Ok to glaze cone 6 pot and fire to cone 06?

[Scott G]

Doing a project with approximately twenty neighborhood kids. I have quarter inch thick cookie cutter pieces that are supposed to be a non denominational holiday Christmas ornament. I Plan to pre fire them before delivering so they don't break. I feel like I have to, or a lot of kids will end up with broken pieces. They're also getting a half a pound of raw clay for an undetermined activity. Maybe a pinch pot or something easy to do via video lessons to that many children. Ideas and comments welcome on the activity for the Raw clay activity.

 Don't have a big enough load for cone 06 low fire, so was wondering what would happen if I fire them to Cone 6 (since I have bigger cone 6 load ready) and deliver them with the raw clay and underglaze for painting by the children. When returned to me I would fire to cone 06 with a low fire clear along with their other pieces that will be greenware. 
I can skip the cone 06 clear glaze on the ornament pieces if flaking or adhesion is going to be a problem when applied to a matured play body. Looking for separate comments on using the clear cone 06 on the already cone 6 fired pieces and also any concerns on firing an underglaze to a cone 6 piece and refiring to only cone 06.

I know this is a weird question, but I'm only charging the kids $10 for all of this so trying to do it as simple and cheaply as possible. Don't want to be firing an empty kiln.

[oldlady]

i think you are OK with this plan as long as you know that to adhere the glaze to the children's underglaze covered items, you will need to warm them before applying the 06 glaze.

and the firings should be slow if you are mixing greenware to cone6 and bisqued things you already have.

[Scott G]

  I was not aware of the heating the pieces to get the clear glaze to adhere better, I assume this specifically applies to glazing an already mature clay body?

Appreciate both of the feedbacks.  Yes, maturity is ^6. I already bought the underglaze, otherwise the acrylic paint is a genius idea I'll save for the future.  Perhaps the answer is to simply deliver the ornaments in greenware state for underglaze application and hope the kids are all careful enough to not break them.  I was aware of slower firing when mixing greenware and bisqueware so none of the greenware explodes. I've had success doing a single fire with underglaze and clear glaze, but only tried at ^6, haven't tried ^06. I'll probably avoid clear glaze and pieces will be matte but good enough. When firing greenware in general,  I usually candle for a few hours or overnight just to be sure. 

  Knowing all of this, and the fact that this isn't making me much of a profit, eliminating the pre firing of the ornament pieces might be the simplest.  I'll just make sure to have extra on hand when they inevitably break.  

Finally dialed in the replacement kiln, and got a good clear ^6 glaze.  Marbled clay bodies all with very similar shrinkage rate and maturity. Had to share so you know you are helping someone at least semi experienced with ceramics. 

[Callie Beller Diesel]

Since they're ornaments, if you wanted the underglaze to be smooth and/or shiny after the underglaze is fired on, you could just spray a coat of Varithane.