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Min

Member Since 31 Mar 2010
Offline Last Active Aug 29 2014 10:08 PM
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Posts I've Made

In Topic: Wood Fired Kilns

29 August 2014 - 10:07 PM

Here's the wood fired earthenware bottle kiln that I did consulting work on for the build back in 1978-1979 (I think).  http://www.centralma...village-june-13

 

The fire it a couple of times a year. I think it is still operational.

 

best,

 

................john

 

Very nice!!! 

 

Any plans on writing a book on kiln building? On second thought, you could write a book on every subject in ceramics, you know, in your spare time.   ;)


In Topic: Honey/amber Translucent /transparent Cone 6 Glaze

29 August 2014 - 08:11 PM

Thanks Min, I have been learning,slowly from books the chem. of glaze formulas but still do not know enough to be confident in these matters. You're right, many decimal points the other way.
Will be testing the glaze on tiles/small pots very soon.
I was reconstituting a glaze which had totally dried out in bucket. On sieving, part of the glaze slurry would not go thro' the sieve after many run through and watering down.
Will be testing that too.
Had any experience with this? Obviously the resulting suspension in my  bucket now is lacking in something.
Don't hae the recipe here but just wondring whilst a t the keyboard.

You could try taking the stuff that doesn't go through the screen and heating it up in some boiling water to see if it will dissolve. I would guess it's some soluble stuff that has crystallized in the dry bucket.

In Topic: Honey/amber Translucent /transparent Cone 6 Glaze

29 August 2014 - 10:31 AM

 

 This kind of colour? This is over porcelain, lowish expansion of 6.11

 

 

EP Kaolin                    14.00
Silica                           23.00
Frit 3195                     16.60
Bentolite L                    2.00
3134                            4.80
Australian Spodumene 15.00
Dolomite                      15.00
Nepheline Syenite        10.00
Manganese Dioxide       3.00
Iron Oxide Red               2.00

 

    total:                        105.40

Min looking to mix this up this arvo and a question: Bentolite in the glaze recipe as an additive?  Total 105.4 but the Mn and Fe are additives, right? and i'm asking if the bentonite is also an additive before I convert to percetages prob going to consider these 3  in this light.

Just wondering how you approach this.

 

 

Hi Babs,

 

 Since there is a fair amount heavy sinking material, (frit, silica, nepsy plus the spod) I added the bentonite to the base and kept it as a "static" ingredient when working out the formula then rejigged it to add up to 100. I worked on the base first then figured out the colourants that's why the bentonite is in the base.

 

I'll redo the recipe if you like to have the bentonite as an additive after the 100 base but it will leave you with a lot of decimal points with the base ingredients. Doesn't matter to the glaze where you put the bentonite, chemical formula will be the same.


In Topic: Massive Crack In Single Firing

28 August 2014 - 11:53 AM

Thanks for the excellent advice! Where did you find this firing schedule? Is there a link to more info on Steven and his firing process?

 

thanks

 

http://ceramicartsda...ricKilns3ed.pdf

 

starts on page 2. hope it helps 

 

Min


In Topic: Massive Crack In Single Firing

28 August 2014 - 11:37 AM

Thanks for the schedule. I'm not sure if I can read it though. 

 

ramp 1 - 200F hr  /  220  /  hold 1 - 3 hours <- this means to hold below 220 for 1 - 3 hours?  Yes

ramp 2 - 100F hr  / 500  / 0 hold <- proceed at 100 per hour until 500?  Yes

ramp 3 - 400F - 500F hr  /  2100  /  60 minutes plus or minus as needed to get to ^6 <- after 500 go as fast as I can? No, go at or between 400 to 500 an hour up to 2100 (which will be approx ^5, just go as hot as you need to for your firing. He soaks for a long time to get the look he wants, if you don't need this then just fire to your top temp or near as you need to get and then soak if you do that to get your cones how you want them. I think he goes at that rate because most electric kilns won't be able to go any faster.  

 

I candled both batches for 33+ hours the first time with propane which mantained a high 100's temp the second time with wood where the temp swund from 150 to 200 mostly at 200. I would imagine this would be ample to dry out the pots, so this would be your ramp 1. It's the second ramp that I think you need to follow.  I would err on the side of caution and go slow until you have a schedule that works then if you want to gradually try speeding it up.

 

thanks