Ads

Collapse

Announcement

Collapse
No announcement yet.

raku reduction process

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • raku reduction process

    i understand that one of the very important factors in a successful raku firing is the speed at which the pieces are removed from the kiln and placed in the reduction containers and the lids secured so that the reduction process can begin

    does this imply that each piece should have its own seperate reduction container so that the proces is not interrupted?

    also, should the pieces be covered over with the reduction fuel (sawdust or whatever) or simply laid on top

    also,where can suitable metal containers be found or bought

    thanks for any help that you can give me

  • #2
    Hi, I've only done Raku at uni using their facilities but from what I remember the water was just in an old black bin (you know the type before wheelie bins!) and the sawdust was in a wooden box. The technician took the pieces out for us but he did it one by one with large tongs.... I think he left the kiln on whilst he was doing it. From what I remember he dipped it in the water for only a few seconds then rubbed the sawdust over for around the same amount of time...then put it to the side.
    Not sure if thats any help?!
    http://www.terrilowedesign.co.uk
    http://www.twitter.com/Hello_TerriLowe
    http://territriestwice.blogspot.com/
    email: [email protected]

    Comment


    • #3
      Hi Chris,

      There are no real or true answers to your queries unfortunately. Ceramics and pottery firing processes are very much experimental, especially when it comes to Raku firing. Each potter develops their own techniques from their own experiences.

      Just like any normal electric kiln, it is almost always a surprise when opening the door, as you can never really be sure what the outcome of your pieces are going to be (and thats what I like about it!) I think that Raku firing is very very spontaneous, you could perhaps not achieve the same effects twice!

      I have had several Raku firing experiences, and from what I understand, the speed in which each piece is removed isnt too important. However it is important that you keep the kiln closed whilst transferring a piece from the kiln to the pit, so it helps to have atleast one other person helping (one to remove the work with tongs and place in pit, another to open and close kiln).

      I remove pieces from the kiln when the glaze looks as if it is melting like lava and is glowing orange and red hot, then put it into an old metal dustbin filled with sawdust/newspaper/hay or any other combustible materials (each one creates a different effect on the surface of your pot), then chuck in more sawdust or whatever you are using on top, then put the lid on. Again it depends how much sawdust you cover the piece with, to what it will look like. You do not have to cover it with any if you don't want to. Why not try a few different methods and see which you like best?

      I sometimes didnt like to put too much on top before I closed the lid, because of the stinky and smoky chemicals that are released from the process - makes your eyes sting! Make sure you wear thick gloves, goggles and a mask.

      I never used separate containers for each piece, I have always put pieces on top or around one another in the same bin.

      When you remove the work from the smoky bin, it will still be very hot so use tongs and dip it straight into a bucket of cold water. You will find that cleaning the pots up and polishing them under a running tap will reveal the most gorgeous colours and patterns.

      Have fun and enjoy!

      Comment


      • #4
        thanks Charlotte

        thanks Charlotte for your comments...all my previous ceramic experience has been in hand building largish sculptural pieces and firing in an electric kiln...having recently moved to live in a remote part of Shetland i decided to try something different...hence raku...very different!!!

        i love the" have a go and see what happens" approach but am also aware that it helps to have some basics sorted to help the spontanaeity to stand any chance...your advice reassures me.

        thanks again, chris

        Comment


        • #5
          Originally posted by chrisclay View Post
          thanks Charlotte for your comments...all my previous ceramic experience has been in hand building largish sculptural pieces and firing in an electric kiln...having recently moved to live in a remote part of Shetland i decided to try something different...hence raku...very different!!!

          i love the" have a go and see what happens" approach but am also aware that it helps to have some basics sorted to help the spontanaeity to stand any chance...your advice reassures me.

          thanks again, chris
          Hi Chris,

          I'm glad I was of some help

          Good luck with it and let us know how you get on. Would love to see your results!

          Comment


          • #6
            Raku is something we've never tried but would love to (but somehow a bit of a scaredy-cat over it). Do you need a gas/solid fuel kiln or can you do Raku firing with an electric kiln? What is the best temp to fire to? Would opening the door of an electric kiln while it's red hot damage the elements or the kiln structure? We always cool down v. slowly and were under the impression you should leave the bungs in until at least down to 200deg. I know you need to use Raku clay, but why doesn't it crack when it's cooled so quickly?
            Kate
            www.cuckoos-nest-fairs.co.uk

            Comment


            • #7
              Originally posted by Cuckoo's Nest View Post
              Raku is something we've never tried but would love to (but somehow a bit of a scaredy-cat over it). Do you need a gas/solid fuel kiln or can you do Raku firing with an electric kiln? What is the best temp to fire to? Would opening the door of an electric kiln while it's red hot damage the elements or the kiln structure? We always cool down v. slowly and were under the impression you should leave the bungs in until at least down to 200deg. I know you need to use Raku clay, but why doesn't it crack when it's cooled so quickly?
              You don't have to use Raku clay - infact I have never used it, I've always raku fired with stoneware, and have even raku fired some thin slip-cast earthenware vases which were very successful.

              I don't think you can use an ordinary electric kiln as its important to do the process outdoors because of the nasty chemicals and smoke that is given off. A lot of raku kilns are hand-built using bricks, metal frames and kiln fibre glass sheets padding out the walls. The ones I have used are fired up with gas. You open the kiln whilst red hot to remove a piece, then quickly close it again - thats the trick with raku, it has to be hot with the glazes melting at exactly the right moment before it is removed and put into the combustible materials.

              Dont be a scaredy cat Give it a go! Treat it as a bit of fun

              Comment


              • #8
                on with the raku....

                ok Charlotte, i'll certainly let you know how it goes.

                Cuckoo's Nest...like you i got very comfortable with the level of control that you can achieve with an electric kiln/programmable controller set-up...but then i was invited to see a raku firing and realised that i was missing out on some serious fun...it changed my whole approach to ceramics and i am now impatiently working my way towards my own first raku firing...i've had to experiment my way (no potters nearby to turn to)and have finally managed to do a slow controlled bisque firing in my very unfamiliar gas updraught kiln ( no mean task, i can assure you) and so am now ready to do the raku bit proper...the fact is that faint heart ne'er wins fair lady/handsome prince and the best way to learn is always to have a go, as Charlotte says...i can't wait

                Comment


                • #9
                  Whilst completing my degree at uni where I spe******ed in Ceramics, I got to do loads of experimentation and try out processes with clay that are not really in "the rules"... and I've learnt that its great to move away from your comfort zone, push boundaries, constantly try new things!! Its also lots of fun!

                  Comment


                  • #10
                    I've raku-ed terracotta clay and high crank white clay and they were fine, others in my class even used porcelain but i think they cracked... its all about the glaze isnt it??
                    http://www.terrilowedesign.co.uk
                    http://www.twitter.com/Hello_TerriLowe
                    http://territriestwice.blogspot.com/
                    email: [email protected]

                    Comment


                    • #11
                      Yes. . . . thanks Charlotte for the wonderful inspirational words and the practical info. And yes . . . Chris, I totally agree with you that you can get 'comfortable' and lose some of the fire (no pun intended) that working with clay can give you. We've been doing this for over 20 years now, and remember well the excitement of opening the kiln in our early days and being devastated and euphoric in equal measure - but wasn't it great!! You do lose that, and get into a a rut where apart from the occasional bloat or firing crack everything is totally predictable. Very sad - because that's not what it's all about. Potting should be elemental and volatile!!

                      We've got a pile of bricks which we kept when we dismantled an old kiln (or should I say it fell apart!) and we've kept saying what are we hoarding them for, but it seems criminal to throw them away. We're now thinking of building some kind of basic fire with them which hopefully we can power with calor gas (we don't have natural gas) and have a play with Raku.

                      Charlotte, how do you know what temp to fire to? And do you have to use a specific glaze? We normally fire to stoneware, and have basic buff stoneware clay and an industrial crank. We don't glaze much (have some purchased stoneware glazes) but mainly use iron oxide. As Chris says, we've become dependant on our kiln sitter which tends to make you lazy really. I'm off to the library tomorrow in hopes of finding a book!! Feel very motivated and excited.

                      Chris keep in touch with the results of your raku firings in the Hebrides. I hope your life there is as wonderful as I imagine it to be.
                      Kate
                      www.cuckoos-nest-fairs.co.uk

                      Comment


                      • #12
                        go for it...

                        hello Kate (Cuckoo's Nest)
                        the book that i kept being referred back to as the best on raku is one called Raku by Steve Branfman which gives really practical advice on the whole process including building your own kiln..i bought it on Amazon and find it very helpful
                        if you are thinking of building or working with a gas kiln then a really good book that has helped me immensely to get to grips with my new and very unfamiliar gas raku kiln is a book called Gas Kiln Firing by Ralph W Ritchie...
                        i think i found my copy of this one on Amazon.com in America
                        it seems to me that the most important element is the ability of whatever clay you use to withstand the thermal shock of being taken out of the kiln whilst red hot and placed immediately in a much cooler environment..with crank and well grogged stoneware this is going to be more probable than with clays with less inbuilt structural strength (such as finer bodied earthenware clays and porcelains)...but it does seem as if the kiln gods have the final say
                        as far as glazes go, the important thing to remember is that raku is a low-fire process and therefore the glazes need to match the temperatures involved (less than 1000 C)...you can also use oxides as the reduction process will work on these also
                        this for me is still all theory, mind you, so take it as untried and untested comment
                        just for the record...i'm in the Shetland Isles, not the Hebrides...quite a bit nearer the Arctic Circle but just as beautiful
                        chris

                        Comment


                        • #13
                          Thanks Chris, I will be on Amazon for them. Sorry my geography's not too good!
                          Kate
                          www.cuckoos-nest-fairs.co.uk

                          Comment


                          • #14
                            Hello it's me again. I've been on Amazon but they are both starting at over £30!!!! Do you know why this should be? There are several copies available so don't seem to be in short supply. It looks like down to the library after all :-(
                            Kate
                            www.cuckoos-nest-fairs.co.uk

                            Comment


                            • #15
                              Re books I can recommend Raku (Ceramics Handbook) Pub:A&C Black and or
                              Raku - investigations into fire ; David Jones.

                              By the way lots of talk about using sawdust as a reducing agent. Please note sawdust can be very explosive at raku temps. On the whole better of with wood shavings damp if possible.
                              www.toppotsupplies.co.uk

                              Comment

                              Working...
                              X