Lampwork Etc.
 
TrueDesign

LE Live Chat

Enter Live Chat

No users in chat


Donate via PayPal to donate@lampworketc.com

Glacial Art Glass


 

Go Back   Lampwork Etc. > Library > Tips, Techniques, and Questions

Tips, Techniques, and Questions -- Technical questions or tips

Reply
 
Thread Tools
  #1  
Old 2006-07-22, 2:58pm
wendbill's Avatar
wendbill wendbill is offline
More ideas than talent
 
Join Date: Sep 17, 2005
Location: Melbourne, Oz
Posts: 2,565
Default But annealed beads don't look any different....

We tested a friend's old scientific kiln yesterday.

I sacrificed some wonky beads for the experiment and they survived just fine. So the question is: Since they don't suddenly have a sign on them saysing "Hey we've been annealed", are there any indicators to look for that would show whether everything happened in the the way it was supposed to?
__________________
Wendy


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 2006-07-22, 5:27pm
LampworkbyLori's Avatar
LampworkbyLori LampworkbyLori is offline
Senior Member
 
Join Date: May 24, 2006
Location: Indianapolis, IN
Posts: 915
Default

I've read of some (negative) color changes happening during annealing for beads with reactive metals in the glass, but other than that.. not that I know of.
__________________
I'm destashing.. If you're looking for something just ask..

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
  #3  
Old 2006-07-22, 5:31pm
Bunyip's Avatar
Bunyip Bunyip is offline
Pyromaniac
 
Join Date: Jun 27, 2006
Location: Out there on the interwebs
Posts: 1,784
Default

I believe you can check glass beads for stress using polarized lenses. The glass without the stress would be annealed.
Reply With Quote
  #4  
Old 2006-07-22, 6:36pm
wendbill's Avatar
wendbill wendbill is offline
More ideas than talent
 
Join Date: Sep 17, 2005
Location: Melbourne, Oz
Posts: 2,565
Default

Do polarised sunglasses count?
__________________
Wendy


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #5  
Old 2006-07-23, 4:04pm
Bunyip's Avatar
Bunyip Bunyip is offline
Pyromaniac
 
Join Date: Jun 27, 2006
Location: Out there on the interwebs
Posts: 1,784
Default

Somehow, I doubt it.
Reply With Quote
  #6  
Old 2006-07-23, 4:36pm
evilglass evilglass is offline
Senior Member
 
Join Date: Nov 12, 2005
Posts: 1,260
Default

You need a polariscope. If memory serves me, it's two polarized lenses placed at 90 degrees to each other. You put your object in the middle (with a light source) and can see the stress that way. I think the object needs to be transparent, too-or something like that.

And as far as I know, yes, polarized sunglass lenses would work. Look up "polariscope" and I bet you'll find what you are after
__________________

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


I've got way cool handmade bags for sale in the Garage Sale area for a buck each!
Reply With Quote
  #7  
Old 2006-07-23, 8:32pm
wendbill's Avatar
wendbill wendbill is offline
More ideas than talent
 
Join Date: Sep 17, 2005
Location: Melbourne, Oz
Posts: 2,565
Default

We pulled out a polarising lense filter for a camera and held that up to a light source and didn't see anythng much in the unnanealed or annealed beads.

However now that I have seen a picture of a polariscope might be worth another try in a slightly different configuration.
__________________
Wendy


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #8  
Old 2006-07-24, 2:50am
wendbill's Avatar
wendbill wendbill is offline
More ideas than talent
 
Join Date: Sep 17, 2005
Location: Melbourne, Oz
Posts: 2,565
Default

Quote:
Originally Posted by LampworkbyLori
I've read of some (negative) color changes happening during annealing for beads with reactive metals in the glass, but other than that.. not that I know of.

Ha ha - with a hot head I get those reactions up front!
__________________
Wendy


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 2006-07-24, 5:23am
Cosmo's Avatar
Cosmo Cosmo is offline
ManBearPig
 
Join Date: Jun 28, 2005
Location: Roanoke, VA
Posts: 8,540
Default

Polariscopes only work on clear glass, or transparents with very little color.
__________________

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
  #10  
Old 2006-07-24, 5:33am
Bunyip's Avatar
Bunyip Bunyip is offline
Pyromaniac
 
Join Date: Jun 27, 2006
Location: Out there on the interwebs
Posts: 1,784
Default

I was in a hurry before, but my answer about polarized sunglasses is correct... Even if the lenses are the correct type, you would have to disassemble the glasses to utilize them as a polariscope. If I recall correctly, Arrow Springs offers a polarizing stress scope for under $50.00, and yes, the glass must be at least somewhat transparent.

I believe you can also buy plastic polarizing filters in sheets relatively cheaply, if you can find them. I know McMow Art Glass has them in stock at their store in Lake Worth, FL for approximately $20.00.

Some Reference material on glass strain: http://www.public.asu.edu/~aomdw/GSI/Glass_Strain.html
Reply With Quote
  #11  
Old 2006-07-24, 7:16am
Cosmo's Avatar
Cosmo Cosmo is offline
ManBearPig
 
Join Date: Jun 28, 2005
Location: Roanoke, VA
Posts: 8,540
Default

You can get polarizing filters at your local photography store. I got a pair of them for $3 a while back.
__________________

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
  #12  
Old 2006-07-24, 4:56pm
LampworkbyLori's Avatar
LampworkbyLori LampworkbyLori is offline
Senior Member
 
Join Date: May 24, 2006
Location: Indianapolis, IN
Posts: 915
Default

I stand corrected! This is very interesting.
__________________
I'm destashing.. If you're looking for something just ask..

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
  #13  
Old 2006-07-24, 9:43pm
Dale M.'s Avatar
Dale M. Dale M. is offline
Gentleman of Leisure
 
Join Date: Jun 10, 2005
Location: A Little Bit West of Yosemite Valley
Posts: 5,200
Default

Annealing is something you have to take a little bit on faith...

IF you know properties of glass and take it to the known annealing temperatures for a reasonable amount of time, you have to trust that the process has happened, and there is no visual indicators process has happened... You have to trust the "science"..

Dale
__________________
You can lead a person to knowledge, but you can't make them think.

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Vendor-Artist-Studio-Teacher Registry

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
San Francisco - A Few Toys Short of a Happy Meal
Reply With Quote
  #14  
Old 2006-07-24, 11:07pm
castaway's Avatar
castaway castaway is offline
sorcerer
 
Join Date: Nov 13, 2005
Location: kangaroo island
Posts: 312
Default

I use a polariscope every day in the normal course of my glass practice. I have built several for friends, you need 2 linear polorising filters (photographic shop )
you need to mount them one above the other with about 50mm ( 2 inches ) between them, you need a small light source beneeth the lower one. turn on the light source and rotate the upper filter untill you cut off as much of the transmitted light as possible when viewed down through both filters. A clear piece of glass with stress when placed between these filters and viewed from above will exhibit a halo effect in the glass. If you make a clear glass ball about 20mm in diameter on the end of a rod, cool it in vermiculite, and place it between the filters you will see a perfect example of stress. This ball should then go into your kiln with your beads to anneal, after which you should check it again, if it has annealed properly there will be no halo. The first of these images is unannealed, the second has been annealed at 480 Deg C for 10 mins.
Bernard
Attached Images
  
Reply With Quote
  #15  
Old 2006-07-25, 1:00am
Kevan's Avatar
Kevan Kevan is offline
Entropy increasing....
 
Join Date: Nov 12, 2005
Location: In a box of paints
Posts: 25,098
Default

Oh that's trippy.
__________________
"I am an artist… I am here to live out loud." Emile Zola
Reply With Quote
  #16  
Old 2006-07-25, 3:15am
Kalera's Avatar
Kalera Kalera is offline
I'm a lilac!
 
Join Date: Jun 09, 2005
Location: Portland, Oregon
Posts: 8,793
Default

Quote:
Originally Posted by castaway
I use a polariscope every day in the normal course of my glass practice. I have built several for friends, you need 2 linear polorising filters (photographic shop )
you need to mount them one above the other with about 50mm ( 2 inches ) between them, you need a small light source beneeth the lower one. turn on the light source and rotate the upper filter untill you cut off as much of the transmitted light as possible when viewed down through both filters. A clear piece of glass with stress when placed between these filters and viewed from above will exhibit a halo effect in the glass. If you make a clear glass ball about 20mm in diameter on the end of a rod, cool it in vermiculite, and place it between the filters you will see a perfect example of stress. This ball should then go into your kiln with your beads to anneal, after which you should check it again, if it has annealed properly there will be no halo. The first of these images is unannealed, the second has been annealed at 480 Deg C for 10 mins.
Bernard
Soooo cool Bernard! Thanks for posting those pics!
__________________
-Kalera

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
  #17  
Old 2006-07-25, 4:19am
wendbill's Avatar
wendbill wendbill is offline
More ideas than talent
 
Join Date: Sep 17, 2005
Location: Melbourne, Oz
Posts: 2,565
Default

Quote:
Originally Posted by Dale M.
Annealing is something you have to take a little bit on faith...

IF you know properties of glass and take it to the known annealing temperatures for a reasonable amount of time, you have to trust that the process has happened, and there is no visual indicators process has happened... You have to trust the "science"..

Dale
I trust the science - I want to know if I can trust the kiln!

I'm also curious about how much stress is in the unnanealed beads given that most of my beads are pretty small anyway.
__________________
Wendy


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #18  
Old 2006-07-25, 4:32am
wendbill's Avatar
wendbill wendbill is offline
More ideas than talent
 
Join Date: Sep 17, 2005
Location: Melbourne, Oz
Posts: 2,565
Default

Quote:
Originally Posted by castaway
I use a polariscope every day in the normal course of my glass practice. I have built several for friends, you need 2 linear polorising filters (photographic shop )
you need to mount them one above the other with about 50mm ( 2 inches ) between them, you need a small light source beneeth the lower one. turn on the light source and rotate the upper filter untill you cut off as much of the transmitted light as possible when viewed down through both filters. A clear piece of glass with stress when placed between these filters and viewed from above will exhibit a halo effect in the glass. If you make a clear glass ball about 20mm in diameter on the end of a rod, cool it in vermiculite, and place it between the filters you will see a perfect example of stress. This ball should then go into your kiln with your beads to anneal, after which you should check it again, if it has annealed properly there will be no halo. The first of these images is unannealed, the second has been annealed at 480 Deg C for 10 mins.
Bernard
Thanks Bernard. That shows it really well. The only other photo I had was in a Warm Glass book and it wasn't even in focus.

I'm hoping that's whetted hubby's interest enough to make me one as a side project when he's in at the studio tomorrow...
__________________
Wendy


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #19  
Old 2006-07-25, 9:23am
Dale M.'s Avatar
Dale M. Dale M. is offline
Gentleman of Leisure
 
Join Date: Jun 10, 2005
Location: A Little Bit West of Yosemite Valley
Posts: 5,200
Default

Quote:
Originally Posted by wendbill
I trust the science - I want to know if I can trust the kiln!

You do simple temperature test on kiln... Place a rod of glass, a couple inches long on two supports (one at each end)... Then take kiln up to annealing point (968 deg. F.) for Effetre and if rod does NOT sag, you are probably good temperature wise or kiln is at least running "cool", then take kiln up beyond annealing point, say to 1100/1200 degs f. if rod sags then kiln is reaching proper temperatures.... Its just simply calibrating the kiln (pyrometer) to test temperatures it achieves...

Dale
__________________
You can lead a person to knowledge, but you can't make them think.

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Vendor-Artist-Studio-Teacher Registry

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
San Francisco - A Few Toys Short of a Happy Meal

Last edited by Dale M.; 2006-07-25 at 7:40pm.
Reply With Quote
  #20  
Old 2006-07-25, 9:12pm
wendbill's Avatar
wendbill wendbill is offline
More ideas than talent
 
Join Date: Sep 17, 2005
Location: Melbourne, Oz
Posts: 2,565
Default

Something else to try this weekend!
__________________
Wendy


To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
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 11:11am.


Powered by vBulletin® Version 3.7.5
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Your IP: 18.212.87.137