New at Pottery- confused and need help please

[gingersmom]

Hello! I am attempting to make small mugs as a gift and am hoping I can find some help with the process and general troubleshooting. I am planning on a finished product that is food-safe, has no color (but shine from the overglaze), and that has some overglaze decals applied (bacon and eggs!). Here's what I've completed so far (please forgive me for any mistakes or errors, as this is my first project with my own kiln): 

1. Formed the mugs out of clay, let them dry until they seemed bone dry, and fired them. I accidentally put a cone 6 instead of 06, and let them fire for about 8 hours on low. The setter still didn't drop at this point, so I turned it off and left the lid on for at least 8 hours. Per manual instructions, the lid was vented for the first few hours and the bottom peep hole was plugged. When I opened the lid the next morning, they seemed fine. 
2. Painted the mugs with overglaze (3 layers) and let dry for two days. Per instructions from my kiln manual and overglaze bottle, I fired them on low with a cone 06. My interpretation of the kiln manual meant that it would take around 3 hours for it to fire before the kiln setter dropped. Again, per manual instructions, I left the lid vented for the first 2 hours. However, it went for about 10 hours and then I turned it off myself and waited another 8 hours to open the lid. This time, when I opened the lid, I expected the mugs to have a shine to them from the overglaze, but instead they were just chalky. When I put it back down, I had chalky residue on my hands. 

 

I can tell something went wrong, and am sure it was user error since I'm so new to this. I am hoping for some ideas on what to do in the future to prevent this from happening, and also some advice on where I can go from here. Are these mugs useless now, or is there a way that I can salvage them? If possible, I'd really like to be able to get the shine I was expecting and still adhere the overglaze decals (from Elan Transfers). My interpretation of the instructions for the transfers was to put overglaze on the project, fire it, then add the transfers and fire again. All help is appreciated! 

[oldlady]

what is the source of your "kiln manual"?   could you define your understanding of the word  "overglaze"?   it has a specific meaning and it appears you may have used something other than  glaze.   your chalky feel tells me that whatever you used for the 3 coats was not the correct  glaze.  

there is a glossary here on the forum.    after checking the definitions that you need to know, you might look at an answer to a kiln firing question  in studio operations and making work, named accidentally started  manual kiln  on high not low.   it is not too long to read and will help you out.

there are experts in determining how to fix a problem but stating the manufacturer name of the kiln, the label on you clay  and whatever is on the "overglaze" container will help.

 

Edited June 11, 2022 by oldlady

[gingersmom]

Hi! I used Duncan Pure Brilliance Clear Glaze Brush-On Translucent Gloss. The bottle states that it is overglaze compatible and safe for food containers. The instructions state: apply 2-3 coats and fire to cone 06. The kiln is a Paragon Model P. The clay used is from Rocky Mountain Clay and says "low fire white clay cone 06".

[Babs]

How are you measuring rhe temperature or cone yourvkiln is reaching?

Cone 06 will need to reach about 100degC .

 

2 hours to reach 1000degC would be an amazingly fast for any pot or glaze to reach maturity.  And would get nowhere near that temp on low.

Research on thIs forum firing schedules or ramps. 

You would have a pyrometer?

 

 

[Min]

3 hours ago, gingersmom said:

I accidentally put a cone 6 instead of 06, and let them fire for about 8 hours on low. The setter still didn't drop at this point, so I turned it off and left the lid on for at least 8 hours.

This won't have reached cone 06. 

3 hours ago, gingersmom said:

Painted the mugs with overglaze (3 layers) and let dry for two days.

I think you might mean glaze and not overglaze?

3 hours ago, gingersmom said:

I fired them on low with a cone 06. My interpretation of the kiln manual meant that it would take around 3 hours for it to fire before the kiln setter dropped. Again, per manual instructions, I left the lid vented for the first 2 hours. However, it went for about 10 hours and then I turned it off myself and waited another 8 hours to open the lid.

What setting was it on for the 10 hours? If it was on low it definitely won't have reached cone 06.

Put some witness cones in the next firing to see what it actually is getting to. 

3 hours ago, gingersmom said:

Are these mugs useless now, or is there a way that I can salvage them? If possible, I'd really like to be able to get the shine I was expecting and still adhere the overglaze decals (from Elan Transfers).

Read the kiln manual again about how to do a glaze firing. Put witness cones in the kiln, if you are aiming for cone 06 then use 07,06 and 05 witness cones. Since you are using lowfire clay make sure you completely glaze the mugs all over and fire them on stilts. Before trying to rescue these mugs I would confirm your kiln is working properly. If you do a search in the Equipment section you will find posts on how to check this.

3 hours ago, gingersmom said:

This time, when I opened the lid, I expected the mugs to have a shine to them from the overglaze, but instead they were just chalky. When I put it back down, I had chalky residue on my hands. 

Glaze wasn't mature, still really underfired glaze that hadn't melted at all.

For the Elan Transfer decals you will need to do another firing. This one will be to a cooler cone, check with them for their instructions for an overglaze decal, not their underglaze transfers, for instructions. Don't do this firing until the mugs are fired properly.

Welcome to the forum.

[neilestrick]

What are the settings on your kiln controls? Lo-med-hi? The kiln will not get to temp on low. Typically, with bone dry pots, you'd do an hour on low, and hour on medium, then high until the cone bends and the sitter turns it off.

Model P is likely the model of the Kiln Sitter device, not the model of the kiln. Somewhere on the kiln is a serial plate with the model number, voltage, wattage, etc. Find it and let us know what it says.

[PeterH]

On 6/12/2022 at 5:56 PM, neilestrick said:

Somewhere on the kiln is a serial plate with the model number, voltage, wattage, etc. Find it and let us know what it says.

It will look something like this