Pitting/hazing on surface or just not a smooth surface. Please help!
- August 24, 2012 at 2:47 pm #9853FlickerFireParticipant
I’m sure this has been asked before and I have searched for answers but I can’t seem to find any info that helps me. I am new to this and I know I should take a class, but money is tight at the moment…
I have an Evenheat Studio 8 kiln with the manual temp adjust and I’m using shelf paper. I’ve researched on how to make “puddles” as this site calls them and I’ve had success making the puddles, however, they don’t always come out perfect. I thought the problem before was temps getting above 1500, so I babysat one firing so this wouldn’t happen and they came out with a hazy kind of surface.
I held the temp around 1450 for about an hour, (babysitting it to make sure it didn’t surpass that temp) then open and closed the lid down to 1000, the left the lid half open until 500, then took them out of the kiln to cool.
The sides are perfectly smooth and shiny, but the surfaces aren’t. I tried heat smoothing them again, but it didn’t do anything. I’m not sure if I did it right.
I thought maybe my kiln isn’t clean? or am I being to hasty? or the glass isn’t clean? (I do tend to forget to wash the glass and my hands before putting them in the kiln..)
I also fire PMC3 in the same kiln.
I’ve done some firings and the pieces come out perfect, then do another and they look bad. I’ve also had some pieces get this haze and others be just fine from the same firing.
I don’t know what type of glass they are since I bought them for the stained glass that I do.
Here’s some pictures. That oval one in the middle probably is the best example.
You can see it better on the one in the back that part of it is fine when another part is hazy.
What am I doing wrong? It is the glass? Is it temps or not the right process? Is my kiln dirty? is the glass dirty?
It makes me sad when they look beautiful, but are so hazy I can’t use them for anything. Please give me advice!
JenAugust 25, 2012 at 3:32 am #12669wordanaParticipant
Stained glass is not controlled during the manufacturing process like fusible glass is. The haze you see is devitrification (or “devit”). Also, pieces that size need to be held at the top temp for much less time than what you are holding at (surely no more than 30 minutes, if that). The longer you hold any glass at higher temps, the more likely it is to devit.
Do some googling on devit — what it is, what causes it, how to prevent it (including devits sprays to help coat the surface of the glass and prevent devit). Also, you might be able to get away with fusing different colors of stained glass in small pieces, but if you ever decide to “work bigger” you’ll be facing glass compatibility issues. Incompatible glass will crack — either during fire or eventually after it is out of the kiln.Do some googling on glass compatibility (COE).
For more consistent results, you’ll want to buy glass made specifically for fusing and ensure it is the same COE.
Jester’s Baubles Fused Glass DesignsAugust 28, 2012 at 4:06 am #12670DZapParticipant
I feel your pain. I was so excited about using up my stained glass stash for fusing projects . . . until I learned the truth that not all glass is created equal. They look pretty. If you can’t get the devit to fire polish out, blast them and make them appear like sea glass with a frosted haze all over. I threw mine into a rock polisher (my pre-sandblasting cabinet days) and they turned out pretty. They were small pieces so not too worried about them breaking due to stress and I then used them up as mosaic items. Figured if they didn’t break in the polisher then I was probably okay.
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