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How to keep parts aligned during fusing?

Posted: Fri Jun 28, 2019 7:01 pm
by Doug Finner
I am new to warm glass and have been messing around with slumping miscellaneous glass bottles; it's working. I have an idea for making a drinking glass from cut bottles fused together. This will entail balancing one piece of glass on another. The balance point is going to be sketchy so I'll need to support the pieces so nothing moves during the fusing process.

I've found posts that say white glue can be used but it's not very good for structural work.

My (well, my wife's) kiln is 15x6 so I don't have a lot of vertical room to work with.

Any ideas what would work best?

Thank you for any tips.

Re: How to keep parts aligned during fusing?

Posted: Sat Jun 29, 2019 10:13 am
by jim simmons
Think on it for a minute.
What happens during the fusing process?
The glass gets SOFT.
Remember that gravity is a LAW and NOT just a good idea/\.
For more info email me.
The other Jim

Re: How to keep parts aligned during fusing?

Posted: Sat Jun 29, 2019 10:21 am
by Brad Walker
For starters, white glue (or any glue, for that matter) will burn off before the two layers of glass fuse together, so you only consider glue as a way to help you get the glass into the kiln without moving, not a way to keep it from moving once its in the kiln. Also, ordinary white glue will sometimes leave carbon deposits on the glass when it burns off; if you have to use white glue, dilute it with water, or better yet, use another glue, such as Elmer's blue gel, hairspray, or a fusing glue made to burn off cleanly.

If you're thinking you can build up a drinking glass shape with glass pieces and fire it in the kiln to retain more-or-less the shape of a glass, then you should know that what you're wanting to do is very, very, very difficult, if not impossible. The issue is that the glass wants to slump down flat again at a lower temperature than the individual pieces will stick together. That's why most people would use a casting process, rather than a fusing process, to create the kind of shape you're wanting to create.

If you can give us a better idea of exactly what you'd like your finished piece to look like, perhaps someone can help point you in the right direction to get there.

Re: How to keep parts aligned during fusing?

Posted: Sat Jun 29, 2019 11:57 am
by Kevin Midgley
Drinking glasses and bottles are made on ribbon machines that will spit them out one per second. Hot glass can move that fast and you want to control melt it in a teeny kiln?
On older warmglass websites before the crashes, there was a members gallery and in those photos was a fantastic glass box assembled and fused without the puddle effect.
Your best bet would be glues and not the kiln. I suggest Lepages 100% Glue in a small red bottle for your experiments. After some success you could graduate to fancier more expensive glues.

Why you copy web pages onto you computer is below. Unfortunately the link below is dead as is my ability to post the photo from my saved document. You will have to message me for the image. ... essel.html

6 captures
22 Oct 02 - 22 Jun 04

  Dr. Ron Coleman RIP made the box and posted way back when this page.


4 x 4 x 6 inches

The vessel pictured above is made from black iridized Bullseye glass.  Each panel was made of two layers of glass (black and clear) fused together.  Fusing was done on a kiln shelf with Thinfire paper, fusing temperature was 1450 f.  The irridized layer was placed face down on the paper.

After fusing, the panels that form the sides and ends of the vessel were cold worked on a grinder to straighten the edges and remove the edge-rounding caused by fusing.  All joints have to fit as close as possible for the next fusing operation.  Note that the end panels are recessed about 1/4 inch back between the long sides.  This was done to eliminate need for grinding perfect outside corners.

With all joints fitting well, the panels were assembled into the vessel shape using Elmers glue and wood blocks to stabilize each piece until the glue set.  Only two or three spots of glue were used on each joint.  Stringers of black glass were applied along the inside of each joint to act as filler to make up for the slightly rounded edge that remained after grinding.  At this point the vessel was VERY fragile but would stand by itself.  Two small cleats of glass were added to the bottom of the lid with a little glue.  These prevent the lid from sliding off the finished piece.

After assembly the vessel was placed on Thinfire paper on a kiln shelf and an 8 inch diameter by 8 inch tall stainless steel tube was placed around the assembly.  Sand was slowly placed around and inside the vessel and the whole thing was buried under about an inch of sand.  The lid was placed upside down on flattened sand above the vessel and sand was added to the top of the tube.

Firing rates were 120 min-1000 f, 20 min-1000 f, 60 min-1450 f, 60 min-1450 f, anneal 4 hours @ 960 f,  4 hours to 750 f, kiln off and natural cool to room temperature.  Please note this firing was done in a side element ceramics kiln which measures 18 x 18 x 18 inches, with a firing rate of 6000 watts.

After the final fuse firing the vessel was cleaned of any sand (no sand sticks to the iridized surface).  The lid had just a small rocking action when placed on the vessel and it was refired at 1200 f  to flatten.   The grip was fabricated from copper water pipe and silver soldered together.  Patina was then applied to the copper.  Screws through holes in the lid hold the grip in place.


Re: How to keep parts aligned during fusing?

Posted: Sat Jun 29, 2019 2:12 pm
by Brad Walker
Before he passed away in 2011 Ron sent me a series of slides documenting his process. He actually made these boxes in two different ways: one was as Kevin described (encased in sand), the other was freestanding. I've done the sand version (used to teach it, long ago), it works well but like any casting leaves marks on the outside of the piece. Ron usually did this with iridized glass because the marks became part of the design. Here's an example:


The freestanding version is a lot more challenging. Ron would prepare the box more or less as described in Kevin's post, then he would coat the edges with a lead-based flux. He would fire it very carefully in the kiln and with luck would manage to get it to stick together without falling apart.

But it's a lot easier to make these by just gluing and not bothering with a kiln.

Re: How to keep parts aligned during fusing?

Posted: Sat Jun 29, 2019 3:55 pm
by Doug Finner
Thank you all for your replies. My take away is 'nope...not gonna happen'.

When I said I was new to fusing, I mean, 'I have slumped 8 random bottles to flat and turned them into a wind chime' new...

What I'm trying to do is as follows.
1. Take a 10 oz soda bottle and cut off the bottom as close as possible to the bottom.
2. Cut off the top right where the curve of the neck turns into the sides. (this bit when turned upside down looks a lot like of like a beer glass)
3. Fuse the cut off bottom to the narrow end of the top
4. Poof
5. Beer glass.

It would look roughly like this only less curvy and a 'foot' more like a champagne glass.

What little I've done strongly suggested that just sitting the parts together would fail and I'd wind up with a Dali or Picasso-like result. I was hoping I'd missed some magic 'make it stick' method.

I've been noodling this around and I may try using kiln posts around the edge to keep things lined up.

Hey, it's a soda nothing to lose. Worst case, I just lay the pieces down flat and make more wind chimes!

Thanks again for the replies.

Re: How to keep parts aligned during fusing?

Posted: Sun Jun 30, 2019 3:40 pm
by DonMcClennen
You could accomplish what you describe using a UV adhesive,,, getting a UV bulb and UV glue is not expensive and certainly more permanent than other adhesives. You can buy beer glasses fairly cheap :P :wink:

Re: How to keep parts aligned during fusing?

Posted: Sun Jun 30, 2019 4:04 pm
by Doug Finner
What you say is absolutely true but where is the fun in doing things the normal way? ;-)

Rught now I am playing with low risk (cheap) materials just to get a sense for how stuff melts and fuse and break. It's all good.

I need another bottle to try this beer blass build. I pics after my experiment is complete.

Re: How to keep parts aligned during fusing?

Posted: Fri Jul 05, 2019 8:33 am
by Doug Finner
OK, I finally got another bottle I could play with. Process:
1. Cut off the bottoms and slump. One came out nice and round, the other was more of an oval.
2. Cut off tops so total height of top + bottom was less than 6"
3. Balanced round bottom on the narrow neck of the top
4. Used the COE 90 'Tack' program (schedule below)
5. Apparently 'Tack' still means 'Melt a whole lot'...

The result was structurally interesting and will look great in my wind chime. Because the times/temps weren't enough to fully slump the glass, it has a nice 3D form. As a vessel to hold liquid...not so much. Pics uploading to here (the two clear pieces sitting on a brown table) I did 2 bottles, each had a slightly different shape. I like that they fell over into totally different end shapes; one retained the overall bottle shape while the other collapsed into itself.

I'm glad I tried this and very much like the results; it was a good learning experience and now I have a much better idea of how the 'tack' program works when working with complex pieces of glass.

My thanks to everyone for their input and suggestions.

Schedule (copied from the kiln manual)
This program heats at 300F/hour to 1250F and holds this temperature for 30 minutes.
Then heats at 400F/hour to 1350F and holds this temperature for 10 minutes. Then
cools rapidly to 960F and holds this temperature for 60 minutes. Then cools at
100F/hour to 700F and shuts off

Re: How to keep parts aligned during fusing?

Posted: Fri Jul 05, 2019 9:19 am
by Kevin Midgley
Now you can begin to understand the difficulty of making the box!
Keep playing with the glass but be sure to keep notes.

Re: How to keep parts aligned during fusing?

Posted: Fri Jul 05, 2019 9:30 am
by jim simmons
Oh, BTW, Did Kevin say "be sure to keep notes?" This is an absolute necessity if you want to repeat a process at a later date.
Or to modify a. result
Not to seem boring,be sure to keep notes, be sure to keep notes, be sure to keep notes.
The other Jim

Re: How to keep parts aligned during fusing?

Posted: Fri Jul 05, 2019 9:56 am
by Doug Finner
Jim and Kevin,

I haven't been keeping notes because I've been working with scrap/crap glass of unknown COE and my goal was to reuse rather than trash random glass objects. I have only been melting/slumping single pieces using built in profiles and one 'how to melt wine bottles' profile I found on line with the goal that the resultant glass 'be flat' after I finish. As I try for more creative results, notes will definitely be useful. If/when I decide to get really creative, I'll be buying glass of known COE.

Re 'the box', even before this little experiment, I had a tiny inkling of how difficult that box was to create. I can only imagine how much glass was destroyed to get to that final result. It's an amazing piece of art and technology.