numbers for slumping. Bisque or SS

deborahbur · Post by **deborahbur** » Fri May 23, 2003 7:44 am

I need some bisque or stainless numbers to slump a number in a plate for my daughters 30 birthday. Any clue where to get them?

Thanks
DEborah

Barbara Muth · Post by **Barbara Muth** » Fri May 23, 2003 7:51 am

Deborah, are you trying to get a relief from the numbers in the plate? If so, just cut out the numbers in fiber paper, lay them in your slumping mold and give it a loooong slow soak....

Barbara

Jackie Beckman · Post by **Jackie Beckman** » Fri May 23, 2003 9:33 am

Just in case a long soak at slumping temps doesn't give you a defined enough look, you may want to actually fuse your blank right on top of the fiberpaper numbers that Barbara suggested. Personally I can never get fiberpaper textures to show enough at slumping temps, so if you have to fuse the blank anyway . . . (Oh and one more thing - I bet she would rather have a plate that reads "29-ish")

charlie · Post by **charlie** » Fri May 23, 2003 12:07 pm

deborahbur wrote:I need some bisque or stainless numbers to slump a number in a plate for my daughters 30 birthday. Any clue where to get them?

Thanks
DEborah

umm, make them?

buy a lump of clay at a ceramics place. cut off a hunk. get 2 pieces of wood of the desired thickness of your #s. put pieces along side the lump. roll out with your rolling pin until the pin rides on the pieces of wood. cut out numbers with a sharp knife. put newspaper on top and bottom of numbers. dry between 2 pieces of drywall for about a week. fire to 1650 for about 20 minutes.

rosanna gusler · Post by **rosanna gusler** » Fri May 23, 2003 2:10 pm

the only problem i can see using clay would be trapping the numbers and cracking the glass on cool down. i guess you could beval the edges but fiberpaper seems the way to go to me. rosanna

Stuart Clayman · Post by **Stuart Clayman** » Sun May 25, 2003 10:39 am

rosanna gusler wrote:the only problem i can see using clay would be trapping the numbers and cracking the glass on cool down.

I dodn't understand the problem here. The cool down difference between the glass and clay?

Stuart

rosanna gusler · Post by **rosanna gusler** » Sun May 25, 2003 3:45 pm

hi stewart, differences in expansion/contraction are why you slump into clay not over it as a general rule. if the shape is gentle enough and the kiln wash thick enough you can cheat this one somewhat. when are you comming down to the obx this year? rosanna

Colin & Helen · Post by **Colin & Helen** » Sun May 25, 2003 7:55 pm

rosanna gusler wrote:hi stewart, differences in expansion/contraction are why you slump into clay not over it as a general rule. if the shape is gentle enough and the kiln wash thick enough you can cheat this one somewhat. when are you comming down to the obx this year? rosanna

Yes but if the clay numbers were thin they could be raw fired with out any expaansion/contraction problems..some may say it can be done..I say it can and works very well...Colin

rosanna gusler · Post by **rosanna gusler** » Sun May 25, 2003 10:17 pm

raw fired huh? i believe you. most clay has a pretty significand shrinkage in the bisque firing. makes sense. rosanna

Colin & Helen · Post by **Colin & Helen** » Sun May 25, 2003 11:26 pm

rosanna gusler wrote:raw fired huh? i believe you. most clay has a pretty significand shrinkage in the bisque firing. makes sense. rosanna

I said raw in glass slumping not bisque.......

Shrinkage on say a buff body ...from plastic to dry greenware about 7% if the clay was bisque fired at 1000c now make that a total of about 12%.. but if it raw fired at glass slumping temperatures.and taking into account you already know about plastic/dry shrinkage the new total may only be a few percent.....

Colin & Helen · Post by **Colin & Helen** » Sun May 25, 2003 11:32 pm

PS....Thin sheets of clay fired this way i.e. raw .....will still be very soft and way underdone...I will see if I can find some photos of how I raw fire..........Colin

rosanna gusler · Post by **rosanna gusler** » Mon May 26, 2003 8:03 am

i understand colin, what you are calling raw firing is slumping glass on green dry clay. but that is also as far as the clay is concerned, a low bisque fire. rosanna

Colin & Helen · Post by **Colin & Helen** » Mon May 26, 2003 8:33 am

rosanna gusler wrote:i understand colin, what you are calling raw firing is slumping glass on green dry clay. but that is also as far as the clay is concerned, a low bisque fire. rosanna

Yes Rosanna you're correct .....raw is the same as dry green ware ..or when clay is fired with glaze or some other element in a green state and not bisque.......at glass slumping temperatures of 800c-820c this is way under the normal bisque. the pottery term for this result of under the correct bisque firing temperature is 'black core ' that is because the clay will look ok on the outside but break it open and you will see a black of grey center that is carbon that has not been fired out ..make any sense??

I roll out very thin slabs of white stone ware clay ....press in some kind of design ( Leaves starfish ect) then dry very very slowly.. coat with a fine coat of kiln wash.( with some clays you may not need this. )place glass on the top and slump...two very important points.. the clay must be 100% drying when firing take it slow for the first 650c degrees

Colin

Suzan · Post by **Suzan** » Mon May 26, 2003 9:34 am

Colin!

Is there any other advantage to raw firing other than you can skip a separate firing?

In two books, it was suggested that when firing ceramics for use as a glass mold, they should be fired at 2 cone levels lower than for normal bisque, but neither book stated why. Any clue?

Cheers,
Suzan

Barbara Muth · Post by **Barbara Muth** » Mon May 26, 2003 10:45 am

Colin & Helen wrote:
rosanna gusler wrote:i understand colin, what you are calling raw firing is slumping glass on green dry clay. but that is also as far as the clay is concerned, a low bisque fire. rosanna
Yes Rosanna you're correct .....raw is the same as dry green ware ..or when clay is fired with glaze or some other element in a green state and not bisque.......at glass slumping temperatures of 800c-820c this is way under the normal bisque. the pottery term for this result of under the correct bisque firing temperature is 'black core ' that is because the clay will look ok on the outside but break it open and you will see a black of grey center that is carbon that has not been fired out ..make any sense??

I roll out very thin slabs of white stone ware clay ....press in some kind of design ( Leaves starfish ect) then dry very very slowly.. coat with a fine coat of kiln wash.( with some clays you may not need this. )place glass on the top and slump...two very important points.. the clay must be 100% drying when firing take it slow for the first 650c degrees

Colin

Colin, can you reuse the clay?

Colin & Helen · Post by **Colin & Helen** » Mon May 26, 2003 7:53 pm

Suzan..

For moulds you must bisque.. the method of raw/green I use firing is for adding some extra design/detail.....as I pointed out in my previous posting......I add extra detail by pressing things into damp /plastic potters clay..these clay shapes are quite small the size would be about 50 mm in diameter or so and only 1 or 2 mm thick..when 100% dry they sit on the kiln shelf in the center of a fibre board cut out moulds.

Slightly under-fired bisque is better than over-fired ,clay type can be a problem terracotta ( I would never use) will need far less than white stoneware as for 2 cones under..this may be for hobby ceramics slip ware.....with potters clay the bisque is1000c the glaze firing at 1200c plus... with hobby ceramic I think the bisque is about 1060c and they glaze at a slightly lower temperature.

Barbara..

Yes it can be reused...but will need extra bat wash..

Colin

[Fern Frond ....image form my glass manual

WarmGlass.com

numbers for slumping. Bisque or SS

numbers for slumping. Bisque or SS

Re: numbers for slumping. Bisque or SS