Lampwork Etc.
 
AKDesign

LE Live Chat

Enter Live Chat

No users in chat


Jelveh Designs - Glass Beads Torched One-by-One

Beads of Courage


 

Go Back   Lampwork Etc. > Library > Boro Room

Boro Room -- For Boro-related tips, techniques, and questions.

Reply
 
Thread Tools
  #1  
Old 2014-11-08, 9:29am
untamedrose's Avatar
untamedrose untamedrose is offline
Senior Member
 
Join Date: Jul 22, 2011
Posts: 410
Default Crackin as I type :/

So made a starry night last night with an opal inside. Garaged at 900, annealed at 1130ish for 2 hours then left to cool over night. Everything else made in that lot is fine.

This one however.
Before...

5 mins later it had the big top crack about ten mins after that a second one appeared....

And nope I didnt drop it didnt even set it down hard or anything like that....
__________________

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #2  
Old 2014-11-08, 1:01pm
Sue in Maine's Avatar
Sue in Maine Sue in Maine is offline
Senior Member
 
Join Date: Jun 14, 2005
Location: The Rocky Coast State!
Posts: 6,620
Default

Was it a gilson (gibson?) opal? They are compatible with boro. I wonder what went wrong.

Sue
__________________
Sue Walsh
The past is history,
The future is a mystery
and the present is a gift.
Reply With Quote
  #3  
Old 2014-11-08, 5:04pm
untamedrose's Avatar
untamedrose untamedrose is offline
Senior Member
 
Join Date: Jul 22, 2011
Posts: 410
Default

ya it's a gibson came from profound, so Im sure it is :/ I am wondering that too :/

Reworked it today its in the kiln again. See what happens the second time around.
__________________

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #4  
Old 2014-11-08, 7:50pm
Sue in Maine's Avatar
Sue in Maine Sue in Maine is offline
Senior Member
 
Join Date: Jun 14, 2005
Location: The Rocky Coast State!
Posts: 6,620
Default

Before I knew the correct opal to use was Gibson, I brought some down to Playing With Fire and Ed was game to try it. The regular opal went pffftttt... and looked like a cloud of powder inside the boro. I don't remember for sure but I think it wound up being water dunked.

I've never tried the correct opal in boro. I've seen them though and they're beautiful.

Good luck with this next one.

Sue
__________________
Sue Walsh
The past is history,
The future is a mystery
and the present is a gift.
Reply With Quote
  #5  
Old 2014-11-09, 9:26am
LarryC LarryC is offline
Senior Member
 
Join Date: Mar 07, 2011
Location: Northern California
Posts: 2,023
Default

why did you anneal at 1130? Way to high for certain colors. 1050 is more appropriate.
Reply With Quote
  #6  
Old 2014-11-09, 11:47am
untamedrose's Avatar
untamedrose untamedrose is offline
Senior Member
 
Join Date: Jul 22, 2011
Posts: 410
Default

Had some amber purple stuffs in there....
__________________

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #7  
Old 2014-11-09, 12:23pm
LarryC LarryC is offline
Senior Member
 
Join Date: Mar 07, 2011
Location: Northern California
Posts: 2,023
Default

Quote:
Originally Posted by untamedrose View Post
Had some amber purple stuffs in there....
Anneal at 1050 and try to minimize the bubbles. Either one of those factors could cause problems.
Reply With Quote
  #8  
Old 2014-11-11, 12:17pm
Cosmo's Avatar
Cosmo Cosmo is offline
ManBearPig
 
Join Date: Jun 28, 2005
Location: Roanoke, VA
Posts: 8,540
Default

The high annealing temp and long hold time are the issues. Never go over 1050 with anything with an opal in it, and don't garage it any longer than you have to.
__________________

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #9  
Old 2014-11-13, 12:54pm
istandalone24/7's Avatar
istandalone24/7 istandalone24/7 is offline
Senior Member
 
Join Date: Mar 14, 2012
Location: Bennington, VT
Posts: 1,776
Default

wait, so it's not a good idea to kiln strike something that contains an opal and a striking color?
hogwash, i do it all the time.
my guess is that somewhere surrounding that opal there was a bubble that wasn't "smooth". after i encase my opals and if there is any bubbles at all, i get the opal gather as hot as i dare in order to round out any bubbles.
__________________
now i've got a Mirage
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #10  
Old 2014-11-13, 1:01pm
LarryC LarryC is offline
Senior Member
 
Join Date: Mar 07, 2011
Location: Northern California
Posts: 2,023
Default

Quote:
Originally Posted by istandalone24/7 View Post
wait, so it's not a good idea to kiln strike something that contains an opal and a striking color?
hogwash, i do it all the time.
my guess is that somewhere surrounding that opal there was a bubble that wasn't "smooth". after i encase my opals and if there is any bubbles at all, i get the opal gather as hot as i dare in order to round out any bubbles.
You kiln strike for two hours? That is how long it was soaked at 1130. I dont think the opal had much to do with it. My supplier does suggest a higher temp anneal for the opals alone after encasing but I would not do that to most Boro color rod. As I said already one of those bubbles could also have been the culprit.
Reply With Quote
  #11  
Old 2014-11-14, 7:21am
istandalone24/7's Avatar
istandalone24/7 istandalone24/7 is offline
Senior Member
 
Join Date: Mar 14, 2012
Location: Bennington, VT
Posts: 1,776
Default

where are you getting two hours? 25 minutes at 1125f is what i do. then down to 1050 for however long/thick the piece is.

2 hours at striking temps just might be problematic.
__________________
now i've got a Mirage
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #12  
Old 2014-11-14, 8:19am
nevadaglass nevadaglass is offline
Senior Member
 
Join Date: Oct 26, 2006
Location: west
Posts: 811
Default

from original post

"Garaged at 900, annealed at 1130ish for 2 hours then left to cool over night"

Quote:
Originally Posted by istandalone24/7 View Post
where are you getting two hours? 25 minutes at 1125f is what i do. then down to 1050 for however long/thick the piece is.

2 hours at striking temps just might be problematic.
Reply With Quote
  #13  
Old 2014-11-14, 9:21am
istandalone24/7's Avatar
istandalone24/7 istandalone24/7 is offline
Senior Member
 
Join Date: Mar 14, 2012
Location: Bennington, VT
Posts: 1,776
Default

ah, i thought LarryC was referring to my reply, as that is the one he quoted.
carry on
__________________
now i've got a Mirage
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #14  
Old 2014-11-14, 9:46am
dragonart glass's Avatar
dragonart glass dragonart glass is offline
just another glass addict
 
Join Date: Feb 06, 2006
Location: Santa Cruz
Posts: 396
Default

Soaking at 1130 is not annealing. Boro is forgiving so maybe it gets misunderstood. Annealing occurs when the glass is brought through the strain point very slowly and evenly throughout. The strain point in boro is roughly between 800 and 950 degrees. Even though brick kilns cool slowly it is not necessarily slow enough. I am no expert on this, but this is how I learned it. I know there is lots of info out there on it for soft glass. The process is the same even if temps and glass is different. Sorry I can't provide a link. in my experience pieces with opals need to be well annealed and fully cooled to not crack.
__________________
Polly

"Confidence, like art, never comes from having all the answers; it comes from being open to all the questions."
-Earl Gray Stevens-

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #15  
Old 2014-11-14, 12:55pm
e. mort's Avatar
e. mort e. mort is offline
Senior Member
 
Join Date: Nov 06, 2005
Location: Austin - Texas
Posts: 2,708
Default

Annealing occurs before you go through the strain point. however, you can still thermal shock a piece if you take it too quickly through the strain point even after it has been annealed.
__________________
Eric

The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing. ---- Albert Einstein


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #16  
Old 2014-11-14, 12:57pm
e. mort's Avatar
e. mort e. mort is offline
Senior Member
 
Join Date: Nov 06, 2005
Location: Austin - Texas
Posts: 2,708
Default

annealing point is 1050. strain point is 950. this link explains it in depth http://www.glassalchemy.com/relieving_stress
__________________
Eric

The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing. ---- Albert Einstein


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #17  
Old 2014-11-15, 6:38am
Dragonharper's Avatar
Dragonharper Dragonharper is offline
Now part of the Dark Side
 
Join Date: Jul 02, 2010
Location: North Central PA
Posts: 966
Default

The annealing process consists of two steps:
1: Reducing the stress in the glass from forming.
2: Slowly reducing the temperature below the strain point so that new stresses are not added. ( The strain point is the temperature at which any stress present in the glass, before cooling below the strain point, become permanent, until a subsequent annealing cycle is performed, and any stress introduced into the glass below the strain point temperature is temporary until the temperature in the glass equalizes.

The trick is to find a temperature, the annealing temperature, where the glass moves enough to equalize the stress forces built up during forming but does not move enough to deform. Typically for boro this is 1050 dF. Annealing can be accomplished at any temperature above the strain point but, the closer to the strain point the longer the glass needs to sit at that temperature. Some boro color has a nasty property of undergoing a COE shift when held above a certian temperature for a long time, that is why the manufacturer of the glass publishes garaging and annealing temps for each color.
__________________
Roy
Hot glass does not crack.
Unless it is glowing and drippy, hot glass looks like cold glass.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump




All times are GMT -7. The time now is 3:10am.


Powered by vBulletin® Version 3.7.5
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Your IP: 44.201.24.171