Question about re-firing

[MsBritt]

This maybe a very sill question, but I am very new to this, so pardon me in advance. I have a question because I see you do kiln crafting. I have some vintage japanese teacups (not of any significant value, mostly bone china)  I wanted to a a permanent design to them that would be dishwasher/microwave safe. Would it be possible for me to put them in the kiln without interfering with the integrity of the current design? I wanted print an image using this fired on decal paper:

https://bigceramicstore.com/products/fired-on-decal-paper-10-pk

[liambesaw]

Not a likely scenario, but you can try it and see what happens. Alternatively you can buy bisque pieces and glaze them yourself.

[Babs]

Only way would be a test one and see..

This has been discussed here before. 

Folk buying stuff from secondhand stores. Place on biscuit of waste clay.

Vitreous china jug here melted into a puddle.....low temp stuff ...who would have thought...obv not me...silliness of youth:-)))

[MsBritt]

I'm going to try maybe I'll start at a lower temp and see what happens.. i have a few i can test with.. I'll post my progress . thank you Both!

[Denice]

Make sure you put a bisque tray under it that is a higher cone than you are firing at.   You don't want a ruined shelf or kiln from the tea cup and tray melting.   I have seen it happen several times in pottery classes.  Denice

[neilestrick]

There's a minimum temperature at which the decals must be fired. I don't know what that temperature is, but that's where you'll need to test it to see how it affects the already fired piece.

[Callie Beller Diesel]

The minimum temperatures for most typical China paint decals starts around cone 016, so usually pretty low. But as others have said, test one with some sort of kiln shelf saving measure just in case, before trying to alter them all. Bone China is its own unusual animal. 

[MsBritt]

Thank you All, you've been so helpful. I have some time this weekend so I'm going to test a few and see how it goes

 

[Chilly]

22 hours ago, MsBritt said:

Thank you All, you've been so helpful. I have some time this weekend so I'm going to test a few and see how it goes

 

Don't forget to report back and let us know what happens..........

[MsBritt]

So I tried it, this was my first time ever using a kiln, I used a small kiln by fuse works:

https://www.amazon.com/Fuseworks-FUSEWORKS-Craft-KILN/dp/B07CY5YXBS/ref=sr_1_4?keywords=kiln&qid=1577373052&sr=8-4

and I used fired on decal paper by Nasco:

https://bigceramicstore.com/products/fired-on-decal-paper-10-pk?variant=30947442131025&currency=USD&utm_campaign=gs-2019-11-12&utm_source=google&utm_medium=smart_campaign&gclid=CjwKCAiA3abwBRBqEiwAKwICA0rd0uis7MbkmI8fH0cwG_T7i7AUiKS3egGCnQU035X-GaO_ZbHVYBoCIXsQAvD_BwE

I have an old set of teacups, I used 1 of them the as a tester, the decal was very easy to put on once it dried it didn't move which I loved, and I let the decal dry completely before I put it in the Kiln.

The manufacturer says the kiln gets up to about 1400 degree in 15 minutes, so taking Callie's advice I intended to coned at 016 , but because I was nervous about using the kiln for the first time, I set it for about 11 min instead of 16/17 min. That was a mistake I took the teacup out after it cold of course the decal burned and left the the text, but i touched it and it was like chalk it hadn't (of course) coned to 016. I smudge the design because I touched it to see if it stayed, so I put it back in for 17 min, and it did work with out messing up the integrity of the cup. However the gold that was on the rim and other parts burned off (as you can see in the attached pictures). 

So now I'm question if this is a technique I should use to achieve what I'm trying to do.  I want to add the text to the cup with out interfering with the current design because these are vintage cups, but I also don't want the text I'm adding to wear over time or when washed, any suggestions? I know people have done this, I just don't know how.

I've attached some before and after pictures.

 

[liambesaw]

The gold will vaporize when fired past cone 018, nothing can be done.  The decal needs to reach a temperature where the glaze is beginning to soften because it is made of iron oxide and needs to absorb into the glaze to become permanent.  

How they're done in industry is that words and decoration are stamped onto greenware before it's fired, and it will go through a total of two firings.  The first is the glaze firing where the decoration and glaze are fired into place (hotter), and the second is a lustre firing where the gold is fired into place (cooler).

 

[Callie Beller Diesel]

The only way I could think of adding your text to these cups would be to have gold lustre decals made, but that may or may not be cost effective. There are places that will make custom decals like that, but they have things like setup fees and minimum orders. Gold lustre has to be silk screened, not printed. 
 

edit: either that, or you could add the decals, and then remove the old lustre and fire again to re-add the gold lustre

[MsBritt]

Ahhh, that makes sense , I didn't take into account the gold evaporating.  I was thinking about adding the gold again but that would be so time consuming. I was trying to achieve something similar to this: 

https://www.etsy.com/listing/493259011/not-vinyl-ginvodkawinewhiskey-tea-cup?ref=search_recently_viewed-4

I think I will try some waterside decals with a sealer and see how that works

[Callie Beller Diesel]

Aha! They’re using China paint decals, which likely fire to similar temps as lustre. The toner or sepia decals usually need a hotter temperature to adhere. You can also have China paint decals made from the same guys that do the lustre ones, or if it’s something you’re going to do a lot of, you can get a decal printer that just does black for about 1k the last I priced them.

[liambesaw]

Or you can cut vinyl resists with a cricut or silhouette vinyl cutter and do them yourself as well.  I picked up a vinyl cutter a few months ago and still haven't had time to set it up, but I'm looking forward to using it fairly soon for paper resists.

[Bill Kielb]

Sounds like China paints for sure and normally they can take say 016 to 022 (1000 - 1400 f). China paints work by firing till the glaze beneath has softened a bit so they can attach in a permanent way. A typical way to establish the firing temperature for China paints is to fire up to the temperature at which the finished result matches the sheen of the base glaze while not burning out the China paint color.

1400 degrees appears to be too much for the existing China paint finish so as mentioned  by many above you likely need to stencil or transfer these in some way using China paint.  Then test starting at 1000 degrees and sliding up gradually as necessary observing the finish of your new application till it matches the finish of the base glaze or your desired look.

[MsBritt]

1 hour ago, Callie Beller Diesel said:

Aha! They’re using China paint decals, which likely fire to similar temps as lustre. The toner or sepia decals usually need a hotter temperature to adhere. You can also have China paint decals made from the same guys that do the lustre ones, or if it’s something you’re going to do a lot of, you can get a decal printer that just does black for about 1k the last I priced them.

Thank you Callie, I knew there was something.. Where would I find one of these printers? or do you know of a company that makes the decals?

[MsBritt]

12 minutes ago, Bill Kielb said:

Sounds like China paints for sure and normally they can take say 016 to 022 (1000 - 1400 f). China paints work by firing till the glaze beneath has softened a bit so they can attach in a permanent way. A typical way to establish the firing temperature for China paints is to fire up to the temperature at which the finished result matches the sheen of the base glaze while not burning out the China paint color.

1400 degrees appears to be too much for the existing China paint finish so as mentioned  by many above you likely need to stencil or transfer these in some way using China paint.  Then test starting at 1000 degrees and sliding up gradually as necessary observing the finish of your new application till it matches the finish of the base glaze or your desired look.

Thank you Bill, I realized the fired on paper wasn't what was being used when I found out about the sepia color, but I just wasn't sure I was thinking maybe they went over the decal with some china paint

[Callie Beller Diesel]

I might have one better. I wanted to message my friend Mariko in Halifax about specs before I chimed in with this as a solution. Forage Studios in Halifax, NS Canada will print China paint decals in small runs with no setup fees or minimum order. She does it as a service for artists and folks that just need a small amount, and she does it for very cheap, as she uses decals *very* extensively in her own work. She just needs a PDF file.  She said hers  are best fired at cone 017 (roughly 1360 F) with a ten minute hold. The cone 016 I started with is about 1422.  She often combines gold lustre and decals, and she’s very knowledgeable. www.foragestudios.com 

If you are interested in a decal printer of your very own, the company you want to research is Enduring Images. 
(I will not link to them because they have abused our no advertising rules here in the past, but google works, and they do have a good customer service reputation otherwise.)

[MsBritt]

Thank you so much Callie I will reach out to her