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Saturday, June 26, 2010

Barrel Firing Experience

...number three. Yes, before you ask you've not missed a post, I'm going to illustrate the third barrel firing and speak about my experiences with the second and what I've learnt thus far. Once again this post will be quite long as I want to catch you up with everything (hope you don't hold it against me). I've not had much spare time as I am still working hard towards my first exhibition.
OK, here goes: I threw another load of 1kg (2.2lbs) pots for this firing. I tried to take a little time over them to make them nice enough to sell if they survived. They were bisc. fired and terra sig was applied.


1. The pots ready to fire.


2.The incinerator was placed flat on the ground to block the airflow from the holes in the base. After the second firing I knew I had to control the airflow to stop the heat from building up too fast (I lost the big bait ball/ fish pot in the second firing).


3. A layer of wood shaving was added and oxides and salt sprinkled on top. The first layer of pots was then laid onto this.


4. Oxides and salt were sprinkled over the pots and wood shavings were then piled evenly in covering the pots completely.
(As you'll see this firing was done entirely with wood shavings).


5. Once again oxides were sprinkled over and the pots laid in place.


6. Next layer of shavings and oxides.


7. Pile on the shavings again.


8. Oxides then pots.



9. More shaving and oxides before another layer of shavings was added covering this last layer.



10. A small fire is built on the top to (hopefully) light the wood shavings and start the firing process. The idea being the shavings will burn slowly and the build up of heat will be gradual.



11. Wait until your neighbours have taken in their washing and the kids have gone to bed (in the UK it is a crime to light fires before 7pm, I waited until 10pm to light this...I should have started a little earlier).
Apply a match... 



12. Gaze at the pretty flames...oooh, aahh etc.


13. Stand further back you idiot...what are you trying to do asphyxiate yourself! Your hair is on fire!



At this point I should explain a little more: To start the firing the holes at the base of the bin were blocked up. As the fire on top died down I and my pyromaniac neighbour Simon decided first to open these holes as we thought the fire was dying out. This didn't seem to make any difference so we put the chimney on top. This was a mistake after a minute there was a great whooshing sound (causing Simon to spill his coffee and almost have a heart attack, as he was leaning in close to the bin at the time) as the updraft suddenly kicked in causing a roaring fire to take hold. We hadn't realised that the wood shaving were slowly burning under the surface. So don't assume the fire is not burning unless there is no smoke at all and the side of the bin (barrel) is cold. I will not put the chimney on again. Even with an inch gap between the bin and the chimney the heat was a little too intense.

14. The next morning. Keeping fingers crossed I approached...


15. and removed the chimney...



16. Remove the pots and brush the ash away. Miracle! no smashed or badly cracked falling to pieces pots!



17. Wash the pots in warm soap water.
These are the survivors. No cracks at all.


These are the ones with small cracks:


I still am not completely certain why some crack while others don't. I think cracking happens when one part of a pot is exposed to a strong heat source while the rest is cool, as the pots which crack have a tendency to have a heat mark at the point of the crack. I must find a way to guarantee an even heat throughout the bin.

18. Polish pots. I used a bees wax finishing furniture polish this time and it seemed to hive a better shine. In case you can't tell: The pot on the left has been waxed and polished. The one on the right is as it came out of the bin after washing.


19. Admire the fruits of your barrel firing. I hope next time to lose even less.




I'm at the stage now where I am trying to decide if I should barrel fire the other two carved pots. 






After losing the big fish pot in the second firing because, once again, the heat built up to quickly I'm worried that losing these would be a real blow. I'm not sure what I would take to the exhibition. I may throw another load of small pots and do another barrel firing just to try to get it just right.
Let me know what you think and don't forget to leave tips and suggestions I need them!
Oh, before I forget: here is the small bait ball (which did survive. You can see why I can't decide whether to take the risk with the other pots):



Thanks for visiting.

Replies: Thanks Kim and thanks to Paul Jessop (we're not worthy etc.!) for your kind comments.
Gai, thank you for your comments. I'm pleased you found my youtube videos useful. I say throwing of the hump, but I don't think there is any rule. It's nice to know that you've got a wheel, however I should point out that the first rule when thinking of becoming a potter is to buy (or build) a kiln. The reason is that you can make fantastic pots without a wheel and fire them, but you can't make fantastic pots with a wheel if you have no way to fire them or you have to transfer them to a class kiln and risk damaging them in transit. This is not a criticism, it's just the first rule I was told that I ignored and regretted my choice when I had slaved over some porcelain bowls only to have them crack transporting them to my pottery class. Let me know how your throwing goes and repeat, repeat, repeat etc.

6 comments:

  1. The pots came out very nice. You did a great job. After reading this my husband said there is no way he will let me do this and to keep firing with my electric kiln.lol

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  2. Dear Friend;

    I'm about to do my third barrel firing in Galway, upstate NY, next weekend. In the past I did my firings in the fall, but now it is winter and I'm wondering if you have experience with this kind of firing in cold temperatures, below freezing at night and in the 40's at best during the day. I plan to start the fire in a barrel with a chimney around noon and then remove the pieces the next morning. My concerns are the cold and the heat variations. Any suggestions or comments would be deeply appreciated.

    Thank you.
    Patricia Kay

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  3. Have you done any barrel firing on green ware? The studio from which I am working is closing in three weeks, and although I am searching tirelessly for an electric kiln, I am also on medical leave after 2 hip surgeries, rendering my pocketbook a bit empty. I attempted my first Raku firing the other day and broke a gorgeous pitcher, as well as a pot that I had already promised to my brother. Fortunately, the colors turned out wonderfully, and he said he would take it glued!! The pitcher appeared intact, but when I picked it up, the handle broke and it smashed to pieces in the patio. This post was extremely helpful - I now know that they were heated much too fast and for too long.

    If you have any experience barrel-firing green ware, however, I would appreciate it!
    Ashley
    Pottery by Ashley Hakes
    Ajhakes@hotnail.com
    Wisconsin, US

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    Replies
    1. Did you get feedback on firing greenware in barrel with sawdust/wood? I've started experimenting, but the clay firing much too soft. I'm doing a small pit with bricks and sawdust, three bricks hight (two-and-a-half wide, sqaure). No damages, but I can still break the fired item with by hand.

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  4. My CORRECT email is: ajhakes@hotmail.com

    ReplyDelete
  5. Loved this post, Brookfield Potter! Those comments around the fire - it is like you are speaking my mhnd while I'm firing (oohing and aahing and getting the hair out of the way)

    ReplyDelete

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