Devit Problem with BE - WarmGlass.com

Devit Problem with BE

This is the main board for discussing general techniques, tools, and processes for fusing, slumping, and related kiln-forming activities.

Moderators: Tony Smith, Brad Walker

Post Reply
GuyKass
Posts: 75
Joined: Tue Jul 15, 2008 9:53 pm

Devit Problem with BE

Postby GuyKass » Mon Dec 16, 2013 10:09 pm

I have sort of a run of the mill problem, but I'm pulling my hair out because no matter what I do, I can't solve it. I was hoping someone here might have some useful input.

I am starting to make a ton of frames for a customer, and I am using Bullseye because they specified it. I normally use 96 stuff.

No matter what I do, I am getting what looks like devit on the top layer of the glass when taking it to a full fuse. The interesting part is that it seems to have the exact pattern that the glass has before it's fired.

I am cleaning it like always, I use Glass Plus with some alcohol mixed it. It's always worked perfectly with Spectrum and Uro.

I wasn't happy with the first batch firing so on the second, I decided to keep it as short as possible.

400/hr to 1250 hold for 30 (probably don't even need the hold, but it's what I've been doing)
600/hr to 1480 hold for 10
ASAP to 900 hold for 30 (I am crashing the kiln to get down to 1000 as fast as I can go.
150/hr to 700 Off and letting it cool naturally (in a brick kiln)

I am firing on BE Thinfire, but I always vent. I keep the plug out of the peephole the entire process.

If any one has any ideas I would really appreciate the input. Once I figure out why it's happening I will just sandblast these two sets and re-fire, but in the meantime, I don't want to keep going this way.

Anyway, thanks in advance,
Guy
Attachments
D2.jpg
D1.jpg

Marty
Posts: 847
Joined: Mon Mar 10, 2003 3:58 pm
Location: Maine
Contact:

Re: Devit Problem with BE

Postby Marty » Mon Dec 16, 2013 11:04 pm

First thought: try kilnwash.

Also, you've got the kiln space so take your time and fire lower and longer (I don't think that will have anything to do with your issue but it's good practice).

JestersBaubles
Posts: 687
Joined: Fri Feb 25, 2011 12:01 am
Location: North Logan, UT
Contact:

Re: Devit Problem with BE

Postby JestersBaubles » Tue Dec 17, 2013 9:20 am

what's on top? If it's Tetka, it's notorious for deviting with thinfire. That's always seemed ironic to me.

Dana W

David Jenkins
Posts: 174
Joined: Wed Apr 29, 2009 10:35 pm
Location: Cypress, Texas

Re: Devit Problem with BE

Postby David Jenkins » Tue Dec 17, 2013 10:02 am

Is the whitish "stripe" the devit you're talking about?

Did you use a piece of TF that was the size of the frame and the interior (empty) area? Or did you cut out a ring (topologically speaking) that was the width of just the glass plus a little extra? I'm wondering if you had a large expanse of uncovered TF, that that might have contributed some way to the contamination?
Dave Jenkins
Glass at Harbor Gates
Cypress, TX

rosanna gusler
Posts: 730
Joined: Mon Mar 10, 2003 2:22 pm
Location: wanchese north carolina
Contact:

Re: Devit Problem with BE

Postby rosanna gusler » Tue Dec 17, 2013 10:47 am

i would lower your first hold to 1100f or a little less. or put in another step with a hold there. your first hold is high enough for the glass to be soft enough grabbing thinfire smutch before it has a chance to get out of the kiln. maybe prop the lid a quarter inch at first. or just use kiln wash.
artist, owner of wanchese art studio, marine finisher

GuyKass
Posts: 75
Joined: Tue Jul 15, 2008 9:53 pm

Re: Devit Problem with BE

Postby GuyKass » Tue Dec 17, 2013 11:12 am

Thank you all. I think the easiest thing to try first is eliminating the TF and lowering the initial hold.

Normally my schedules are a bit more logical than this, but I started thinking to keep the glass in the heat as short a time as possible.

Dave, I just popped an entire sheet of paper in and layed the pieces on that.

And Dana, no the top sheet is one of their steel blues on top of the streamer sheet.

If it doesn't work, I'll come back whining a bit more.

Again, thanks to the 4 of you.

Guy

David Jenkins
Posts: 174
Joined: Wed Apr 29, 2009 10:35 pm
Location: Cypress, Texas

Re: Devit Problem with BE

Postby David Jenkins » Tue Dec 17, 2013 12:34 pm

Why not try cutting a "ring" of TF - just enough to separate your glass from the shelf?
Dave Jenkins
Glass at Harbor Gates
Cypress, TX

GuyKass
Posts: 75
Joined: Tue Jul 15, 2008 9:53 pm

Re: Devit Problem with BE

Postby GuyKass » Tue Dec 17, 2013 1:41 pm

Hi Dave-

Actually after I wrote the last note, that is what I decided to try. I combined your and Rosanna's advice.

If that doesn't do the trick I will just go to KW. My shelves are coated and in good shape anyway, I just thought using Thinfire the pieces might come out even better. I will see this batch tonight with any luck at all.

Thanks again,

Guy

Morganica
Posts: 1079
Joined: Mon May 19, 2003 6:19 pm
Location: Portland, OR
Contact:

Re: Devit Problem with BE

Postby Morganica » Tue Dec 17, 2013 2:08 pm

Take out the thinfire--I never use it (or any fiberpaper) with a finish firing unless I'm planning to coldwork--and you may need one or two firings to completely clear the kiln. I think if you cut out a piece of thinfire to conform exactly to the footprint of the piece you'll have fewer issues, but they won't go away entirely. You'll still get the outgassing and probably see scum at the edges of the piece.

But steel blues..when I've done tack-fuses with steel blue I'll sometimes see what looks like the start of devit scum surrounding the areas of metallic filming. I think it's simply an incomplete filming reaction although I've no real basis other than personal experience to say that's the cause.

Are you seeing the scum with other glasses as well?
Cynthia Morgan
Marketeer, Webbist, Glassist
http://www.morganica.com/bloggery
http://www.cynthiamorgan.com

"I wrote, therefore I was." (me)

GuyKass
Posts: 75
Joined: Tue Jul 15, 2008 9:53 pm

Re: Devit Problem with BE

Postby GuyKass » Tue Dec 17, 2013 2:22 pm

No, but this is the first time I've ever fired anything from BE other than some casting billets.

Someone else pm'd me and said it happens with BE's steel blues unless you somehow cap with clear.

When I first bought the glass it struck me for whatever reason, that it must have a fair amount of copper in it (I don't know what made me think it, just doing too much for too long) and I am starting to think that is the problem.

At the moment I have a load in with a minimum amount of paper under the glass, I've slowed down the beginning of the firing and I've cracked the kiln about 1/2" for additional venting.

If this load comes out crappy, I will do the layups reversed and see if that helps. I have a sneaking suspicion that is what is going to fix this.

Thanks again,

Guy

Valerie Adams
Posts: 587
Joined: Mon Apr 19, 2004 2:49 pm
Location: Santa Rosa, California
Contact:

Re: Devit Problem with BE

Postby Valerie Adams » Tue Dec 17, 2013 3:13 pm

Looks like the scum I started getting with Thinfire.

Morganica
Posts: 1079
Joined: Mon May 19, 2003 6:19 pm
Location: Portland, OR
Contact:

Re: Devit Problem with BE

Postby Morganica » Tue Dec 17, 2013 5:23 pm

GuyKass wrote:No, but this is the first time I've ever fired anything from BE other than some casting billets.

Someone else pm'd me and said it happens with BE's steel blues unless you somehow cap with clear.

When I first bought the glass it struck me for whatever reason, that it must have a fair amount of copper in it (I don't know what made me think it, just doing too much for too long) and I am starting to think that is the problem.

At the moment I have a load in with a minimum amount of paper under the glass, I've slowed down the beginning of the firing and I've cracked the kiln about 1/2" for additional venting.

If this load comes out crappy, I will do the layups reversed and see if that helps. I have a sneaking suspicion that is what is going to fix this.

Thanks again,

Guy

I guess I don't get why the paper is necessary if you're already kilnwashing the shelf?
Cynthia Morgan
Marketeer, Webbist, Glassist
http://www.morganica.com/bloggery
http://www.cynthiamorgan.com

"I wrote, therefore I was." (me)

GuyKass
Posts: 75
Joined: Tue Jul 15, 2008 9:53 pm

Re: Devit Problem with BE

Postby GuyKass » Tue Dec 17, 2013 5:27 pm

Really just figured it would give me a better finish. In my head, nothing is ever good enough so I am always trying to find a better way.

Susanbuckler
Posts: 68
Joined: Tue Aug 18, 2009 10:31 pm

Re: Devit Problem with BE

Postby Susanbuckler » Tue Dec 17, 2013 9:07 pm

I keep the plug out of the peephole the entire process.


why?

Susan
Susan Buckler
Woodstock, NY

GuyKass
Posts: 75
Joined: Tue Jul 15, 2008 9:53 pm

Re: Devit Problem with BE

Postby GuyKass » Wed Dec 18, 2013 10:32 am

My logic is so that way anything that may be in there other than glass such as Thinfire, humidity, any types of adhesive I may have used, etc. have a way to escape. And I don't think it slows firings down, nor do I think it wastes much energy.

Lynn Perry
Posts: 103
Joined: Sun Jun 08, 2003 5:27 pm
Location: East Tennessee

Re: Devit Problem with BE

Postby Lynn Perry » Wed Dec 18, 2013 7:25 pm

Hi, Cynthia. I use paper and also coat my shelves with kilnwash. However, I only coat them once about every five years unless I have spillage which is the reason they are coated at all. Perhaps Guy does the same.
Lynn Perry

JestersBaubles
Posts: 687
Joined: Fri Feb 25, 2011 12:01 am
Location: North Logan, UT
Contact:

Re: Devit Problem with BE

Postby JestersBaubles » Wed Dec 18, 2013 10:43 pm

GuyKass wrote:My logic is so that way anything that may be in there other than glass such as Thinfire, humidity, any types of adhesive I may have used, etc. have a way to escape. And I don't think it slows firings down, nor do I think it wastes much energy.


Perhaps it doesn't matter much, but it will create a cold spot.

Dana W.

LDGlass
Posts: 22
Joined: Sun Mar 23, 2003 2:54 pm
Location: Milwaukee, WI
Contact:

Re: Devit Problem with BE

Postby LDGlass » Thu Dec 19, 2013 5:10 pm

I stopped using Thinfire because I got scum so often. I use Papyros exclusively if I'm going to use shelf paper but kiln wash always works best for me.

GuyKass
Posts: 75
Joined: Tue Jul 15, 2008 9:53 pm

Re: Devit Problem with BE

Postby GuyKass » Thu Dec 19, 2013 6:45 pm

It's funny, out of literally thousands of pieces, only had a problem like this once before and that was on a cast piece.

It turned out (and that's necessarily to let Thinfire off the hook) but if I flip them and use the clear/stringer sheet as a cap and put the blue on the bottom, the shmutz is gone. Someone sent me a note to try it as he said it happens with all of the BE Steel Blue colors.

It was really the first time I used anything from Bullseye "for real."

I really appreciate all the thoughts and suggestions.

Thanks again,

Guy

Steve Immerman
Posts: 208
Joined: Sun Mar 09, 2003 4:55 pm
Location: Eau Claire, Wisconsin
Contact:

Re: Devit Problem with BE

Postby Steve Immerman » Fri Dec 20, 2013 6:06 pm

I agree with Marty, try eliminating the Thinfire. Also, eliminate the hold at 1250. Try a lower top temp. This should work just fine with Bullseye glass.

http://www.clearwaterglass.com/Tutorial ... ation.html

http://www.clearwaterglass.com/Tutorial ... Frame.html

Steve


Post Reply

Return to “Techniques and Tools”

Who is online

Users browsing this forum: Bonnie Rubinstein and 7 guests

Warm Glass

2575 Old Glory Road, Suite 700
Suite 700
Clemmons, NC 27012
Phone: (336) 712 8003
Email: wg@warmglass.com