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next to last row

Today I mortared hard bricks for the 23rd row, and mocked up the soft bricks.
Lots of measuring - and trying to use the odds & ends of soft bricks remaining.
I'm trying to save the last really good back-up bricks for when they will be needed soon.

I can see my stock of really good hard bricks is going down fast.
There are a couple of stacks of hard bricks still to have the old mortar ground off, approximately 40 more bricks. Then there are about another 40 bricks that have a whole lot of junk ground off, that may or may not get done. Last resort bricks they will be called. Only to be used in desperate measures like for the top of the chimney, if a few more bricks are needed.

The arch will lie on the 24th row. The right & left sides of the kiln will have the bricks laid in soldier courses. This means the hard brick will lie from in to outside of the kiln wall. This will facilitate the angle iron that will hold the bricks in tight - and keep the arch from falling.

I will mortar the 24th row of bricks on the back wall, but not the front wall. I think it will leave it easier to handle the arch support from the front.

Before the arch support is laid, I have to cut skewback bricks to help support the arch.
The photo shows the arrangement of bricks in the arch. There will be 5 rows of bricks laid in the exact same way from front to back of the kiln. Howard & I decided to lay the arch without cutting any bricks. He has made kilns in this manner and assures me they work just fine.

I have finished reading Daniel Rhodes Kilns: Design, Construction, and Operation which was first published in 1968 and updated in 1981. It is amazing to me how much of the info is still current - 99%. He has some great kiln designs in the back, and my kiln is just a variation of a couple of his designs.
I seriously considered a catenary arch kiln, but it would have had 2 fireboxes on opposite sides of the kiln, with 2 stokers needed. I really want a kiln that could be fired by one person, with the option of 2 persons if desired.

I've now half mortared the 22nd row out of 24 rows or courses.
YES! There is a light at the end of the tunnel.
Howard came over this morning and we discussed my progress and the next steps for a couple of hours - time flies when you are having fun!
After the 24th row, the angle iron has to go on all the corners, with attachments welded onto each corner that will connect to all the other corners.
Then an 'L' shaped piece goes on each side to support the arch - keep it from falling down.
We had a long discussion on how to fit the bricks into the 'L' shape and support the arch.
Bricks need to be cut at an angle to support the angle of the arch - these special bricks are called skewbacks.
Apparently they are custom fit to each kiln and arch design.
In the past there were standard skewbacks that one could purchase, but kilns are all so different these days, and arch configurations so different, that standard skewbacks were going the way of the dinosaurs.
I had a brick supply company in the Portland area say they now sell castable for custom skewbacks. Meaning that one makes a form and pours or tamps a mixture into the form to make custom skewbacks.
After much discussion, we decided that I will cut skewbacks from soft bricks, and use hard bricks to back them up against the angle iron.
Everything is such an experiment... But I trust Howard's experience.

I have had incredible support from a neighbor of mine, Claude Green.
He has loaned me tools and given much moral support.
He will build the arch support for the kiln.
He built the arch support for my first kiln over 25 years ago.
The dimensions and criteria are much different for this kiln, so again, much discussion has gone on. The big problem to overcome is how to remove the arch support from the kiln after the arch is built. In this kiln design, the support has to come out of the doorway.
Claude came up with the ingenious, yet elementary, idea of making the arch support in 2 pieces - a right & left side - that would be screwed together, and easily dismantled.
Sounds great - now to make it work.

Good night - I'm beat - will pick up again tomorrow.
Kiln building is great work for a good night's sleep.

20th row - almost there

Wow - it has been a few days since I last wrote - guess I get tired at night.
Sometimes I get frustrated. Like: isn't it done yet?
But the walls are getting close to as tall as they will go.
Today I finished mortaring the 20th row, and started the 5th bucket of mortar.
I think I'm using mortar because of the different brand of bricks I'm using on each row.
Some bricks just look more dense - therefore they appear to me stronger and longer-lasting.
Others seem flakey, like they may last just a couple of firings.
(am I talking about bricks?)
I've been using the dense-looking bricks on the door jamb. But those are the touch larger bricks, so I need a touch more mortar on every brick in that row to keep things even.
Not enough of the touch-larger, denser-looking bricks left to do an entire row... I'll look closer & count again.

I have to decide which row to put the top peep hole in the back wall.
Bottom peep is in the 4th row from floor, which is 7th row from the very bottom, including foundation.
Middle peep is in the 12th row from floor, which is 15th row from bottom of foundation.
To keep them evenly spaced from top to bottom, the top peep should be on the 23rd row.
But the 23rd row may be where the arch sits, so I have some figuring to do - again.

My kiln guru, Howard, informs me the row of bricks the arch sits on needs to be all hard bricks.
And those bricks need to be laid across the wall from inside to outside of the kiln. These are called 'soldier' bricks. Because they support?
Howard is due to come see my progress in person this Monday.
I want to have another couple of rows laid by then.
Can be done - 2 rows in one day.
I'm a very slow kilnbuilder. Possibly because I don't want to make a stupid mistake.
At least, not too many stupid mistakes.
I measure, and remeasure when the bricks are dry set, and again when each brick is mortared.
Takes lots of time.

I've mentioned that I feel like a weightlifter because I'm constantly moving 8.5# bricks.
My son read that and decided I needed a talk about how to lift weights correctly:
He said that I need to think like a weightlifter. This means that before lifting a brick, I need to pause, exhale and tighten my stomach muscles. I'm trying, kid. (ok, he's a grown kid, but still and always, my kid)
How about lifting bricks at head level? Now the kiln walls are getting higher, that's where I'm moving them. Will it help my stomach muscles get tighter? Give me a 6-pack?

shopping trip

Today I drove to Portland for supplies.
At Hi Temp NW, I picked up 3 buckets of mortar ( sometimes I think my kiln is drinking mortar) and a box of insulation fiber.

My bricklaying & mortaring ability has improved immensely in the past few weeks.
I expect to be using a significantly smaller amount of mortar than the last couple of weeks.
Learned that I will not be mortaring the arch - it is to be laid loose to allow for expansion during firing, and contraction upon cooling.

Insulation fiber now comes in a 'much-less carcinogenic' form for about $15 more a box.
Because I want to use fiber as a back-up insulation behind hard, then soft bricks, I can use fiber that is rated to a lower temperature: 2300F.
My plan is to back-up the fiber with sheet metal, held in place by angle iron on the kiln corners.
I have left-over sheet metal from taking down my old kiln, and expect to need very few more panels.

The drive up to Portland was on a warm first day of autumn.
I was aware of significant haze in the Willamette Valley and farther south, also.
This evening I heard of wildfires in the mountains that were sending ash as well as smoke into the Oregon valleys.

I am disappointed that readers of this blog cannot post comments for others to read.
If anyone knows of another blog address that allows for comments, please let me know.
I welcome comments at my new pottery email address: susanpotsatgmaildotcom
please substitute@ for at and . for dot.

I read that stops (probably more properly deters) robots & spam from my email address.

I'm looking forward to mortaring tomorrow.
Will have a photo to upload then.

grinding bricks & gathering wood

Today was a slow day - I think I mortared a dozen bricks. Since I just counted how many, it is more than I thought I got done.
Some things for the kiln did get done today.
My hired worker did grind old mortar from some bricks this morning.
Then he cut apart the angle iron braces from my old kiln. Now I have pieces of angle iron than can be handled and configured to fit the new kiln.
Before the arch is put on the new kiln, angle iron braces need to be put on all the corners.
Then tie rods will be attached between the corner braces.
And angle iron braces need to be put behind the skewback bricks that have yet to be cut to support the arch.
Wait and see, photos to describe the above will be posted as they come.

Paul, the hired worker, also brought up many pieces of wood that were around the land.
We lost a number of trees last winter, and they were cut into logs earlier this summer.
Now they are near the kiln for firewood. There is a lot of wood splitting still to be done...

I also got Paul to dig some holes in the garden for me today.
While I harvested tomatoes & strawberries.
We've had some very warm days, but the nights are clear & getting quite cool.
So much for the first day of autumn.

Then Paul had another hour to work, so he ground some more bricks.
Looks like the brick supply will be good for some time to come.
I think grinding bricks is one of the worst jobs - the dust is incredible.
And one really doesn't want to get in the path of that floating dust.
Dust masks are a pain, but we each always wear one.

Half built kiln walls

Today the 18th row, pictured here, was mortared.
The middle peep hole is barely visible in the back wall through the doorway.

I've patched holes in the 3 rows of foundation bricks that were seeping sand. Sand had been swept between the bricks of the 3 bottom courses to keep the bricks from moving. But it kept slipping out - I guess as the earth rotates, it shakes the sand down, or something like that. Perhaps, as I walked on the kiln floor, it shook the sand through.

I'm feeling like I'm making progress. I can tell the walls are getting higher because it is hard for me to read my tape measure across the top. I placed cinder blocks along the front & back, so I can reach the top easier. It will be the next row or two that I'll have to use a stepladder.
Just as I am picking up time in my bricklaying technique, I'll be moving slower as I tote a stepladder around.
If I was taller and could see the top of the row I'm working on, I would just have to lay more rows. I'm going to make the kiln just tall enough for me to stand up inside. That will make it easier to set kiln shelves when loading pots for firing.

Measuring:
After placing the inside hard bricks for each row, I measure across each direction on the inside. Need to make sure the walls are even & parallel. As every brick is mortared, each measurement is double checked with the tape measure & a level. Before setting a brick the place is swept with a small hand broom, and the brick itself is swept. Only then can the brick be mortared.
Also, the diagonal measurement across inside corners is checked, so it stays the same from the bottom to the top of the kiln.
Today I learned how to use a 4' level vertically and see how straight the walls are. Sounds easy, but as with many things there are tricks/techniques to reading the tool properly. If I'm making it sound like there is something to it, it is because I was doing it wrong, and needed to be shown the correct way. I guess I'm saying that when I think something should be easy, sometimes I find I'm doing it all wrong - as I did with this. Now I know how to check the verticality of each corner.

Enough for today...

bricks

I've been collecting bricks for a long time.
This year I acquired most of the hard bricks I have.
The biggest haul of bricks is at least 6 different brands or brick makers. That is in the foreground.
Against the building is another couple of hundred bricks.
In the shadows on the right is another stack of bricks, and the arch bricks.

Hard bricks come in a standard size.
But just like standard sizes for clothes, I found that the brands can differ by 1/8" in any one direction. Now this may not sound like much, but it adds up as the kiln grows taller.
I realized this when I found myself using buckets of mortar.
I'm now into my 4th bucket of mortar.
And I wanted to use as little mortar as possible!
What am I doing wrong?
Well, for one, I am just learning to be a bricklayer.
As I've now mortared 17 rows of the kiln, I can see my bricklaying craftwomanship has improved immensely.
The entire row is level and square.
It just took a bit of mortar to get to that point.
Well - I can see another trip to Portland to pick up a few buckets of mortar is due this week.

It wasn't until I had the first few rows mortared that I decided to separate the stack of bricks into each brand. Who'd have ever thought there was so much business in making hard bricks (those that can take a high temperature: over 2400 degrees F), that there are that many different makers. It took a few days of sorting - each brick weighs over 8.5 pounds, so I'm also a weightlifter now - to get the stacks of Idaho, Diablo, Dad (really, that is stamped on some of the bricks), Yukon, Columbia, Zed, Morex and some others.
The pretty, unused bricks have straight sides and sharp corners.
Most of the bricks have rounded edges and remains of mortar and soot on them.

I've been at the winery for the past 2 days, and fighting a cold.
Hope to mortar another couple of rows tomorrow.
Am on row 18 of about 23 or 24 rows.

The stacks of bricks are going down fast..

15th row

I email Howard every day I work on the kiln. Pic on the right is of the stoke hole. On the left is me mortaring the 4th row.

This is tonight's message to Howard:

This morning I mortared the 14th row, tonight I mocked up the 15th row.
14th row includes the lintels that top the stoke holes, soldier bricks on the side walls, and the bottom of the middle peep hole on the back wall.
Did I email you pics of that this morning?

I measured how many more rows to the row the arch sits on.
The inside floor of the kiln is row 3 (row 1 is hard brick, row 2 soft brick), I can see row 15, in 10 more rows, I will be ~5" from the top of the wooden door frame.
The arch has a rise of approx 10".
If I take the sides up 55" (4' 7"), I can still walk in the kiln & stand up easily since the inside height would be around 65" (5' 5").

I have put aside nice bricks to brick up the door, put in the arch and for the door jam.
Need to count to learn how the brick supply is holding up.
So far, so good.

I got oxygen for the cutting torch.
Measured the angle iron I have here. Looks to be 4 of corner angle-iron pieces for the kiln, and 4 of smaller angle-iron for the chimney.
Don't know that there are channel-iron pieces long enough to back up the skew-back bricks.
45.5" is the inside measure from front to back in the kiln, the depth of the arch.

Am getting much better with the mortar. As the rows of bricks are getting more even, I use lots less mortar.

I wonder if I can do these 10 rows in the next week? I'm getting faster, and measuring lots more.

That's the end of my email message. Here's some of my kiln-building thoughts:

There are lots of brick-layers tricks of the trade, I feel I am learning already. I wanted as little mortar as possible in the kiln, and Howard said he likes to use mortar to level the bricks in a row. I use the level on every brick. As I go along the row of bricks, some bricks need more mortar than others to keep that row level with itself & the other rows.

I learned that when I put a slab of mortar in the middle of the brick, how to mentally calculate how much mortar to slop on. The hard bricks used on the inside or hot face of the kiln are very dense and do not absorb much water. On the other hand, the soft bricks which are insulation and face outside the kiln are porous and absorb water easily. They need to be dunked in water before mortaring so the soft brick will not suck the water out of the mortar too fast and not stick.
Looking back, the brick-laying in the first few rows is not near as good as what I'm doing now. And I'm sure I'll get much better.
And this will be my last kiln to build myself - it is a lot of work!

Susan's New Kiln

Friday, September 11, 2009

I've typed my first blog, and rereading, I find it quite technical. Ok, it is my kiln-building diary. Will try to lighten things up next blog.

I've wanted a wood-fired kiln for a long time. My gas-fired kiln is 25 years old, and the floor was starting to fall out. After much thought, I decided to tear down my (then) existing gas kiln and rebuild on the same spot. There should be no reason the entire project could not be completed during the summer. Well, there is now 10 days left in summer, and the new kiln is not quite half done. Actually less than half done. Of course, I can't give up now - so I stumble forward.

I would never have attempted this project without the complete support of my kiln guru and master kiln-builder: Howard Kiefer. I told him from the start: I want your brain, not your body.
And he's been very generous teaching a beginner to be a bricklayer & kiln designer.
I'm quite confident the kiln will fire well - but then Howard gets alot of the credit.

I've been taking digital pictures of this project as I go along. Often to email Howard of my progress, and ask his advise about a particular problem.
Since I'm just now starting the blog I've been contemplating for awhile, I will slip in the beginning parts of kiln building as I go along.

I've learned so many tidbits of kilns, bricks, kiln design, and much more. Will share as I think of things. I've been accumulating materials - hard bricks - for a number of years. The date of my first bucket of mortar was 1997 - so it's taken awhile for the right time to come about.
Last fall, a fellow potter mentioned he had a number of hard bricks that he was willing to part with. My first trip was to check out the bricks and bring 40 or so home in my Honda. At over 8.5# per hard brick, that was more than 300 pounds. I called around and priced new bricks; delivery alone was not going to be inexpensive. It took over 6 months to coordinate a vehicle to move bricks and everyone's schedule. I should have taken this as a warning that things take much longer than anticipated. Even when we planned the brick moving day, it got postponed at the last minute.

* * * * *
First Pic: Old Kiln with door & chimney bricks taken down

Second Pic: First row of bricks of the foundation - This is hard bricks with soft bricks at each end - the soft bricks are insulation. Three rows of foundation bricks were used. Bottom is hard bricks, middle is soft bricks, upper row is hard brick floor of the kiln.
I had concrete under my old kiln, but needed more square footage. Had to raise the level of the old kiln foundation with cinder blocks to raise it up. Layed hardibacker over the cinder blocks to level, and another sheet of hardibacker to insulate the concrete from the firebricks.

* * * * *
I opened a new bucket of mortar today. It was so thick, I phoned the manufacturer to find if I could add water to desired consistency without ruining it. Was told to put some of the mortar in another bucket (used about half a 50# bucket of mortar) (I'll ruin another good bucket), add water then mix. Used about half my mixed mortar to level the soft bricks around the inner hard bricks. Then mortared the 11th row of bricks - ran out of mortar 2 bricks short. Will do them next time - possibly tomorrow.