Fuse, Slump, Fuse?

draco_myst · Post by **draco_myst** » Mon Mar 15, 2004 11:19 am

Hi everyone. I'm just getting started with warm glass (I'm taking the kiln fired glass class at Snow Farm in MA this May), and I've been doing a LOT of reading / research about this subject on the web. When I came across the Aussie Roll-Up technique, it started me wondering about the limitations of the warm glass process. With the Roll-Up, they start with a typical kiln fused sheet, and then move to a hot glass method (glory hole, and blow pipe) to roll, and fuse the sheet into a cylinder. So here is my question . . . if one wanted to make a slumped vessel that was reasonably deep without ending up with folds in the sides (lets take as an example the shape of an inverted truncated pyramid with four angular flat sides, and a flat bottom) would it be possible to start with a sheet that was cut / fused into an "unfolded" truncated pyramid (a central square with a trapezoid attached to each edge) that would them be slumped into the desired shape (at which point the edges of the four trapezoids would be in contact with each other, but not fused) and then fuse the remaining edges with a subsequent firing without drastically altering the basic shape of the piece? I'm asking this question in order to have an understanding of the limitations of the warm glass process, and to understand just what shapes are possible with this process.

Brock · Post by **Brock** » Mon Mar 15, 2004 11:21 am

The short answer is no. Brock

draco_myst · Post by **draco_myst** » Mon Mar 15, 2004 11:25 am

Brock, any chance of getting the longer version?

Brock · Post by **Brock** » Mon Mar 15, 2004 11:31 am

Okay. What you are proposing is difficult in the slump stage, (having all 4 trapezoids slump perfectly, to make contact exactly with all 8 sides meeting) then you would have to go to a full fuse to meld those edges, and that temp, being far above slumping, would cause your shape to change, and not for the better. Brock

draco_myst · Post by **draco_myst** » Mon Mar 15, 2004 11:38 am

Brock,

I know that hot glass is a bit off-topic for this forum, but are you familiar with the Roll-Up technique? I'm wondering how it is that they can manage to fuse the closing edge in the glory hole without losing the shape of the cylinder?

Brock · Post by **Brock** » Mon Mar 15, 2004 11:48 am

draco_myst wrote:Brock,

I know that hot glass is a bit off-topic for this forum, but are you familiar with the Roll-Up technique? I'm wondering how it is that they can manage to fuse the closing edge in the glory hole without losing the shape of the cylinder?

I am familiar with it, and the shape of the cylinder is maintained the same way a totally blown cylinder is maintained, by constant rotation of the pipe or punty, plus all the normal glassblowing manipulations. Brock

draco_myst · Post by **draco_myst** » Mon Mar 15, 2004 11:51 am

OK. Thanks Brock.

Barbara Muth · Post by **Barbara Muth** » Mon Mar 15, 2004 11:58 am

And I can't see the slump happening with all four sides and the bottom.

If you slump an open (baseless) pyramid from the top down, all four sides are triangles projecting from the apex. in other words you have a maltese cross sitting on a point (the top of the pyramid) and you want the four sides to slump perfectly over the sides of your form. Your kiln has to be perfectly level, the glass has to be perfectly balanced, your coils have to heat perfectly evenly and you have to fire very slowly and probably baffle to ensure evenivity of heat throughout the glass. Plus I would not recommend any running or jumping anywhere near the kiln. It's worse than a souffle. Maybe then it will slump without slipping.

If you slump from the square base down to the point, you don't have the apex issue. But, your sides will slump down straight, not in towards the apex. And if you could find a miraculous way to get them to slump in to the apex, how would you remove the mold?

The only way to do this is in pieces and then chemically fuse them or attach them with wires fused into the glass. Unless of course your name is Ron Coleman, and you have the breadth and depth of experience he has, together with a degree in mechanical engineering. There's no one like Ron for a challenge like this!

Once you actually start fusing you will begin to understand how the laws of chemistry and physics rule our world.

Have at it, and have a blast!

Barbara

draco_myst · Post by **draco_myst** » Mon Mar 15, 2004 12:28 pm

Barbara,

Thanks for your input. Just as a clarification, this is the shape that I was thinking of for the blank (if I can make inserting an image into this post work!) [img]D:\temp1\Blank.jpg[/img].

draco_myst · Post by **draco_myst** » Mon Mar 15, 2004 12:33 pm

Nope, I guess that didn't work. Well anyway, I was trying to describe a blank with a central square sitting on top of mold, with four trapezoids extending out from the four edges of the square so that those four trapezoids would slump down against the sides of the mold. The central square section would not move (assuming everything is level of course).

Cynthia · Post by **Cynthia** » Mon Mar 15, 2004 12:52 pm

draco_myst wrote:Barbara,

Thanks for your input. Just as a clarification, this is the shape that I was thinking of for the blank (if I can make inserting an image into this post work!) [img]D:\temp1\Blank.jpg[/img].

The image has to be on a website or accessible online somehow. Then you can bracket that address with the img button and it will show up.

I think you can get there from here with this idea. You sound like a creative problem solver. I would tell you to look at casting techniques and see if you see something there that might work for you. If you are willing to modify your concept and explore a multitude of ways to achieve your goal, you will come across a way.

gone · Post by **gone** » Mon Mar 15, 2004 1:01 pm

draco_myst wrote:Nope, I guess that didn't work. Well anyway, I was trying to describe a blank with a central square sitting on top of mold, with four trapezoids extending out from the four edges of the square so that those four trapezoids would slump down against the sides of the mold. The central square section would not move (assuming everything is level of course).

I see what you're trying to accomplish. The one problem with it is that the edges won't seal because slumping temps are lower than fusing temps. If you don't mind that it would leak, it could still make an interesting project. I'd also like to say to you that I, for one, appreciate that you're really thinking. Try these things and see how they work out. That's how new techniques get invented.

Barbara Muth · Post by **Barbara Muth** » Mon Mar 15, 2004 1:11 pm

draco_myst wrote:Nope, I guess that didn't work. Well anyway, I was trying to describe a blank with a central square sitting on top of mold, with four trapezoids extending out from the four edges of the square so that those four trapezoids would slump down against the sides of the mold. The central square section would not move (assuming everything is level of course).

Ah! I was picturing a pointy pyramid. Less pointy is easier! Like the others I do think this can be made, and even without casting, but it will be more work than fuse slump fuse and will involve some outside the box (no pun intended) thinking. Look at other people's work and let them inspire you. You could get a lot of inspiration just from the gallery! Think lots about the physics and the chemistry of glass, gravity, etc, etc, etc and real all of Ron's posts on his boxes. Then experiment, until you get it. Ask all the questions as they come up and you will get answers here and then post the photos when it's done!

BTW, to post an image here it has to be residing on the internet. We can't see images that have addresses on your D drive. Lost of folks use picture hosting sites, that could be a solution!

good luck and have fun experimenting!!!

Barbara

draco_myst · Post by **draco_myst** » Mon Mar 15, 2004 1:14 pm

Cynthia / Els,

Thanks for the encouragement. Coincidentally, as Barbara happened to mention being a "Mechanical Engineer" . . . well it turns out that I have a BSME from the University of Connecticut. I've been working in the aircraft industry for over 15 years, and am interested in making a career change (the artistic side of me wants it's time in the sun). My engineering experiences with injection molding, metal forming, and other manufacturing methods lead me to this idea. I'm hoping I can make good use of my technical side in this aristic pursuit.