Cracks in Large Focal Beads

Boopdidoop · #1 2006-02-17, 9:34am

Please ignore my sniffles as I am almost done crying. This will be my first posting and I would be so grateful if someone could solve this problem(s). In the last two days I have made 2 very good looking, LARGE, encased focal beads. The interiors made with a variety of Moretti twisties, encased dicroic stringer and small chunks of clear Lausha and other Moretti colors. The outside was incased with clear Lauscha. I use a hothead torch. The first bead developed 2 small cracks after I removed it from my Chili Pepper annealer. It was apple shaped and they happened on the larger end from the outer edge inward. I assumed I didn't evenly distribute the heat prior to putting it in the kiln and probably didn't get it hot enough throughout either. I did manage to slowly reheat it yesterday and heal the cracks. So far it looks ok except it developed a hazy appearance. When I finished I decided to try again. The same thing, twisties, encased dicro, and Moretti, big blobs of clear Lausha then encased with Lausha. This time it was even LARGER...lol (1 1/4" by 3/4"). It was more even from end to end through one end was wider. I took extra time to heat it through and through evenly and put it in the Chili Pepper at 960 degrees (my normal temp) at what I thought was a pretty good glow. I annealed it for 3 hours at 960 degrees then ramped it down to 800 degrees for a short soak then down to 400 degrees before it shut off. So sure that it was going to be perfect, I could wait to see it and took it out at about 125 degrees and it was gorgeous! My husband instantly claimed it as his and I stared at it for an hour. No cracks, very clear, gorgeous! I put it on my nightstand on a lovely soft kleenex bed and went to sleep. The first thing I did this morning was look it through and there it was....the crack. Again and the larger end from the outer edge inward and small. It looks like just the Lausha layer on the outside. I LOVE making these large focals but it's so frustrating. Are my annealing and ramp temps off? Is it the scrap pieces I use - like an incompatability issue? Did I take it out to warm? Any advise would be deeply appreciated because this style of bead is my favorite. By the way, you are all awesome and this is my favorite web site ever. Hope I did this posting right..

GinnyHampton · #2 2006-02-17, 1:10pm

Quote:

Originally Posted by Boopdidoop

It looks like just the Lausha layer on the outside.

Does this sentance mean that it looks like just your outside encasing layer looks like it's kind of sheared off?? And your crack doesn't go to the core . . . kinda looks like it was put through a slicer or something?? If so, that would most likely be an incompatability crack. Are you sure your dichro is 104 COE like the rest of your glass??

A thermal crack will usually run the length of your bead, along the bead hole.

Boopdidoop · #3 2006-02-17, 6:22pm

Thanks for helping Ginny, I really appreciate it. It does appear to be the encasing layer only and not slicing through the center but more tip thowards the middle. By the way, when I got home tonight I found another "sliver" of a crack appeared on the other thinner end. Again it looks like encasing layer only from end towards the center. Not sheared off and not sliced, you cant feel it by touch yet, just a visual. So maybe a more thermal problem then an incompatiblity problem?

CharleneN · #4 2006-02-17, 7:17pm

You've gotten 2 great answers from 2 very experienced beadmakers. I am not sure I can add much here.

I make large encased beads also and I do use Lauscha for the encasing layer. I mix Effetre, Vetrofond and Lauscha in one bead a lot of the time.

I would try 2 things.

When you check the glow on your bead do it in an area slightly darker than your work bench lighting. Be sure the glow is even through out the entire bead. You may have some cold spots on the ends that you're not aware of. I try very hard to put my encased beads in evenly glowing and just cooled off enough that the outside tinks if I tap it.

If that doesn't work, I would try leaving out the dichro and seeing what happens.

Also what's your full annealing schedule. Big beads with lots of diverse elements like slower schedules.

I'm sure you'll figure this out!

Boopdidoop · #5 2006-02-17, 7:22pm

Hi Kimberly,

I just ran down and checked the schedule on my Chili and the ramp schedule was 550 degrees per hour down to 400 degrees then off. I used that schedule last time I brought cold beads to annealing and thought that might be ok. ( just to explain a little - I have only recently purchased the Chili and used to use a fiber blanet then annealed in my floor kiln. I was never succesful then with the LARGE focals and have just started to try again to be CRUSHED lol.......thinking my lack of an annealer was the problem. Soooooo I would love to get an idea of an ideal schedule for the LARGE ones (and I promise I won't peak...urgh). I think everything glass-wise is compatible ok. As far as the glow, I have been thinking all day about that (it takes a pea brain a little while) and I think that a nice "Glow" for Lausha clear is sort of clear orangey shade and I wonder to what depth should a "glow" go to? For instance, the center parts where made of blues and whites, so should I have seen the white glass go clear and risk losing my design? or is there an in-between? I will gladly try another clear but my local supply place is limited and other clears have burned and been cloudy..what type do you suggest?

I won't let you give up on me either! lolololol

From a trying and grateful pal,

Peggy (Boopdidoop)

CharleneN · #6 2006-02-17, 7:31pm

Ok..that's probably the problem right there.

Here' my schedule

960 anneal temp hold for 1 1/2 hours

Ramp down to 750 (well below strain point) at no more than 100 degrees an hour.

Then ramp down from 750 to 600 at 240 degrees per hour.

Don't take them out till the kiln is really cool.

I did some experiments to see how fast my kiln ramped down to room temp after it was shut off. I came to the conclusion that at 600 degrees it cooled down on it's own no faster than 240 degrees per hour so I am safe shutting it off at that temp. Your kiln may vary so it's worh doing so experiments.

As far as glow is concerned, you should not being seeing white in the center go clear. Just be sure it's cooled just enough to hear a tink when you tap it. And be sure the glow is even.

This bead is about the size of yours.

Good luck!

Boopdidoop · #7 2006-02-17, 7:45pm

Oh Charlene!....any advise as to how I should program my Chili would be much appreciated. I have only 2 programs so far...cold to annealing temp and a straight in temp of 960 degrees with a 10-45 min ramp time (for most of my normal beads) then off. I haven't been doing the LARGE ones since the kiln appeared (via my DH! Smooch) and can program this thing to stand on it's head if thats what it takes!!!!!! I love it. What's your secret and thanks for taking the time...

?

Boopdidoop · #8 2006-02-17, 7:54pm

Thanks Charlene,

I missed you by minutes and I will re-read your second reply in detail tomorrow a.m. I AM GOING TO PICK YOUR BRAIN!! Thanks until then.

hummingbird3172 · #9 2006-02-17, 9:06pm

Just to put my two cents in....I make a lot of large encased beads...I was using a HH until very recently....I had the same thing happen to me before...the bead was fine (or so I thought) and then it cracked a day or so later...I cheated and pulled my bead out before it reached room temp...I know that was part of the problem.

I also make sure my bead is totally reheated through before I put it in the kiln...just in case it has cooled too much in some parts...doing these things have helped me avoid cracks.

When I was using my HH I really loved the vetrofond clear...even better than lauscha...it is less expensive too!

I am sorry about your bead, I'll bet it was gorgeous! I know it can be pretty heartbreaking when that happens.

CharleneN · #10 2006-02-18, 7:26am

Hi Peggy,

I don't have a chili pepper kiln so I'm not sure what type of controller it has.

My paragon has an Orton Sentry Express 3.0. If your kiln happens to have the same controller I could walk you through it if you need the help. If it doesn't, and you need help with it I would suggest starting another thread specifically asking for that help. Someone here will be sure to chime in!

I'll answer anything else that I can.

I do think it's the thermal issues....a too fast ramp and probably too early shut down plus probably coming out to early and maybe not evenly heated before going into the kiln. All thermal issues.

It's important to move the temp of the glass slowly from the anneal temp down to past the strain point before you increase the speed of the ramp down. The strain point is slightly different for the different types of glass and since all kilns could read abit off in temp it's best to ramp down well past the strain point before speeding it up. That's why I go to 750 before increasing the amount per minute drop in degrees.

I just got out of work and I'm brain dead so I hope that made sense.

Also, you can ramp up when batch annealing much faster than you can ramp down. Ramping down must always been done slowly and gently. The bigger the bead with more different ingredients such as frit, silver, dichro...the longer the anneal time and slower the ramp....but in truth I use the same ramp for everything I just increase my annealling time.

I hope this has helped.

Boopdidoop · #11 2006-02-18, 11:04am

Thanks again Charlene. You've given me hope..

. I am going to try again this afternoon with your ramping schedule. I promise to control myself and not look until it's cool. Everything made perfect sense and I really appreciate the info. I think my kiln was coming down pretty quickly and instead of programming all the extra annealing time I needed to make sure it came down slower. I didn't know you could ramp up faster then down. I actually thought the opposite. I will let you know how it goes. I can't wait!

Peggy

Boopdidoop · #12 2006-02-18, 11:17am

Thanks Anna,

Your right, I put the "i" in sigh that day. I was wondering if my HH was just not hot enough but I have learned to have patience. What did you switch to? I have been using what I can get at my local supply shop as far as glass selection. They don't have Vetrofond and don't really cater to Lampworkers. Do you order your glass or go to a shop? I may have to broaden my horizons. Thanks for your 2 cents, I'll pay you back some day.

Peggy

Islandgirl · #13 2006-02-18, 12:19pm

Hi

circular end cracks don't appear to be your problem... but the last thing I do is heat both ends of my bead before I stick it in the kiln... Your pyrometer could be off a little too try increasing the initial annealing temp by 15 or 20 degrees...

Lynne

www.fireballbeeds.com

Islandgirl · #14 2006-02-18, 12:21pm

Hi

circular end cracks don't appear to be your problem... but the last thing I do is heat both ends of my bead before I stick it in the kiln... Your pyrometer could be off a little too try increasing the initial annealing temp by 15 or 20 degrees...

I use clear vetrephone too... or moretti... just don't get the moretti too hot and it works not to badly....

Lynne

www.fireballbeeds.com

CharleneN · #15 2006-02-18, 5:54pm

Peggy remember once you start your annealing cycle no peeking!

Good luck and be sure to post how it goes.

Boopdidoop · #16 2006-02-19, 7:47pm

So...here's the rest of the story...

I redid my ramping schedule to much slower and started by making the components for THREE of these beads (a purple, a red and a blue). I was so hyped up and ready for a marathon session you should have seen me! I got the first one encased and was shaping and smoothing when my flame just up and vanished! Luckily I had been heating from end to end so I popped it in the kiln. My husband came running downstairs after hearing my frustrated cry. He lifted up my tank and sure enough, EMPTY! Really! Can you believe it...lol. I had been using small tanks (like the kind you use on your gas grill) and they would always run down pressure wise so I could always tell many hours before they ran out but the new company I'm using gve me a taller tank with more fuel and evidently it's pressurized. I was so disgusted that "peaking" never crossed my mind. Now the good news, the next morning I checked the thing and NO CRACKS. I will have to reheat it and finish it (hopefully avoiding the clouding) but NO CRACKS!!..HEHEHE....I was embarassed to write this but I hope you all get a laugh. What an amatuer.

I read your suggestion Lynn, so I can increase from 960 to say 975?

I remember using Moretti clear when I first started and it was smoky looking so I switched to Lausha and have had no problems since. I will let you all know what happens when I get my new tank. At least I have had all your help and will probably be successful with the big beads now.

Thanks ALL!!

Peggy

CharleneN · #17 2006-02-20, 1:36pm

Hey Peggy we've all been there! And what a bummer it is to run out of gas right in the middle of a great bead!

Ramping up can be done faster than down but when I used to do it I think I ramped up at about 500 per hour to 960. I know some people go faster than that but for big beads it probably isn't a good idea. Even slower for big beads wouldn't hurt any. Remember slower won't hurt the bead but faster can hurt.

You probably want to bring that bead up to something more like 1050 if you want to try to heal it. It'll probably make it a little easier to reintroduce it to the flame....still take your time tho. Put it way out in the far reaches of the flame so it doesn't explode on you! And remember to change your kiln back to the 960 or so annealing cycle.

I think you're doing super! I'm amazed you're on a Hot Head. I started out on one and it was just so slow for bigger beads...esp encasing. You're doing just great!

Vicki B. · #18 2006-02-20, 4:24pm

Some colors just are more finicky than others about being encased. The ones that I've particularly had trouble with are Moretti coral and Lauscha opaque purple. Others have also mentionned both of these on this site and WC.

I did adjust my kiln to a much slower ramp down when my encased florals got bigger. I use 960, soak for an hour after last bead goes in. Ramp down to 400 at 2 degrees per minute. Then the kiln shuts off. I don't open it until the next morning.

Boopdidoop · #19 2006-02-21, 12:19pm

Hi Charlene,

Being the impatient person I am, I read on my JenKen manual that I could ramp up 850 per hour (ha! guess that would be for "little' beads, duh) so away I went to 960. The scary thing was that I sat and made cane while I was waiting and I watched that sucker get to 960 in 55 minutes. Scary. I'm thinkin my spedometer is off...umm digital controller? Anyway, luckily it was fine and went right into the flame no problems. I will however, take it up higher in the future, now that I know I can. I am going to experiment to see how accurate this Chili Pepper is though. This morning (yes I waited all night) it came out lovely as well as the next one I made which is hanging around my neck as I type away. OOOH's and AAHH's at the chiropractors office this morning! Thanks alot for all the help. I might be looking to move up to a hotter torch, it is truly time consuming to use the HH.

Stay in touch,

Peggy