slumping and draping

[fwbgirl]

my slumped and draped items are lopsided.  Everthing is even and appears to be centered properly.  What’s going on here?

[bhawbaker]

Pictures?

Description of kiln & glass project?

Firing Schedule?

More info would be helpful.

 

[Piranga]

Uneven slumping and draping usually happens with a smaller kiln, more than one item in it, and is affected by placement of the pieces in the kiln.  If an item is not in the center, the edge closest to the side of the kiln, and therefore closest to the side elements, will get more heat, so that glass will soften and move before the rest of the piece.  If you are slumping or draping more than one item at a time, you are more likely to have problems of this type unless you have a large enough kiln to allow good placement of all articles.  Slower ramp up rates, lower slumping temps, and longer hold times can lessen the problem.  Big thing is – don’t overload the kiln.

Keep really good notes/logs describing placement – even drawing diagrams or taking a photo (digital cams are great!), glass used, and the firing schedule – review your notes and comments – that is the best way to learn when and why something is happening in your kiln.

Hope this helps, and

Happy fusing!

Piranga

Fused Glass, Wood, Beads, PMC, Ceramics

Usable and Wearable Art

Art for the Sake of Art

[fwbgirl]

 think you hit it right on. I have a clam shell, 20″ shelf–i.e. top elements.

All the items are slumping more so in the back than the front. I don’t
know where to move the stuff so they will slump more evenly.

I guess it will be a lot of work (and glass) to figure out the correct
position as far as forward or back or if it is even possible with this
configuration.

Any more suggestions would be good.

[Piranga]

I haven’t used a clamshell that size, but it is certainly big enough to handle a few pieces at once.  I wonder if there is a problem with the elements.  It sounds like it is heating unevenly.  The owners’ manual should have some info on element arrangement,and you should be able to talk to the company about the problem.  They may be able to help you find a kiln repair shop or a glass studio that builds or works on its own kilns to help you pinpoint and correct the problem.  Sorry I can’t be of more help.

Piranga

Fused Glass, Wood, Beads, PMC, Ceramics

Usable and Wearable Art

Art for the Sake of Art

[linn]

hi!

before you do anything else, i would suggest you get a level, at least a 12″ or 18″ long one, and use it to check and see if the kiln itself really is level, or just looks like it.  i would check it along each of the edges and across the middle.  if necessary, shim to achieve level.  once i knew the kiln was level, i’d check the shelf inside, set on the usual kiln posts used to elevate from floor of kiln.

when you know the kiln and shelf are level, then i’d go to the bullseye site and in the education section there is a kiln test you can do to determine hot/cool spots inside the kiln when firing.

once you know what’s affecting the glass during the firing cycle, you can start trying to resolve any kiln problems.  then it becomes a matter of using the right schedule and your slumping should be more consistently successful.

good luck,

linn

 

 

linn

down in the valley……

[Stephen Richard]

You don’t indicate anything about the rate of advance you use when fusing.  In general, going slow and to a low temperature with a long soak  provides the best results.  You do need to observe when the glass has fully slumped on the first few firings and when you change your layup to get the right combination of rate, temp and time.

Stephen Richard

blogs at: http://www.verrier-glass.blogspot.com/ and  http://www.glasstips.blogspot.com/

[Author]

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