boro annealing schedule, conflict of info

istandalone24/7 · #1 2012-09-06, 2:28am

so i just got my fancy new kiln, with a PITA digital controller. programming it isn't that easy, but i figured it out.
my issue is the annealing schedules, i read in one spot that says for every .25" of thickness i need to anneal for one hour.
then another schedule i read says up to .9" for 15 mintues at 1050.

here's a schedule i found here that i think is more proper, but not sure:
http://www.lampworketc.com/forums/sh...56&postcount=2

and another i found on Northstar's website (this is the one that says 1hr for every 1/4") here it is:
http://www.nortelglass.com/downloads...nealChtRev.pdf

which should i follow?

Bunyip · #2 2012-09-06, 5:52am

I adapted mine from contemporary lampworking as well, though I incorporate a kiln strike and anneal everything for 90mins, with a nice safety stop near the strain point in my main program. (SAFETY STOP NOT SAFETY BREAK SHUSH). I feel that this type of program is very appropriate for just about all ornamental pieces up to approx 2.5" in thickness.

Northstar's program, however, is more appropriate for items where breakage could umm.. cause internal injuries, for example. Better safe than sorry.

Hope that helps at all.

istandalone24/7 · #3 2012-09-06, 12:47pm

it does, a lot! thanks bunyip!

menty666 · #4 2012-09-06, 12:55pm

I was always taught 15 minutes per 1/4". (based off the thickest area)

If you ever get into fusing and casting, don't forget to count the mold in your thickness calculations.

edit: Oh, and I go a little more conservatively for the internal novelty items. Bunny's right, safe than sorry.

istandalone24/7 · #5 2012-09-06, 1:12pm

thanks.
and this is off topic, but i don't want to start a new thread.
in regards to fuming silver/gold, i can't seem to figure out how to aim the fume. i usually get it everywhere, save for where i want it.

is there a rule of thumb that states i should have the workpiece off to the side, in the stream of green fume or just directly behind the back of the flame?

i did a search and could not find anything.

Alaska · #6 2012-09-06, 1:49pm

Also use the one from "Contemporary Lampworking" and it is working well.

Dragonharper · #7 2012-09-06, 2:00pm

I also use a modified schedule from "Contemporary Lampworking" for both soda lime and borosilicate with excellent results.

istandalone24/7 · #8 2012-09-06, 2:42pm

thanks for that pdf alaska!

Bunyip · #9 2012-09-09, 11:48am

Fuming results are very torch, technique and flame dependent. I'd suggest working with a smaller flame and doing some experimentation. I'd also suggest getting used to the idea that you won't be able to be very exact with your fume application. Possible idea is masking the glass you don't want fumed with a marver, or even another piece of glass (as long as you don't accidentally touch 'em)

Oh, and remember you can burn fume off if it overshoots...Well, kind of anyhow

istandalone24/7 · #10 2012-09-10, 4:32am

thanks i've been able to play around a bit and get some interesting results. i'm going to post a pic of a marble (not made by me) that has some "wispy smokey" effects at the top.
i think this is referred to as "crystal growth" but i'm not sure. can someone say if that's the proper term for this effect? it's at the top of this mib:

Bunyip · #11 2012-09-10, 7:35am

That looks like fuming, for sure. Possibly reduced. Probably only silver, and somewhat heavily applied.

When people discuss "crystal growth" though I feel that they're most often referring to distinct colors, like the hint of blue you can see in the fume. As I understand it, silver will actually go through the entire spectrum when struck though I've only seen yellows, blues, reds and purples in my own work and in the work of others, though greens are easily obtained with the addition of gold fume.

I'm not a fume master, my results are very much hit or miss but gosh when it hits it's nice.

Knowledge: {this is a direct quote from a post on the boro forum} Check it out, in the Flow magazine, there was an article called "Amber/Purple Glass - A molecular approach". It's in the Fall 2007 issue - or online if you have access to subscriber benefits. It pretty much gives the rundown on silver as a colorant in borosilicate glass. (google it)

castaway · #12 2012-09-11, 5:03pm

useful information about the properties and temperatures for simax can be found here.
B http://www.kavalier.cz/en/section/32...lass-mass.html