issue with BE white opaque 013

[david n]

I've looked in the archives but haven't found a definitive answer. Does BE white opaque 013 become incompatible with repeated firings? I've used the med. frit in my vitrograph to make rods (which I anneal) and then to pull stringers, which I full fuse in my multi-layered frit paintings. This latest piece has undergone 7 firings so far (15mm thick so far) and I've just noticed very tiny breaks in the white stringer on previous layers. When I check it with polarizing film, there's stress around the 013 stringers. The top layer has the exact same stringers with 2 firings and shows no stress (or breaks) at all. I use a conservative annealing schedule and have not had this problem before, but I had to repeat more firings than usual on this one. Will an exaggerated anneal help this piece, or will it get worse with each additional firing?

[twin vision glass]

Hello! what temp are you going to. I guess creating vitrograph pieces you have had to take it quite high and stringers. So that is your first firing. Take those and put on 1101 clear and do a test fire and then check under polorized film. Do numerous testing , as you would with your piece. You will get a good answer on how far you can take this glass. As for the piece now, no more firing will help it sad to say. BUT if it is just around the white stringers, then perhaps it will not go farther, but it will not be able to go out on the market I do not believe. I know that some RODS are not compatible with fusing and kiln casting and you can find that information on the Bullseye site. Not sure if that particular glass is one of them. Sorry for your problems. Les
http://www.bullseyeglass.com/images/sto ... tes_02.pdf
http://shop.bullseyeglass.com/x_archive ... torchtips/
Opaque 013 seems to be o.k. in Rod form so perhaps you just fired tooo many times. (or perhaps took it tooo hot on an occasion. )

[david n]

Thanks for the response Les, I followed the bullseye vitrograph schedule - 450dph to 1700F hold 2hrs to make the rods. My full fuse temps for the pieces are 1435F in my kilns with a 5min. hold. I'll try test firing stringers in the future. I've done these with 013 through 3 or 4 firings with no issues in the past. Maybe 7 or 8 is too many? I wonder if 113 is more forgiving than 013?

[twin vision glass]

Hi again, There are 17 rods that are NOT compatible with Kiln forming and fusing. So if you make your own in vitrograph I am sure the same concept applies. But check the colours out:
-Cobalt Blue Opaque 000014-0576
-Turquoise Opaque 000016-0576
-Mineral Green Opaque 000017-0576
-Periwinkle Opaque 000018-0576
-Bluestone Opaque 000046-0576
-Sterling Blue Opaque 000064-0576
-Dense White 000313-0576
-Gold Purple 000334-0576
-Amber Lustre 001701-0576
-Green Lustre 001707-0576
-Blue Lustre 001714-0576
-Copper Green Lustre 001717-0576
-Clear and Pink Opal 002010-0576
-Clear and Sunflower Yellow Opal 002020-0576
-Clear and Salmon Opal 002050-0576

[twin vision glass]

The beauty with that list is it tells you what happens in the kiln and other uses and how it moves and behaves. Some glass performs better than others in multiple firings I think and high temps like Vitrograph. I would LOVE to hear from others who have been creating with Vitrograph pieces. I LOVE the technique so very much and have to just really be aware of what glass is best for this technique and which perhaps could give us a few issues later on in Multiple firings .
Leslie
Opaque White
Kiln: Very viscous; will flow later and less than other glasses. Consider a design solution to avoid or remove potential devitrification: cap with clear or sandblast/remove devitrification through coldworking methods.

[david n]

Les, I see now that the 013 ROD is designated as not for kilnforming in the BE catalog. Unfortunately, there's no such designation on the FRIT page. They probably assume you won't turn it into a rod first. Crap, there goes a month of work.

[twin vision glass]

Oh I missed that part . It just says it does other things. Hmm! oh dear eh! Glass creating is like a Science and how kind of Bullseye to put it out there for us to do our homework. I just lost a lovely large piece toooo that took a month of colour bar creating and things but it was because of the power going out again.
Les
P.S. BUT on the Tech Sheet is says different.

[twin vision glass]

But all is not lost for you is it. Cannot you figure out a way to make your pieces with less firings.

[david n]

Probably not less firings, I feel I need to do as many as it takes until I like the imagery. BUT, I'll never use 013 again, I'll switch to 113. I've used 243 through many firings with no problems. I did try to use 243 in my vitrograph before and found out it turns clear (I would have known this if I looked at BE info first). Too bad this piece didn't go bad in the beginning instead of almost the end.

[Bob]

Hi David,

I have seen several projects where opaque white white has cracked during firing. One has been discussed in the photo section ... see Cave Art by Babette (Shawn) posted Dec 1. She remade the piece with white 0113 and there wasn't any problem cracking. Shawn has posted Bullseye's response to her inquiry... see her post on the cave art thread for Dec 6. It might be worthwhile for you to contact Bullseye and let them know of your problem.

In a recent shipment from Bullseye a jar of opaque white powder has a label saying "recommended for surface use only. It may crackle when used between sheet glass layers". So I don't think encasing it in clear will help.

I have only used 0013 for wafers that have been tack fused to the surface of glass. There have not been any problems. If I used it for other applications I would definitely test, and I would retest every time I used a new jar of frit. It might be easier and safer to use 0113 instead of 0013.


Hope this helps.

Cheers,

Bob

[david n]

Thanks Bob for pointing me to that BE response. It's interesting that unlike Babette's piece, mine is cosmetically fine, the breaks are miniscule. However also unlike hers, mine has residual stress in it.

[Morganica]

It's not so much the number of firings as the degree of heatwork. But yes, I think your glass has been overfired and probably has become incompatible as a result. So nope, longer annealing won't help.

Technically Bullseye only guarantees compatibility to three standard fuse firings. Seven is pushing it, and you ran it through a vitrograph (a high-temp firing) to begin with. So...at least eight firings, and one of them is high-temp, i.e., this glass has had a LOT of heatwork. I know the dense white rods don't work well in casting, and I've learned to be very careful about overfiring the more opaque whites in murrini and other compositions, especially if I've got them in close proximity to hot colors.

I think you're better off starting out with white stringer intended for kilnforming, or if you need variable dimensions get a stable white rod and pull it yourself in a flame. That eliminates a bunch of heatwork.

[david n]

Thanks Cynthia, I wish I could buy the rods I need instead of making them, but they don't come in the colors I need. For most tree/branch shapes I use 1109 with 100 mixed in varying proportions. These have been stable through many firings. The white is to make a 2-tone rod that's half white and half brown/black (for snow covered branches). I think I'll try 113 and test some until it fails. To get the results I want, I usually have to fire a piece 5-8 times. This is the first stress I've found in the pieces.

[Bob]

Hi again David,

I am assuming that you are lampworking the rod made in the vitrograph kiln to get the delicate branches for your trees.

Have you tried making your rods in a "rod pod" (I think that is what they were called) rather than the vitrograph? They used to be in the Bullseye Catalog but I don't see it in the recent one. It is essentially a deeply grooved kiln shelf. Load the grooves with frit , stringers or scrap and take to full fuse. The grooves were semi circles in profile. Load them with glass to a bit above the top of the shelf and let surface tension round them off into nice rods. The grooves were about 3/8 inch wide.

If rod podz are no longer available I am sure you could make one out of fibre board and a router... or thin strips of thick fibre paper.

You wouldn't have to do the vitrograph pull (although it is lots of fun) and you could get very detailed setup of colour by layering frit and or stringers. Just a thought.

Cheers,

Bob

[twin vision glass]

Bob, although a good suggestion, I think his work is all about thin to thick great branchs and trunks pulled out of the vitrograph. BUt it is a great idea but for lamp working the canes are just a bit toooo thick. After watching my twin , it is alittle tricky. BUt hey!!! all ideas are good ones.
Leslie

[david n]

Thanks guys. I've never heard of rod pods, but the idea is interesting. I do use the vitrograph just to make my rods, my branch shaping takes place at the torch (sometimes my minor burner, but mostly a plumber's propane).

[twin vision glass]

Oh I am not sure you could get the rods hot enough and even enough on a plumbers torch though. Perhaps the minor. Les

[Bob]

Hi yet again David,

Here is a link to one supplier for a Rod Pod;

http://fusedglasswarehouse.com/Straight ... egoryId=-1

Just in case you want to pursue the possibility.

Cheers,

Bob

[Babette (Shawn)]

Interesting...more problems with 0013 opaque white? I wonder if this particular glass is on the edge of incompatibility? I would love to know if anyone else has had problems with 0013 opaque white?

I contacted Bullseye over a month ago and they started an investigation...I shared my firing schedules, many photos, batch dates and a list of all quantities and materials I used. They OK'd my schedules and all the glass I used in "Cave Art" -see posting I made December 1 in Photos. Cave Art was fired just once, top temperature 1500F so heat induced incompatibility is not the issue here yet it has what looks like incompatibility cracks. I did some tests; first I made a new piece and replicated the cracks and then I omitted only the 0013 opaque white powder and made a new piece with no cracks. Bullseye tells me they were unable to recreate the problem in their tests. They have come back to me assuring me that 0013 is completely within the acceptable range of compatibility. Bullseye is suggesting that maybe the fiber paper I used is incompatible, because the fiber paper has shards of glass in it? I am going to stop using 0013 opaque white.