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Anyone explain how to make a glass that looks like this...but will only need it to be 1/4" thick.

Looks like it's poured hot into a ring on a marver. Might be tough to make it 1/4" . . .

Fired on fiber blanket powdered with finely ground alumina hydrate. The blanket compresses as it is fired, so the first firing will look different from subsequent firings. The powder fills in the deep pits. There is a lot of control relative to how much powder you use. 1365ºF hold for one hour, works for 10mm float glass. 6mm might want higher temp. Fire tin side down for float. Clean really well. No borax. No devit. No dimensional change. I prefer Unifrax 1/4" thick 8lb density Durablanket. This is usable over and over. A totally different material than fiber papers.

Bert Weiss wrote:Fired on fiber blanket powdered with finely ground alumina hydrate. The blanket compresses as it is fired, so the first firing will look different from subsequent firings. The powder fills in the deep pits. There is a lot of control relative to how much powder you use. 1365ºF hold for one hour, works for 10mm float glass. 6mm might want higher temp. Fire tin side down for float. Clean really well. No borax. No devit. No dimensional change. I prefer Unifrax 1/4" thick 8lb density Durablanket. This is usable over and over. A totally different material than fiber papers.

Bert, I wonder if Brock is onto something and there is pouring going on? If you click on the image to see the embiggened versions, you can see finely-nested concentric distortions, which look to me like they result from spreading from a central pour. You can see this in all three, but the largest/rightmost one shows it best in the photo.

What do you think?

That looks like float glass, but definitely has chill marks like poured hot cast glass, like Brock said.

I don't think it's kiln formed at all.

You could however make some similar in the fashion that Bert suggested, you won't however get the rings (chill marks) that may or may not be a good thing.

It is hard for me to tell from the photo. I think I would know in person if it were hotcast or kilncast. My opinion is that it is probably kilncast. The method I described could not be simpler, once you have the materials.

Here are a few blow ups

Rick Wilton wrote:Here are a few blow ups

Yes, but... I can make marks like that with a toothed trowel, if I have something stiffer in my powder mix.

Who do you know who would melt float glass (or even green tinted sodalime) and cast it out on a marver to make a perfect circle? I find that highly unlikely. Creating textures on a circular piece of sheet glass is pretty easy in comparison.

I agree with what you are saying but look at the edges, it's not a perfect circle either. Nor does it look even in thickness.

I agree it would be much easier to make something similar and likely nicer with float, some powder and an beat up edge.

The answer to the original question is.... we don't have a consensus.

Consensus or not, it's a pour--those are obvious chillmarks from a center pour. The glass most likely isn't float but rather made from whatever's in the tank, which in Mexican hotshops (where I've seen this type of stuff made) is a mix of recycled glass and whatever else is on hand.

You can use just about any glassmaking technique to replicate another if you work hard enough at it. At some point though, and especially with commercial work, it makes sense to pick the easiest, cheapest method.

Yup!

Morganica wrote:Consensus or not, it's a pour--those are obvious chillmarks from a center pour. The glass most likely isn't float but rather made from whatever's in the tank, which in Mexican hotshops (where I've seen this type of stuff made) is a mix of recycled glass and whatever else is on hand.

You can use just about any glassmaking technique to replicate another if you work hard enough at it. At some point though, and especially with commercial work, it makes sense to pick the easiest, cheapest method.

If the answer to my question about who would make this, is Mexicans, I can buy that. I've never been in an American hot shop where something like that was made. I have cast rolled sheet in a hotshop. After a few sheets we warped the hell out of an inch thick marver at Haystack, in 1982, rolling sheets with Paul Marioni. The cheap easy way for me to make a textured circle is kilncast on blanket...

I'd like to see that duplicated in a kiln. Post a picture . . .

Bert Weiss wrote:

Morganica wrote:Consensus or not, it's a pour--those are obvious chillmarks from a center pour. The glass most likely isn't float but rather made from whatever's in the tank, which in Mexican hotshops (where I've seen this type of stuff made) is a mix of recycled glass and whatever else is on hand.

You can use just about any glassmaking technique to replicate another if you work hard enough at it. At some point though, and especially with commercial work, it makes sense to pick the easiest, cheapest method.

If the answer to my question about who would make this, is Mexicans, I can buy that. I've never been in an American hot shop where something like that was made. I have cast rolled sheet in a hotshop. After a few sheets we warped the hell out of an inch thick marver at Haystack, in 1982, rolling sheets with Paul Marioni. The cheap easy way for me to make a textured circle is kilncast on blanket...

When I saw patties being made in Mexico they were dropped on the concrete floor--they had to move around a bit to keep from heating one section of the floor up too much. Saw it done at Blenko for mixing color, similar effect, and they used a graphite plate, I think because it was handy. I suppose you could also drop them in a sandbed. If you don't have a hotshop you could do this in a kiln, but the nature of the beast says the chillmarks would be simulated.

In any case, the folk at Bullseye drop great galumping whacks of molten glass on a steel plate all day long, roll them out like piecrust to make sheet glass. If those plates warped every few sheets they'd need a new one every half hour or so, right?

Morganica wrote:
In any case, the folk at Bullseye drop great galumping whacks of molten glass on a steel plate all day long, roll them out like piecrust to make sheet glass. If those plates warped every few sheets they'd need a new one every half hour or so, right?

At Bullseye the rollers and marvers are extensively water cooled. At Haystack, it was just an inch thick steel plate, and a rusty iron pipe for a roller. On the one hand I think somebody was pretty pissed at Paul for warping it. On the other hand, blowers have told me that they would much rather work with a warped marver.

I love the image of pouring patties on cement floors. You'll melt your tire tread sandals, walking around... They would have to have that furnace really hot to get the pour to flatten out, unless they were somehow pouring in to a kiln that reheated it, or they torched the hell out of it. That must be quite the pizza paddle that gets it over to an annealer if cast on the floor.

Are these furnaces or crucibles on a rig that tilts and pours out molten glass? Multiple ladles would chill the glass too much. The third world can be quite exciting...

Glass like this is coming from Mexico, Africa and China. Definitely looks poured. The quality of the glass is dubious but it looks OK. To replicate the look Bert's suggestion is good, cut a circle of float or whatever glass of your choice and slump it on a textured surface. I use the same paper Bert does and it is good stuff.

Best,

Keoni