spiky and slightly cloudy ... Help

[Saskers]

Hi, I'm a noobie at this wonderful fusing lark .... I will start from the beginning ... I have a large Skutt ceramic kiln and have managed a great first full fuse just using the center shelf away from the sides and only one shelf not layered as I do with ceramics .... I used thin fire paper and everything looks great for a novice I think, well I was happy with the out come.

I was so excited I did a second firing, I used the same schedule but used some fiber paper and also added a second layer of shelves (being greedy I guess) this time I had spiky edges and slight clouding on most pieces. I have read a lot trying to figure out what I am doing wrong ... LOL so many things and probably too many variables ..

The thin fire paper pieces were fine but the pieces on fiber paper were not, has anyone else had this result?

Also what is the best way to fix the cloudiness?

My full fuse schedule was: 8 segs
300f/hr to 900, 15 hold
500f/hr to 1100, no hold
100f/hr to 1250, 30 min hold
9999 to 1475, 10 min hold
9999 to 960, 60 min hold
50f/hr to 800, no hold
100f/hr to 700, no hold
300f/hr to 100, no hold

If spiky edges are due to over firing where should I cut back or down within my schedule?

Any ideas would be awesome as I love this glass fusing and want to get some great results... thanks

[rosanna gusler]

what kind of glass. r.

[DonMcClennen]

pottery needs to feel the heat, glass needs to see it!

[Saskers]

I'm using Spectrum System 96 Glass. I cleaned it well with 70% iso alcohol before using scent free hair spray as glue.

[Lori Schinelli]

Hi Saskers
I don't work with system 96, but I believe some of the same conditions apply.
I never use alcohol by itself to clean the glass, it sometimes leaves an oily residue that might be causing your cloudyness. I found that a mixture of white vinegar, alcohol and water gave me the best resultsfor a final cleaning. Of couse, if the glass is really dirty,
I would wash it with soap and water first. It is also important to know if the water you are using has a great deal of minerals. If so you will get a cleaner result using distilled water as a rinse.
As far as spiking, that is often a result of over firing. When using several shelves in a pottery kiln you need to keep in mind that the entire kiln will not be the same temperature. the placement of the shelves may block the heat from some of the elements and the kiln might naturally be hotter at the top.
Damming a piece using fiber paper around the edges may also cause the edges to be spiky under certain cercumstances.

Years ago, before I purchased my glass kilns, I was able to get good results with my pottery kiln, and I still use it when needing a very deep slump or when my other kilns are in use and I need more room, but I never use more than one shelf and I make sure that the shelf is at a level where the thermocouple is reading the temperature very near the position of the glass.
I would also be very careful not to use more than very small drops of hairspray,and only if necessary, as it can discolor your results.
Lori

[rosanna gusler]

heat work and ventilation. the more shelves you have in the kiln, the more heatwork the glass will get using the same schedule. ..... the more fiber there is in the kiln the more reason to vent. i vent all firings at least to 1100f. this allows burn out products to get out instead of setteling on the glass and promoting devit. ...i have a scutt ceramic kiln that i fuse in. i generally use 4 shelves. this works just fine . shelves closer than 4" to each other tend to promote devit. i always do a final rinse with distilled water and always use distilled to mix anything that will be used in the kiln. r.

[Brad Walker]

In addition to the comments above, 1475F is probably too high of a top temperature for System 96 in a pottery kiln. Try 1460 or even 1450 or lower. Firing too high causes the needles (sharp edges) and also contributes to the haziness.

[Saskers]

Great info thank you so much ... I have the kiln running as I type so am excited to see the results !

[Bert Weiss]

The big trick is to take notes, and assess the difference between the successes and the not so much, outcomes. The keys are in the differences, sometimes subtle ones. This forum is excellent for getting a realm of experienced fusers to tell you their takes on what happened. We learn a lot more from the failures than from the successes. Repeatable perfection is always the goal. Nobody here is immune from surprises... Oh, and if you want something perfect, go to Walmart, everything there is perfect.