Dismantling of kiln for repair

Ugh...I've been really upbeat about this whole catastrophe until today. Tearing down what you just built isn't fun. In fact, it's pretty depressing. :(

I numbered all the arch soft IFB and removed them in order. Peeled off the fiber blanket layer and numbered all the arch hard brick.

When I tried to fit in my old arch support that I used to build the hard fire brick arch I couldn't fit it in because of all the expanded and melted brick. I don't want the arch brick ruined by dropping them (they were a different batch of bricks and are in great condition) so I filled the kiln with old towels to provide cushion and tried dropping it in rows. It worked with no brick damage. 

Everything is then stacked in order off to the side. I'll keep them covered with a tarp until they are reinstalled.

Here's a few more pictures of the damaged brick that will all be replaced. 

The rear wall is so interlocked with the chimney that I think it will be my hardest, but, at least I have started and I am well on my way to fixing my kiln. 

The rear burner port was the biggest fail as it was occluding the burner port during the firing. What a mess!!!

Still hoping not to remove any ironwork. The damaged brick is very brittle and needs to be hammered to break off. It splinters and sends glass-like slivers or rocky chunks flying. I just might have a few cuts and scratches when I'm done! Will update again soon.

Another road trip for new super duty high fire brick

Another drive for replacement bricks, this time to a brick plant in Grayson, KY. Thank you Mathew G for the contact. Extremely reasonable bricks, new with minor cosmetic flaws (jeez...I don't think the pots will be offended...heehee). Picked up 250 of them to repair/replace my melted ones.

But, the best was getting to check out the massive round kilns! Too cool and he let me take pics so I can show you guys. Now those are real kilns!!!

Me for scale. :)

And those are some massive burners!

The inside

Looking up at the ceiling.

These kilns are no longer in use as they have moved to tunnel kilns but he said their other plant still uses a couple of their round ones. Neat.

Well, loaded down heavy with these bricks so driving back to SC and hopefully finding good BBQ on the way.

Melting brick horror...sigh

Now for the bad parts...the pictures speak for themselves...

Yup, it's as bad as it looks. Many of the bricks just melted/marsh mellowed!!! The worse part is that they fused together so repair will be a bear. Such is life. I consulted lots of people about this is what I've learned. The wonderful helpful people gave me tons of useful info on the Facebook soda and salt firing page so I'd suggest you read up on it there to get all the details. The gist of it is that these first 288 bricks were used ones I purchased knowing they had been used as the subfloor and outer layer of a salt fired kiln for 10 years or so. They were jet dp heavy duty high fire brick and would under normal circumstances hold up great to cone 10 firings but these, though they looked perfect, were spent. I have 3 other sources of used hard brick in the kiln and those all held up fine. This batch was just done. I couldn't have afforded to build this kiln had I not purchased used brick so I don't regret my choices, this was just bum unlucky. The gentleman who sold them to me felt awful and even offered to reimburse me but it is no more his fault than mine own. Perhaps I could have prevented this by testing the brick by firing them to cone 10 in another kiln first but not all of them failed so the testing would only had helped had I tested the right bricks. My conclusion is that I should have tested them but it may still not have prevented this. 

Well, I built this kiln and I am very proud of how it performed. If I built it, I can and will repair it! ;) 

Stay tuned for repair posts. One of the kind kiln builders (thank you Mathew) who shared his expertise when I started my build has directed me towards a great inexpensive source for new high fire heavy duty brick for my repairs. I am on my way this Friday to pick them up. In the meantime I have been throwing another whole load of pots and they are just waiting to be fired in my "new" repaired kiln.

Result of First Soda Firing

So I stressed for days as the kiln slowly cooled. I tried peeking through the bung holes and couldn't see anything. I did pull out the last test ring 2 days post firing and spent hours trying to guess what everything was going to look like.

And finally I was able to open the kiln.

You get the idea. Please ignore the fact that most of these pieces were just practice pieces I threw at my week long throwing course up at the John c Campbell folk school a few weeks prior and many aren't really "my" style work. I really liked the results though there is plenty I'd do different. The deep reds, the lustrous quality to many pieces, all of it I loved!!! So, I count it as a success and I ignored the big (huge) problems for a day to just enjoy my pieces first. 

Yeah, sometimes I think it's ok to bury my head in the sand if only for a day, lol.

First Soda Kiln Firing...

Well, the first firing was definitely an experience. Sorry it has taken me so long to update the blog but I took tons of pictures and notes so I can share the full thing.
Finally got everything loaded in the kiln and closed it up tight at 7PM on May 22nd.

Turned on one burner to 1psi. Temp rose 92 degrees in 20 minutes so decreased to 1/2psi. Had to lower to the needle barely above zero psi to decrease temp rise. By 8pm temp rise slowed and we were at 244 degrees. Hubby and I sat watching the sunset and pretending we were sitting by a gourgeous fire (lol, which we were, sorta)!

At 11pm were at 401 degrees, had tested the safety valves and trusted them to work so we headed to bed, fingers crossed. I woke up at 4:30am and dud a quick kiln check. All good and temp 540. Back to sleep. By 6:10am I gave up on attempting to sleep and headed down to kiln sit. Temp was now 566.

Russ and I settled down with our coffee (in mugs made by my fellow potter Christy), still in our pjs to kiln sit. 6:40 psi increased to 1/2 and second burner fired up. 6:45 temp 608, 7:45 temp 720, 8:30 temp 766 burners increased to 1 psi, 8:45 temp 812, 9:00 temp 845, 9:30 temp 882 burners increased to 1.5 psi, 10 temp 942, 10:05 increased to 2 psi, 10:30 temp 1021.

11 am issued started... Psi dropping. Checked everything and noticed propane tank was freezing up.

Yikes! Did an emergency tank swap (we had several tanks fortunately). At 11:30 we did a quick tank swap that caused about a 40 degree drop in temp according to the pyrometer and restarted on a smaller tank at 4 psi. By 11:45 the small tank started freezing. Temp dropped to 1108 before we were able to hook up our larger house tank and temp was rising all running well by 12:05 temp 1169. At 1:18 psi was 4.5 and the 3rd tank was freezing up too! Uuuggghhh...we wrapped the tank in a warm towel, found an old heating belt I used to use on my car boys for beer brewing and pushed onwards. 2:00pm temp 1440 and psi 6, 3:00 temp 1665, 4:00 larger (3rd tank) was empty so swapped out. We filled a large storage tub with warm water and placed the tank in it to keep from freezing. I've heard since then from several people that this is a BAD idea but others say it is effective and not dangerous. I still have mixed feelings so planning on avoiding this choice in the future by looking into purchasing/renting a larger tank. Sad part is that a year ago I had them remove a much larger rental tank because we weren't using enough propane at the house to justify it and had purchased the smaller tank as a replacement...sigh...

Sent my boys out to get a refill on one tank as I was afraid we'd run out before the end of the firing. At 4:15 temp 1733, closed damper to 2. 4:30 temp 1761 psi 8. 5:42 psi 10 damper3, 6:50 temp 2041 psi 13 damper 5. 7:50 noticed blockage buildup near rear burner causing burner to back up. Knocked off blockage (appears to be melting brick) using an angle iron, damper at 7. 8:00pm temp 2182, Sprayed soda 3 seconds per opening (6 openings). Allowed temp to return and did again a total of 4 times. 8:22 decreased to 9psi. 8:25 removed first test ring. 8:28 temp 2194 added round of soda, 8:37 removed 2nd ring, 8:45 added soda temp 2215, 8:55 temp 2228 added soda and removed 3rd ring, 9:00pm temp 2230 added soda one last time psi 7.

9:40 pm pyrometer reads 2225 and cones down. 10:00 burners shut off all bungs opened and damper opened. 10:45 temp 1781, kiln clammed up damper closed and bung holes closed.

may 24th 6:00am 1152

31 hours post firing temp 582

May 27th, temp 320, second wicket layer removed and kiln unloaded 10:00am.