10 replies to this topic

[TomD]

Hi all, 

 

I'm looking into making a lamp shade out of ceramic and was wondering how thin does the ceramic layer need to be for light to pass through it? 

 

And from this how strong/durable would this be? 

 

Any help appreciated, thanks 

 

Tom 

[schmism]

It was my understanding that it also depends on you clay body.  for example.  fine porcelain clay is one thickness while a stoneware body is entirely different.

[High Bridge Pottery]

He also failed to mention what wavelength of light 

 

My guess would be some kind of porcelain 1cm thick would let a little light through it. Never tested that theory though.

[TomD]

He also failed to mention what wavelength of light 

 

My guess would be some kind of porcelain 1cm thick would let a little light through it. Never tested that theory though.

 

Hey thanks for the reply! I'll be using a UV light with a wavelength of around 375–395nm. I'm a bit of a newbie when it comes to this, could you tell me what exact material and process would need to be involved to get a thickness of 1cm, that would still allow light to pass through? Thanks again! 

[Karen B]

Hi Tom,

I use Frost porcelain for translucency. It has a cone 4 to 6 firing range. There are cone 10 translucent porcelains as well.

 

It needs to be about 1/8th an inch for translucency, which is a bit less than a cm, though you could probably get to 3/16ths. If throwing, plan on trimming to get that thin.

Casting is also a beautiful option.

 

As far as durability, it is as durable as if it were made of glass, because that is basically what it is.

Karen

[High Bridge Pottery]

I have never tried any light tests. My guess of 1cm was just what I thought could be maximum to let some light through.

 

I was kind of joking about the wavelength of light  so are you actually using some uv bulbs?

 

The best place to start is by finding a porcelain that you can get some light through and find out what thickness is the best. Slip casting is a good process for an even thickness but it is hard to make good moulds. Really depends on what you final shape is going to be. There is rarely one way to make something.

[PeterH]

I think that it needs to be really thin.

 

Saw a demo by Tim Gee who does shellac resist

http://www.studiopot...profile/Tim/Gee

Somebody asked about how thick he threw (he doesn't trim), don't remember the full answer

but he throws the top of his pots 0.5mm thinner than the bottom, and aims to get within 0.25mm
of the thickness he aims for! So pretty thin, and porcelain for translucency.

 

Other potters mention the advantages of rolled porcelain paper-clay. You can roll it really thin,

and still handle it afterwards.To get variations in thickness/translucency, roll it out on something

thin, perhaps a few bits of torn paper, leaves, a textured surface ...

 

You may find Margaret O'Rorke's book  Clay, Light and Water of interest

http://www.amazon.co...TF8&me=&seller=

... you can pick up a new copy for £10.48 in the UK, and even cheaper 2nd hand.

Clay, Light and Water

Clay, Light and Water

 

Regards, Peter

 

PS I would be interested to know why you are using UV? Vaguely related: I know some people have

played with lo-fire luminous glazes.

[Tristan TDH]

Depends on how many holes are in it for light to pass through it.

;-)

[ayjay]

It needs to be about 1/8th an inch for translucency, which is a bit less than a cm, though you could probably get to 3/16ths. If throwing, plan on trimming to get that thin.

Casting is also a beautiful option.

 

 

1/8" is a lot less than a cm.

 

1cm = 10mm

 

1/8" = 3mm

[Karen B]

 

It needs to be about 1/8th an inch for translucency, which is a bit less than a cm, though you could probably get to 3/16ths. If throwing, plan on trimming to get that thin.

Casting is also a beautiful option.

 

 

1/8" is a lot less than a cm.

 

1cm = 10mm

 

1/8" = 3mm

 

 

 

Yes, I know. That is why I wrote this. I wonder if anyone who thinks porcelain is translucent at a centimeter has actually seen it, because I haven't.

[mss]

?  You know that UV light can damage your eyes, right?