Lampwork Etc.
 
AKDesign

LE Live Chat

Enter Live Chat

No users in chat


Frantz Art Glass & Supply

Beads of Courage


 

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

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

Reply
 
Thread Tools
  #1  
Old 2012-12-19, 9:12pm
hilltowner hilltowner is offline
Junior Member
 
Join Date: Oct 15, 2012
Posts: 4
Question thermal bead cracks due to studio in basement?

We are new to lampworking. We are having trouble with beads cracking before they are annealed. What may be causing this and how can we keep it from happening?

After doing some reading, I'm pretty sure they are thermal cracks. They are right down the middle of the bead. My daughter is working in an unheated basement, due to space and safety concerns. She has an electric heater, but it still cold down there. Could this be the issue? If so, what options do we have?

Thanks!

Marla
Reply With Quote
  #2  
Old 2012-12-19, 9:18pm
dusty dusty is offline
Senior Member
 
Join Date: Jul 18, 2007
Posts: 568
Default

What is your daughter you doing with them directly after making them? If they go from flame temperatures to just room temp, it doesn't matter much whether it's 30 degrees F or 100, because it's potentially dropping a whole 2000+.
Reply With Quote
  #3  
Old 2012-12-19, 9:19pm
dmmcnair's Avatar
dmmcnair dmmcnair is offline
....uhm...
 
Join Date: Sep 24, 2012
Location: Texas
Posts: 1,155
Default

Maria, are you batch annealing or do you put the beads right into a kiln? If you are batch annealing what do you put the beads into while you wait to anneal them?
__________________

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 2012-12-19, 9:28pm
KJohn's Avatar
KJohn KJohn is offline
Slogan Challenged...
 
Join Date: Mar 21, 2009
Location: Maricopa, Arizona
Posts: 6,273
Default

Hi Marla.

Options include a thicker fiber blanket if she is using one. I don't know if it matters you heat the vermaculite in a crock pot. The size and shape matter. I find thermal cracks occur more often with larger, pressed or sculpted beads with different size parts. A good rule of thumb is the glass on either side of the bead should not be thinner than the width of the mandrel, or there will be thermal cracks.

Flame annealing will definitely help. This means you even out the heat through the bead by "soaking" it at the tip of the flame for a minute or so. This is not proper annealing, and you will still need to do that, but this will help the bead cool evenly and hopefully prevent cracking.

Edited to add : yes, definitely use something to place the bead into if you are batch annealing later.

HTH
--------------
Kristin ~

Last edited by KJohn; 2012-12-19 at 9:30pm. Reason: adding
Reply With Quote
  #5  
Old 2012-12-19, 9:31pm
losthelm losthelm is offline
Senior Member
 
Join Date: May 27, 2008
Location: Albion NY
Posts: 517
Default

What ventilation do you have in the basement.
Are you useing fiber blanket or vermiculite to slow down the cooling?
Do the beads have overly thin spots?
Reply With Quote
  #6  
Old 2012-12-19, 10:34pm
hilltowner hilltowner is offline
Junior Member
 
Join Date: Oct 15, 2012
Posts: 4
Default

Thank you so much for all of your replies and ideas! It is so appreciated.

Part of the problem is we don't own a kiln (yet) so we bring them to her teacher's kiln when we get the chance. As soon as my daughter completes a bead she puts it in a fiber blanket. Just as she does in class, where the beads are placed in a fiber blanket for the instructor to bring home and anneal later. With her class beads,cracking hasn't been an issue (but she has only done round beads in class, so the different shapes she does at home may be the problem, along with extreme temperature changes).

Another issue which is a possibility is she is making different shaped beads, like octupi, snowmen, and horses. She's only been lampworking for a couple of months and is very new to it, so this may be a problem, as kjohn mentioned. I'll also mention the flame annealing to her as well.

For losthelm, I built her a ventilation system out of foam board, aluminum tape, and a greenhouse fan that was 720 CFM. I bought the beginner's bead kit from Howacoglass.com that has a small hot head torch. For Dusty, Dawn and losthelm, we use a basic fiber blanket to cool the beads down. They are later batch annealed at my daughter's teacher's house. I don't think the beads have overly thin spots, but they are not just round but different shapes.


Thanks for your time and expertise.

Last edited by hilltowner; 2012-12-19 at 10:37pm.
Reply With Quote
  #7  
Old 2012-12-19, 11:44pm
dmmcnair's Avatar
dmmcnair dmmcnair is offline
....uhm...
 
Join Date: Sep 24, 2012
Location: Texas
Posts: 1,155
Default

I always find it better when doing sculptures to put them straight into a garaging kiln...since there are different thicknesses to the glass, the thinner parts will cool down so much quicker than the thicker. And with how cold it is in the basement, even with the fiber blanket it's probably cooling too quickly. It might be better for your daughter to keep making round beads instead of sculpture until you get a kiln. Although there are folks here with way more experience than me that may have ideas to keep sculptures from cracking until you can anneal.

I have to add, that if you have a kiln, and garage while torching...it will warm up her area very nicely. At least mine does. It was really hot when it was warmer...it's pretty darn nice now.
__________________

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
  #8  
Old 2012-12-20, 2:20am
Alaska Alaska is offline
Alaska Boro
 
Join Date: Dec 10, 2009
Location: Anchorage, Alaska
Posts: 1,065
Default

With boro the same issue can be caused by using colors that have a tendency to crack. i.e. NS white is one such color if thick. That solution is to first use boro clear as the base and then build up the color on top. Or mix the NS white with boro.

Have batch annealed beads with very few cracking issues. However, marbles are a different issue!!
Reply With Quote
  #9  
Old 2012-12-20, 2:53am
Anne Londez's Avatar
Anne Londez Anne Londez is offline
Senior Member
 
Join Date: Apr 11, 2006
Location: Switzerland
Posts: 575
Default

With soft glass there is that tendency too. In the Effetre assortment for example the COEs are not all exactly 104 and some combinations of colors are known to be troublesome, like yellow and cobalt. That puts additional tension into the beads. As long as you are batch annealing, I would keep the shapes uniform and try not to mix too many colors in one bead.
__________________
Anne

Sea Rocks Tutorial
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
- Ebook
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
- Follow me on
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
- My
To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
shop
Reply With Quote
  #10  
Old 2012-12-20, 3:06am
Role Role is offline
Cave Dweller
 
Join Date: Mar 29, 2012
Posts: 275
Default

We bench cool (no blanket, no vermiculite) soft glass all the time with
no cracks and batch anneal at a later date.

The cracking problem is caused by having uneven heat in the glass
as it cools.
(one part of the bead is cooler and contracting faster so it cracks)

Try to make sure there is even heat throughout the bead when it is
removed from the flame, keep spinning it until there is no visible heat
indication, then spin it a bit more because it's still hotter than Hades,
and finally put it into the thermal blanket.
(heat travels upward, rotation helps to give the heat much more even
distribution in the glass as it cools.)
__________________

To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts.
Reply With Quote
  #11  
Old 2012-12-20, 7:28am
cgbeads's Avatar
cgbeads cgbeads is offline
Senior Member
 
Join Date: Aug 28, 2005
Location: Sanger, Tx
Posts: 3,552
Default

Since your basement is cold the fiber blanket will be cold too. Try using vermiculite in a heated crock pot instead.

-Donna
__________________


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

Donna Felkner -
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 2012-12-20, 9:44am
dusty dusty is offline
Senior Member
 
Join Date: Jul 18, 2007
Posts: 568
Default

I like the annealing bubbles from ArtCoInc better than vermiculite.
Reply With Quote
  #13  
Old 2012-12-20, 3:44pm
hilltowner hilltowner is offline
Junior Member
 
Join Date: Oct 15, 2012
Posts: 4
Default

Thanks to everyone for all their help. We did get some vermiculite for now, but ordered some of the annealing bubbles, too. Malcolm at ArtCoInc was really nice!

I think a lot of this is learning to keep the bead at a consistent temperature after it is finished. My daughter has only been doing lampworking for a couple of months, so she is still getting familiar with these things. She also has only done classes on round beads, so is struggling with the sculpted beads she wants to make. Fortunately, she has a great teacher and after Christmas we'll schedule some time for her to work with her teacher on sculpted beads.

For now, we'll use vermiculite and focus on round, symmetrical beads.

Thanks again for everybody's posts!

Happy Holidays!

Marla
Reply With Quote
  #14  
Old 2012-12-20, 10:44pm
losthelm losthelm is offline
Senior Member
 
Join Date: May 27, 2008
Location: Albion NY
Posts: 517
Default

Round,barrels,lentel/disk and cones beads are good for basics to build on.

You can try heating the bead evenly and slowly backing it out of the flame untill it's hard, then put it in the bead "hot tub" to soak.

Expect to loose a few as you learn and keep praticeing.
Reply With Quote
  #15  
Old 2012-12-20, 11:00pm
dmmcnair's Avatar
dmmcnair dmmcnair is offline
....uhm...
 
Join Date: Sep 24, 2012
Location: Texas
Posts: 1,155
Default

And practicing dot placement and size and applying stringer can be beneficial to working sculptures. If she wants to do anything with eyes...she needs to be able to place dots well. I personally like sculptures too, but I have to master basics to make my sculptures good. Post some of your daughters beads in the Newbie/Intermediate thread, we'd love to see and we are very supportive. Everyone on this forum is very supportive.
__________________

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
  #16  
Old 2012-12-21, 12:17am
hilltowner hilltowner is offline
Junior Member
 
Join Date: Oct 15, 2012
Posts: 4
Default

Thanks again everyone. Dawn, I'll get her to post a few when she feels confident enough.

You guys have been wonderful!!!


Marla and Amy
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 2:34am.


Powered by vBulletin® Version 3.7.5
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Your IP: 100.26.140.179