How To Repair Cracks In Art Clay Copper After Firing?

Last week, I talked about many of the current base (non precious) metal clays available. For the adjacent few weeks I hope to embrace some of these types of clays more in depth.

Today, I am going to start with Fine art Dirt Copper.

Art Dirt Copper like other metal clays is made up of microscopic particles of metal (in this case copper) mixed with h2o and a binder. In one case fired pieces made with Art Clay Copper end up being pure 100% copper.

Outset let me commencement past maxim that Art ClayCopper is somewhat unique compared to most of the other base metal clays as it does non require to be covered with firing with carbon which makes information technology highly-seasoned to those who wish to stay away from carbon (messy and not a good idea to jiff in) or those of you who want to torch fire or use your Speedfire Cone system.

TOOLS:
The tools that one uses to create pieces with Fine art Clay Copper are the same every bit the ones you would use with any other metal dirt. Wash your tools betwixt use between different clays to preserve the purity of you metals and any problems with firing.

Handling:
1 important deviation I accept noticed with Art Clay Copper is that too much oil mixed into the clay tin can create a crumbly and difficult to work texture. Now don't panic. What I accept found is that you can all the same you olive oil on your hands and textures but you don't want the oil to exist pooling in the texture sheets or to observe that when roll out the clay you get a pic of oil over the clay. I have found that adding a driblet or two of oil to your texture canvass then rubbing it in with a toothbrush to spread hte oil works fine. If you have as well much oil employ a paper towel to remove the excess. Bottom line, if you discover that your clay begins to be crumbly and volition non course a ball fifty-fifty with efforts to rehydrate it too much oil may be your problem.

The other important tip that I have constitute is that the clay needs to exist conditioned when it is removed from the package. Frequently I take found that the clay is tough to piece of work with straight out of the package. Kneading the dirt and adding moisture for a few minutes will meliorate the clay significantly. There are different techniques to accomplish this, my method includes rolling the clay painting on a layer of h2o and then folding the water in and then rolling and repeating. I will often repeat this technique at anytime the clay gets dry or hard to work. (You tin refer to my postal service groovy clay on how to rehydrate silver clay for some photos of this technique, Sometimes I will recommend to do this betwixt two sheets of plastic helps contain messes for beginner, I notice that over time you will learn to handle your clay more easily and neatly)

The concluding tip is to brand sure that you attach your pieces well when you attaching two pieces of Art Dirt Copper. I have establish that my students have a harder time making a good attachment with Fine art Clay Copper. As for suggestions, I take two thoughts: showtime, brand sure yous apply fresh paste (yous need to brand your own paste with Art Clay Copper and the paste can oxidize over time, noted past it turning darker, this paste will not attach as well as fresh and shouldn't exist used) and 2d, hold your pieces together for 20 seconds to enhance the sticking.

DRYING:
Drying Art Clay Copper is similar to silver metal dirt. Some people will utilize a course of heat to dry their clay (such as a dehydrator or an mug warmer). The key as with any metal clay is to make sure y'all don't estrus the piece and so hot that you fire off the folder. My general rule of thumb is to continue the piece no hotter than 200F merely the literature for Art Clay Copper states that information technology is at 480F where the binder will be destroyed.

Once your piece is dried you will tin burn down the piece.

FIRING:

Torch Firing
The full general guidelines are: "fire a piece no big that a United states of america Silvery dollar and 35 grams on a firing brick and estrus until cherry red for at to the lowest degree 3-v minutes, depending on size. Pieces 10 chiliad and 1mm or less in thickness can burn for 3 minutes: pieces upwards to 25 one thousand and 2.v mm thick can fire for v minutes."Art Clay Earth – Art Dirt Copper Booklet

I have two comments on these guidelines.

First, is that I think that anything over xv grams will likely be a challenge to continue hot enough with a simple butane torch. The sintering temperature for Art Dirt Copper needs to exist effectually 1778F which is much hotter that traditional silver clay. I have establish that at times information technology is hard to maintain the heat with a handheld butane torch. (of course there are other torches you lot tin can apply but this is what I have found with the common butane torch)

Second, l recommend torch firing any piece for at to the lowest degree five minutes! It is important to make certain that you start timing only one time the piece commencement glowing red and that you demand to keep it glowing bright red for the full five minutes. I experimented once while firing my Art Clay Copper where I allowed it to drift away from this brilliant red colour briefly during the catamenia of five minutes (what I mean is that its colour became a lighter rosy color indicating that the temperature has reduced slightly – below platonic sintering temperature). I decided to see what would happen so I quenched the piece and and so began to castor it with a steel brush. I noticed the texture didn't seem quite right so I tested it by banging information technology with my hammer. The slice broke indicating information technology was not sintered properly. This is a big problem with torch firing, under firing, and then be aware.

Once you have fired your pieces you need to quench them. Quenching is of import equally it volition reduce the amount of oxidization on the piece.The longer the copper is exposed to high heat and oxygen the thicker the layer of oxidization over the slice.

Hither is a moving picture of the bits from oxidization that accept fallen off in the bottom of my quenching bowl.

I have constitute that kiln fired pieces will develop more than of a coating on them as they are exposed to oestrus and oxygen longer. I have likewise noticed that due to the coating that you lot loose y'all volition loose some thickness in your pieces. Art Clay Copper will shrink approximately x percent. I have institute that you volition loose some thickness in any copper wire that you lot embed fire due to oxidization.

Below is a picture show a fired slice (on left, notation the burgundy oxidized layer) and a dry unfired piece on the correct):

Kiln firing:
The General rules for kiln firing are: "Pre-ramp the kiln to 1778F. Place the piece into a preheated kiln at 1778F and concord for 30 minutes. Remove the red hot piece with tongs or tweezers immediately after firing is compete and quench with cool water so that nigh of the oxidized layer peels off to reveal perfect copper. You may also put the piece into a room temperature kiln and ramp up at maximum speed to the listed temperature, merely pre-heating the kiln is recommended."

I accept a couple of thoughts hither. One is to exist sure you use proper safety equipment when doing this (kiln goggles, heat resistant gloves, tongs and other) Another of import thing to note is that I have establish there are times that my pieces will stick to the kiln shelf at loftier temperature (they will come off when cooled). In society to prevent them from sticking you tin can employ kiln paper on your shelf under your piece. Other recommendations I take heard information technology that you volition go less oxidization on the piece that is adjacent to the shelf so put your "good side" down. One other affair, if you cull to proceed brand sure your kiln is on a burn down proof table and that you have a big pot to put your pieces in to quench (Exist really careful you don't want to drib these 1778F fireballs on the ground or your Torso!!! – I work in a room with a concrete floor and a large metal saucepan full of water that I slide the pieces into )

PICKLING & POLISHING:
Once the pieces are fired they will often require pickling. Pickling is used to remove any remaining bits of oxidization. I found that I need to apply Sparex to pickle my pieces and was not able to use whatever less toxic solutions.Put your pickle into a container that you will not use for nutrient. Brand sure yous do not put whatsoever steel into the pickle. I have copper tongs but discover information technology easier to attach my pieces to a copper wire (as I find information technology difficult to fish out my pieces from the bottom of my pickle pots.) Be sure to apply safety procedures when working with your pickle!!!!

Once y'all accept removed your oxidized layer you lot tin brush your piece then smooth and/or tumble.

This clay was showtime released to the public in December 2009. I believe nosotros will see information technology grow and change over adjacent few years. 1 surface area that I hope to come across improved is the ability to make repairs on fired pieces. I have yet to figure that one out.

Art Dirt Copper can be a fun medium to work with and with it almost a fith of the price of silver clay information technology more economical besides!!!. Enjoy.

At that place are detailed directions on Fine art Clay Copper at the Fine art Clay World website in the Fine art Clay Copper Booklet.