A new kiln

I am constructing a new kiln. This one will take all that I have learned and put it together in a new indoor barn kiln.

Update on my wood furnace construction

Ive been working here and there on the brick building that houses my outdoor wood furnace boiler. I have recently added the archway over the door frame. I think im getting the hang of laying bricks and mortar now. Not a pro, but im satisfied with it.

More salt glazing practice.

Here I am again firing some clay pots and tiles. Some pots are refired to try to put glaze on the sides that didnt get any last time. I think I may have gotten the kiln a bit hotter this time from the color of the glow. Took me about 8 hrs because of the cool wind early on. I also used alot more salt at the end this time.

I had a few tiles and one vase from the last firing that had really good glaze coverage this time. The rest will need to go back in again to get glazed fully. My crummy kiln is probably the main cause of the partial glazing.

Here are some results to share with all of you!

I wonder why red clay turns almost black when salt glazed. Is it the heat or carbon from reduction firing.

The tile warped because I had it leaning against a brick.

Here are the pots that didnt get a full glaze effect from the salt.

They will have to go back in for a second try. I will place them in different locations of the kiln to even the glaze out. The back of the chamber seems to get the best glazing effect. Must be the way the gasses are flowing to the chimney flue.

My first try at salt glazing. Very cool!

I fired a few quickly made pieces of red clay pottery and tiles. It took about 7 hours total to fire. Let it cool down overnight and the next day, then unloaded it. Over the last hour of firing, I added about 20 lbs of rocksalt to the firebox while stoking the fire. About 2 cupfulls at a time. This is how it turned out! I will have to consider placement of the pots and tiles next time.
I am wondering if I could place the same pottery back in again facing the other side to complete the glaze. I will let you know if it works out.

The volcano erupts again!

Another week has passed and I have looked over my results from the last firing. I made some nice pottery last week but didn't tell you much about the bricks. They were bad! Very over fired. I have made some changes and went at it again. My results are much better this week.

I had too coarse a mix of glass fragments in the clay. That made for glass to melt out of the bricks.
That along with placing them stacked ontop of eachother also supporting the weight of the kiln top too much. The heat destroyed them into glued together ckinkers.

I lowered the entry point of the chimney flue and added a metal door to the front of the firebox.

I also took the stacked weight off of the green bricks by putting firebrick support posts inside the heating chamber to hold the kiln rooftop up. The new clay/glass mix is still 50/50, but the glass is tripple sifted to the mesh size of wire window screen.

This is the result of that effort!

My last name is Hendrix, but my wifes family name is Kennedy. So her brother asked me about bricks with their name on them. All the bricks passed the water submersion testing with no ill effects.

First successful pottery made! In the Volcano.

Here you go! Made out of field clay and glass dust.
They all have ring to them and passed the water test.
This is my beginning! Very excited now.

With the help of my kids I now have named this kiln the "Volcano"

Wood Furnace Boiler Heat Update

Ive been doing alot of work on my wood fired heater boiler since last time I posted about it. Here are a few pics of the progress.

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.

Third kiln design and brick firing.

Its my biggest kiln yet. Double the capacity of my last one.

Hottest yet! It takes alot more firewood now too.

Look at the glow. I need to get some sort of pyrometer or cones

to know better what temp is being reached.

Notice the white bricks. They along with the pottery are from streambed clay instead of red field clay. I next will be working on fluxing agents like lime and used glass to improve hardness and vitrification of the bricks throughout.