Antoinette Brown

Babs, do you think a flue over the kiln would improve the draft? The lady I bought it from didn't use it at all. I am really puzzled that the temperature rises when I close the flue it should be the other way round! When I open it it drops! And by closing I don't mean a tiny gap I mean at least three quarters. But if I reduce heavily the temperature rises. Yes, fibre kilns go up fast I remember my very first firing in that port- kiln It was at 600C in half an hour. There are a couple of things I could try : Not staggering the shelves at all Using the flue (I would need some heat resistant flashing I don't want the rain on the kiln) blocking the gap between the lowest shelf and the floor (grill) 1 inch if it would do something

The flue is basically in the middle of the picture. These fibre kilns don't have a real flue, my old one was the same. At least in Australia. The flames are blue with little specks of yellow every now and then. I left the bagwall out in the end.

I did fire a second time. I did not get the bagwall in because it takes too much space. first I stacked the kiln with a whole shelf 7 cm from the kiln floor, but after reaching 400 or so C I stopped because it went up way too slow. I did let everything cool down unloaded and then loaded once again but this time the lower shelf only 2.5 cm from the floor and voila it climbed nicely! The firing is finished in due time and tomorrow I'll see weather the pieces came out nicely. Cone 10 went down when my pyrometer said around 1235 C or 2255 F for those on the other side of the planet, but it did so before. The weird thing is that when the kiln hits around 840 C (1544F) I reduce, but when I wanted to open the flue it goes down. Picture 2 shows how far the flue is closed (well the picture is crap). It went up very nicely when I opened the air at the burners fully and the flue at least 3/4 closed. I wonder whether there is a problem if after 900C it's fired in reduction all the time. It's the second time this happened to me. I had the same issue with my old kiln once changed the way I stacked and it would not go up. IMO one of the most important issue in gas firing is the right stack!

no I rang them!

That kiln is named high-tech kiln. That makes me assume that they thought something when they did this ( things were usually thought through back then) . But what I will do is to sacrifice one kiln stilt and cut a notch in it to have a half shelf standing up. I attached a pic on this it worked well.

dYes it's weird with the perforated floor. My old port-o- kiln didn't have thadt. It was otherwise a very similar design. And I used to use half a shelf upright as a bag wall. As a first step I try to rise the lower level. In fact you're right I used to use a full shelf at the bottom, maybe that will improve it! But I will stagger the top ones. I had that clearance of say 6 cm. And basically what you say use a bag wall, how about half a shelf upright? Babs, the temperature ROSE while reducing!! and I did not reduce a bit so this is weird.

Thanks all the kiln does make cone 6 but not cone 10 probably it would. The previous owner did not fire very high and yes I had a nice reduction (if you burn your fringe then you have reduction no need for a hairdresser). And a multimeter does not show all these fancy stuff it shows a figure that's it, no voltage...That S is probably the right thing feels right. I will tell how it goes next time. I will probably do a lot of white glaze and De Boos oatmeal, they are very forgiving and then stray around some other trials.

It is natural draft. I should have used more than one cone pack, but the whole kiln was underfired. If staggering shelves is important then which way is best? And is it best to have the kiln top heavy or bottom heavy? Bill thanks for the input, I have a multimeter it does not show every degree it shows a number and then you read the degrees in a table. Yes I was told that opening and closing the damper should be done in small intervals, the lady I bought it from had a lovely red clay on her property which probably was low fire and she left the flue open. I did the same,but then realised that closing it half is better. But to my astonishment when I reached the temperature to reduce, and closed nearly the flue (maybe left 1/4 open or less the temperature was rising. And there was clearly a reduction atmosphere in the kiln! As said I had the same problem with my old kiln once and it was clearly the stacking which made the difference, much more than anything air or pressure.

yes. this is how the floor looks like. The flue is right left from the perforated floor and you can see were the flame gets in on the right. I know from my old kiln that stacking makes all the difference but I could not find some "rules" and did it more intuitively.

The burners are sitting under the kiln (that piece of in is against spiders when not in use) and there is a tube out of kiln brick going through the fibre. The perforated floor is way left from were the flame goes in, visible in the first picture. I did not stack any shelves over the flame path and left that area free. thank you for asking! BTW your artwork is great (did you know that your shop pages are not loading?)

I have a new kiln and my first firing was awful. Everything was severely underfired and it took a lot of gas. I know from my old kiln that stacking the right way makes all the difference, I thought I got it right but obviously it was all wrong. No matter how I changed the air, the flue and the pressure I would not reach cone 10. I probably change to cone 6 but still it makes a lot of difference in gas consumption. So here's the question: The kiln has the flu on the left and two burners at the right. How do I stack: 1) shelves at the same height and a gap in the middle? 2)shelves lower towards the flu and higher towards the burners? 3 ) shelves lower towards the chimney and higher towards the burners? Overall should the load be more top heavy or has more air space at the bottom or should it be even? As seem on the photo the right shelf probably was way too low. Also the it was completely weird the temperature went up when I closed the air more and the flue at least three quarters! In my old kiln I used a bag wall (half a shelf upright went nearly through half the kiln. My guess is that I placed the right shelf way too low. What do you think of stacking? I attach a couple of photos. Unfortunately there seems to be no manual around anymore and the factory is long gone.

That's a nice white! And it has all the characteristics of a cone 10 glaze. It's maybe these heavily coloured glazes which did put me off in the past. I do a lot of RIOX backwash on texture and then glaze over it. Good idea with the equipment, I am in the wrong category!

thanks for the input all! I will try it out and compare simple. I'll start with some white glaze recipes or other rather simple ones. Regarding firing I know that with my old kiln the way I stack (or stuck??) was important. I always did half shelves in a staircase or alternating. This kiln has two burners on the right and the flue on the left downdraft. I guess what I got wrong was that the right shelf I only set it around 3 cm from the floor. I wonder which way is the right way to stack 1) shelves on the right and left at the same height with a gap in the middle 2) shelves on the left lower and the right higher 3) Shelves on the right higher and on the left lower. Also: big spacing on the bottom or on the top?

Thanks! This firing was the worst I've ever done. I don't blame it on the kiln but I have to draw some pictures and ask about the load. In my old port- o kiln it was very crucial to load it in a certain way. And def. the lower shelf had to be 7 cm off the floor. The lady I bought it from didn't do high firing she did lovely sculptural work with a really nice red clay she dug in her yard. She told me that she left the flu open and the lower shelf wherever. I decided that I buy a couple of bags of cone 6 once I drive past that shop (which does not happen often) and simply give it a try and compare. I am not super methodical, but with the old kiln I figured it out, but yes I should do that more methodical and match the pressure (I got nearly up to 30!!!)

I didn't like it that much. I find that there are too many dry lumps on the upper part but that might because I poured the liquid clayinto the pillow case and I can't lift the whole bucket. I tried old bedsheet in garden, worked somewhat OK.

I do agree. If I read in forums everyone with cone 6 has some sort of problems and me having no clue what I'm doing have no problems other than a glaze recipe comes out different then what I expected. However, I fired my new kiln (and there is no manual anymore and the supplier is not around anymore I think it was built 30 odd years ago or more) and the gas consumption was simply nerve wrecking and the difference between 6 and ten more than significant. I know that the packing has huge implications. It was also completely weird that if I closed the flue at least two thirds and the kiln was clearly in reduction the temperature was rising and when I opened the flue and the air at the burner it was falling! i still have some packets of cone 10 clay laying around and some buckets of reclaim so I'll see. It also depends a bit what I find locally because I want to include local stuff because I like it and also the next clay supplier is two hours drive away. I'm in Australia and sometimes local clays are high fire, but that's altogether a different topic.

Hi I am an amateur and do fire cone 10 gas. My kiln has two burners. I really think that it would be reasonable trying out cone 6 reduction firings because of the amount of gas needed. I looked up recipes in glazy and the results seem nice. What do you think? Are there constraints if I use cone 6? Aesthetics? Ash glazes and glazes with natural materials? I'm not a big fan of very colourful glazes.