Schedule help and other questions. - WarmGlass.com

Schedule help and other questions.

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SusanHyatt
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Schedule help and other questions.

Postby SusanHyatt » Mon Jan 21, 2013 8:05 pm

I made sushi dishes (2) and used BE glass two layers. I wanted a full fuse, the schedule I used was 300-1150- 30; 200 -1370-20; 400 -1480- 20; 9999- 950-60; 150- 800-10; 300-100 -0. This seem to fuse too much it looked okay but I thought they were flatened out too much. I have an evenheat kiln with a rampmaster II control. Where do I cut back to control the fusing? Soak time which segment? etc.

Also I notice that BE has a thin glass and the decription said good for jewelry making. Can thin glass be used on top of 3mm glass for other projects also to help with the cost or is that not a good idea?


Thank you all for your help.

Chris J
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Re: Schedule help and other questions.

Postby Chris J » Mon Jan 21, 2013 8:22 pm

Glass wants to be 6mm after a full fuse. If you use the thinner glass it will shrink up until it is 6mm thick. When you do jewelry making you are using many layers.
I don't see a bubble squeeze in your program. You might want to put one in if you do something very large.

JestersBaubles
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Re: Schedule help and other questions.

Postby JestersBaubles » Tue Jan 22, 2013 12:19 am

From my experience/with my kiln 1480 is high for a full fuse, unless, like you experienced, you are really wanting to flatten it.

Dana W.

Jeanne
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Re: Schedule help and other questions.

Postby Jeanne » Tue Jan 22, 2013 9:42 am

You can use thin on thick without any problems. I do it all the time. Which model Evenheat do you have? Does it have elements in the the top and side? Your schedule does seem long.

SusanHyatt
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Re: Schedule help and other questions.

Postby SusanHyatt » Tue Jan 22, 2013 12:56 pm

The items were not very big and I did not see any bubbles, I used french vanilla and woodland brown. I am very new at this and I was using a schedule from one of my suppliers (a general schedule for fusing).

My kiln is an Evenheat GTS 2541 9" deep. Any other suggested schedules would be greatly appreciated. Also does Bullseye fuse at a lower or higher temp in general than Spectrum? I know I can not use them together b/c of the COE but I have heard there is a difference in the fusing temp.

Also thank you for the information on the thin glass. I have only bought 3mm thickness so far this helps in future glass purchases. :)

Susan

Al Bray
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Re: Schedule help and other questions.

Postby Al Bray » Tue Jan 22, 2013 8:59 pm

SusanHyatt wrote:The items were not very big and I did not see any bubbles, I used french vanilla and woodland brown. I am very new at this and I was using a schedule from one of my suppliers (a general schedule for fusing).

My kiln is an Evenheat GTS 2541 9" deep. Any other suggested schedules would be greatly appreciated. Also does Bullseye fuse at a lower or higher temp in general than Spectrum? I know I can not use them together b/c of the COE but I have heard there is a difference in the fusing temp.

Also thank you for the information on the thin glass. I have only bought 3mm thickness so far this helps in future glass purchases. :)

Susan



Hi Susan,

Since you mentioned your new to all this I thought I would share a link to Bullseye's "Technote 4 - Heat and Glass" that will help a great deal in understanding what is suppose to be happening at the various temperatures during the different processes (fusing, tack fusing, slumping, etc.).

http://www.bullseyeglass.com/images/stories/bullseye/PDF/TechNotes/TechNote_4_2012.pdf

I didn't see a reference to the specific size of these two sushi dishes, but you made reference to the fact they were small. If they were under 12" , then Schedule 1 at the bottom of the last page ( Page 8 ) of Technote 4 - First full-fuse firing of a 12” (305 mm) diameter piece composed of two layers of 3 mm (1/8”) - should be great starting point. Of course different kilns fire differently but this schedule is pretty conservative yet at the same time does not have one introducing steps that are not efficient or worse, cause issues because of excessive heat work.

That is where the other contents of the technote come in to play. They help you understand what should be happening and based on your observations of what is actually happening in your particular kiln, allow you to tweak the schedule to achieve a desired result. While it would be convient to have canned schedules that work across the board, for every project, and in every kiln, it just is not that way. To many variables that can be different. So one starts with a schedule that is close, and adjusts form there. Be skeptical about using canned schedules without understanding what is going on with them and what the purpose of each step is.

As to the schedule you posted that was used, I am not sure what the 30 minute hold at 1150 was suppose to accomplish. To me that temp seems a to low to be of use for a pre-rapid heat soak (bubble squeeze) step which is normally used to minimize trapped air.

The fairly slow climb (200 dph) that is happening between between 1300 and 1370 along with the 20 minute hold at 1370 is in the devit forming range (a range that one tries to move through as quickly as possible to avoid the dreaded scumy look on the surface of the glass that can develop when spending to much time in this range) and again to me seems to be unnecessary given the description of the project you are firing.

Hope this helps and if you have already read BE Technote 4, than I apologize in advance for being redundant with the information.

- Al

Stephen Richard
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Re: Schedule help and other questions.

Postby Stephen Richard » Wed Jan 23, 2013 5:04 am

Two comments
Thins are more costly for the area than the standard 3mm
You need to observe what is happening in the kiln rather than just putting a temperature into the controller. As has been stated, each kiln has different characteristics, so you need to peek into the kiln as it nears the top temperature you have scheduled to determine when to stop heating and start cooling.

Oh yes, keep records of each firing - bullseye have a good sheet for recording on their site.
Steve Richard
You can view my Blog at: http://verrier-glass.blogspot.com/

RachelM
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Re: Schedule help and other questions.

Postby RachelM » Thu Jan 24, 2013 6:43 pm

All - I thought I posted this earlier but I think I may have forgotten to hit submit...that's the kind of day that I am having.....or perhaps it posted elsewhere.

I have a question related to the first post wherein Susan says "this seem to fuse too much it looked okay but I thought they were flatened out too much".

Perhaps this is a dumb question but for the life of me, I cannot figure out what it meant by saying "flattened out too much". When you look at the schedule presented, it is a schedule for a full fuse, not a slump. Don't full fuses normally flatten out?

I read and re-read all the posts to see if I was missing something and maybe I still am? Simply cannot figure out what is meant by "flattened out too much".


Thanks!

Rachel
imaglassydiva@aol.com

Stephen Richard
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Re: Schedule help and other questions.

Postby Stephen Richard » Fri Jan 25, 2013 5:19 am

I took "flattened out too much" as being more than she wanted. Presumably the desire was for a profile or tack fuse. This is why I suggested observation rather than relying on published or others' schedules is necessary.
Steve Richard
You can view my Blog at: http://verrier-glass.blogspot.com/

RachelM
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Re: Schedule help and other questions.

Postby RachelM » Fri Jan 25, 2013 12:28 pm

Stephen:

Thanks. I was looking too much into it. That would work, using the term flattening out to mean a full slump when she might have wanted a tack fuse.

Rachel
imaglassydiva@aol.com

SusanHyatt
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Re: Schedule help and other questions.

Postby SusanHyatt » Sat Jan 26, 2013 2:02 pm

Okay all,

Sorry about the terminology.."flattened out too much"... I did want a full fuse, not a tack fuse. I do think I could have full fused in a shorter time or lower temp. I think it could have been fully fused and still not been as fully fused as it seemed ( i know that sounds crazy but I don't know how to say it) I have this large evenheat kiln that I bought used and I have not gotten comfortable with it yet. I only have short periods of time in my shop and I have read and read on line information, been to a couple of classes, have books but I am insecure.

I love glass, the colors and the things you can make with it. I really wish I could dedicate myself to this full time but I can't at this time.

All of you are a life line to me and I appreciate this board so much.

thank you,
Susan

SusanHyatt
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Re: Schedule help and other questions.

Postby SusanHyatt » Sat Jan 26, 2013 2:11 pm

Me again,

I guess I should have also said. This kiln has a Rampmaster II control on it. I am not exactly sure if I can peek into the kiln without messing up the schedule and if the piece has gotten to the point of where I would like it to be...then what? If I close the kiln lid I guess the kiln would continue on with the program...not sure if I can skip a segment or not or where I even should skip to.

Thank you all again.

Susan

Laurie Spray
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Re: Schedule help and other questions.

Postby Laurie Spray » Sat Jan 26, 2013 2:52 pm

In my kilns.......if I peek and want to stop the cycle i just stop the program. I will then enter a new program for the annealing cycle. If you want to stop something from getting hotter just vent your kiln for a min or so by holding your lid open a few inches. You need to keep an eye on the temp. Never let it go below 1100 and shock the glass. In the beginning glass days we used to crash cool alot of loads of glass. Rarely do i do this any more unless i am doing a drop ring. On a slump load it can shock molds so be conservative and just let enough heat out to stop the process.
Laurie Spray

New website!! Http://bonnydoonfusedglasstools.com
Maker of stainless steel rings,pattern bar formers, pot melt pots, and Bottomless Molds
glass: http://lauriespray.blogspot.com

Bob
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Re: Schedule help and other questions.

Postby Bob » Sat Jan 26, 2013 3:07 pm

Hi Susan,

Yes you can peek into the kiln without messing up the schedule... with a few provisos.

If you are in a soak segment the temperature will drop somewhat when you open the lid because the warm kiln air is venting out of the kiln. When the lid is closed the temperature generally rises above the temperature programmed for the soak because the controller is designed to achieve an average temperature for the soak segment. If you do not reopen the lid then the temperature reading will stabilize back near the soak temperature. It is important to remember the pyrometer is measuring the air temperature... not the temperature of the glass. Glass is a poor conductor of heat so, even if the air temperature changes, the temperature of the glass does not change substantially. I regularly peek in the kiln. I have adopted the realization that once I start peeking in the kiln the temperature readings will start to fluctuate but I since I am using visual observations to decide the outcome of the firing I am not concerned what the controller says.

If you open the lid and the pyrometer reading drops more than 50F for more than 18 seconds an error (E-5) (RampMaster II) is triggered, a warning beep sounds and the kiln shuts off. This is a safety device. Opening the lid will commonly activate this error code.... and it becomes a pain. There is an option (press "other" on option panel) "ERCd" that can be turned off which deactivates this error code. I use this option frequently but I do reactivate the codes once the firing is over. They are an important safety feature.

There is also a "skip segment" option on the RampMasterII which is very useful. When activated the program will exit the current segment and advance to the next one. To skip a segment press the "View Segment" button and then press "enter" within 2 seconds. Press "enter" a second time and you are now in the next segment. When d you use "skip segment"? I use it when my observations of the glass tell me I have the achieved the desired effect. If the firing continues then there is a chance that the glass will overfire. I generally use it when the firing schedule has reached the process temperature.. full fuse , tack fuse or slump. The next segment is the anneal soak so the kiln starts to cool. I find this option particularly useful, especially when slumping.

Make sure that you follow safety precautions when opening the kiln. Wear natural fibre clothing and heat resistant gloves. Proper eye protection is advisable.

I know how daunting it is to open the kiln to make visual observations. When I first started fusing I would get stress headaches and pace near the kiln when the kiln was near top temperature. With experience the stress disappears. The value of making visual observations to control the outcome of the firing vastly outweighs the initial stress.

Hope this helps.

Cheers,

Bob

Laurie Spray
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Re: Schedule help and other questions.

Postby Laurie Spray » Sun Jan 27, 2013 12:56 am

Well said Bob..... I was thinking moreof the
kiln did not have a "skip segment" as my skutts do not. My genesis does and it comes in very handy.
Laurie Spray

New website!! Http://bonnydoonfusedglasstools.com
Maker of stainless steel rings,pattern bar formers, pot melt pots, and Bottomless Molds
glass: http://lauriespray.blogspot.com

SusanHyatt
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Joined: Wed Feb 15, 2012 2:07 pm

Re: Schedule help and other questions.

Postby SusanHyatt » Wed Jan 30, 2013 4:58 pm

Thank you Bob and Laurie...I will try this next time I get to work in my shop. You all are the very best :D


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