ACS Work Tips

[Metalman]

Tip for 3/12/03 Cores and Armatures
You can build or paint the Art Clay on and/or over a core material. As long as it is completely organic materials, the core will all burn out when you fire it.  With cores, you will have to use a kiln, torch firing will go too fast and you would have problems with the gases burning off and the organic materials burning. You can paint a paper object, leaves, flowers, etc.  Using the cork clay [see Rings and Things catalog, 337] works great. Build, paint or wrap the clay around the shape you have made.
There are paper clays as well, but some of the paper clays have minerals in them and the minerals can cause problems [go ahead and test them, but do a test before you use them].
I have had good results with the cork clay up to about 1 1/2".  If the form is almost completely enclosed, with very few small holes, it is my impression that it is best to  fire slowly so as to allow the gases to dissipate as the materials burn off; this is how I fire it. If you are working larger than this, you could build an internal structure of metal clay, fire it in blanket -- then adjust the structure, build the cork clay around it and do your surface design, then fire again.  I have done some experiments along these lines with good results.  This is the experimental edge so you will have to play it out a bit.   One problem that does arise is shrinkage factors.  I am working with Art Clay Silver and some times need to do a third firing [or more], patch, and repair. But the end results have been fine.
A further idea would be to work with porcelain or bisque ceramic 'armatures' or cores. Because the porcelain is set already, when the clay shrinks, there may be cracks and/or other shifts in the metal material. These are repairable in additional firings. The Art Clay Silver 650 Overlay Paste works great and I have had good results using the overlay paste as an interface to regular clay elements. Again shrinkage considerations apply.

<!---->

[Metalman]

Tip for 5/28/03 - Shelf life and ??
With the foil packs currently in use, ACS stays on the shelf quite a while just fine.  Once you have opened it, the important factor is keeping it humidified the same as when you are working with it. Good sealable containers with a small sponge to humidify the product work great. I have been doing a lot of work with thinned down paste and have a wider mouth container I mix it in - seems to work just great.

[Metalman]

10/20/03 Rings in Art Clay - updated
If you are interested in ring making, a wooden mandrel works great.  You can cut a strip of the teflon work surface and wrap on the mandrel.  [This will allow you to slide the ring off the mandrel once it drys abit] Then adjust for the approximately 9% shrinkage by sizing up 1 to 2 1/2 sizes for a narrow band, 2 to 4 sizes for a wide band  and 4 to 5 sizes for wide and thick bands.  This is an inexact science so experiemnt a bit to get it fine tuned.  Once you start building, you can rotate the mandrel and work all of the sides.  Carving, building, filing  all work as methods for designing a ring

[Metalman]

RING MAKING  - some details 4/7/2004
We have had a fair number of inquiries regarding ring making.  As you make one up, you need to account for the 8-10% shrinkage. A rule of thumb is:
A: When the band is 3mm thick, make the ring 1 to 1.5 sizes larger
B: When the band is flat (1.5mm thick) and 10mm wide, make the ring 1.5 to 2 sizes larger
C: When the band is greater than in thickness and width than the ring shapes mentioned in A and B, make the ring 2 to 2.5 sizes larger
If I am relly making one to specific size, I make a trial ring to get targeted in.  The ACS doesn't stretch like milled silver will so you will want to get the sizing pretty close.  Remember that when you sand the inside of the ring before firing, you can take off enough material that you can alter the ring size, so don't blame that on the shrinkage. I think the best approach if you want to do rings is to do a number of them, start slow so you can check your sizing, etc. and after just a few you will have the details down as to how to get the size you need.

[Metalman]

We've graduated to more pages!
 GO DOWN TO THE END OF THIS THREAD (use "next page" button) TO SEE THE MOST RECENT TIP

[Metalman]

Tip for 2/18/03 Olive oil
Before you start working, a little oil on you fingers helps keep the clay from accumulating on your fingers.  I use an olive oil spray and I keep a small container and brush near by as well.  A thin wipe of the oil on my roller helps keep my roll outs from sticking.  I apply a very small amount and spread it very thinly. Sometimes I put the oil on and wipe the tool or mold or my hands off with a paper towel which leaves a thin layer which is just the right amout to keep the clay from sticking.  This way I can keep the clay a little damper and not have to worry about it sticking. Most people use olive oil because it is slow to become rancid. I think any cooking oil will work but not mineral oil or petroleum jelly or petroleum based oils.

[Metalman]

Tip for 3/5/03 [2/2005 update]
If you are thinking about Art Clay and stones here are some guidlines.
1]  You can fire Cubic Zirconium stones right into the clay.  Just let the piece cool slowly.  You can fire them in the kiln or by torch. The important factor is slow cooling so the stones don't crack.
'>  Note: Most of the greens are not stable.  You should probably test your stones to see if there is a color shift unless they are vouched for by the dealer.[These will frequently be called 'cast in place']
2]  If you have other stones you want to use and are willing to give them the 'Trial by Fire'  then put the group of stones you want to test in the kiln and fire them up to the firing temperature of the metal clay product you are using. Regular Art Clay Silver fires at 1470°F for  30 minutes and Art Clay 650 fires at 1200°F, also for  30 minutes. Let the stones cool slowly and see how they came through. This can cause stones to crack, change color, lose any plastic fills, make minerals shift, burn off most dyes, cause natural flaws to split or ??!!?.  You will probably have a stone that looks a little different from when you started but - if you still like it after it comes through this firing, then you can build it into a piece and fire it again. For natural stones as opposed to man made stones, every firing is a risk but once tested, the risk will be 'somewhat lower'.  
Once you have built and fired your piece, you may have to do repairs due to the shrinkage shift of the clay[8 to 10%]. You will sometimed have to fire a second, even a third time.

[Metalman]

Tip for 3/19/2003
I have had an inquiry about molds for Art Clay. I have done a variety of things along this line.  Sculpey or any polymer clay is great for snatching textures and/or relief molds from all kinds of things.  This makes a good one part mold of relief type textures or details. We have used plastic toys, dinosaur skins, door knobs - the sky appears to be the limit.  A caution here - fine details that are deep are hard to get out of the mold.  A thin film of olive oil may help release the Art Clay, just the lightest wipe of oil will do.
I have also used the 2-part silicone putty [product #87-041 in the Rings and Things catalog] and have gotten fantastic detail results.  This is a very easy and fast product to use, no muss and low on the measuring fuss. Long, thin clay details are hard to get out of one piece molds - the solution here may be use two part molds.
This is a way to make up repeats, and work them together while the clay is still moist.
Member Quicksilver asks:
Hi Metalman,  Out of the sculpey,polymer clay and the putty which do you prefer the most [for making molds] ( if any ).
Thanks, Quiksilver

And you thought you would get a straight answer out of me.
The answer is YES.  Okay, if I have extra, left over or colors I don't like of polymer clay, I use that for general molds, especially textures.  If I need to buy some more, I buy the beige Super Sculpey [R&T cat #85-516] because it is the most material for the least $$.
I use the Silicone putty for extra fine detail molds, there are those things that just don't come through well when you press the polyclay/sculpey on to them.
So, it depends on the usage.  Also if the mold will have deep recesses, you may need to experiment with the different materials to work out what gives you the best results.
There are a number of other molding materials which can be used, depending on the need/usage, the durability and the number of repeats you want to get out of a mold before it wears out.  These tend to run up in cost.

[Metalman]

Tip for 4/16/2003 - Let's Talk About Oil Paste
Art Clay Silver Oil Paste is made of the same micron ground silver that other ACS products have but instead of the water based organic binders it has an oil based binder system.  It comes in two containers, one of paste and one of solvent. This stuff is great for repairs when something cracks or breaks after firing,  and for joining findings or other fired pieces together.  Just put the pieces together with the paste and MAKE SURE it is dry before you fire it again.  Same temperatures and firing methods.  Once its fired, it matches the Art Clay completely.
Just a note: sometimes the solvent leaks a little bit in the packaging - this is how it comes from Japan.  We haven't been able to do anything about it. Packaging is much improved
2nd note:  The solvent is a naptha related solvent from Japan - I wouldn't mix it with US solvents like paint thinner or?? - my sense is they won't match.

[Metalman]

Work Tip for 5/16/2003
Just a brief one today.  There are a number of metal clay products available these days.  Each one has different characteristics.  Because of this - make a point of carefully reading the directions that come with your product - do this several times running, so you can be confident, also watch out for changes.  Some of the products are shifting in formulation and the firing directions change then.
Have a great time with it all.
By the way, in the FAQ section is a firing list for all the ACS products.

[Metalman]

6/6/03  Here is a quick and dirty [actually clean] tip.  A fast, repeatable mold, with easy release - Use a bar of soap, you know that infinitely carvable one and carve a low relief mold in it. Then press the ACS into it, make one or 2 dozen.  If you want to save your new mold, use a ziplock bag so it doesn't dry out on you. Want to do quick variations or don't like your first effort - just rework it or shave it off and start over.

[Metalman]

Tip for 8/24/2003
Just a quick note today.  When I am working on pieces, I frequently do multiple firings.  This means I can build up a piece. Fire it so that I can detail it, work it and/or finish it abit - then I add on further details to refine the piece, fire it again.  Then I check it for any shrinkage cracks or what ever, sometimes I have to fire it a third time.  This is a method which allows me to build up certain aspects of a piece that would be difficult or impossible with only one firing.

[Metalman]

Tip for 9/26/2003 Glass and Art Clay
You can do a lot with glass and  Art Clay.  If you fire to 1472 for 30 min. the glass will melt and move quite a bit. Because of the porosity of the Art Clay, the air which might cause bubbles doesn't have to be trapped.  This would be a method when you are firing the Art Clay and including the glass at the same time.
You can also 'tack' the glass by fitting it into already fired Art Clay and running it up to 1470F for a minute or two and then cooling.  Most of the time when I am firing with glass, I get it up to temperature. and then crash cool it to about 1100F and then do a short soak at 1050F and let it cool slowly to anneal the glass.

I think our best results are with the dichroic side up or inside if there is more then one layer.  If the dichroic side is against the ACS, it sometimes separates or gets discolored.The silver can and/or will stain the glass. This is most prominent on clears or light colors.  There are 3 things to do here:
First - fire the Art Clay first, then add the glass in a second firing, this will minimize the staining.
Second - make sure, if you are building the glass into the clay that the glass is really clean before you fire, I had one piece where there was small residues of Silver Clay in the ripples of a piece of dichro and the silver interacted with the metals  of the surface of the dichroic and what a mess.
Third - This is a strange one but it works - if you use a "sharpie' pen made by the Sanford company and coat your glass with it before you fire it, it will keep the silver stain off - Don't ask me why, but this  works.
Caution:  there can be a residual build up of silver in your fiber blanket from firing the ACS.  I have had silver stain problems on glass from this residue.We have been experimenting for about 3 years with this with generally excellant results.  Some of the time when the silver part of the piece surrounds the glass too closely, we get incompatability cracking - I haven't quite figured out what the problem is when this happens yet.  I feel like sometimes it cracks and sometimes it doesn't but I know there is a detail I haven't observed yet.

Suffice it to say that this is one of the experimental zones with new materials and methods, and off you go. All in all, we have not had many failures so go for it.
As always, you have further and/or more specific questions send the in to me and I will try to answer them.

NOTE:This tip was written before Art Clay 650 came out, 650 changes things, the info here is still godd but check further for info regarding 650 and glass

[Metalman]

2/23/2004
LETS TALK ABOUT GLASS
There are a number of factors related to glass, glass fusing and combining glass with Art Clay Silver.  Those would be the materials [glass, metals]; the equipment [kiln]; and the methods.  There is a fair amount of tech in this.  Its not overly intense but moderately critical.
Glass:There are 3 critical factors with glass.
1] Annealing: This is necessary because as the glass cools, stress builds up. Glass must cool through the range from about 1050 F down to 900/850 F slowly to allow the stress lines to relax. The thickness of the piece of glass affects this temperature ‘ramp’ as it is called. Small pieces under ¼” shouldn’t be a problem.
2] Compatibility:  All glass is not made the same.  As the chemistry changes, the COE changes. The COE is the Coefficient of Expansion, this has to do with how much or how little the glass expands or contracts when heated or cooled. If you fuse glass together, the glass needs top be ‘compatible’, meaning that the COE for each piece of glass matches.  A number of glass companies have been doing a lot of testing and balancing to make their glass compatible across their line of colors.  There are currently listings for COE 90 and COE 96.  You can only fuse glass that has the same COE.  You can fuse any glass to pieces of itself, but they should come tfrom the same sheet of glass, as the chemistry changes from sheet to sheet of glass.  This is why some manufacturers are making an effort to make their glass to a controlled range.
3] Shock:  Glass, as well as many natural stones are sensitive to heat shock. You must leave the kiln closed until it comes down in temperature to room temperature, that is, to a temperature you can touch without pain.
Kiln:For glass work, you need to run the temperature up in a controlled way [‘ramping up’] do your fusing, you can cool quickly down to 1050/1100 F then you need to ramp down slowly through the annealing range, then cool slowly. There are books and charts and more information for all of this.  Your kiln needs to have the controls to do these operations as well as enough insulation to allow for slow cooling.  Glass does not take kindly to sudden temperature changes.  I find it easiest to use a computer driven time-temperature controlled kiln.
Methods:Reading through the above notes will give you an idea of what is necessary.  There is information available out there.  If you are going to do a lot of fusing, getting some additioanl information will be a benefit.  There are kiln wash/kiln paper/ shelf texture issues, the glass compatibility already mentioned, cleanliness concerns with some of the dichro work [some materials, oils, etc. can mark the dichro when you fire.

Final Note:  There is a lot to experiement with glass and the metal clays so some of what you may be trying is an experiment that no one has done  as of yet.  On the other hand, you may not want to be ‘reinventing the wheel’ when it comes to the basic tech.

[Metalman]

1/5/2004
Just a mention:
The new 'Art Clay Silver & Gold' book by Jackie Truty is excellant.  R&T cat # 62-399.  Great projects, good text, comprehensive background material.