A few Batch Annealing ????

[cem]

1. Is it possible to batch anneal moretti and lauscha glass at the same time?

2. Why did the light colors (Moretti White, Ivory and Lauscha Thuringen Herb, Milky Way)
lose their lustre?

My annealing temp. was 950 degrees F. Last time when I set my annealing temp to 960 deg.F it devitrified the light blue. This time the light blue is fine and others have lost their lustre. They look as if they had been etched.

Thanks in advance.

[beadsoncypress]

I think I can help with one answer. As long as the COE is the same, you should be able to batch anneal them together. I was told 968F is the right temp, but had some similar problems, so I am keeping mine at 960F now.

[cem]

Thanks Susan,

I wonder if my kiln runs hot and that is what caused the light colors be dull, no shine and somewhat rough to touch, like an etched bead.

Or could it be that I held them at the annealing temp. too long???

[RyanTheNumberImp]

The best way to test if your kiln is at the right temperature is to prop up a rod. Leave the kiln at 960 for a few hours and check for any bending or slumping. There should be absolutely no distortion in the rod. If you are slumping set the temperature a few degrees lower. If you suspect the kiln is too cool go up until you slump and then reduce the temperature a bit.

The test will vary based on the rod you use so try something soft like white or something in the middle like clear or black.

I have never had nor heard about the problem you are describing so I can't suggest much else.

[cem]

Thanks for the help Ryan.

The beads do not appear to be slumped but I will do that test.

The only other thing I can think of that may have caused the dullness is the shelf paper. That was the first time I used shelf paper for annealing beads. I have only ever used shelf paper for system 96 glass. Maybe moretti and lauscha reacted with the fumes of the paper???

Any ideas on that???

[jaci]

the shelf paper should not effect the batch annealing unless your kiln is too hot. The beads may not actually slump and loose their form,but they may be dull and etched looking because they are actually hot enough to melt into the shelf paper just a bit. try the slump test... you may be surprised! I also anneal a bit low (just a few degrees) and compensate with a longer annealing time. no problems here my beads and larger items last through ice storms and humid summer days, no problem, sometimes frozen in the car, and straight to warm when i put the heater on... and have lasted for years.

[ellyloo]

do you use your kiln for anything other than glass? (IE: ceramics, silver clay etc) or has it been used for that before?

[houptdavid]

Why the shelf paper? Just put them on the KW shelf. Try the same glass without the paper

[papimom]

If you choose too lay them on the kiln shelf, be sure to brush layers of kiln wash over the entire thing firsst. Run the kiln through one quick cycle to burn off the nasties. Then annea away.
Joan

[cem]

David and Joan,
I was in a hurry and decided not to take the time to use KW the shelf, so I used the paper.

ellyloo,
No I only use my kiln for glass, fusing, slumping and annealing.

Jaci,
I agree, I must do the slump test. However, I have annealed beads before at 960 F (used kiln wash on the shelf) and the ivory, whites, etc were NOT dull. However, the light blue, (perwinkle,I think) devitrified.

It's a mystery!!

Thanks

[cem]

Originally Posted by RyanTheNumberImp

The best way to test if your kiln is at the right temperature is to prop up a rod. Leave the kiln at 960 for a few hours and check for any bending or slumping. There should be absolutely no distortion in the rod. If you are slumping set the temperature a few degrees lower. .

I did the test. I supported a few rods betwen/over two rod rests on the kiln shelf and ran the annealing schedule at 950 F. I used white, ivory, and blue.

The rods slumped. The longer rods slumped more than the shorter ones. They sat at 950F for 1 hour.

So, this means the annealing temperature is too hot.

Should I try the test again at 940F?

Thanks,

[houptdavid]

Your TC may also be bad

[jaci]

yes try a lower temp. Usually as a rule of thumb, if you are lowering the temp a few degrees you extend the time a little longer just incase... Always works for me

[Lyssa]

I'm having the same problem with my beads becoming "devitrified" while batch annealing. Did anyone figure out what's going on?