Happy Thanksgiving, Interesting pressed brick history website.

Google searching today and came across this interesting site. A very detailed list of pressed bricks and their makers. Its great to be able to see examples of historic brick like this.

Have a Happy Thanksgiving everyone!

http://www.penmorfa.com/bricks/index.html

My first customer!

Ive been hired by the Delphi chamber of commerce to make 50 promotional bricks for them. So far I with the help of my son have pressed out all 50 bricks and a few extras. 20 have been fired in my electric kiln to 1900'F with only one breaking. I should be ready to fire another 20 tommorrow if all goes as planned.
On another note, it looks like I may have a chance to show off a few of my Delphi and Carroll bricks at a local antique art gallery soon. Pretty cool!

New brick bottle kiln. The 'Monster'

My latest clay furnace is a small bottle updraft named 'Monster' by my daughter after an energy drink she says it looks like.

Ive wanted to experiment with a different design, hoping to gain easier firings and higher temps.

Just a bunch of firebricks surrounding an old cut up 55 gallon barrell. That surrounded by red brick.

It took me only 4.5 hours to reach 2000'F, and it could have went further if I pushed it. May have went too hot for the clay I was using for the test bricks inside.

Looks to be a real improvement so far though. I will post the results soon.

I pressed out 12 clay bricks last week just for this test firing today. Finished drying them in my electric kiln last night.

Heres a peek inside at the end. See the brick slumped over. Got too hot I think. Gonna have to slow down this beast and run it to 1850 - 1900'F max.

Firing temps and brickmaking

The finished color and hardness of a clay brick has alot to do with the highest temp achieved and length of time held there before cool down. There doesn't seem to be as much effect on outcome if the ramp up time to peak temperatre is varied shorter or longer. Obviously the type of clay will have a profound influence on the finished product as well. But here I will focus on firing temp of a single type of clay.

Below are tiles and bricks of the exact same source of clay, prepaired the same way before firing.

They are identical except for the one brick on the lower left. The three of the same color were fired to 1900 deg F over an 8 hr period in my electric kiln. The darker brick made at the same time as the others, was fired to 2000 deg F over 9.5 hrs in the same kiln. All settings on the kiln were identical.

The surface of the darker brick is closer to that of a paver or clinker. It has a reflective quality to it that the others do not. All the bricks and tiles are fired fully and have a strong 'ring' when tapped together. The darker brick has a higher ptched ring to it.

If I were to ever try to make pavers or outdoor tile, they would be fired much like the darker brick. I believe the water proof qualities should be higher.

Notice the small paw prints on the one tile. My kittens were having fun after I made up the tiles.

Graphic example of clay shrinkage from firing.

I hadn't ever really gave much thought to clay shrinkage from the firing process. I had read about how it is a normal thing to happen. After making a few more pressed clay bricks for a later firing, I put a finshed brick next to them to compare the colors. What caught my eye though was the size difference of before and after. Pretty amazing when you get a side by side like this.

Trial kiln run needs some improvement.

I fired my latest kiln up last saturday on a test run to work out any bugs it may have. There was alot of it that needed improvement! This is my first arched chamber and the location of the exit flue is low. This makes for weak draft until the chimney warms up. It smoked like crazy the first hour or so. Even after that it didnt draw like I wanted until after a few hours stoking.

Since I built this kiln at my new site, I had to bring over everything from the other location I was working at before. I hadnt bothered to bring the blower for the firebox. Wasnt sure I would need it. I think I do. Couldnt get it up past red. I couldnt reach the temperatures needed without it in my short firing timeframe. 1 day. So that little blower is gonna be a must have for this kiln too.

I built the upper part of the chimney in a hurry the days before the first firing. I didnt like its look or the gaps in the brickwork. Neither did the local policeman on duty. lol. That night he payed me a visit worried that the flames he saw shooting up from it were gonna burn down the barn. Guess he wasnt used to seeing chimneys shooting out flames after wood stoking. I have since rebuilt it taking the time to do it right and make it a couple feet taller for better draft.

Ive found a new sorce of field clay I am excited about that it seems to work much better. I will post when I have some results for all of you to see.

I did it! I have made fully fired clay bricks.

I finally have been able to make a hard, durable brick. I was lacking a flux that would work in the short firing time frames I am forced to use. Salt and lime didn't work fast enough. But ground up glass dust did. What takes pure clay several days firing to do, I now can do in 1 day!

Old scrap glass from bottles, windows, and television picture tubes is smashed down in my mixer with heavy round stones.

Then I sift the crushed glass down to remove all large pieces

before adding it to the clay to press out bricks.

I am using a 50/50 mix of clay and glass.

Then I fire the bricks same as before.

The three bricks to the left are regular clay bodies for a control. The forth, sixth, and seventh are 50/50 red field clay and glass. The fifth brick is 50/50 grey streambed clay and glass.

The controls were not vitrified and crumbled easily. The red clay/ glass bricks were solid and passed water absorbtion testing averaging 11% and maintained full strength. The grey streambed clay / glass brick had absorbtion at 22% and split minutes after submersion in a bucket of water.

I attribute the failure of the streambed clay brick to the high level of lime pebbles in the clay mix it was made of. The lime swells as it absorbs water causing fractures in the clay body of the brick. I will work on removing the lime pebbles for the next tests as I really liked the near white look of that brick and would want some of them to hold up for me.

Bricks from my latest wood firing.

Here they were before firing.

After firing.

Here are the results! 12 good light reds, 11 underfired soft salmons, 5 clinker ringers, 9 junk clinkers.

These were the best of the whole batch. They all had 'ring' to them when tapped. I still would like to see them fired a deeper red and a bit harder. But its hard to get it just right without going too far and making cracks in them.

Overfired 'clinkers. Taken from the back and the lower part of the kiln.

Firing up the brick clamp part 2

Saturday morning I went out to find the fire out but for some coals in the firebox. The bricks were still very hot though the glow was gone. I restoked up the fire and had it glowing again in about an hour. During that time I added a curtan wall of red brick around the firebrick to help hold in the heat that was excaping from all the cracks. It made a big improvement in the overall heat and glow inside.

Black sooty smoke is bellowing from the top just after I put more wood on the fire.

After about 10 hours I shut it all up and let the cooldown begin. Sunday I opened it up to see the results.

Out of 24 clay brick I had made and burned in the clamp, none broke! A few had cracks. They were in various states of firing. Over half were underfired to different degrees. A few had glazed overheated spots on them. And six or so had the nice orange almost red look from the iron oxide in the clay. About a third had a noticable ring to them when tapped instead of the thud when tapped of an underfired brick would.

Overall I rate this firing as a success. I made marked improvement over last years attempt. I got rid of the milky chalky haze last years bricks had too. None of the bricks from the last try were very tough or had a good ring when tapped. These had many that did. Just wait for my next try!!!

Before and after!

New brickmaking frogs.

I have made new frog plates for my small brick press. HENDRIX and KENNEDY are mine and my wifes' family names.

I think it gives a more prefessional look to my pressed brickmaking.

I am now also trying out drypressing bricks of pure clay. No sand or cement. These would need to be kiln fired to make hard and weather proof. More details comming soon.

Wood heat furnace update July 11, 09

Done with the fire brick installation now. Have also finished the chimney with the addition of a tall stovepipe to aid fire draft.

I will pour the firebrick secondburn tray over the next few days. Then is will be time to set the water boiler tank for gap sealing.

Pressing firebricks

Ive been working on a home addition at my house for over a year now. I dug out along the foundation to lay drainage pipe and heating tubes from the wood furnace. The soil is a very sticky clay here. Perfect for the firebricks we have been making for the lining of the furnace.

After sitting in the sun for several days with no rain, the clay hardens into stiff clumps that need broken down for mixing with sand.

50% clay, 40% sand, and 10% portland cement.

Here is a pile of free creek sand taken from my property.

The mix is damp but not soggy. It will clump in your fist.

And here is the result from the press!