Can I use this bowl as for slumping?

pam l · Post by **pam l** » Tue Jan 20, 2004 3:21 pm

Hi all,

I purchased an small dish with a nice low slope to use for slumping. It was silver in color, no markings to say what it was made of, so into the kiln it went to soak at around 1400 for about 30 minutes.

As expected, the silver "stuff" burned up, leaving a lovely layer of black crud. I think the dish is brass (makes sense...it's heavy like a brass ashtray would be and yellow in color). I buffed most of the crud away and fired it again just to bring any other stuff to the surface, so to speak.

Two questions:

- with a good coating of kiln-wash, is it okay to use this as a slumping form...if more crud comes up, will the kiln-wash keep it from getting to the glass? (not so experienced with "found" molds)

- do I need to fire my kiln without anything in it to burn off any possible contamination from when I fired the dish? It looks fine, but...

Thanks! It's a lovely shape and it didn't melt - it would be great if I could use it. I appreciate your help -

pam l.

rosanna gusler · Post by **rosanna gusler** » Tue Jan 20, 2004 4:01 pm

kiln wash it and slump some float into it. that will tell the tale. rosanna

Paul Tarlow · Post by **Paul Tarlow** » Tue Jan 20, 2004 7:31 pm

Be careful putting unknown metals into the kiln.

Some (anything galvanized, zinc ?) give off toxic gases at high temps.

- Paul

Nikki ONeill · Post by **Nikki ONeill** » Wed Jan 21, 2004 2:47 pm

Paul..
Speaking of toxic fumes, I recently bought several pieces of glavanized steel nipples for making cylindrical pattern bars, not knowing at the time that I should have bought black pipe. I'm thinking of firing them anyway, just venting well to clear out the zinc fumes. Do you know how hazardous zinc fumes might be? I have a ventilation hood and separate hepa filtered air circulator.

(also, I really liked your new lanterns...nice job. Simple, elegant frame, but not so simple to build, I bet.
Nikki in freezing cold MD

pam l · Post by **pam l** » Wed Jan 21, 2004 4:15 pm

Thanks Paul - that's good to know...and I probably should have posted my question before I fired. The good news is there wasn't any smoke or odd/foul odors when I fired the bowl and I'm still here. Lucky this time, and more knowledgeable for the next time.

Thanks again,

pam l.

jerry flanary · Post by **jerry flanary** » Wed Jan 21, 2004 9:12 pm

Nikki
Just return them and get black- Once you try black you won't go back! But seriously Zinc , there is no good reason to breathe in or deal w/ zinc if you don't have too. Seen big tough foundry guys throw up and go home for a week from that crap. Most big stores will give you credit w/o even having a receipt.

Paul Tarlow · Post by **Paul Tarlow** » Thu Jan 22, 2004 12:05 am

Nikki O'Neill wrote:Paul..
Speaking of toxic fumes, I recently bought several pieces of glavanized steel nipples for making cylindrical pattern bars, not knowing at the time that I should have bought black pipe. I'm thinking of firing them anyway, just venting well to clear out the zinc fumes. Do you know how hazardous zinc fumes might be? I have a ventilation hood and separate hepa filtered air circulator.

(also, I really liked your new lanterns...nice job. Simple, elegant frame, but not so simple to build, I bet.
Nikki in freezing cold MD

According to the American Welding Society, the "metal fume fever" that can result from breathing the zinc oxide fumes that can result from welding glavanized steel can make you pretty sick -- but does not cause permanent damage. All the same, the stuff is toxic and I'd err on the side of playing it safe.

http://www.aws.org/technical/FACT-PDF.EXE/FACT-25.PDF

Thanks for the comments on the lamp. Fusing to manipulate light transmission is a whole new ball game. I'm still in the mode where I could be running my kiln non-stop just on experiments -- if the bill paying job didn't eat up so much time

- Paul

Nikki ONeill · Post by **Nikki ONeill** » Thu Jan 22, 2004 10:44 am

Jerry and Paul: Thanks for the info on zinc fumes; the effects are very unappealing, even if not acutely toxic. I'll pass on using galvanized pipe.

Paul: You have taken on a great challenge! I'd like to comment on making glass for lamps, as I am working in that area too. The quest for beautiful light through glass was realized by Tiffany and Company. If you ever get NYC, I'll send you the info for two galleries whose owners are happy to let you spend hours enjoying and examining Tiffany lamps, even if you're not buying. I'ts simply inspiring, to bring a beautiful little piece of nature inside. Roger Thomas, in one of his classes, mentioned that after several years work, his quest for beautiful, painterly images in fused glass was an attempt to achieve the beauty that Tiffany did in his lamps. Roger produced beautiful, Tiffany-like panels before his fusing days. For over 20 years, I've made and taught lampmaking, until bitten by the warm glass bug. There's still nothing from my fusing workshop as beautiful as the lamps, not that I'm discouraged...far from it. For me a more feasible direction has been learning casting, so as to be able to explore the type of light and beauty that comes from the lamps made by turn-of-the-century pate de verre artists. These small lamps just glow with color and show design relief, as well.
And we experiment on...
Nikki

ianj · Post by **ianj** » Sun Jan 25, 2004 1:40 pm

Hi

My concern about slumping "into" anything made of metal is the fact that it will clamp onto the glass. Slumping into ceramic and over stainless steel is my understanding.

Regards

IJ

Brock · Post by **Brock** » Sun Jan 25, 2004 1:51 pm

ijeffery wrote:Hi

My concern about slumping "into" anything made of metal is the fact that it will clamp onto the glass. Slumping into ceramic and over stainless steel is my understanding.

Regards

IJ

It ain't necessarily so . . .

It's not the mold material, it's the mold shape. I slump into metal molds all the time and have for 20 years. Also, metal molds have a certain amount of flex, totally absent in ceramic molds. Brock

WarmGlass.com