A big hello, and questions...

[bivbeadies]

Hello everyone...

My name is camille and I am in Minnesota...I've been lampworking for three and a half years now and have been delving into fusing and slumping.

I took a class last year, got the basics of how to cut the glass, do basic techniques, blah blah blah (and the instructor was very secretive about a lot of stuff - insisting that I bring my models with me and take another class of his because HE'D like to have a mold of my project too...All I wanted to know was what ceramics clay I should get if I wanted to make my own molds and fire them at home, what size frit to use to do castings with and so on...it was a little disgusting, to tell the truth and I didn't sign up for another of his classes...yuck) so most of what I know has been learned there and through trial and error.

Ok - here's where slumping questions come into play...the instructor had told us that we did not have to spend "all that money on those expensive molds...just go to Target or Walmart, find a plate shape that you like, scratch up the surface with sandpaper and then give it a coating of kiln wash and you're ready to use it to make plates" - ok - so I go out and I find these great square plates with a gentle curve at the edges so that whatever's on the plate won't roll or fall off...fine...I gave it a gentle sandblasting to rough up the surface, coated it with my kiln wash (three layers, each going a different direction and allowed to dry overnight inbetween applications) and I'm ready to go. My aunt and I bought some gorgeous glass back in January at Bullseye and before using it to slump into my new great square plate mold, I wanted to do a trial run with a piece of 'unimportant' glass...just to make sure that it's going to work and look like I want it to...here's where the trouble begins...

Since I'm just simply slumping the glass into the mold and it's single thickness, I went up 300 degrees per hour - I got to about 1000 or so degrees and whammo! - the plate splits right in half...ruined. What happened here?? Such a nasty little surprise when I opened my kiln! Should I perhaps take the temperature up by 200 increments, rather than 300? Or was the advice about using 'molds' made from other dinner plates, bowls, platters, etc. a bunch of hooie?

Second...my little sqare plate had rounded edges...I cut the piece of glass just slightly larger than the square mold size and just perched it on the top of the mold before starting...question for this paragraph is this...exactly HOW do you precisely size the piece of glass to perfectly fit the mold that you are using...do you cut the glass slightly larger than the edges of the mold or do you cut it precisely to size...

I would surely appreciate any sort of help with this dilemma as I'm headed out Portland way again in a month and would like to have my aunt's plates finished...I found more square plates but if they aren't usable as molds, I'll simply return them to the store...

I have not had any issues with fusing tiles...I buy large quantities of the Bullseye scrap boxes because I really like mixing a lot of colors in the random patterns...one of these days I'm planning on taking the Painting with Light course they offer since I really enjoyed doing my frit 'picture' fusing in my class...that was fun since I made lampworked components that I tack fused to the top surface...it was fun.

Anyway - thank you in advance for any advice or information...I really appreciate it and am looking forward to participating with this group! Such a helpful bunch!

OH! Also - would anyone recommend a book for learning pate de'verre?

Sincerely,

Camille

[Jerry]

Hellow to you as well, and welcome.

I'll get to the easy question and leave the other responders to ponder the rest.

A Commandment; THOU SHALT NOT OVERHANG THY MOLD!

If the glass is larger than the mold, the edges will slump over towards the outside as the inside is going down into the mold. The result is a "tear" across the piece. And it comes from "overhanging" the mold. Make your measurement such that an overhang can't occurr.

I will on occassion buy a ceramic piece from one of "those places" as well and typically get a couple of firings off it before it goes into the dumpster. They are made to serve warm steak on, not 1400 degree glass. They will crack and, in the worst case, transfer some of the glaze to the glass. Usually this is in a dull film but can actually become fused. The other problem is you never know how hot they were bisqued to. I had a beauty, I thought, that made it to about 1000 degrees before it MELTED! If you find one you like, take your chances. Drill out some vent holes and try it with cheap glass. Another option would be to have a potter replicate it in high fire clay that he/she would bisque fire to over 2000 degrees. Molds made in high fire clay will usually last for a long time.

Don't dispair about your failures. We all have been there and will probably be there again. So, keep us posted on what you are doing and we will help as we can.

Jerry

[Lorelei]

question for this paragraph is this...exactly HOW do you precisely size the piece of glass to perfectly fit the mold that you are using...do you cut the glass slightly larger than the edges of the mold or do you cut it precisely to size...

For my purposes, I've taken some plain brown paper and smooshed (is that a word?) it into the mold I want to use. I hold it against all the sides, upside down, and trace around the mold with a sharpie. Then I cut the paper JUST outside my lines. I put the paper in the mold again, face up this time, and trim along the edges until I have an exact replica. Then I put the paper on my glass and cut around it. So far....so good.

[Pat Zmuda]

Welcome, Camille:

For pate de verre info:

"The Art and Technique of Pate de Verre"
Tokyo Glass Art Institute

"Pate de Verre and Kiln Casting of Glass"
Jim Kervin and Dan Fenton

Both available from www. Whitehouse-Books.com.

and, of course, the tutorials and archives on the WGB.

Hope this helps,

Pat in Chicago

[Amy Schleif-Mohr]

Your mold question:

I wouldn't ever use a "plate" from Target that has glaze on it.

You can, however, go to one of those places that has the bisque ware ready to be glazed and use one of those. To use these you need to drill vent holes in the bottom so that the air can escape.

You can also make your own. I personally use Raku clay and bisque fire it at 100F/hr to 1800F. Once that is done, I coat with kiln wash and slump glass into them. I don't ever slump above 1170F.

Amy

[lyndasglass]

One little addition to Amy's post: If you are going to buy the bisque ware from a ceramic shop be sure to run your hand across the bottom where the glass is going to slump into. Often I have found that these molds are NOT smooth. For the paint and fire ceramic it may not matter, but if you are going to slump glass into it and it isn't smooth, then your bowl/plate will not set level on a table.