Friday, November 16, 2018

From Pottery Kilns to Brick Ovens

Forty-five years ago I was making stoneware pottery and firing it in a wood-fired kiln to 2381 degrees Fahrenheit (1303 Celsius).

Today I build brick ovens that need not reach temperatures higher than 800 F.  But there is still high temperature material, FIRE and at the end, a wonderful product.

Last weekend, I joined my friend, Willi Singleton in Kempton, PA to fire his norborigama kiln at Pine Creek Pottery.  The twenty-two hour firing brought together Willi's many friends, colleagues, and students for a round-the-clock effort.
Willis starting the fire in a lower chamber

For those unfamiliar with the process of making clay into pottery, Willi's approach is complete.

Willi Singleton
His clay comes from two regions of Pennsylvania and is prepared at his pottery so that it is pliable enough to throw on a potter's wheel.

first fires are stoked in a lower chamber
His glazes are made from wood ashes, corn stalk ashes, and bamboo ash, which all grow around his place.

The wood that fires the kiln is local from sawmills.

Noborigama kilns are built on a hill.  This kiln has four chambers, with the exit ports of each passing to chamber above.  A 25 foot double chimney creates the draft to pull the flames through the chambers.

It is an elemental experience.  The forms, materials and skills are timeless.

Like brick oven building and baking, it is a link to our ancestors.

After a long night, the stoking proceeds to special ports in the pottery chamber itself

a couple of the families
have been helping to fire the kiln
since their children were young

ports are stoppered with clay after the kiln reaches temperature

Wednesday, November 7, 2018

Brick Ovens and CAD (Computer Assisted Design)

Most oven projects require planning.  This begins, if feasible, in a site visit with the potential customer.  The conversation often starts with the person's cooking goals and moves through the location, dimensions/capacity, and finally to the style of the oven.

Although my website shows a number of previous oven projects, I have found that every oven can be designed as a perfect fit with the customer, the customer's place and needs.  The result is that a look at the nearly 40 ovens I've built reveals that each one is different: variations on a theme.

A CAD drawing helps the process in a number of ways:

  1. It describes dimensions: footprint, elevation, roof or chimney route, wood box and oven mouth.
  2. It allows for an accurate quote on cost (and comparison to other options)
  3. It prepares me for the quantity of materials needed.
  4. It can be forwarded to the local building inspector and/or architect/contractor so that we are coordinated.
  5. It is the reference point for alterations, if needed, during the project.
  6. And lastly, it may allow the design client to build it him or herself.  For this, I provide a design consultation service.
So, what do these CAD's look like?
I originally had a CAD company set up one for cutting bricks.  I also got separate drawings for each brick in the oven. The master dome looks like this:

I've since found ways of cutting accurate brick chains for any size dome.

Depending on the situation, CAD's took these forms:

Saturday, November 3, 2018

Beyond Cob Wood-fired Ovens

bricks fitted over sand mound/form

sand as the form for later brick setting
A long-time friend built a small cob oven a few years ago.  As cob will, it didn't keep the heat for long, developed cracks, and although it was very inexpensive, wouldn't allow his partner to start baking any quantity of bread for sale.A long-time friend built a small cob oven a few years ago.  As cob will, it didn't keep the heat for long, developed cracks, and although it was very inexpensive, wouldn't allow his partner to start baking any quantity of bread for sale.
using off-cuts of bricks to create solid mass
Interior inspection and clean-up
Slim bodies only!
As his long-time friend, I gave him some hundreds of stray fire bricks and off-cuts from the precision bricks I'd previous cut for the custom ovens I build for my clients.

The four-cornered dome

Applying the vermiculite and Portland cement insulating layer

The result is a hybrid.  The mouth and flue assembly is from a cast-refractory company, who shall remain unnamed, that I represented early in my oven career.
A slow warm-up to drive the water out of the mortar
We mounded sand as you would if you were covering it in clay and sand, the cob method.
But instead of clay and sand going over the sand, we began mortaring fire brick chunks up and over the mound, filling in behind with refractory mortar.  As with cob ovens, the sand was removed when the dome was finished and set.

We also chose to make the floor rectangular but build a four-cornered dome so that the maximum space would be available for bread baking.  Low cost vermiculite and Portland cement had been cast under the floor bricks and more of this was applied to the exterior.

Subsequently, a box will be built around the oven and the cavity filled with loose vermiculite.  Roof over all.

Wednesday, October 24, 2018

Brick Ovens: Curves, Cobbles and Water

Columns with glass capitals that periodically emitted mist.
Glass waterfall and 'floating' walkway of Irish limestone.
In 2003, I spent an entire winter preparing for a flower show exhibit in Portland, Maine.

The theme was 'the space between buildings', which I interpreted as 'what can you do in an alley 15' x 40'?

The result was an insane amount of work and care to build a water garden and inhabit it with greenery in Maine, in the first week of February for five days only.

The day of the load-in, the temps outside were below zero.  Leafed out trees and perennials needed to be transported sixty miles without freezing.

Okay, you get the picture.

Artists and artisans sometimes have the chance to push the outside of the creative envelope.  Generally, we don't worry about the extremity of the effort (like planning a 'manned' mission to Mars).  These projects, however speculative, however complex or reaching, give us a distant landmark for future, perhaps more grounded projects.

 In 2006, I designed and built the landscape and stonework for the half acre in front of Bridgton Academy's new Humanities Building.  Central was a circular stone terrace constructed of reclaimed cobblestones from Commercial Street in Portland, Maine.   As the site was on a steep hill and I wanted to imbue the project with a sense of history, I built a breach in the wall from which a dry stream bed wound downhill.  Note that approximately 50,000  square feet of pavement drained into this stream bed from a culvert when it rained.

Conceptually, I determined that I was building a 'Tower Remnant'; the structure that might have stood there before the academy was ever built.

"Tower Remnant", when mentioned drew blank stares so I opted for 'Outdoor Classroom', a more prosaic term.  This goes to demonstrate that beginning with a strong theme will strengthen the final outcome even when the metaphor is not mentioned.

The project below, in New Hampshire, used curved reclaimed curbing to frame a patio and garden beds.  It is tempting (and necessary) to lay brick in straight patterns.  However, the variety of patterns exceeds the space here to describe them.  By making the intersection of the brick pattern at the bottom of the granite steps, I gave the terrace an off-center focus.  The curved terracing up the slope echoed the curves.

Then four years later I came back and built a granite and cobblestone water feature to frame the lower end  of the property.  

When building a brick oven for a customer, whether it is a residence or an institution, I strive to be aware of the potential metaphors at work. They are often specific to the person or place. 

Material choices DO make a difference; that is why I build the ovens from real fire brick, not cast refractory and why the exteriors change subtly or dramatically from project to project.

Tuesday, October 23, 2018

Brick Oven Dedication

Twelve years and forty brick ovens ago, I brought forth on an old trailer a new portable oven, conceived from used fire brick and dedicated to the proposition that all bread is not created equal.
Now I have engaged a boom truck, testing whether that oven, or any oven so conceived and so desiccated, can long endure.

I've met hundreds of people, built them ovens, far afield.  So I have come to designate a place for that first oven, as its final resting place that that hearth might live to bake more food.
Is it altogether fitting and proper to do this?

But, in a larger sense, I could not dedicate more travel-- can not allow--this oven to be sold.  I am resolved that this first oven shall not have fired in vain-- and that brick ovens, of the people, by the people, for the people, shall not perish from the earth.

A few days ago, a boom truck arrived, picked up the 1600 pound oven and swung it onto a base I'd built last summer.

The sturdy original is home.

Thursday, October 18, 2018

The Long Dome option

In some locations there is not sufficient space for a fully round dome.  In these cases it is possible to elongate or stretch the dome shape without losing its structural benefits.

Six years ago, an oven I built in St. Charles, MO.
Due to the other cooking elements desired in the same space, we designed a long dome 4' wide and 5' deep.
I built the 'core' and the on-site masons finished the exterior, which included a charcuterie (left).
There are some ways a long dome
can provide more versatile cooking options.

The dome for the Georgia project has its mouth on the long side providing two half-domes at either end.  If the cook wants, he or she can cook fast and hot at one end and at more moderate temperatures at the other.   The pre-cut bricks show where full bricks are used to stretch the width of the dome.  Cut bricks on the side are simple doubles of the set ones that will be used for the opposite half-dome.  This oven is 32" deep and 48" wide.

Starting the St. Charles oven.