WarmGlass.com

Hello,

I'm still a newbie when it comes to fusing. I'm looking for help on a ramping schedule for a thick piece of glass on a drop ring that will be fairly close to the elements of my hobby fuser kiln. The piece is 1.66 cm thick (approx 5.5 layers of glass made from a screen melt) and it is 14 cm wide (5.5 inches). The opening on the drop ring mold is 10 cm/4 inches wide. The schedule I normally use, successfully, for a two or three layer drop with a flat bottom is as follows, but it is also not as near the elements as these drops aren't as deep. I'd like to know how much to change the ramping up time for the thick glass near the elements. Do I need to adjust the ramp down time as well? I'll be watching for the time at process temperature anyway so I can adjust that as I go. Thanks for any help you can offer!

Celsius:
167 p/h to 538 hold for 10
125 p/h to 663 hold for 30 (check)
Full to 760 hold for 4 (check)
Crash Cool to 516 hold for 60
Full to 482 hold for 60
28 p/h to 427 no hold
56 p/h to 287 kiln off

Fahrenheit:
333 to 1000 hold 10 min
257 to 1225 hold 30 (check)
Full to 1400 hold 4 (check)
Crash Cool to 961 for 60
Full to 900 for 60
82 to 800 no hold
133 to 549 Kiln off

I would go 100F/55C per hour to your top temperature and then hold until it has slumped.

You'll also need a longer anneal because the piece is thicker. I would hold for at least 3 hours.

One more thought: I never fire drops higher than 1325F/720C. If I've waited half an hour to 45 minutes at that temperature, I'll increase it to around 1350F/730C, but I don't like going higher than that. I'd rather just wait for the drop.

Thanks Brad, That's helpful.

I would be very worried that the whole thing will fall through the drop ring hole. You said the glass is 5.5" in diameter and the drop ring hole is 4". That only leaves 3/4" of glass on the edges and it also looks to be chipped out. I don't see how it can hold on.

However, I hardly ever do a drop so I may be completely wrong. We'll see.

Jim

The Hobbyist wrote:I would be very worried that the whole thing will fall through the drop ring hole. You said the glass is 5.5" in diameter and the drop ring hole is 4". That only leaves 3/4" of glass on the edges and it also looks to be chipped out. I don't see how it can hold on.

However, I hardly ever do a drop so I may be completely wrong. We'll see.

Great point, Jim. I like at least one inch on each side of the hole. Firing to a lower temperature should help with that, but it's definitely risky to only have 3/4" per side.

Fiber paper on the drop ring will help give the glass something to hold on to.

Dana W.

I've weighted the glass down on top of the ring with uneven success but haven't tried anything as thick as this.

Thanks for all the input. I still haven't fired it yet. I keep second guessing myself.

I have been concerned about it sliding through the ring. I do fire on fiber paper to help the rim stick and I have done rims this narrow but never with a thick piece. I've been thinking about using rigidized silke mat to make a ring with a smaller opening, but I've had trouble with my silke mat drop rings not sitting perfectly level and creating a vase that is uneven. I kind of hate to add another variable to the mix, but I think it might be my best option. Would you recommend a three inch opening?

My other idea was to set the disk back in the kiln and fire it to a full fuse letting it spread so I have a bigger circle, but I had to grind the fiber paper from the screen melt off the bottom and the last time I tried refiring a ground, thick piece like this I ended up with devit on the ground surface, which I fired face up in the kiln. (I don't have access to a sandblaster). Any tricks to prevent this? Would you recommend taking this approach?

It was mentioned that the edge was chipped out: it is, I used silke mat to line the mold and it actually melted into it in places (I know to use fiber paper now instead). Do I need to grind it? I assumed it was ok since I'll cut the rim off in the end. Or was it just because of not having enough width around the ring that it was mentioned?

I suppose all I can do it try and see, but I'd like to at least try to get it right. I appreciate all the input!

Maybe tack fuse some clear scrap to the outside before the drop? Below and above the disk, give it some help......

And if the chip or anything else wrong is outside the drop ring hole (far enough away not to get pulled into the drop), you can ignore it.

Hello. I just wanted to say thank you for all the help! It worked. Now I just have to cut the top off without breaking it.

Thanks for trying.

This is the way we all learn.

Tony

looks beautiful. it's nice to read the problem solving and then see positive results.