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Saturday, December 28, 2013

2nd Times the Charm.. perhaps..

Ok, so I posted before that i could not get the kiln to temp.  IT has been a long time since the weather and my schedule hit it right so I could try again. Today was that day.  I removed the top ring. It was empty so I do not know, had it been full, if it would have worked or if I have found the right "size" for this kiln given the burners I have.

Now I can leave this alone, or I can change burners or I can add a burner. The last two would allow me to add the third ring back in. If I add a burner on the side, which I am thinking of doing, I could do so and use this to add wood to the firing adding and taking away the actual burner as I work the say through it.  Not totally easy but not too complicated.

Anyway, on to the firing.


So above you can see the kiln finally getting hot. I fired basically all day last time and could not break 700*c but today in an hour I hit over 600*. This picture was taken around the time ^010 fell, so I started reduction which you are seeing the flue setting for below.



I did not take any further pictures (nothing much to see) after I moved back into oxidation and tried to fire up to temp.  I was doing good until I  hit 4pm. This is almost five hours into the firing and... I was loosing temp. I was not clear why. I played with the flue, the gas level and then found that the top shelf was at 1096*c but the bottom shelf was 1146*c, far more of a difference than I expected given the form of the kiln.

Also my target was ^5 or ^6, whatever I could get to be honest.  The estimated temp was between 1200*c to 1255*c, depending on time and such. Well around this time I noticed, ^6 was soft and falling.  So I threw the kiln into reduction and removed the thermocoupler. I can't have it in when I am spraying.



Above you can see the flames from this reduction (glaze reduction).  I let it sit for around 15min while I did the final prep of the spray. This is 3# in 1 gallon of boiling water.  Reduction during this period is totally sealed up except a small slit in the flue.  All peeps are closed. I then removed all the peep holes when I was ready to spray. You can see the flames below out the flue.



I was all alone this firing so it was interesting trying to do pix of me spraying. Below is the best I have. You can see the metal sprayer going in the peep hole and of course you can see me and the phone in the reflection.  I sprayed in spurts moving from peep hole to peep hole and then pumping more pressure into the sprayer so it will spray.  Spraying creates water reduction so the total body reduction time is more like 30 min total.


Once I was done, I threw open the flue. And.. I cracked up the gas.  No clue what temp as I wasn't measuring.  Instead I cleaned and let it run like this for 30 min.


I then turned off all the gas, closed the peep holes and closed the flue 100% to leave it sealed to cool. Below is the last picture, all gas is off. It was taken right before I closed the flue. In the few seconds it took the camera to focus I could feel the heat on my phone.


So it will now sit till tomorrow when I will check the temp. No opening until it is below 200*F.

To recap.  This was a six hour firing.  I hit ^010 about 4 hours in and completed a moderate body reduction for an hour.
I struggled with temp around 1130*c, it started to go off. Not clear what I needed to do but as the cones were close enough I called it good.
About five hours in I hit ^5, put it into 30min glaze reduction (heavy reduction with soda added). Soda was 3#/1gal.
Finished it off with 30 min full oxidation and then shut if off and sealed to cool.
This is not very far off my written firing schedule.

Sunday, December 15, 2013

No I did NOT Blow Up the Backyard....

So, I got the soda kiln firing right now.  Below are pix from loading.  You can see an empty shelf.. ya I really wanted to fill that but folks did not send pots to be fired.  I think this is too new for our community studio. And... well we are trying to get some of these fired in time for Christmas and so could not just let them sit...

Not a problem, it is just fine for an experiment. So a quick review:

 So you can see the holes for the burners.  Now basically a Flue has to be at least as large.  This set up offers a template, which I ignored... I made the flue twice as large.  Here is why. We can always cover more of it. This also sets us up if I do a hole on the side to add wood that we have the secondary air needed to fire the kiln.
Below you can see the kiln after loading, it is firing. But you can see how the flue is constructed.  Fire brick and then a damper on the top.
 

So shelves were all kiln washed.

A kiln pack set in wadding (ignore the 9mm in the background).  From Right to Left it is ^010, ^6 & ^7.  Ideallly I would have a ^5 but I didn't get any for this firing.  The ^010 is the marker so I know to put the kiln into body reduction (as opposed to glaze reduction later).
the other three (here I have two) are the Sacrifice Cone, Witness Cone and Guard Cone. The Sacrifice cone you are killing off and lets you know you are about at final temp. Also suggests the time to put the kiln in glaze reduction.

Witness Cone lets you know you are there, you soak and seal the cone and finally the Guard Cone lets you know if you are going over temp and need to do something about it.

This is the base shelf and the pots on there.  Yes this is a very loose pack. Loose is good for a Soda kiln but... ya.  I could fit a lot more if we had them...

This is the second shelf from the bottom. You can clearly see I staggered the half shelves. This is a good Soda Kiln practice to manipulate air flow. Would not be as important in a straight reduction fire.  You can also see the ton of ornaments.  If not for them we could also fit a lot more pots on this shelf as well.

This is the top shelf. And yes it is empty.  If not for the height of some of the pots I would have been able to skip this ring and shorten the kiln.

So clearly this kiln can fit quite a bit of pots even with the lost space due to converting from electric to gas.  Below you can see one of the burners. Look close and you can see the blue flame.


A better look at the burner system. This is a WARD conversion system if you were wondering.


I was originally told I could use one tank and fire the kiln. I have two (they are not full) so I can alternate as one tank freezes up.  This is a propane issue but by being able to turn off one tank and then turn off the other we can quickly switch tanks and dodge the freezing issue keeping the fuel moving smoothly.


Really hard to see in the picture, I was trying to catch the shadows from the exhaust on the kiln.


And again, not a great pic but if you look close you can see my eyebrows were every so slightly burned....


Friday, December 13, 2013

Gearing Up for SODA!!

Ok, here are my posts, and my shelves and the kiln wash...

tomorrow I will liner glaze and decorate my few pots and make the wadding. Then sunday I will load the kiln, ash spray some of the pots and we are firing!!!!




Sunday, December 8, 2013

Soda Kiln is READY!!....

So Here is how this came together...

As discussed, it was to damn cold lately. This is propane that will be used as fuel. Now propane "freezes" up due to it being cold, so the longer you run it the more cold to the point it doesn't leave the bottle efficiently. So, logically, if we start out cold outside... well it doesn't take long to get to this stuck spot.  Further, even when it isn't super cold the colder outside is the less efficient the firing.

Based on this and how cold it has been in general, so we put off the firing till next sunday.


So cold as hell I got myself motivated to get the kiln itself fixed.  We planned on this and we simply could not get it done. Other things screwed with the time, and when it is both cold and dark it is hard to get moving. But finally we had it set... then Zeke had to go into work at 2am...


All the same, it had to get done. I am very flooded at work and this was really the only time that still bough us wiggle room to fix any problems. So I fired up the old wood stove.  My studio is still chaos due to the remodel moving so slowly.


I then kidnapped the creator of the chaos in the studio and he helped me get this going.  Here you see him just finishing up with the flue.


Here you can see where I added some brick to have a much broader base than is offered simply by the burner unit. The burner unit really is the same size as the original base. But with the kiln outside, well extra stability seems to be a good idea.  Here you can also sort of see the burners and you can see the gas connection.



Here is the inside.  The odd square you see is actually the stain from the original frame. This was flipped when we put it together. No, this actually makes no difference.  You can look carefully in the holes and see the burners.  You can also see the posts created by cutting the holes. This will be used as the post for the addition of the bottom shelf.  I must create enough space between the burner and the bottom of the shelf to circulate the air and flame.  I will add one large shelf rescued from an old gas kiln for this purpose (I think, I think it fits... I really need to pick it up...)


Here is the flue. I will add soft kiln brick to cover the top to regulate the air. This allows the flue to have a dampener. So this allows some control over secondary air. This is how you control the oxygen and therefore set the kiln into reduction and to what degree. Larger is better because if the source of secondary air (the flue) is not equal to or larger than the source of primary air (the burner ports) then you can not place the kiln in neutral or oxidation. This places the kiln in constant reduction causing it to fire very inefficient. 

If the flue is too "large', well you simply cover the hole more.  So that you can fix, too small you only can fix by cutting a larger hole.


Here you see the hole kiln.  If you look at the holes on the middle portion of the rings, see the double holes? Those are "peep holes".  Ignore the holes to the right. Those actually are only large enough for a wire and therefore not an issue.

Now in some designs you seal up these peep holes... only to knock larger holes into the side of the kiln. These are the soda ports and peep holes.  Well, by using the existing peep holes and making the hole larger (we did this, it is hard to see) there is less damage done to the kiln helping keep it stable. Another reason holes are added is to get to both sides.. but by spinning the ring.. well it took care of itself.  

I think my design will work just fine.  From brick built versions the soda ports are few and far between and so I think I have plenty going on here.

I think we are ready to fire.









Friday, December 6, 2013

ARG.....

So, my real life has made it difficult to move forward with projects. This whole need to make enough money to keep the business running, employees paid, and my own finances in the black.

But I have not had time to actually fix the kiln. This will finally be done tomorrow... despite the cold...

But I have an issue.  I wondered about firing when it was cold. Well I was told today there might be a serious issue.  For Raku the night before they could not get the little Raku kiln up to temp.  The bottles of propane kept freezing up.... ya....

So if the little Raku kiln could not make it to temp in 12* F weather then I am unsure the large soda kiln can do it between 14* and 27* (after all it will take all day anyway).  The issue is not really the kiln, it is the freezing tank.  So with two tanks, we can move back and forth, this will help the tanks under normal circumstances work without issue. But if the starting outside temp is so cold.. well the tanks will quickly freeze up and the unused tank will take a long time to warm back up.

So... I'm not sure. We may have to put this off... certainly not what I wanted to do in anyway shape or form. But not much I can do about the weather....  Time is an issue as well of course...

Tuesday, November 26, 2013

In Progress

These are all in progress but ready to be bisques and then Soda Fired.


This is the Sake Set with the cups trimmed up.  I may need to sand a bit but we are good.


This is the container to hold cooked rice. You can see the notch to allow for a spoon.


If you look close you can see a color difference at the bottom of the handle.  This is due to me adding paper clay as the handle started to pull off.

The jar... well I did not do a new picture of the jar. However it seems the lid has sealed onto the jar.  I hope this is not an issue, I think in Bisque it will separate... I hope....

Porcelain

Porcelain, it's a lot easier to throw now.  I am not throwing extremely thin, but this is functional ware and so that is not really an option. All of these, if everything works out, will go into the soda firing.


So this is a lidded container with an odd lid. This is totally untrimmed. I did clean up the lid a bit.

This is a rice container, think Asian Restaurant when they bring you steamed rice. That is a lid next to it. I need to cut a notch out for the spoon and then clean up the lid and bottom a bit.

 

This is the Sake set.  Cups need to be trimmed, they were thrown off the hump.  the serving bottle is below as well. Traditionally such sets are really only for two, sometimes three. So I did it for two.





Saturday, November 16, 2013

Holly-Fest




Out of Laura's Kiln



So I did the outside with Rutile Green.





The inside is with Amber.
This was palate with white slip on SB-Red.  It was decorated with iron oxide and Chrome Oxide. The glaze is Fuzzy White.

 This is Porcelain slab plates in Celadon with Iron Oxide designs.

There were four Porcelain mugs, different handles on each. But all done in Celadon with Rutile Green on the handle. You really can't tell that though.

Here we have my kiln god, made from paper clay.
the pot is from Reclaim Clay, white slip and then decorated with underglaze. The plants are blue and purple, though they look like blue only. The "ground" was orange, though it comes out relatively red. The glaze over it is Fuzzy White.


This is fuzzy white on the outside with iron oxide decoration. The inside is Amber.