A beginner annealing question

A beginner annealing question

Post by Gary Schulthei » Wed, 06 Nov 1996 04:00:00



I'm new to lampworking and have an annealing kiln ordered. In her article
in Lapidary Journal on setting up a beadmaking studio, Cousette Copeland
says, "If you use vermiculite, you must kiln anneal your beads within 9
days". I have a bunch of beads here that are several weeks and months
old. Should I pitch them? What's magic about 9 days? From the
explanations about annealing that I read, I don't see why they couldn't
be annealed at any time if they are not cracked. Please enlighten me.
Gary

 
 
 

A beginner annealing question

Post by sylvie.. » Sat, 09 Nov 1996 04:00:00


Gary,

I don't think there's anything "magic" about 9 days.  Cousette took
classes with Kim Osibin and Leah Fairbanks and that's what they reccommend
after their experiences with waiting LONGER than that then annealing.  I
think their main point is, if you wait any longer than that to anneal, you
might get cracks.  You might get them anyways if you DON'T anneal at all
though.  

I think this was a guideline for those who are taking their beads to be
annealed somewhere...for people who don't have their own kiln and might be
renting time from someone else.  Nine days would be the maximum time you'd
want to wait if you were going to do that (according to their experience).

I think, if you don't anneal you're risking cracks anyways, so you should
disregard that guideline for the beads you already have that you want to
anneal, but follow a schedule close to that for future beads if you're
going to take them somewhere to be annealed.

Good luck!

Sylvie

 
 
 

A beginner annealing question

Post by Roger Peterso » Sat, 09 Nov 1996 04:00:00


Gary,

I had lots of beads that had not been kiln annealed until recently.  I
started with some of the less desireable ones and found that I had
problems if I ramped up the temperature too fast.  If there is any
"magic", is happened to me around 500 degrees F.  Now I ramp up normally
to about 400 degrees and then go slow from 400 to 600.  The rest of the
profile follows Brian Kervelit's (sp?) article in Glass Art.  Don't know
if the slow down at 400 is necessary, but I have not had a bead crack
(or explode) since.

Glass is an amorphus material and as such does not have any sharp
transition temperatures.  However, we have to keep in mind that
different colors have slightly different temperature coefficients.  I
strongly suspect this the source of most of our problems.  If you notice
a difference in working range between different glass, you can be sure
that difference shows in the tempco.  

Roger...