Brickology Part 3

This Brickology lesson is for making handmade, antique style, miniature sized bricks using paper mache/clay air drying products.

The clay I am using today is Plus by Activa, their Acitv Clay formula works too. I have tried the Das brand of clay but did not like the results, it has too many paper fibers to give a clean cut. All of these clays are made from earth minerals which are the clay part and for strength they add paper fibers along with a few other ingrediants. I started with a terra cotta colored formula. If you let this product dry it won't look like terracotta, it will be a pale pink which is sad because it means more work to get the right look.

Right out of the package the Activa Plus clay is too wet to roll out with a pasta roller. If you simply take it out of the packackage and immediately roll it out with a rolling pin the surface will be very smooth and that won't look like hand made brick. So I started messing around with the clay to see if I could dry them out, improve the color and achieve the textures of hand made bricks.

The idea for the ability to make the  clay behave differently and get a different surface texture on it is based on my experiences of making the perfect pie crust. The idea there is to create crumbs and then add just enough moisture to get it to stick together. The dough has to be handled gently so you keep the crumbs, which are fat coated with flour, intact enough to create flaky layers. Too much water and it turns to mush, too little and guess what the crust is not smooth it cracks and flakes. So that is how I approached making bricks that have texture with cracks. But I will tell you up front that getting the mix just right can be frustrating and there is a learning curve to it.

I do the mixing in a small food processor. I tried it in a full sized machine and it did not work for this method, too much volume to get the clay to crumb. I got a very nice small Kitchen Aide machine that was on sale for $30.00. You don't need a high powered machine. The only speed button this machine has is for pulse.

Because the clay is too wet to start with you need to do something to dry it out. You could pinch it into lots of little pieces and let them stand for a while to evaporate some of the moisture. I added in some powdered earth pigment which soaked up the excess liquid. I also added in some PVA glue for extra strength. Adding more PVA helps moisten the clay if you get too dry of a mix. The ingredient I added to increase the strength of the color is tinting medium which I purchase at a local paint store by the ounce. I put in a terracotta color. Even with the added color the bricks will dry too light but you can paint on toning colors after they dry.

photo copyright Karin Corbin 2009

I make up lots of smaller sized batches. If I get a batch that is too dry or too wet I set some of it aside in a lidded storage container. Those not quite right batches can be used to adjust other batches that don't have the right moisture content. Also you start to get many color variations which is perfect for a hand made brick wall.

In the photo below the clay mache has had powerded earth pigment, glue and tinting medium added to it. It is nicely crumbed but it is too dry to roll into bricks. I do try to get my mix to this stage as it is easy to add more moisture to get it to begin clumping. Be sure to set aside in a covered container some of these too dry crumbs in case you need to adjust a mix that becomes too wet.

photo copyright Karin Corbin 2009

The photo below shows a batch that is just about right, a little more moisture is OK but not any more dry than this image shows. To the crumbs I have now added more PVA glue and also some water. Adding glue only will make the clay much too sticky to go through the rollers, it needs to be a little slick to pass through. You can tell you are at the right stage because the crumbs start to clump together, just like that pie crust making method. A perfect mix is the instant when the clay suddenly becomes a ball but it is easy to make it too wet so I stopped just before that point. A spray bottle of water is an easy way to add just a little bit of water without going too far. So it is pulse, check to see if it clumps, if not then spray some water, check again and keep going until the mix starts to bond together. My mix turned out to be a little too dry for perfection but it still worked out OK.

photo copyright Karin Corbin 2009

Now that you hope you have a workable mix you need to see if it will go through a pasta rolling machine. I am using an Atlas machine I found at a thrift shop. You can now purchase these pasta rollers for using with Fimo type clays. As seen in the two photos below first make a clay burger patty.

photo copyright Karin Corbin 2009

Now cover the patty with a piece of flexible cutting mat and take it down to about 1/4 inch or so in thickness. That will allow you to run it through the pasta machine. I am using the #3 setting on my machine. How thick you want to make your bricks is your choice, there is no rule to this game. All that matters is getting the look you want for your miniature building.

photo copyright Karin Corbin 2009

Now run the clay sheet through the pasta rollers. The sheet should just hold together. If it does not hold together and come out as a sheet because it is too dry put it back in the food processor and add more water. If it is too wet and sticks to the rollers then put it back in the food processor and mix in some of the reserved dry crumbs. The rolled clay sheet might come out pretty rough looking and it might even have long pieces flaking off the surface (or it might look perfect). Both those factors are great, you want this, you don't want a perfectly smooth surface. Mine came out pretty darned rough with a few holes, I was in doubt it would be good enough to use. Look at the photo below,I catch the dough as it comes out on that extra piece of flexible cutting board.

photo copyright Karin Corbin 2009

In the photo below I have just trimmed off the dough into a rough rectangle and I have patched up the holes. Then I slid the clay dough onto my cutting board placing the flex mat on top for the next step.

photo copyright Karin Corbin 2009

Take the rolling pin and using it over the top of the flexible mat smooth out some of that rough texture that came out of the pasta roller. Your piece should look something like the photo below. Maybe it has more cracks and rough spots, maybe it is smoother. The point of making small batches is that you will need a lot of variations in textures to make a good looking brick wall. No two batches will roll out the same and that is good.
My friend Don noticed something in my finished brick samples. There was a trend for the details to run from right to left on the same direction of diagonal. Don has an incredible eye for detail, I sure did not pick up on it. This was caused because I always rolled the pin from right to left on a slight diagonal; be sure to vary the direction you do the final, smoothing with the rolling pin on each of your small batches so you get random details on the surface of your bricks.

photo copyright Karin Corbin 2009

Now things get much easier, all you have to do is make the cut lines. You need very thin blades for this, thick blades mess up the edges. So there are two tools of choice a scalpel and one of the very thin, long razor blades made for slicing Fimo type clays. The scalpel works good for the long lines and the blade is good for the short cross cuts. I find using the scalpel for the second cut leaves little pulled out of shape hooks of clay. Those can be trimmed off later if all you have is a scalpel. I tried using the long blade for the long cuts and it is hard to get it to line up if not long enough for a row. I am using a steel ruler and lining it up with the marks on the grid sheet under the cutting mat. My ruler was cork backed so I put the cork side up to keep it out of the sticky clay. Steel washes better than cork. Take any leftover scraps from around the edges and toss them back into your covered container of mix, you can add them into the next batch.

photo copyright Karin Corbin 2009

photo copyright Karin Corbin 2009

Now let your bricks dry. If I place my boards in front of a fan the air movement dries the bricks to leather hard in 10 to 15 minutes. I can then transfer them onto a baking sheet and finish the drying job in a few more minutes at low temperature, 150 degrees in my convection oven. But that is the hurry up way, you can be green and let them dry for a day or so. The sun makes a great, quick energy source for drying but that is in limited supply at the moment. If the bricks start to warp cover them with another cutting board, flex mat side down or the spare sheet of flex mat and a magazine. Let them breath once in a while to evaporate the moisture off.

photo copyright Karin Corbin 2009

The next part of the lesson will be cleaning up the bricks, adding more texture and painting them. The long tutorial is almost over!