Jump to content


Photo
- - - - -

Need Advice On Barrel Firing Pots

Barrel Firing Firing Question Advice

  • Please log in to reply
9 replies to this topic

#1 GaragePotter93

GaragePotter93

    Newbie

  • Members
  • Pip
  • 2 posts

Posted 29 July 2014 - 01:07 AM

Hey Everyone,

 

I just started a little studio in my garage and figured I would reach out to the community for some advice. I plan on barrel firing

 

my pieces to cut down on my costs but I've never done it before and have some questions. I bought a 31 gallon galvanized

 

steel trash can and am wondering If I have to burn the zinc off before using it for a firing? I read online that this is the case

 

but I was thinking that maybe the fumes from the zinc burning off would impart some color on the pots. Also I'm wondering

 

what types of clay people are using for barrel firings? The guy at the pottery store told me low fire white clay but the internet

 

seems to think I should be using groggy stoneware. Hopefully someone knows about this stuff but please feel free to post any

 

other advice you have on this type of firing, I'll be grateful for any help I can get. 

 

Thanks



#2 Benzine

Benzine

    Socratic Potter

  • Members
  • PipPipPip
  • 1,636 posts
  • LocationThe Hawkeye State

Posted 29 July 2014 - 08:03 AM

Welcome to the boards.

 

Will you be bisque firing, these pieces first?  With any type of pit or barrel firing, bisquing is recommended.  You will have much less loss, from cracks and spalling.  Even if everything survives, it will be fairly weak, if you only barrel fire it.  The temps don't get hot enough to harden the clay.  Barrel firing is used to create surface effects on the wares, from the smoke and other additives added in.

 

I'm not sure if the zinc fuming off will do much, in terms of the wares.  You are right though, the zinc fumes are nasty, so you do need to be cautious when firing.

 

For pit, barrel and Raku firing a clay that can handle the thermal shock of quick heating and cooling, is a must.  So you can buy a specified Raku clay, but a grogged stoneware works just as well.  


"Anything worth believing, is worth questioning"

#3 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,981 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 29 July 2014 - 08:26 AM

The zinc fumes are toxic so beware. 

As benzine says, you should bisque your pieces first. Robert Peipenburg has a great video on barrel firing.

Basically he has a grid raised off the bottom about 4 inches. Newspaper under it to light from 1" holes drilled around the side. 4 will do. Thn some more half way up and again about 3/4 way up. 

He loads paper , sawdust, wood, laced with copper carbonate and salt.Layers and layer with pots added. 

He lights from the bottom and keeps it covered. He uses the holes for adjusting air intake. Works great. He lets it smolder overnight.

Best to stay nearby to watch out for flying embers.

 

Marcia



#4 Tyler Miller

Tyler Miller

    Advanced Member

  • Members
  • PipPipPip
  • 325 posts
  • LocationOntario, Canada

Posted 29 July 2014 - 01:23 PM

Zinc fumes have a limited effect on glazes in my experience, reacting with the glaze a little, but for the most part the zinc just condenses on the pot and is easily wiped off.  I would imagine that zinc fumes on a bare clay body would be absorbed to some extent, but the result wouldn't be robust.

 

As said above, the fumes are pretty poisonous, and can put you out of commission for some time if you're not careful, sometimes permanently.  Exercise caution, and if you're going to play with zinc fumes, do it outside, in an open space.  They disperse fairly quickly, but you don't want to be too close to that barrel.  If you feel a headache come on, or get a metallic taste in your mouth (or any of the symptoms of metal fume fever) a little after working with it, or even the next day, seek medical attention. I've had it once, never again, no fun.



#5 Marcia Selsor

Marcia Selsor

    Professor Emerita, Montana State University-Billings

  • Members
  • PipPipPip
  • 3,981 posts
  • Locationwhere Texas, Matamoros, Rio Grande and Gulf of Mexico come together.

Posted 29 July 2014 - 02:14 PM

I use an old 55 gallon drum. I don't like galvanized steel for burning things as Ty mentions. That zinc is nasty.

 

Marcia



#6 TwinRocks

TwinRocks

    Member

  • Members
  • PipPip
  • 25 posts
  • LocationOregon

Posted 29 July 2014 - 04:46 PM

After playing around with unbisqued raku clay and heavily grogged sculptural clay in pit firings, I would say get things bisque fired first, even if you have to pay to do it else where.

If you are determined to proceed, we had the most success when using a (clay only!) toaster oven to slowly warm our green ware, being careful not to up the temperature too quickly. Bringing the green ware to the toaster ovens maximum temperature then using raku tongs and glove to move it in the pit yielded some okay results but the failure rate was still pretty high....because we where just playing around with the idea, most of our test pieces where simple pinch pots).

Planning on doing more for the effect, but having pieces kiln fired first. It is still fun if you don't mind loosing a lot of pieces.

#7 TwinRocks

TwinRocks

    Member

  • Members
  • PipPip
  • 25 posts
  • LocationOregon

Posted 29 July 2014 - 04:50 PM

I forgot to say, without the toaster oven the pieces broke over 90% of the time. Failure rate with the pre-heating dropped to around 20%. High fire clay doesn't work well under this circumstance either. Low fire clay with lots of grog!

#8 GaragePotter93

GaragePotter93

    Newbie

  • Members
  • Pip
  • 2 posts

Posted 01 August 2014 - 01:28 PM

Hey guys thanks for all of the great advice! I'll definitely be more cautious with the zinc now, probably just do a burn to get it off the barrel before I do a real firing. I am going to bisque my stuff first I just meant I'd save some money by only having to rent out kiln space once for each form. Picked up some Raku clay the other day and made a bunch of bowls to do a test firing with. Going to the studio with the kiln now to do my first bisque, probably do my first barrel firing on Sunday. I'll post pictures if anything comes out well. Again thanks for the advice its really going to help me out. 



#9 TwinRocks

TwinRocks

    Member

  • Members
  • PipPip
  • 25 posts
  • LocationOregon

Posted 02 August 2014 - 11:13 AM

We actually ended up doing another this weekend, and all survive this time (one broke after, but it may have been for reasons unrelated to the firing).

#10 dwinton

dwinton

    Newbie

  • Members
  • Pip
  • 1 posts

Posted 17 August 2014 - 08:10 AM

i've done a few barrel firings in a galvanized trash can. did burn out the zinc first. punched holes in the sides and bottom. use bisqued highfire stoneware clay and have had no cracking problems. best results from whitest clay you can get. burnish or terra sig before bisquing for a nice shine on the finished pot. beware the fumes, especially when unloading. this is a really fun technique, so enjoy!





Also tagged with one or more of these keywords: Barrel Firing, Firing, Question, Advice

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users