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Alaska
2010-06-03, 1:08am
Have not found any definitive information about the requirements to slump half boro beads into cabs. Beads are in the range of 18 to 22 mm (diameter) and 9 to 10 mm thick. i.e. broken in half beads with release removed.

Someone did suggest 2000 F for 20 minutes but not sure if that will produce cabs or a sheet of glass.

Anyone have any specifics for NS mixed with Simax clear?

Bunyip
2010-06-03, 4:42am
Why not just give it a whirl? :) Start low, add 100 degrees every 20 mins until you get the results you desire?

This thread on warmglass.com has some good info (http://www.warmglass.com/phpBB/viewtopic.php?f=2&t=18935&start=0&st=0&sk=t&sd=a)

Cosmo
2010-06-03, 5:02am
2000 is too hot. I have slumped borosilicate at around 1700. Doing so without devitrification is a different matter all together, however...

Bunyip
2010-06-03, 6:31am
Can you flame polish the boro after slumping? Or is it the devit of death?

HWCGlass
2010-06-03, 8:09am
i know this sounds wrong, but with objects that size you are far better off using the microwave than your kiln. true story; nuke 'um, then move them to your kiln.

search here on LE for microwave fusing.

Mr. Smiley
2010-06-03, 6:49pm
Yep... microwave kiln works awesome...

Mr. Smiley
2010-06-03, 6:50pm
do it in a throw away microwave, outside... ;)

Bunyip
2010-06-04, 5:07am
Garage sale meecrowavies are the best. It's amazing what you can pick up for cheap.

Alaska
2010-06-07, 5:23pm
The threads just do not support the use of a microwave. However, it is an interesting idea. Just heat the glass up to red, then microwave. But perhaps, it would be better to place the half bead on a ceramic plate with kiln wash and heat to the desired slump and then anneal with only the torch. Or even use a graphic plate without kiln wash.

Or as suggested, place in a kiln at 1700 F and see what happens. Looks like this will be a matter of experimentation as different colors and different sizes will all have a slightly different viscosity which will make for a lot of trial and mostly error on my part.....

Bunyip
2010-06-08, 5:33am
I'm not sure which threads you're talking about, but are you aware that there is a special microwave kiln you can get? They work awesome and are (relatively) inexpensive. I've only seen them used with soft glass, but I'd tend to take Harold's word that they work with boro as well...

Alaska
2010-06-08, 4:03pm
Here is the thread....

http://www.lampworketc.com/forums/search.php?searchid=5527568

See what you think.

Bunyip
2010-06-08, 7:11pm
That link didn't work sorry.

Alaska
2010-06-08, 7:59pm
You are correct in that the link does not work.

Just search for microwave fusing in the LE search box and there will be 10 threads to view.

Bunyip
2010-06-09, 6:04am
I see what you mean, and you can get an 8" x 8" x 4" kiln for a round $300.00 to $400.00 - not unreasonably more than the microwave kiln + microwave.

I've seen the microwave kilns in action - as long as you go with the American-made one they're pretty handy. On the other hand they only last a couple hundred firings. On the third hand the firing is done in 10 minutes... and of course the fourth hand: will it do boro? Harold says yes...

getdul981
2010-06-09, 6:26am
I was just wondering how many hands you had.

Alaska
2010-06-09, 1:57pm
Think I will pass on the microwave aspect. Great for warming up food but not so much for cooking glass IMO.

Did find a nice tutorial on another site and they suggested 1350. Good for soft, but a bit on the low side for boro. Will try 1700 to 2000 F and see what happens. It is just one of those time vs temperature things to achieve the desired degree of slump.

Have a nice top loading small Paragon pottery kiln which will go to cone 04. It has been retrofitted with a Fuji PXR-3 for ease of operation. With plenty of kiln wash available it looks like the project can move forward.

Thanks for all of the suggestions......

Mr. Smiley
2010-06-11, 5:44am
1800 and watch it... as soon as it goes "glossy" molten, crash it to annealing temp... and i mean OPEN IT UP... normally you have to let it fall below 1050, because as soon as you close it, it climbs way up again...

The microwave kilns work for boro... have seen it...

It's not just a microwave all by itself... there seems to be some confusion about that. This is totally different than getting the glass liquid and ploping it in the microwave... that's a neat parlor trick, but not what we're suggesting. :lol:

Bunyip
2010-06-11, 5:59am
good link for those who might be confusificated: http://www.microwavekiln.com/KILNINSTRUCTIONS.HTM

Not an endorsement just a quick google search

ginkgoglass
2010-06-11, 7:45am
Brent is right -- this is the big issue with borosilicate fusing is that it is difficult keep it from devitrification. The kiln crash is crucial to get it out of that temperature range as soon as possible.

HWCGlass
2010-06-17, 7:31am
before:
http://hphotos-snc3.fbcdn.net/hs092.snc3/15938_1254148763762_1530859917_30699849_127987_n.j pg

After:
http://sphotos.ak.fbcdn.net/hphotos-ak-snc3/hs114.snc3/16133_1253670151797_1530859917_30698880_6609815_n. jpg

total hand to hand elapsed time, less than 20 minutes.

the microwave and boro is the same as any other piece of equipment and boro; it doesn't work, except it does.

celtcraft
2010-06-18, 7:16pm
207961207960I don't remember what temp I took em up to but the last time I tried to melt split boro beads into cabs, the temp definitely messed with the color. The one with all the dots was a base of GA black pearl. Color not even close to the original...

Kerry
www.celtcraft.etsy.com

Bunyip
2010-06-18, 9:29pm
I have heard that it is possible to have a kiln with a reducing atmosphere...maybe that's what happened there? Looks like there's devit on the one in the right-hand pic too. Out of curiosity did you try to run the black pearl through a regular annealing cycle after it was slumped? That green color is kind of weird..