technē and poiēsis

During my first week here at Grymsdyke Farm, I was introduced to the work of Erwin Hauer . I was really captivated by the beauty of his repeating modules, especially the way light seems to bounce around within the thickness of the wall. His installations suppress any hint of materiality, but the same effect happens, for example, in Eladio Dieste's Cristo Obrero church, where it seems like the brick panels are always glowing with sunlight you never see directly.  These two have been in my mind a lot as I have been designing my walls. I wanted to keep a sense of depth- in most brick walls, you only see one surface- a relief pattern and not a three-dimensional construction.  One reason I like the colour of the fired clay here so much is that it really catches the sunlight well, especially in the predominantly green landscape.

At first I didn't want to use any module other than the main one, hoping that the unit itself would be versatile enough to accommodate every condition. I have realized that sometimes, 'specials' are necessary- the exceptions that make the system work. In my case, in order to finish an edge properly, I need some half modules. These were made simply by slicing the brick before drying. The shape, I've realized, is interesting because it has the exact same profile on four of its sides.

After a visit and lesson from a builder, I have changed my mortaring technique and my mixture. He suggested using equal amounts cement and lime, to make the mixture even more workable, and also told me to add more parts of sand, since mortar should always be weaker than the bricks, and these bricks are pretty weak to begin with.  I also found out that the mix I was using was way too dry, which would explain why it wasn't sticking well to the bricks. Whereas before I was working with a very hard, crumbly mortar (sort of like natural peanut butter), his mix was soft and very runny, like warm butter. (Side note: I keep finding ways in which bricks and bread are similar. In the ways that they are mixed from two main ingredients, formed, baked, and even buttered! When the kiln is firing, it even gives off a moist, dough-like aroma) The builder shows me how to hollow out the bed so that it has somewhere to 'squish' when I put the brick down. Since the mortar is so wet when...

Mortar, like clay, is another of those neither-liquid-nor-solid substances that can take any shape- although it is best at filling gaps between things more solid than it. The mortar I'm using is roughly 4 parts sand, 1 part cement, and 1/2 part lime. The lime, I've found, makes the mixture slightly stickier, although I still have trouble sometimes getting it to adhere to the brick.  I've found that when it comes to mortar, more is more. It's better to overfill and then scrape off the excess, rather than to try to go back after and patch it up. Especially for the joints I'm dealing with- they are anything but regular, and have to be clean on many sides. As well, excess mortar allows me to push the brick down into place, ensuring good contact. I am still figuring out a good technique for working, as well as trying to decide exactly how I want the joints to be finished. Bevelled? Curved? Recessed? Flush? At the moment, each brick is an experiment. This simp...

To maximize cohesion between the mortar and the brick, there are two measures I take: brushing off the sand with a wire brush, and  soaking the brick in water.  The brushing also removes the darker sand so the orange of the clay shows through.

Formwork is the unfortunate, essential-yet-absent material that can 'make or break' the concrete pour (or the budget, for many architectural projects!) I'm happy to say that my formwork did its job well- but sadly, it is now waste. I chose to make the frame out of MDF, knowing that it would not be salvageable after use. The inside is thin plywood, in order to  follow the curvature. There are, of course, different kinds of formwork that are reusable, but for a small, unique slab like this, its life ends with removal.

After many weeks of working with clay, today I was working with concrete. It's funny, even during the most stressful times of brick-making, I never felt like I needed to be a machine- it was always distinctly human work, and the laborious tasks, such as sorting clay, also had a meditative side. Concrete is a different story. Perhaps due to the shorter working time, and the irreversible nature of the process, I was acutely aware of the limits of my body and the inefficiencies of working by hand. Luckily I had help, in the form of Paul the gardener.  We marched the formwork across the field. For other, heavier, things, we used the lawn tractor with the trailer.  In order to use less concrete, we put a base layer of flint (there was lots lying around, of course). It worked well to space the wire mesh, too. We stretched a chain of extension cords across the field in order to get the concrete mixer going. We also had very long hose, but it didn't stretch quite as...

This mold was unfortunately unsuccessful, but I did learn a thing or two about metal. Ten minutes' bike from the farm is a forge and metal workshop, and one of the techniques they use is sand casting. A full-scale pattern is packed into sand, then removed, and molten aluminum is poured into the void.  The pattern and the cast. I made my pattern quite thin, thinking that metal would allow for an economy of material that wood does not permit. However, when the blacksmith examined my pattern, he remarked that the cast would be liable to break, because cast aluminum is very different from sheet aluminum and can be brittle. He said that it would be better if I brought a solid block with the hole cut out- exactly like First Mold! The blacksmith examines my pattern. The cast did not turn out because it was hard to remove from the sand. The sand must be damp in order to hold its shape, so the pattern must be 'smooth like glass'.

Sand left in kiln after removal of bricks. When I opened the kiln after my first firing, the bricks were...dark. Burgundy. Comparing this colour to the vibrant orange that I had seen before, I knew something was wrong.  First, the sand I am using changes colour. It must contain a lot of iron, or some sort of clay-ish rock, because it turns from brown to burgundy when fired. Second, I had fired the first batch to 1100C, whereas for every firing prior to that one I had only fired to 1000C. I think this changed something in the clay-sand mixture- maybe the sand melted at the higher temperature. When I made test bricks with 50% grog, they were much stronger than just with clay. I thought that sand would work the same way, but turns out that sand makes the clay a lot weaker. The bricks from the first firing are very brittle and crumbly. I have changed the proportion of sand in my mix, so that it's now not more than 25%. I can't give up sand as a mold release, though, so I...

Clay too wet- it coats my hands. I have been struggling with the consistency of the clay. Mostly, it's too wet, which results in sticky fingers and misshapen bricks. Too dry is also a problem, since that makes it very hard to fill the mold, and leaves deeper creases on the surface.  A further problem is that clay dries extremely unevenly. I can spread it on a board in the sun, and if I don't look after it every 15 minutes or so, the top develops a crust (too dry) underneath which the clay still retains all of its moisture (too wet). Different batches require different working methods. For a wetter clay, I pound it into the mold with the side of my hand, because it's the only thing that doesn't immediately stick. With a dry clay, I use a rubber mallet, for more force. During demolding, I have to be very careful with a wet clay, because the brick tends to fold in the middle, so I have to tap harder on the corners to loosen it before letting it slide directly ...

Part of the infrastructure required for brick-making is a place to dry the formed bricks before they are fired. Since this brick-making operation is being built from the ground up (literally) I had to design and construct a shelving system. It is composed of simple wooden frames with slats for shelves, to allow for the maximum flow of air. At first I was worried that the slats were making lines on the bricks. I was thinking that I would have to let them dry longer on the sand rows, or touch up each brick, or make different shelves, but then I found a very simple solution: a shim to angle the slats to almost the same slope as the brick.

There's something about the friction between the clay and the mold that seems to require an impact to loosen it. The pieces of Second Mold do not come off the brick as easily as I had hoped. I also have a hard time getting very clean edges, as the clay sticks to the lip of the mold. I thought that my mixture was too wet, but even with a drier one the problem remained.

I wanted to make a mold in parts, with the thought that I could minimize the distortion of the brick by setting it down on the sand instead of having to drop it. I like the corners on this mold better- the CNC machined corners on First Mold have a radius due to the drill bit. This one is more tedious to work with, however, because of the separate pieces.

Oval kiln with rectangular bricks, Castel Viscardo, Italy Hoffman kiln, near Radzymin, Poland Stacking a kiln with bricks to allow for ventilation and even firing is quite an art. As well, the places where they are touching during firing often get 'kiss marks', lighter patches of colour, so the stacking influences the final appearance of the brick. One thing about having a non-rectangular brick, though, is that it is very easy to stack them in a way that allows the passage of air. I ended up just laying them directly on top of each other, in two layers of three courses. This allows me to fire 105 bricks per kiln Now, I just have to hope for the best...