colour research

[Colin Reid]

I have secured a modest grant from the Arts Council of England to enable me to do some research into ways of applying colour in the kilncasting process.

For about 10 years I have mostly worked with only two colours: clear colourless glass, and a blue copper patina. I made this choice because I wanted to focus on form. Now I want to look at using colour in my work again.

My aim is to develop colours which relate to my work, rather than using an ‘off the shelf’ product. By using oxides etc in the mould which react with the molten glass I want to create colours which are born of the casting process and relate to the form.

I am especially interested in getting a copper red as opposed to the copper turquoise I currently use. I think it is a question of having a reduction atmosphere in the interface between the glass and the copper and I plan to do some tests.

Clearly this is only one possibility and I want to explore as many as possible. I am looking for something more akin to the way a glaze works on a pot than just sprinkling powdered glass into the mould.

I am at the start of this process and I am asking around for ideas of things that work or things that seem like a good idea and worth pursuing or indeed useful contacts or previous research. I’m no chemist and I don’t even have the benefit of having melted colours as I’ve never been a blower. I am prepared to try things out.

If you have any thoughts on this I would be very grateful to hear from you. I am of course happy to share the results of any suggestions that I try out.

Many thanks,

Colin

www.colinreidglass.co.uk

[Pete VanderLaan]

dissolve some stannous chloride in water and paint it on the glass. Then apply the copper. You may get red. You also may get bubbles. Silicon carbide will absolutely give you a red with the copper. It will also absolutely give you huge bubbles.

No free lunch, not in kiln stuff. Too much surface area and too much oxidation and not enough potential to localize the reduction beyond just surface stuff. Adding hydrogen to the kiln atmosphere might help but it is a potentially explosive step.

[Henry Halem]

Originally posted by Pete VanderLaan
dissolve some stannous chloride in water and paint it on the glass. Then apply the copper. You may get red. You also may get bubbles. Silicon carbide will absolutely give you a red with the copper. It will also absolutely give you huge bubbles.

No free lunch, not in kiln stuff. Too much surface area and too much oxidation and not enough potential to localize the reduction beyond just surface stuff. Adding hydrogen to the kiln atmosphere might help but it is a potentially explosive step.

I don't think the temperature is high enough to get "local" reduction of the copper. Hydrogen to the kiln? Yikes!

[Edward Dluzen]

Hindenburg kiln...... oh the humanity.....

Pete, when you say add copper are you refering to powdered metal or glass with copper in it?

e
d

[Colin Reid]

Peter thanks I'll try both suggestions (not the hydrogen one though!) Both these materials are ones you might find in a glass studio. Do you suggest them because someone tried them and they worked or because you know what is taking place? If the latter could you enlighten me so I can look at other materials that might have the same effect, hopefully without bubbles?

I'll let you know when I have some results.

Thanks

Colin

[Colin Reid]

Henry thanks for the idea about ceramic body stains. I actually used them for years. Because they are not fluxed they do not melt or really combine with the glass so I mixed them with crushed glass of the same type as the casting glass. The advantage is that the lack of flux means they do not modify the base glass too much so it is all quite compatible. I was really looking for something that develops colour in the firing rather than an off the shelf product.

In the UK there is a central register of university research dissertations so you can see if someone has already done research into a given topic and dont end up re-inventing the wheel. Does such a thing exist in the States?

Thanks

Colin

[Brian Blanthorn]

Originally posted by Pete VanderLaan
dissolve some stannous chloride in water and paint it on the glass. Then apply the copper. You may get red. You also may get bubbles. Silicon carbide will absolutely give you a red with the copper. It will also absolutely give you huge bubbles.

No free lunch, not in kiln stuff. Too much surface area and too much oxidation and not enough potential to localize the reduction beyond just surface stuff. Adding hydrogen to the kiln atmosphere might help but it is a potentially explosive step.

I have been trying 2 think arround the way Colin currently works

As I understand it in brief

U got a big open mould with a single lump of glass on top

This is then softened n kinda drops in2 the mould

The kinda senario I was thinking of 2 get his colour is

A layer of pate d vere type crushed glass on the mould with stuff in like copper metal ( or whatever ) / silicon carbide / charcol

Then the lump of glass on top

During firing introduce more charcolal 2 maintain a smoky atmosphere and continue until glass cooler

The thinking being that the bubbles n weirdness that may happen will B on the outside rather than througout

Just so U know who U all R

Colin is one of our formost UK glass workers exhibiting arround the world + large commisions

Member of the elete Lapland Club + he got some other big glass equipement

Henry n Pete r probably the formost experts on hot glass stuff Pete being in2 colour

I C this as a meeting of minds

Colin U might like 2 take a look at Henrys new book

Consider also patenating the surface after there is a realy good book the patination of metals

Brian

[Brian Blanthorn]

Originally posted by Pete VanderLaan
dissolve some stannous chloride in water and paint it on the glass. Then apply the copper. You may get red. You also may get bubbles. Silicon carbide will absolutely give you a red with the copper. It will also absolutely give you huge bubbles.

No free lunch, not in kiln stuff. Too much surface area and too much oxidation and not enough potential to localize the reduction beyond just surface stuff. Adding hydrogen to the kiln atmosphere might help but it is a potentially explosive step.

Further

The temp is low n that is realy a potential problem

But I suggested using a flux like borax with this pate d vere mix 2 reduce the melt temp localy

Or make U a minny batch of glas in a pot in kiln then crush this up n use that as the outer mix

Compatability may B an issue

Consider on glaze colurs as these have a lower temp and R alredy fritted out

Add flux n U can realy get a lower temp but without the bubbles

We fuzers live in a strange etheral world of low tempuratures with 4 the most part ready made glass

I use a lot of technology from ceramics n hot glass but am unable 2 do stuff like gass off bubbles n get much reactions

But with the majic of flux U can achive wonders

Brian

[Colin Reid]

Thanks Brian. I cast optical Bk7 or equivalent which is a borosilicate glass. As the typical annealing time is 3 weeks I really dont want to go down the route ofapplying something after the casting and re-firing. Moulds are plaster/silica.

Colin

[Colin Reid]

Casting temp is 880c (1616f) for a couple of hours usually, then approx 3 week anneal and cool.

Colin

[Brian Blanthorn]

Originally posted by Colin Reid
Thanks Brian. I cast optical Bk7 or equivalent which is a borosilicate glass. As the typical annealing time is 3 weeks I really dont want to go down the route ofapplying something after the casting and re-firing. Moulds are plaster/silica.

Colin

I would add that a further complecation while ur all mulling this over is Colin does a long soak just over aneal temps 2 burn stuff out of mould

So any additions 2 give a reduction wold possibly B burnt out by then

However something like silicon carbide my not give a reduction till later being bound up chemicaly

Brian

[Colin Reid]

Thats right, Brian knows all my secrets (well maybe not all). I fire the moulds wet and soak at 620c/1150f for 12 to 15 hours to get all the chemically combined water out then up to 880c in a couple of hours, 2 hours soak, then down to annealing.

Colin

[Brian Blanthorn]

Originally posted by Colin Reid
Thats right, Brian knows all my secrets (well maybe not all). I fire the moulds wet and soak at 620c/1150f for 12 to 15 hours to get all the chemically combined water out then up to 880c in a couple of hours, 2 hours soak, then down to annealing.

Colin
Colin

Well I was pritty vague just in case

Any way here is some stuff that is secret

One of the guys actualy destroyed his notes B4 his death

But I have a bit on him

Read on 4 the next thrilling installment


quote:
--------------------------------------------------------------------------------
Originally posted by Pete VanderLaan
dissolve some stannous chloride in water and paint it on the glass. Then apply the copper. You may get red. You also may get bubbles. Silicon carbide will absolutely give you a red with the copper. It will also absolutely give you huge bubbles.

No free lunch, not in kiln stuff. Too much surface area and too much oxidation and not enough potential to localize the reduction beyond just surface stuff. Adding hydrogen to the kiln atmosphere might help but it is a potentially explosive step.
--------------------------------------------------------------------------------



Thinking a little more on this

The pated dv vere idea is more akin 2 a glaze where U could gass off during the firing

Another idea which mayB possible is

Fire up mould with pate d vere only - U would probably need some reseses 4 it 2 hang on to

Do a higher fire get the colours + reduction -- cool

Then refire with the glass block in

U would likely need 2 maintain the reduction on second fire while glass is soft or U will re oxidise the



I have always found that steeling technology from a number of disaplines is a good way 2 a free lunch n still have something left over 4 tomorrow



Coilin this is the potter -- studio was just up from Stourbridge

Ruskin pottery owes everything to W. Howson Taylor.

http://www.thelyndacottongallery.co.uk/antiques.htm

Found a better one ( pic from here )

http://www.ceramic1900.com/servlet/q.QDisplayItemDetail?in=%20%20%20%20%20%20%20%2060 23

I love this stuff so pleased to find it again

http://www.ceramic1900.com/images/ruskin_det.jpg

Is this what Ur after ???????

OK U experts the gallery say the green spots is iron

I say its copper --- what U say ???????????


My suspision is the spots R either from bits of stuff in glaze or in pot body

The story is he destroyed all his notes b4 his death

But the basic technology is not a secret

He used a sagger which is a ceramic pot U put ur object in

Also used copper reduced in wood fired kiln

There is a little book on him U may get it from the Birmingham museum who had a good collection or Smethic libuary

So in your case U would make a box arround the mould or have a lid U have proped up

Chuck in the charcoal n put lid on

Colin, wait there is more

U thought I was crazy when I said

Sang de boeuf

. The term might sound like a gourmet French entree, but in fine pottery circles, the phrase refers to the striking blood-red glaze that was first used by Chinese potters hundreds of years ago. The French term literally means "oxblood," and Chinese potters often painted the opaque glaze on a white base that simulated bone. These imperial artists, aware of the glaze's beauty, protected its formula for centuries.

http://www.pbs.org/wgbh/pages/roads...angdeboeuf.html

But dont worry I am still crazy

I just love the internet would have took me weeks 2 find all this stuff B4

Wait even more

I told U people sent a lifetime on this elusive red

Take care here is one unfortunate ( from the same article )

James Robertson, who established Chelsea Keramic Arts Works in 1872 in Massachusetts, also approximated the prized color, although his experimentation mimicking beautiful Chinese glazes eventually led to his bankruptcy.

Brian

http://www.ceramic1900.com/images/ruskin_det_s.jpg

[Pete VanderLaan]

Having Brian post non stop is like getting James Joyce's "Ulysses" in stereo.

The BK7 makes it even worse. Copper reds don't like Boron. They tend towards browns. These reds like really clean calcium potassium glasses. Further, the BK has a really low L.E.C. which makes using commercial reds unlikely.

I wasn't joking about the hydrogen but if it scares you, then you need some sort of reducing agent to get the kiln atmosphere away from oxidation to at a minimum neutral and preferrably reducing. Little chunks of wood. M&M's work but are messy despite the advertising claims. Otherwise you will get many colors but none of them red. Gray and green and blue are all .
possibilities, but not red.

Painting it red after firing with an oil of carmen may actually get you the result you want but the aesthetics of how you got there will sort of suck. It's a nice red.

The Sange de boeuf stuff was all based around potassium sodium bitartrate as the reducer in the late 1800's if I recall correctly. It also, I believe used iron in the formulation as well as copper. The iron had the multi valency to do the job and lots of the old formulas call for it. It's been a very long time since I've seen that reference. Black tin is really quicker but it's not feasible to use black tin with cullets in a kiln since it's not water soluble.. That's why I suggested the chloride form. It is water soluble so it could be painted on. The chlorine release in the firing could cause bubbles but it just might keep the copper on the reducing side long enough to roll over. I have never tried it, I'm hypothesizing. I do it in batch glasses all the time but BK7, a high potash/boron crown glass, which I use in our optical work is simply going to be unhappy in a teleological kind of way. If you believe that glass is sentient I mean.... ( and I do. I swear it's spiteful too).

I have to write like this after reading Brian extensively so I can reconnect with the mother tongue.

[Jon Myers]

I'm going to guess that this is Cu (metalic) in a slightly larger than powder size in an almost neutral very runny glaze (or a light coat of not so runny glaze) The outside layer of the Cu bits satisify the reduction they melt a bit more into the now neutral glaze and turn teal ringed with black (interface). Or it could be a piece rolled in a small feldspar (chicken grit) that had been coated with hairspray and Cu carb then glazed. Those glazes are beautiful when they hit. (but don't hit so often) Kind of like Cu ruby glass.

[Brian Blanthorn]

Originally posted by Jon Myers
I'm going to guess that this is Cu (metalic) in a slightly larger than powder size in an almost neutral very runny glaze (or a light coat of not so runny glaze) The outside layer of the Cu bits satisify the reduction they melt a bit more into the now neutral glaze and turn teal ringed with black (interface). Or it could be a piece rolled in a small feldspar (chicken grit) that had been coated with hairspray and Cu carb then glazed. Those glazes are beautiful when they hit. (but don't hit so often) Kind of like Cu ruby glass.

I awlways thought it was a grain thing



The Ruskin pottery is kinda hidden on the site but if U click on the potters marks U get more

http://www.ceramic1900.com/cgi-bin/markcat.pl?markcat=ruskinpottery&markname=Ruskin%20Pottery

Here is another pic

Enjoy

Brian

[Rich Samuel]

Originally posted by Jon Myers
I'm going to guess that this is Cu (metalic) in a slightly larger than powder size in an almost...

Whew, for a minute there I thought that was a dental x-ray from an alien autopsy! :crazy:

[Zachary Jorgenson]

Originally posted by Pete VanderLaan

...the BK has a really low L.E.C.

...BK7, a high potash/boron crown glass, which I use in our optical work


Pete, what does the term 'crown glass' mean?


thanks,

Zach

[Steve Stadelman]

Obviously, I am not Pete but "Crown" and "Flint" refer to the refractive indices of optical glasses.

If I remember correctly, in the past when glass manufacturers would batch optical glass they would use tall clay crucibles and allow the glass to freeze and kind of anneal in the pot. The glass from the top was referred to as "Crown" and the glass at the bottom was referred to as "Flint".

When optical doublets of each kind of glass are used they have less chromatic aberration and poop.

Modern manufacturers of optical glasses can make tons at a time of mostly whatever they want and "Crown" and "Flint" refer to specific refractive indice ranges.

I may be full of bullshit, in part or whole so you should do a little Google on your own.

[Douglas Terry]

Well I'm not Pete either. But, the only reference I've heard that fits crown glass is in Roundels used in windows when there was no true flat glass. It was basically a round bubble spun out as flat as possible and broke off the punty and annealed. If you watch some of the European TV dramas, you can see the windows in the old bar doors and such. Typically they have bullseye looking wrinkles around the punty flowing toward the edge of the window. Doug Terry

[Scott Novota]

Man Steve I had a "how things where made " moment reading that last post of yours.

Thanks,


Scott.
.

[Mark Wilson]

industrial companies often create reducing atmospheres by injecting forming gas inside their furnaces. this would have the same effect as adding hydrogen, but it is much less explosive. it is made by cracking ammonia and it is ~92% nitrogen, and 8% hydrogen. it is available from most any industrial gas supplier.

[Rich Samuel]

Steve and Doug, like Certs being a candy and a breath mint, you're both right:

Window (http://en.wikipedia.org/wiki/Crown_glass_(window))

Optics (http://en.wikipedia.org/wiki/Crown_glass_(optics))

[Steve Stadelman]

Tastes Great!

[Pete VanderLaan]

Crown glass is probably an overused term by extremely few salespeople who marketed "tastes great / less filling" in another life. Ideally modern crown glass is drawn from the middle of the melt neither top nor bottom. When larger castings of such glass as F-2 from Schott which is a high lead, incredibly soft glass with an amazing refractive index that are around 12x12x12 inches ( Jon Kuhn uses lots of this stuff), the very core glass in that cube has the best optical qualities. That core glass is where all the seriously expensive lens come from. F-2 is runaway the best out there but it is profoundly expensive and so Schott also makes a crown glass using boron and potassium ( therefore the BK name, B being Boron and K being Potassium). It's nowhere near as nice as F2 but it's still got wonderful optical qualities. It's a lot harder than F2 which is so soft as to be incredibly easy to scratch. MB and I use the BK7 for the tops and bottoms of our optical solids. F2 would just get wrecked. It's amazing to buy it. I get these slabs four inches thick by 12 inches wide by 3 feet long. It takes two people to move it.

It's probably the case that Schott and Corning are the only two makers of crown type glasses and Corning doesn't commercially market them. If Hoya makes it I don't know of it. Corning just can't make this stuff profitably. Schott makes all of Cornings Pyrex glasses on contract for them.

I really like " chromatic aberration and poop". And as Mark says, there's lots of ways to skin the reducing cat. I always though M&M's was really very original and quite low tech. But Copper reds are going to give you heartburn in this application. It kind of reminds me of this sign over the desk in one of the lumber mills here. It's over the boss's desk. it says " If it has tits or wheels, sooner or later you're probably going to have trouble with it. " Man have I ever switched cultures.

[Zachary Jorgenson]

Thanks for the info.

That BK7 has a high annealing point (1034˚F): almost that of Pyrex, yet a much higher LEC (83) than regular boro products (33). S1 has about the same annealing point and a 96 LEC and is termed a borosilicate. Are some of those Schott specialty glasses bridging the gap between conventional 'soft' and 'hard' glass?

[Colin Reid]

BK 7 has been made for years by Pilkington Special Glass in North Wales until last year when they closed production because the Chinese are selling it cheaper than they could make it (sound familiar?) Probably the majority of it in the world is now made in China and the quality looks good although its not so nice to work with as Schott or Pilkington.

Thanks for all the thoughts about copper red. I think my comclusion so far is that I'll give some of the ideas a try but I suspect that I wont get a result that is reliable enough to be able to use in my work because by the time the thing gets in the kiln so much time and money has been spent I need something thats going to work at least most of the time. What was the name of that paint? Oh yes , what are M&M's

What about other colours than copper red eg amber, yellow, purple, blue. Any ideas of how to produce them in the firing? I mean by using something like an oxide, not body stain or powdered coloured glass.
Colin

[Rosanna Gusler]

i need to go dig up my kiln logs. i got some yellows and purple if i remember using some glaze chemicals. ferro corp makes some clear fluxes that can help making things stick at lower temps. ferro sunshine series colors might also work. will go out to the shop later and get numbers for you. rosanna

[Brian Blanthorn]

Originally posted by Colin Reid
BK 7 has been made for years by Pilkington Special Glass in North Wales until last year when they closed production because the Chinese are selling it cheaper than they could make it (sound familiar?) Probably the majority of it in the world is now made in China and the quality looks good although its not so nice to work with as Schott or Pilkington.

Thanks for all the thoughts about copper red. I think my comclusion so far is that I'll give some of the ideas a try but I suspect that I wont get a result that is reliable enough to be able to use in my work because by the time the thing gets in the kiln so much time and money has been spent I need something thats going to work at least most of the time. What was the name of that paint? Oh yes , what are M&M's

What about other colours than copper red eg amber, yellow, purple, blue. Any ideas of how to produce them in the firing? I mean by using something like an oxide, not body stain or powdered coloured glass.
Colin

Trouble with oxides is they got the oxigen in which has a habit of burning off n giving bubbles possibly after the glass has fuzed

If U try this pate d vere idea and soak just prior 2 the fuze U might get the gass out

Or mayB just paint it on mould

But ur gona need some flux 2 help it disolve in2 the glass

A good ceramics / glass book will give U an idea of colours n this info is not secret

I think Pete has done some colour info in the shiny new Henrys book, sounds 2 me ur moving in2 hot glass technology if U do a melt first n then crush

But due 2 budget cuts n extra post costs there is no Henry Dolls included

Hopfully this will all B sorted out in the next book, Final Notes

But cobalt will give a blue

Iron / copper will give various colours depending on reduction or not

U can alter colours depending on other stuff in with it

The guy I suggested Charles Lamb understands all this much better than I

But the under glaze / on glaze disolved in flux will give U the look of oxides but without the problems of bubbles

Well not so much

M+Ms r a kinda sugery sweet will give reduction in kiln or make coke bottles explode, but there R some who will insist on eating em

As a kinda work arround U might try this bits of glass in a pot + ur oxide / whatever in kiln heat till done then pour it in water

Then crush in ball mill

U could then get whatever look U wanted in this glass bits or totaly disolved

Intersting project I look forward 2 seeing some

Brian

[Pete VanderLaan]

What? M&M's. Milk chocolate candy hard on the outside and soft milk chocolate on the inside. No Sticky Chocolate Mess! Originally made in just brown in the 1950's but now available in yellow, blue, red, and around Easter some pastel colors that just say "Yes" to me.

And they will cause reduction in the kiln but the promise about the "no chocolate mess" won't be true anymore.

[Brian Blanthorn]

Originally posted by Pete VanderLaan
What? M&M's. Milk chocolate candy hard on the outside and soft milk chocolate on the inside. No Sticky Chocolate Mess! Originally made in just brown in the 1950's but now available in yellow, blue, red, and around Easter some pastel colors that just say "Yes" to me.

And they will cause reduction in the kiln but the promise about the "no chocolate mess" won't be true anymore.

Just so no one sues me

Its mintoes in the coke bottle

If U got a sad n empty life or would like one

Type in mintoes in youtube

Brian

[Colin Reid]

but do M&Ms come in copper red??

[Pete VanderLaan]

Interestingly, red M&Ms turn gray at the edges when you suck most of the color off which is a characteristic color shift found in Copper rubies that are cooled too quickly. I have been doing research on them for decades which all began with a modest weekly grant from my mother of I recall .50 cents a week and had no restricting guidelines on it. It went mostly into illustrated fiction, highly carbonated sucrous beverages and the incipient phases of my color ( not colour mind you) research. Thanks Mom, Rest in Peace.

[Colin Reid]

Well its very frustrating for us Europeans stuck in this cultural backwater without access to the technical wizardry you all take for granted. Now that I think about it a friend did bring some M&Ms back from the States but unfortunately they got eaten so my quest for a copper red will have to wait for another day.

Have a nice weekend

Colin

ps but how did the Chinese do it? Dont tell me M&Ms are made there too!!

[David Schimmel]

The origins of the terms "crown" and "flint" go back hundreds of years. Crown glass was an early type of window glass, dating from the 14th century, which was blown into a "crown" or hollow globe and then subsequently flattened into a disk.

In optics, the term "crown glass" refers to glasses with low refractive index. On the Schott glass map, the refractive indices (nd) of crown glasses range from about 1.49 to 1.76, with Abbe values (vd) of 50 - 55 or greater.

"Flint" glasses traditionally contain lead oxide and exhibit high refractive index and low Abbe value. On the Schott glass map, flint glasses are those with refractive index (nd) from about 1.53 to over 2.0 and Abbe values (vd) from about 54 to 20.

The origin of the term "flint" derives from the flint nodules found in the chalk deposits of southeast England that were used as a source of high purity silica by George Ravenscroft in the 17th century to produce potash lead glass that was a predesessor to English lead crystal.

[David Schimmel]

The nomenclature for Schott optical glasses consists of German abbreviations (after all, Schott is a German company). Thus, BK7 is short for Borkron (in English: boron crown) composition number 7. The Schott optical glass families and their abbreviations include:

Fluorkron / FluorCrown - FK
Phosphatkron / Phosphate Crown - PK
Phospatschwerkron / Phosphate Dense Crown - PSK
Borkron / Borosilicate Crown - BK
Kron / Crown - K
Zinkkron / Zinc Crown - ZK
Baritleichtkron / Light Barium Crown - BaK
Schwerkron / Dense Crown - SK
Schwerstkron / Extra Dense Barium Crown - SSK
Lanthankron / Lanthanum Crown - LaK
Lanthanschwerkron / Dense Lanthanum Crown - LaSK
Kurzflint / Antimony Flint - KzF
Kronflint / Crown Flint - KF
Baritleichtflint / Light Barium Flint - BaLF
Doppelleichtflint / Extra Light Flint - LLF
Baritflint / Barium Flint - BaF
Leichtflint / Light Flint - LF
Flint / Flint - F
Baritschwerflint / Dense Barium Flint - BaSF
Schwerflint / Dense Flint - SF
Lanthanflint / Lanthanum Flint - LaF
Lanthanschwerflint / Dense Lanthanum Flint - LaSF

[David Schimmel]

Originally posted by Pete VanderLaan
It's probably the case that Schott and Corning are the only two makers of crown type glasses and Corning doesn't commercially market them. If Hoya makes it I don't know of it.

All optical glass manufacturers make crown and flint glasses. In addition to the two companies cited above, yes, Hoya melts crown glass. So do Ohara and Sumita in Japan; Lytkarino in Russia; along with a Chinese manufacturer or two.

[Pete VanderLaan]

Well, you would certainly be in the position to know. I actually meant in the USA. Back when I first started using Schott, I was down at Harvey Littletons home and we were looking at a pickup full of the stuff I had just brought down from Duryea. Harvey was amazed since he had in his proud possession a chunk about 2x6x10 inch that he had gotten from Corning and told me that Corning would not sell the stuff and here I had a truckful of optical glass from another source. That was back in the days of Horst when things were really cheap.

BTW, have you had any three and or four inch thick BK7 lately?

[Marc Leva]

Colin
You might try ceramic stains. Website (http://www.masoncolor.com/newfiles/ceramicstains.html)

[Paul Wheeler]

Originally posted by Colin Reid
Now that I think about it a friend did bring some M&Ms back from the States but unfortunately they got eaten so my quest for a copper red will have to wait for another day.

Have a nice weekend

Colin

ps but how did the Chinese do it? Dont tell me M&Ms are made there too!!
Hey Colin,
I'd imagine that Smarties would do the same thing. This is what I love about Canada, we get both American and English junk food!

[Dave Bross]

Along the lines of the M&Ms, sugar is mostly carbon and reduces things pretty well.

[Marc Leva]

Originally posted by Dave Bross
Along the lines of the M&Ms, sugar is mostly carbon and reduces things pretty well.
M&Ms, Mentos, Smarties, etc., they are going to be long gone by the time you get to casting temp. The high temp hold removes carbon-bound water (carbohydrates) leaving carbon that, hopefully, volatizes with minimal ash.
The stains are not without problems of their own. They need a minimum of cone 6 - about 1000°C- to develop and they have an opacifier. In a perfect world the opacifier burns off and a casting temp to 1000°C substitutes for 880° soaked for two hours.

[Cynthia England]

[URL=http://www.standardceramic.com/glazes.html]

Waay back.. I did kiln work and sand casting
and remebered that
I used Standard Ceramics.. they come in many many different
formulas.. some are opaque and some are transparent..
and
the best part is they did not burn out!!
we got great reds and oranges..
used both leaded and lead free..

ok.. thats my 2 pence!!

Congrats on your grant!!


MT

PS .. if yu post yur address I am sure you will recieve
pounds of M&M's in the mail and NO they are NOT like
Mentos (ugh!! yucky exucse for candy!)

[Pete VanderLaan]

no reds and oranges in lead glasses at least not from cadmium or selenium. The M&M's are a continuous contribution made during the firing. It helps pass the time. It was more of a joke actually.

Steve Stadelman wants to sponsor my doing a color class in Portland OR next winter if there is sufficient interest.

[Rick Sherbert]

Originally posted by Cynthia England
[B
... they are NOT like
Mentos (ugh!! yucky exucse for candy!) [/B]

Yeah but they make great fountains. Some video (http://www.coca-cola.com/challenge/google.html?WT.mc_id=exp214ps&WT.srch=1) for those who havent' seen it or can't stop watching it..

[Richard Huntrods]

Originally posted by Pete VanderLaan


Steve Stadelman wants to sponsor my doing a color class in Portland OR next winter if there is sufficient interest.

Portland, eh?

One to "count in"!!!

I'm even relatively close!

-R

[Paul Wheeler]

Originally posted by Pete VanderLaan
no reds and oranges in lead glasses at least not from cadmium or selenium. The M&M's are a continuous contribution made during the firing. It helps pass the time. It was more of a joke actually.

Steve Stadelman wants to sponsor my doing a color class in Portland OR next winter if there is sufficient interest.
If all goes well I will have received a couple raises by then, so count me in.

[Malcolm Spann]

Steve Stadelman wants to sponsor my doing a color class in Portland OR next winter if there is sufficient interest.

I'd be interested too.

[Kraig Richard]

"My aim is to develop colours which relate to my work, rather than using an ‘off the shelf’ product. By using oxides etc in the mould which react with the molten glass I want to create colours which are born of the casting process and relate to the form.
"

Instead of straight oxide.....Watering down the oxides for Pre-initiating the reaction and developing control.

For making "happy" (C.O.E.) color dust
Consider Pre coloring your own casting base glass .
Water to Frit
Grind that frit.
Three mini pots in a gloryhole or small high temp annealler could yeild three colors a night.
This seems like the way to water down the chems . Melting slightly heavy oxide.

Maybe not melting until fully disolved an oxide rich "formula" would leave the right amount "non fining" remainin to achive reaction.

Using frits from those melts in the following melts for different hue/shades or watered down versions of the same hue/shade. maybe pull stringers. Broken Stringers are interesting.

Over the course of a few weeks a lot of shades could be developed just from using four common cullet coloring oxides.

The Pate' previously described in this thread seemed interesting.

[Brian Blanthorn]

Originally posted by Colin Reid
Casting temp is 880c (1616f) for a couple of hours usually, then approx 3 week anneal and cool.

Colin

I was thinking a little more on this

I know U wonder arround getting textures from nature

In ur travells U probably noticed red or orange patches or kinda small run offs

This will B raw iron oxide n could be used in any of the ways previously discribed

U can also get it in other forms as well

There must b lots of other colouring minerals out in the wild

Brian

[Pete VanderLaan]

particularly at the outlet pipes from major factories going into rivers and streams...

[Brent Hickenbotham]

there's a great one coming out of downtown portland into the willamette river, looks delicious, I'll take samples.