Yellowing Clear on Silver Glass

Deb L · #1 2011-11-09, 5:02pm

I've finally got the hang of striking glass. Made some nice beads and batch annealed along with lots of other beads. Nearly all the silver glass (mostly Terra 2 or Terra), which were all encased with super clear, have turned an ugly shade of yellow brown. I'm sick! I did have some unencased aurae beads in the kiln. Did I screw up? Does silver glass or at least unencased silver glass get a sauna by itself?

Thanks for the help!

Sue in Maine · #2 2011-11-09, 5:24pm

Your silver fumed your white. It is pretty much inevitable unless you put clear over the white where you want it to stay white. Do the clear before you add the silver.

Sue

squid · #3 2011-11-09, 5:26pm

That sounds like your kiln might be striking your glass - do you have a pic? I would bet your kiln is hotter than it says it is. I had the same problem and my kiln was almost 200 degrees off temp.

Deb L · #4 2011-11-09, 5:36pm

Sue, these weren't white beads. These were all Sedona, encased with terra, encased with super clear. I don't remember seeing any white while I was striking, but maybe I'm misunderstaning your comment.

Squid, I don't have any pix. I might be able to take some shots tomorrow. The clear encasement has a yellowish-brown look. Doesn't even look like silver glass anymore.

I had done some prior beads in another load (that, of course, weren't nearly as nice as these) and there wasn't a problem, so I'm doubting it's the kiln. This is my small fusing kiln-JK bead annealer (sure wish I'd been smart enough to buy the bead door when I bought it 7 yrs ago!) I'm still wondering if it was the aurae unencased beads that were near the silver encased beads. Beads that were on the other side of the kiln were ok, and I can't see any yellowing on any of them.

Sue in Maine · #5 2011-11-09, 5:56pm

Quote:

Originally Posted by Deb L

Sue, these weren't white beads. These were all Sedona, encased with terra, encased with super clear. I don't remember seeing any white while I was striking, but maybe I'm misunderstaning your comment.

Squid, I don't have any pix. I might be able to take some shots tomorrow. The clear encasement has a yellowish-brown look. Doesn't even look like silver glass anymore.

I had done some prior beads in another load (that, of course, weren't nearly as nice as these) and there wasn't a problem, so I'm doubting it's the kiln. This is my small fusing kiln-JK bead annealer (sure wish I'd been smart enough to buy the bead door when I bought it 7 yrs ago!) I'm still wondering if it was the aurae unencased beads that were near the silver encased beads. Beads that were on the other side of the kiln were ok, and I can't see any yellowing on any of them.

Sorry, Deb. I didn't real thoroughly enough. I still think your silver fumed your other colors but I thought it was white. You may want to try putting a bit of activated charcoal in your kiln. If you do a search on "activated charcoal," you will find threads that deal with issues similar to what you have going on. Has to do with the environment inside your kiln. I'll see if i can find the thread I'm thinking of... brb.

Sue

Sue in Maine · #6 2011-11-09, 5:57pm

http://lampworketc.com/forums/showth...vated+charcoal

http://lampworketc.com/forums/showth...vated+charcoal

Here are a couple I found.

Sue

squid · #7 2011-11-09, 6:18pm

Quote:

Originally Posted by Deb L

Sue, these weren't white beads. These were all Sedona, encased with terra, encased with super clear. I don't remember seeing any white while I was striking, but maybe I'm misunderstaning your comment.

Squid, I don't have any pix. I might be able to take some shots tomorrow. The clear encasement has a yellowish-brown look. Doesn't even look like silver glass anymore.

I had done some prior beads in another load (that, of course, weren't nearly as nice as these) and there wasn't a problem, so I'm doubting it's the kiln. This is my small fusing kiln-JK bead annealer (sure wish I'd been smart enough to buy the bead door when I bought it 7 yrs ago!) I'm still wondering if it was the aurae unencased beads that were near the silver encased beads. Beads that were on the other side of the kiln were ok, and I can't see any yellowing on any of them.

Was one side closer to the elements than the other? My kiln - that was over 200 degrees off - is a jen ken.

Is is definitely the clear that is discolored and not the glass under the clear?

Deb L · #8 2011-11-09, 6:40pm

Sue, thanks for the thread links. I'm not sure if my kiln has an oxidizing environment or not. How do you know? I have always left my peephole open for fusing glass. Maybe I shouldn't for beads. The first thread lead to a great explanation of kiln striking, which seems what Squid thinks if happening. I know that this load of beads was a big one with lots of silver glass and lots of unencased aurae. Beads were close to the elements, which might have contributed to the problem. I don't have a pyrometer so I'll try the 10 degrees lowering method mentioned on the one thread-using one silver bead as a test subject.

Squid, the beads were close to the element. I wish I had a pyrometer but I don't. If the kiln is 200d off I have no way to know for sure. I'll have to check the beads again in the am. My shop is away from the house. I was so frustrated I just left them there. It sure looked like it was the clear. If I etched one would that help? I'll check them again in the morning.

Whatever the problem is, it hasn't happened before. The only change was the fact there was a lot of silver glass encased and unencased in this load.

Cinnamon · #9 2011-11-09, 7:30pm

Here are 2 threads that could be of help:

http://www.lampworketc.com/forums/sh...ghlight=charco

Laserglass (Mark Wilson) commented in the next thread: [/size]"I have used charcoal in the kiln many times. first off you should use the small granuals made for aquarium filters. they are small, clean, and cheap. if you are kilning a few small objects, it is much better to put the objects (beads, marbles, whatever) under a stainless steel bowl inside your kiln. then you only need to use about a thimble full of charcoal to cause a reducing atmosphere under the bowl. if you work without a bowl, then you have issues. the larger the volume you need to maintain in a reducing atmosphere, the more charcoal that is required, and the more ventilation becomes an issue. also, kilns are not sealed. so IMHO, if you cannot minimize the reducing volume using a steel bowl, then you will need to use a lot of charcoal and it will need to be done outside. using the bowl, you can safely do it inside as long as you have a good ventilation system and its on and being used. the closer the kiln is to the ventilation hood, the better."

http://www.lampworketc.com/forums/sh...d.php?t=123537

Hope this helps!
Neomi

MelanieG · #10 2011-11-09, 10:36pm

I don't think it's your clear... I think it's the Sedona. When you use silver glass on top of Sedona, it changes colour, and I think it's the reaction between the Sedona and the Silver Glass that you are seeing.

I haven't done my test beads for Sedona yet, but it behaves really similarly to Effetre EDP and Reichenbach Flamingo and they both have fairly dramatic reactions with silver.

Before giving up on your clear, try a different, less volatile base colour? I like Terra2 on top of Ink Blue or Great Bluedini or Light Brown Transparent, cored with an opaque if you don't want to be able to see the mandrel.

Deb L · #11 2011-11-10, 7:22am

Ok, here are two shots of my ugly beads. The ones on the left are sedona encased with terra encased with super clear. The ones on the right are sandstone with terra with s clear. Hope the pix are clear enough.

Squid, it does look like the yellow/brown is within the glass. I am seeing them in natural light today instead of incandescent and they do look "overdone." Perhaps if I struck them less?

I put 3 new beads in the kiln this morning on a shorter hold at a lower temp. I'll see how they go. My brick kiln won't allow me to open it until very late, though.

Melanie, thanks for the info on sedona-it's does devit just like edp. They look so nice in sedona! I have to work today so I probably won't be able to torch this evening. I have some ink blue so I'll try it next.

MelanieG · #12 2011-11-10, 8:21am

Quote:

Originally Posted by Deb L

Melanie, thanks for the info on sedona-it's does devit just like edp. They look so nice in sedona! I have to work today so I probably won't be able to torch this evening. I have some ink blue so I'll try it next.

You're welcome

I don't know how much experience you have with the Terra2, so if you already know this just ignore me...

Get it screaming, glowing, almost white-hot, then let it cool down to the point where you fear it might crack. Give it a dose of reduction - only a small one, and just enough to heat the bead back up a touch, and then encase it under the flame without getting it screaming hot again or you'll lose your colours.

GlassyEyedGirl · #13 2011-11-10, 10:12am

What kind of torch are you using? A hothead will not get hot enough to do as Melanie describes with the heating and cooling for the Terra2.

Deb L · #14 2011-11-10, 10:13am

Basically nil experience. These were the first beads that looked really good. I might have gotten it wrong, though I had nice coloring. I put the T on the sedona, got it the way I wanted it and then encased it. I THEN got it hot and alternately cooled-sort of like MCD. They looked nice after cooling but not after the kiln. I thought I was suppose to strike it. Maybe I got too much color early-maybe they shouldn't have been so pretty until after the kiln? I imagine I worked it too much based on what you said.

While you are here, just what IS the difference between Terra and Terra2? I have both and at least so far don't see a lot of difference.

I use a Mega/Minor.

Deb L · #15 2011-11-10, 2:50pm

Well, I'm not too happy. My 3 sample beads I put in the kiln this morning that looked pretty good going in are just as yellow/brown as the others, even though I lowered the anneal temp some and the hold time. I'm mystified. I did try Melanie's way on a bead and I guess it'll get a run through the kiln tomorrow. Maybe I'm just cooking them too much before they even get to the kiln.

Damselfly · #16 2011-11-11, 11:06am

Do you have any vermiculite? Maybe you should try one bead and cool it in the vermiculite instead of putting it in the kiln. That way you'll know if it's your kiln.

Deb L · #17 2011-11-11, 2:45pm

I cool everything in a little heated (Ha!) crockpot in bubbles. Then I batch anneal. That is why I can't figure this out. I KNOW I'm inexperienced with silver glass, but being I was getting some nice color (which was easy to see before they went in the kiln) I can't figure out why they are all brown after annealing. I think I might be overcooking but I don't know how to fix it. I figure I was just doing SOMETHING wrong-I just don't know what!

MelanieG · #18 2011-11-11, 7:08pm

Maybe you should try working directly into the kiln instead of batch annealing - being in the kiln for the ramping up phase might be overstriking the silver glass?

Does your kiln have a bead door?

Deb L · #19 2011-11-11, 7:35pm

It's possible-I know that a kiln can easily go over the set temp while ramping up. The way my kiln is set up I'd have to carry the mandrel around my work table and across the room. Just how much time do I have to get a bead in the kiln? My biggest problem with garaging is I don't have a bead door. I'd have to run my mandrel through the peephole. Not impossible, but in order to make sure I don't hit the coils on the opposite side I'd have to open the lid. That would mean putting on my leather glove.

I might try it though. I've been thinking about trying it anyway; I just thought that by the time I walked around the table, put on a glove to open the lid and threaded the mandrel through the hole I'd have a cracked bead!

I appreciate all the suggestions from everyone. I've been reading a lot of old threads and it seems I'm not the only one that has had trouble with this at one time or another. I'm also wondering if maybe I'm overheating when encasing. I know I sometimes take awhile to get my bead round and balanced after encasing so maybe I'm getting it too hot. The few samples I did last night look good in my crockpot. I dread putting them in the kiln. Maybe I'll just not anneal them and keep them for myself!

SuzyQ · #20 2011-11-13, 6:52am

Quote:

Originally Posted by Oenone

I don't think it's your clear... I think it's the Sedona. When you use silver glass on top of Sedona, it changes colour, and I think it's the reaction between the Sedona and the Silver Glass that you are seeing.

I haven't done my test beads for Sedona yet, but it behaves really similarly to Effetre EDP and Reichenbach Flamingo and they both have fairly dramatic reactions with silver.

Before giving up on your clear, try a different, less volatile base colour? I like Terra2 on top of Ink Blue or Great Bluedini or Light Brown Transparent, cored with an opaque if you don't want to be able to see the mandrel.

I think Melanie is right. Sedona is probably the culprit. It's pretty funky glass.

Deb L · #21 2011-11-13, 8:05am

I tried so more yesterday. The one with ink blue is way light-I might not have worked it enough. Some others I did by themselves and encased. I worked them quickly and didn't overly try to encase every part. Only one looks overcooked. The rest look nice, so maybe I just take to long to get the encasement the way I want it. The ones that look nice I'm afraid to anneal for fear of ruining them. I just might put this on the back burner for awhile; I'm getting pretty frustrated and about out of silver glass anyway.

Thanks to everyone for the suggestions.