Help With Saggar Firing

[AndreaB]

I'm in a bit of a quandary regarding saggar firing.  I'd really love to try it, but here's the thing. From what I've read on internet saggar can't be used on functional ware. I've thrown a tall lidded pot and a bud vase/oil holder and I think they both would look really great with the effects of saggar.  My question is - having been thrown in stoneware, bisqued to 960 deg C, how would glazing on the inside be affected by saggar firing.  I know if I leave unglazed the pot can be used to store spaghetti etc ie. non porous items but the oil pot would not be food safe. If I glaze with earthenware glaze and fire to about 1100 (electric kiln) what's the possibility of the saggar affecting the inside? (my idea is to glaze and saggar fire at the same time)

 

Or should I glaze fire with stoneware glaze to 1200 first?

 

Any help would be much appreciated.

 

Thanks 

[Marcia Selsor]

I agree that saggar firing is not meant for food. The effects of saggar firing work well if the clay is porous enough to absorb fumes and smoke from the firing. I have seen some innovative functional ware using saggars ..urns, lamp shades, murals, sculpture. Check out some of my saggar firing friends: Judy Motzkin and Linda and Charlie Riggs

http://motzkin.com , http://www.cclay.com/criggs/

 

riggs pottery and clay art studio videos

and my own (shameless self promotion)  http://www.marciaselsorstudio.com/saggar-fired-pottery-gallery.html

http://community.ceramicartsdaily.org/gallery/album/824-recent-pieces-in-october/

Marcia

[Rex Johnson]

I've been trying to solve this question (in my head)  for a while. The saggar effects are coming along well, though I tell buyers that they are earthenware, not terribly sturdy, usable as decoration or vases and planters.

It would be nice to have a finish inside certain forms, but in the end, they're still not useful in a utilitarian sense.

My advice would be to try it. Do your glaze and then saggar the piece(s).

What's the worse that can happen?

Let us know what you find out....it could be a good thing.

[Marcia Selsor]

The terra sig finish that absorbs the colors of saggar chemicals will not be porous enough if you glaze the piece to ^04 or even06. Go ahead and try it, Please post the results.Please include some of your recent pieces without glaze so we can compare.

 

 

One thing you can do it seal the inside after firing with a sodium silicate solution like that used on dry flies for fishing. I think even deck sealant would work. Then you could have a vase that holds water.

Marcia

[Pentapus]

I wanted to raise this post back from the dead instead of starting a new thread (I tried to find an answer online and by searching the boards).

 

I am searching for a method to use the smoke/carbon capture of a saggar fire on functional food-safe items like cups.

 

My plan is to bisque fire my white stoneware first then use a saggar in a separate firing (probably only to 1500 degrees). I would then fire the cup again to a full cone 6.

 

My concern is that the cups will leach the carbon/ash during use with tea or spirits.

 

Would "sealing" the results of the saggar firing with a clear glaze and then firing to cone 6 solve this potential issue?

[Min]

I wanted to raise this post back from the dead instead of starting a new thread (I tried to find an answer online and by searching the boards).

 

I am searching for a method to use the smoke/carbon capture of a saggar fire on functional food-safe items like cups.

 

My plan is to bisque fire my white stoneware first then use a saggar in a separate firing (probably only to 1500 degrees). I would then fire the cup again to a full cone 6.

 

My concern is that the cups will leach the carbon/ash during use with tea or spirits.

 

Would "sealing" the results of the saggar firing with a clear glaze and then firing to cone 6 solve this potential issue?

 

Hi Pentapus and welcome,

 

Any carbon will burn off when you fire again to cone 6. 

[Pentapus]

Thank you Min, and I appreciate the welcome.

 

I have some low fire cone 05 glazes to try out. Maybe that's still hot enough to burn out the carbon but I'll keep playing around.

 

I'm stuck on the look/feel of pit and saggar fired clay. The commercial glazes I have access to feel too controlled, like there isnt enough room for surprises.

If anyone has any suggestions on how to get the spontaneity of smoke and fire in dinnerware safe pieces I'd love to keep researching.

[Anton Kulebyaka]

dear Pentapus, any success/results on the process?

[JohnnyK]

I have been doing some horsehair Raku recently, all of which are essentially non functional in that they will not hold water, but I am planning on experimenting by lining my pots with a rubber material, something like  FlexSeal clear. They won't be useable for food purposes, but should be useful as water holding vases, which is a step up from their current status. Another option would be a clear acrylic or urethane product for the inside of the pots...

[Marcia Selsor]

There is a sealer used in Australia and is very expensive. It is applied after firing. https://madeofaustralia.com/liquid-quartz/

Liquid quartz

Marcia

[TonyC]

On 9/28/2019 at 3:08 AM, JohnnyK said:

I have been doing some horsehair Raku recently, all of which are essentially non functional in that they will not hold water, but I am planning on experimenting by lining my pots with a rubber material, something like  FlexSeal clear. They won't be useable for food purposes, but should be useful as water holding vases, which is a step up from their current status. Another option would be a clear acrylic or urethane product for the inside of the pots...

Some one I know recently mentioned Flexseal as well.   Do you know how it would be applied?   This could be an approach for some vases that I've created.  Thanks.

T

[JohnnyK]

4 hours ago, TonyC said:

Some one I know recently mentioned Flexseal as well.   Do you know how it would be applied?   This could be an approach for some vases that I've created.  Thanks.

T

You can buy it in either a spray or quart cans. If the pieces are wide mouth, you can use the spray. If narrow mouthed the pourable quart would be best. pour it in and pour it out and let dry. If used the spray on the inside of a painted cinderblock fountain that was leaking and it hasn't leaked in more than a year with it being exposed constantly to water...

[Marcia Selsor]

Liquid Quartz is food safe and restaurants are using sagger fired pottery coated with Liquid Quartz for their dinner ware.

Marcia

[TonyC]

On 10/1/2019 at 10:18 PM, Marcia Selsor said:

Liquid Quartz is food safe and restaurants are using sagger fired pottery coated with Liquid Quartz for their dinner ware.

Marcia

Marcia

Where do you find the liquid quartz?   Are there various forms of it?   I have actually heard of it for auto detailing.  Not sure if it is the same stuff.

[Bill Kielb]

1 hour ago, TonyC said:

Marcia

Where do you find the liquid quartz?   Are there various forms of it?   I have actually heard of it for auto detailing.  Not sure if it is the same stuff.

Many sources I believe which probably had origins in sealing granite counters. As to effectiveness, unsure. One product I looked through (Liquid Quartz) included the following disclaimer in their promotional material:

Important: Liquid QuartzTM will not create a seal over a glaze. It cannot make your underfired, lead based, or other toxic glazed surfaces food safe. It is effective for sealing porous surfaces only. It will not seal over Raku glazes.
Likewise, if you use a post firing chemical or potentially toxic ingredient in the firing of your work that will not burn out or cure at the temperatures you fire to (or has a particle size of less than 20-100nm) you should always test your work for food safety before using it.

Google is your friend, just type in something like liquid quartz and clay

[TonyC]

1 hour ago, Bill Kielb said:

Many sources I believe which probably had origins in sealing granite counters. As to effectiveness, unsure. One product I looked through (Liquid Quartz) included the following disclaimer in their promotional material:

Important: Liquid QuartzTM will not create a seal over a glaze. It cannot make your underfired, lead based, or other toxic glazed surfaces food safe. It is effective for sealing porous surfaces only. It will not seal over Raku glazes.
Likewise, if you use a post firing chemical or potentially toxic ingredient in the firing of your work that will not burn out or cure at the temperatures you fire to (or has a particle size of less than 20-100nm) you should always test your work for food safety before using it.

Google is your friend, just type in something like liquid quartz and clay

Thanks Bill.   I found that one as well.   I am intrigued with the product, although less so for food safety as I would have my concerns.   However, I would love to simply offer saggar fired pots/vases which could hold water.   Liquid quartz looks like a nice option except for the price.   FlexSeal could work but I wonder about the "look" it creates.   

[Bill Kielb]

3 hours ago, TonyC said:

Thanks Bill.   I found that one as well.   I am intrigued with the product, although less so for food safety as I would have my concerns.   However, I would love to simply offer saggar fired pots/vases which could hold water.   Liquid quartz looks like a nice option except for the price.   FlexSeal could work but I wonder about the "look" it creates.   

For really nice functional vases I have used clear pourable slow set epoxy, mixed it up, poured it In and thoroughly covered all surfaces pouring out excess. Pretty permanent for vases and not silly expensive as I recall. Now when possible I try and make them so I can fit a plastic liner inside as another option. (When I remember while throwing that is)