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cabako

Soda Firing Questions

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look into slips. I don't think straight iron would be that interesting. Google some flashing slips. Try a matt glaze  They'll turn shiny.. glaze the insides of functional pieces like mugs. put some texture on the surfaces salt and soda respond well.  Black magic slip is a nice dark blue glaze in salt or soda. Helmar kaolin slips flash beautifully. 

 

Marcia

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1 hour ago, Marcia Selsor said:

Hey Mark. We use to fume. But we used old metal orange juice cans which don't exist anymore. 

Marcia

I buy metal measuring cups-that have handles and are very cheap. I wire them to a steel rebar rod-the fuming eats them up so life is short..

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I remember reading  that the sodium may affect the watch cones making them bend sooner is that true?  And this will destroy a thermocouple too?

One last thing, I have a concentrated lithium chloride solution.  Could that provide any glaze effects?  I may do that in a separate firing.

Thanks all for your input

 

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19 minutes ago, cabako said:

I remember reading  that the sodium may affect the watch cones making them bend sooner is that true?  And this will destroy a thermocouple too?

One last thing, I have a concentrated lithium chloride solution.  Could that provide any glaze effects?  I may do that in a separate firing.

Thanks all for your input

 

The atmospheric soda will indeed flux witness cones causing them to bend sooner.

A note regarding salt and chlorides when introduced in a kiln the result is hydrochloric acid. Sodium carbonate and sodium bicarbonate release carbon dioxide - a much friendlier byproduct.

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7 hours ago, C.Banks said:

The atmospheric soda will indeed flux witness cones causing them to bend sooner.

A note regarding salt and chlorides when introduced in a kiln the result is hydrochloric acid. Sodium carbonate and sodium bicarbonate release carbon dioxide - a much friendlier byproduct.

Soda will break down to sodium hydroxide, a caustic base that isn't really any less dangerous than the hydrochloric acid produced from salt firing. Read HERE. Ideally you shouldn't be breathing much of either, but salt isn't any worse than soda. From an environmental pollution standpoint, soda firing is worse than salt, although driving your car is far, far worse.

Edited by neilestrick
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1 hour ago, neilestrick said:

Soda will break down to sodium hydroxide, a caustic base that isn't really any less dangerous than the hydrochloric acid produced from salt firing. Read HERE. Ideally you shouldn't be breathing much of either, but salt isn't any worse than soda. From an environmental pollution standpoint, soda firing is worse than salt, although driving your car is far, far worse.

@neilestrick, couldn't read the entire article as it cut off before the end. Got me interested,  if anyone else wants to read the whole article I found it here, 3rd piece down. 

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12 hours ago, Min said:

@neilestrick, couldn't read the entire article as it cut off before the end. Got me interested,  if anyone else wants to read the whole article I found it here, 3rd piece down. 

Thanks for this.

Phil Rogers is one of my favorites so I'm reluctant to admit to a certain educational bias.

:)

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Just use the regular cones , not a pyrometer. During the infusion cycles which may last an hour , you will drop the cones. Use 8,9,10,11.  Make your cone pack ahead of time. Make at least 12 pull rings to check the build up on the clay surface. have a poker around for pulling them. The cones can sit behind the pull rings in the peep holes. 

Marcia

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Ok kiln is loaded and firing, in the first pic you can see the aluminum beads spread on the floor. The pieces placed directly on top. I'll knock/chip them off if they are stuck.  I tested a room temp saturated solution of soda ash through the venturi nozzle and it worked fine, but rinsing with pure water helped to increase flow. I think with a spray/rinse cycle it should work fine.   THe only cones i had on hand were 04, 6 and 10.  so I guess I will wait about an hour and a half???  after cone 6 drops to start spraying in the soda.

I also placed a couple loaded cups of soda directly in the flame path.

photo 1.JPG

photo 2.JPG

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Well things didn't go quite according to plan.  The propane tank & line froze up about an hour and a half after cone 04 dropped.  I didn't have a bucket and warm water to put it into. Its been getting colder out lately and temp dropped off pretty fast once sun went down.  So not even cone 6 bent. 

However I would say the soda spraying was successful.  The 1.0 gph venturi nozzle (delavan brand, ebay) allowed me to spray in about a half gallon of saturated soda water with no plugging.  Vapor was good and it was immediately noticeable when introduced into the kiln by color flashing orange, yellow and green.  THe little pots of soda  I had also melted and vaporized.

Going to open the kiln later today. Will post pics then.

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These came from 50lb bags that were so old they had split and the names were erased, I think if I had to bet they would be either parker/parker balston Or BASF F-200 type activated aluminum beads for gas phase drying applications. Not sure what mesh size but they are probably similar to here:

http://www.ecompressedair.com/activated-alumina-desiccant-316-in-(48-mm)-(50-lb-bags).aspx

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About 30 (+/-) years ago, alumina beads,  similar to what you are describing,  were used to remove alkali vapor species from hot gases in research pilot plants developing the technology for the production of syngas from coal and biomass to be power stationary gas turbines.  The beads captured the sodium and potassium species as alkali aluminate,  a reaction product of the vapor species with the alumina.   Much of the work on alumina pellets for alkali vapor removal was done at Argonne National Laboratory.
 
The important point for potters to keep in mind is that porous alumina pellets are very reactive with sodium vapor species in combustion environments at temperatures above about 600 c. The good news is that the reaction product is not a glaze, just a crystalline solid that is soluble in hot water.  ANL was issued patents on an alkali vapor analytical probe based on alumina bead technology. 

LT

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Ok heres the results, pretty interesting how the soda turned green on the brick and the cups 2nd and 4th pics.

I can vouch that the beads were definitely crumbling apart in spots and they were easily brushed off or pulled off the pieces. 

Everything cracked or split in places because I think of the quick cooling once the lines froze.  But some of the shot glasses came out okay (even though the liner glaze was baby vomit orange) and the ones in the path of the soda vapor definitely got a shiny coat, there was one behind the bottle further back and it was not shiny. Although it may have just been underfired. The back side of the bottle was still red with iron oxide, the front was shiny and the red color gone.  The stoneware pieces in there definitely had good blushing and some green effects. 

 

photo 1.JPG

photo 3.JPG

photo 5.JPG

photo 2.JPG

photo 5.JPG

photo 4.JPG

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On second thought I think the sodium may have just fallen down inside the port?  The venturi nozzle spray was very very fine.  Maybe the garden sprayer and hotter saturated solution will help.  I think the porcelain glasses closer to the flame were just more vitrified rather than coated with sodium.

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gallery_63667_1303_234452.jpegSoda effects are indeed very directional. 

The green colour is totally normal. You know how glass of a certain thickness looks greenish? It's really aparant on office buildings. That's because it's soda glass. You're re-creating the same chemistry (sodium, silica and calcium) in the kiln. Here's another shot of the kiln from Medalta. I was trying to see if I could see anything through the peep as the kiln was cooling, but it wound up being a better shot of the inside of the peep itself. 

Edited by Callie Beller Diesel
Added photo from phone

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Callie,

Thanks for the pic & info, very useful.  Cool about the kiln in medicine hat, my mom's side of the family is from lethbridge & barnwell. Small world.  

I forgot to add i took a quick video during the firing i've put it up on youtube, not the best quality. But you can see the burner nozzle spraying into the side port, i also sprayed it directly into the flame in front. 

Thanks to everyone for the help & info. It was a fun experience and I hope to eventually do salt and soda firings using biodiesel & veg oil as the fuel source. 

 

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On 12/10/2017 at 9:26 AM, cabako said:

Well things didn't go quite according to plan.  The propane tank & line froze up about an hour and a half after cone 04 dropped.  I didn't have a bucket and warm water to put it into. Its been getting colder out lately and temp dropped off pretty fast once sun went down.  So not even cone 6 bent. 

However I would say the soda spraying was successful.  The 1.0 gph venturi nozzle (delavan brand, ebay) allowed me to spray in about a half gallon of saturated soda water with no plugging.  Vapor was good and it was immediately noticeable when introduced into the kiln by color flashing orange, yellow and green.  THe little pots of soda  I had also melted and vaporized.

Going to open the kiln later today. Will post pics then.

If you keep a pot of water boiling during your spraying time and dissolve the soda ash into boiling water...spray it hot. the soda ash dissolves into the water . use it up each spray session and mix into boiling water again.   You got some good results for the first shot.

. The best way to keep the propane tanks from freezing is to put them in tandem. or get a bigger tank. They freeze because the surface evaporation inside the tank is not keeping up with the vapor going out the the tank. I have 2 tanks on each of my burners just for raku. 

Marcia

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