites, but here's an typical one: http://www.dickblick.com/zz305/22/ . The sheets are kind of small, but you could create your crane or other origami directly without all the layering steps.
botronics7 years ago
Does someone make a PMC using copper? It would be cheaper to experiment with and can be electroplated.
i found this a few days ago. its german though so it might be more expencive and you would have to translate it http://www.metalclaystudios.de/epages/61647883.sf/de_DE/?ObjectPath=/Shops/61647883/Categories/110_BronzClay
roughtyper (author)  botronics7 years ago
I've never seen copper. But I agree it would lower the cost of experimenting. I'm told the real manufacturing expense is creating the ultra-small particles of the metal being used. That's why even silver is so pricey...
TheJester7 years ago
Awesome instructable! I'd love to make one, but I don't have access to a kiln. You mentioned that there are other ways to fire this besides a kiln. Would a torch work, either butane or propane? I'm not too sure how regulateable the temperature would be using a torch though. What ways did you have in mind without using a kiln?
I know it's a bit late (now 2010), but your answer can be found at: www.riogrande.com or www.firemountaingems.com Both have a lot of stuff and online videos/instructions You can use a torch and they are not expensive--a whole kit from Fire Mountain will cost about $85.00, although the type of silver clay that they have is not as good as Rio Grande. There's Gold, Bronze and Copper clays and slips/papers now.
Thanks, I appreciate the reply even though it's three years later haha you've piqued my interest in this project again!
SNACKS5 years ago
  This  sound like a fun idea. can you use other things? what about a rose, would that turn out the same way? 
chalky7 years ago
hey thats pretty damn cool if i may say so myself!! i like your kiln where did you get it from?
roughtyper (author)  chalky7 years ago
The kiln link is at PMCSupply.com
roughtyper (author)  chalky7 years ago
We've had our kiln for a couple of years. However, you can get them any number of places, including: http://secure.cartsvr.net/catalogs/index.asp?category=193480
zaro123457 years ago
This is really cool. Now, finally, I can make homemade jewlery that actually looks good! Thanks alot! *faved*
rusty13jr7 years ago
VERY COOL!!! Where can I find PMC?
Kazooie7 years ago
I'm thinking using this with small origami pieces would be pretty cool... mini silver cranes...
A "silver" peice of popcorn? more like silver plated.
If you use something to hold the silver loop, such as those locking forceps used in surgery, you won't have to use the skewers. And as a result, no big hole in the bottom of your pendant. Oh, and doing it with a bug would be VERY cool!
OMG a bug would be awesome. If someone sold them, I would buy one! A spider one would be awesome!
roughtyper (author)  FreeBaseBuzz8 years ago
Unfortunately, you need a place for the popcorn smoke to escape, so you still have to have some kind of hole! Using the forceps, however, could mean that you could leave a much smaller hole than the skewer! Maybe (?) even a pinhole!
Yes, a pinhole would be preferable over a skewer hole :) Perhaps a toothpick? I did full silver casting when I was a kid. We'd get a wax ring shape and set it in paster of Paris. Then while it was still wet, we'd vibrate it to get all the air bubbles out. Once it'd set, we baked it in the kiln to burn off the wax, and then while still hot, pour in molten silver. I can't remember how we got the plaster off the outside, but there was some easy trick. Maybe we dropped it in water or something while still hot to crack it. Of course, silver was much cheaper 20 years ago..
roughtyper (author)  FreeBaseBuzz8 years ago
Unfortunately, lost wax casting is still a lot more complicated than the additive approach I talk about here! But you're absolutely right about just dropping a lost wax casting in water! Once the metal has cooled enough to be solid you can just pop the piece into a bucket. The plaster just fizzes off, leaving just a little left to clean up with a toothbrush.
Vendigroth8 years ago
instead of lost wax casting,m its more like lost popcorn casting
gets my +
and a VAMPIRE award
roughtyper (author)  Vendigroth8 years ago
Thanks!
1D10T8 years ago
Could this be done with a bug or a fish or something like that?
roughtyper (author)  1D10T8 years ago
Any organic form can be used! Just remember that the organic materials have to burn out. So, I'm not so sure about the fish...might be kind of smelly... ;-( That's also the reason I don't use plastics!
Neat. I recently did a short course with this type of stuff, though the stuff we used was clay, not a paste. Also it's rather expensive here in Australia. How much is it to purchase where you are?
roughtyper (author)  Building Books8 years ago
Hi!

We'll be using the clay you mention in our next Instructable: "5 Minute Earrings", currently in production!

The jar of paste I used is currently about $25US. I used about 6 gms of paste, so the PMC for this project cost roughly $10US. That's really good for a one-of-a-kind piece of jewelry!
oh, don't I know it! The stuff we get here in Australia from http://www.silverlab.com.au/ is about $15 AUSD for 7gms. You might want to quote your source for your silver.

Looking forward to your next instructable.
roughtyper (author)  Building Books8 years ago
Glad to help: PMC Connection or Dick Blick is where I usually go. Or you could just do a quick Google search on "PMC" and "Cart"!

I did a quick currency conversion, though, the prices I pay are about the same as you!
cool, but baby corn would be cooler :-P
roughtyper (author)  !Andrew_Modder!8 years ago
Baby corn would be cool. It might be possible to skip the step where I dip it in wax. I would dry a piece of baby corn on paper towels, then test it the same way I show testing the wax in step 5 of this instructable. If the PMC sticks, go for it!