Search found 260 matches

by charlie holden
Mon Mar 01, 2004 3:48 pm
Forum: Kiln Casting
Topic: Box Casting.Has anyone experienced devit?
Replies: 22
Views: 29112

I have recently learned that kaolin (china clay?) is about 40% alumina. On "Mixing it With the Best" they recommend adding about 8% by weight of kaolin to other dry ingrediants to help packing, (very small particle size) and improve release from glass. Haven't tried it yet myself though. ch
by charlie holden
Mon Mar 01, 2004 3:42 pm
Forum: Kiln Casting
Topic: Glass Brick project - your advice on texture.
Replies: 2
Views: 4917

Go to the Bullseye Connection website and download the two technotes articles on working deep and box casting. This sounds like a good combination project using aspects of both techniques, (if you go with option #1.)

ch
by charlie holden
Sat Feb 28, 2004 12:16 am
Forum: Techniques and Tools
Topic: kiln casting with metal... please help!
Replies: 50
Views: 48483

Just to follow up on ancient history: if you do want to look for some lead crystal it is made by Schott in optically clear and Gaffer in colors. You have to get softening points and annealing points from the manufacturers or retailers. I've also had a thought about your aproach. You may have more su...
by charlie holden
Thu Feb 26, 2004 8:35 pm
Forum: Kiln Casting
Topic: Box Casting.Has anyone experienced devit?
Replies: 22
Views: 29112

Alumina is a refractory that can be used in place of silica, as can olivine sand and zircon. It has to get to a higher temperature than silica before it becomes reactive and starts to bind to the glass. I think, though I'm not sure about this, that silica is also more susceptible to being softened b...
by charlie holden
Thu Feb 26, 2004 8:27 pm
Forum: Techniques and Tools
Topic: kiln casting with metal... please help!
Replies: 50
Views: 48483

You are trying something that is going to be very difficult. Few people are successful with their first attempt at glass casting. And even when the glass ends up where you want it and in the right shape it is often rough and/or scummy looking, which means it needs cold working -- which is a whole no...
by charlie holden
Wed Feb 25, 2004 7:04 pm
Forum: Kiln Casting
Topic: Box Casting.Has anyone experienced devit?
Replies: 22
Views: 29112

Bullseye may be using a very smooth grade of fiber paper if they have clear edges with no cold working.

When I said that I may be cold working all of mine I didn't mention that I'm using cullet, sheet and pot drips. I can't afford billets yet.

ch
by charlie holden
Wed Feb 25, 2004 6:57 pm
Forum: Kiln Casting
Topic: big bubble dilemma
Replies: 5
Views: 6879

Thinking thedictionaru. I have thiought casting is from frit - directly or with flowerpot, and sheet glass is slumping. Do I interprete the terms right? -lauri Slumping almost always means the deformation of sheet glass. Other terms sometimes used are sagging or draping. It usually means heating th...
by charlie holden
Wed Feb 25, 2004 11:34 am
Forum: Kiln Casting
Topic: big bubble dilemma
Replies: 5
Views: 6879

You don't say how thick the mold is, but in any case, imagine the temperature at the center of the mold where the mold and the sand meet. The heat has to get through the glass and the mold to warm that spot up. Meanwhile the sand is even colder and the kiln bricks underneath are colder yet. The air ...
by charlie holden
Wed Feb 25, 2004 11:09 am
Forum: Kiln Casting
Topic: Box Casting.Has anyone experienced devit?
Replies: 22
Views: 29112

I think the key to avoiding devit and spiking around the edges of box casts is to keep the edges of the billets well away from the sides of the molds. You want the glass to melt down into the center of the molds then flow out to the walls when it is very hot. You also want the binder to burn out of ...
by charlie holden
Wed Feb 25, 2004 10:54 am
Forum: Kiln Casting
Topic: volume calculation
Replies: 4
Views: 7235

Many people, (Anna Boothe teaches this technique) build large pate de verre molds in seperate sections or rings. If you want to try it with the partial mold that you already have you only need to do a couple of things: Leave the poured mold around the wax and in the box. Carve a couple of notches or...
by charlie holden
Mon Feb 23, 2004 12:11 pm
Forum: Photos and Stuff
Topic: First Heat!!!!!
Replies: 14
Views: 15790

That's a good looking kiln. It should do a great job for you. I see several switches on the panel. These are to selectively turn on or off the wall and/or ceiling elements? I'd like to see the wiring diagram. You have the only kiln I've ever seen that can flip over. Now you should build a wall of ki...
by charlie holden
Sat Feb 21, 2004 11:46 am
Forum: Techniques and Tools
Topic: I'm in LOVE!!
Replies: 27
Views: 30669

If you want to dam a piece that you are firing on sand, this is how you do it: prepare the surface of the sand, lay your glass down, cut strips of fiber paper at least as wide as your glass is thick, lay the fiber paper against the edge of the glass like a dam, pull sand up in a pile around the outs...
by charlie holden
Tue Feb 17, 2004 12:08 pm
Forum: Techniques and Tools
Topic: Plaster/silica thickness??
Replies: 4
Views: 5729

Thanks, Tony. I've made up some patterns to these numbers. I've gone through the archive and settled on a simple 50/50 hydrocal white/230 flint blend. I'me assuming the water requirement is based on the plaster content and that the flint just goes along for the ride, right? Cheers, Glenn The flint,...
by charlie holden
Sun Feb 15, 2004 8:41 pm
Forum: Photos and Stuff
Topic: What the H*** am I doing wrong???????? Help!!!!!
Replies: 3
Views: 5432

Those look like annealing cracks to me, even though your schedule is conservative. The orange one may have cracked on the way up because it wasn't annealed properly in the previous firing. Are you baffling the glass? It may be a situation of the pot shading the pour from your lid elements so the gla...
by charlie holden
Sun Feb 15, 2004 7:49 pm
Forum: Techniques and Tools
Topic: Coincidence or trouble?
Replies: 5
Views: 5933

That's a strange thermal shock crack. For it to curve around like that it must have traveled through the glass quite slowly. I don't know what that might mean though. Maybe there was a small check in the clear that you missed and it ran through during heat up. AFAP to 1450 is risky for glass this bi...
by charlie holden
Sun Feb 15, 2004 7:36 pm
Forum: Techniques and Tools
Topic: flosing vidriarte flashed glass sandblasted
Replies: 8
Views: 10986

It depends on how hot you fire and how long you soak whether the sandblasted area will smooth out or not. At slumping temperature the sandblasted area will soften some but still be translucent. It is often called a satin look. At hotter temperatures and longer soaks the glass may smooth over complet...
by charlie holden
Sat Feb 14, 2004 7:46 pm
Forum: Photos and Stuff
Topic: A little splash of color
Replies: 30
Views: 32522

All this talk about a book has me thinking that there might be room for a warmglass wiki page. It would be a permanent, though fluid, repository for instruction, tutorials and definitions. A good place to organize the archives. It is written, edited and policed by the community. Which means that any...
by charlie holden
Fri Feb 13, 2004 7:48 pm
Forum: Techniques and Tools
Topic: Why can't I melt my pot...er, I mean...
Replies: 30
Views: 31161

I have written that fiber paper won't work. I should have been more specific and said it won't work underneath the glass. The glass will consume it as it spreads across the surface which will leave little incompatible bits in the bottom of your glass. Apparently Brad uses 110J paper under pot melts,...
by charlie holden
Fri Feb 13, 2004 7:36 pm
Forum: Techniques and Tools
Topic: Big seamless shelf, help!
Replies: 9
Views: 9893

If you really want a good large mullite shelf look at Dyson Precision Ceramics extruded batts. They have a chart that lists the sizes and weights but they make bigger sizes than those listed on the chart. Not cheap, plus shipping from the UK. But lighter and stronger than a similarly sized solid she...
by charlie holden
Thu Feb 12, 2004 1:47 pm
Forum: Techniques and Tools
Topic: Eating Silica? German anyone?
Replies: 27
Views: 28868

3 mm glass has very littly weight to push itself into small details. You will need to go higher, longer or add another layer of glass. You are getting quite close to casting when you are picking up detail that small. You don't say what type of glass you are using, at least not in your most recent po...