Drop with Dropring

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Jan de Jong
Posts: 114
Joined: Sun Mar 09, 2003 3:31 pm
Location: The Netherlands

Drop with Dropring

Post by Jan de Jong »

Hello, Never done it before, so I need help.
I have a metal dropring: diameter 25 cm with a border of 5,5 cm. The height of my kiln is about 28 cm. The heat comes from above (in the lid)
I plan to drop to circa 25 cm. How many layers do I need. Is it right each layer delivers circa 2,5 cm ( 1 inch) ? Which diameter I have to cut ( the best in connection with the border !) What is the best way to get a good bottom ? Ceramic paper 3 mm on the metal is okay ?

Please some idea about a schedule (for window glass for testing the first time, and please also for System96 )
Thank you very much in advance for your help ! Jan de Jong (Holland)
Lynn Perry
Posts: 128
Joined: Sun Jun 08, 2003 5:27 pm
Location: East Tennessee

Re: Drop with Dropring

Post by Lynn Perry »

I found this with a search, and it seems to have some information you could use. Good luck.

https://www.gofusing.com/blog/how-to-ma ... drop-ring/
Lynn Perry
Jan de Jong
Posts: 114
Joined: Sun Mar 09, 2003 3:31 pm
Location: The Netherlands

Re: Drop with Dropring

Post by Jan de Jong »

@ Lynn Perry: Thank you very much for this link !! Jan
Jan de Jong
Posts: 114
Joined: Sun Mar 09, 2003 3:31 pm
Location: The Netherlands

Re: Drop with Dropring

Post by Jan de Jong »

Is it necessary to fire the 3 - 4 layers first, or just fire at once ? Jan
Lynn Perry
Posts: 128
Joined: Sun Jun 08, 2003 5:27 pm
Location: East Tennessee

Re: Drop with Dropring

Post by Lynn Perry »

Hi Jan. I primarily make jewelry, never any ring drops. Perhaps someone else can give you first-hand knowledge. If I understand your question about the layers, you must first fire all of the layers together before doing the drop. Otherwise, each glass will drop separately. Since the drop temperature is well below the fusing temperature, the glass layers will not be connected together after the drop and might be interesting, but not what I imagine you are trying to do. Also, if you do not dam the glasses when firing them together, your piece will seek a 6mm thickness which might be sufficient for your drop distance or might be too thin when stretched.

I do not know how much experience you have, but you might need to buy a good fusing book, like Brad's, and do some reading and trials. Pardon me if you are beyond that level already.
Lynn Perry
Kevin Midgley
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Location: Tofino, British Columbia, Canada

Re: Drop with Dropring

Post by Kevin Midgley »

Be prepared for lots of testing.
Residual heat within your kiln will be the problem.
You will peek at the glass and say that looks perfect only to realize that the piece you are making is like a car with no brakes.
The effects of your peeking cannot be ignored either.
Take Notes. Lots of notes.
You may find the glass will move with much less heat than anticipated.
Remember the formula time and temperature.

As for the simplicity of having once determined a schedule that works, you will find it to be inconsistent particularly with coloured glass.

I also would suggest a firing setup where the glass drops and fuses onto another piece of glass which forms an anti tip over bottom.
One caution: ensure the bottom can go through the drop ring at the top.

Rules are also meant to be broken regarding fusing together first as everything is an experiment when doing drops.
Jan de Jong
Posts: 114
Joined: Sun Mar 09, 2003 3:31 pm
Location: The Netherlands

Re: Drop with Dropring

Post by Jan de Jong »

Lynn and Kevin: Thank you for your help ! I understand... much trying. Jan
Lynn Perry
Posts: 128
Joined: Sun Jun 08, 2003 5:27 pm
Location: East Tennessee

Re: Drop with Dropring

Post by Lynn Perry »

Jan, just in case you have not see these, here are a couple of links to other information:

https://www.warmglass.com/tutorials

http://www.bullseyeglass.com/methods-id ... icles.html
Lynn Perry
Jan de Jong
Posts: 114
Joined: Sun Mar 09, 2003 3:31 pm
Location: The Netherlands

Re: Drop with Dropring

Post by Jan de Jong »

For help to others: Like to share the link I found: https://www.warmtips.com/20060303.htm Jan
Jan de Jong
Posts: 114
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Location: The Netherlands

Re: Drop with Dropring

Post by Jan de Jong »

After posting I was thinking: what happens by 5 layers ? Will these be visible ? Jan
Kevin Midgley
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Location: Tofino, British Columbia, Canada

Re: Drop with Dropring

Post by Kevin Midgley »

Who knows. experiment.
The more layers the more variability.
Jan de Jong
Posts: 114
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Location: The Netherlands

Re: Drop with Dropring

Post by Jan de Jong »

@ Kevin: Okay, I go for 4 layers and see what happens :wink: Jan
Michael Stevens
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Re: Drop with Dropring

Post by Michael Stevens »

I think if dropping 25cm might want 5 or 6 layers. I use four layers for a 6 inch drop. also as mentioned just tack fuse them first if you don't use a dam. make sure things are perfectly level and centered. it's annoying when doesn't drop even. I often add a clear layer in the center, sometimes 2 if glass is dark
michaelmace
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Joined: Sun Aug 16, 2020 9:16 pm

Re: Drop with Dropring

Post by michaelmace »

Hi, Jan.

My wife and I have made a lot of drop vases, many of them using a 9-inch ring that is similar to yours in size, but is made of ceramic. Is your metal ring one solid piece? I ask because metal generally shrinks more than glass as it cools, so I worry that the ring might trap your vase.

We use boron nitride spray on our ceramic ring, and that works great. For your metal ring, I think 2mm or 3mm ceramic paper is a good idea, and maybe cut the hole a little smaller than the ring to avoid getting the glass trapped in the ring.

We usually make vases that are 15 cm tall. For that height, we use a blank that is 12 mm thick. This results in a vase that has a wall that’s about 1.5mm thick. If you try to do a drop of 25 cm with a 12 mm blank, I worry that you may get very thin walls on the vase, or you may get holes in the walls. I think Michael Stevens is right, you may want a thicker blank.

You asked how wide your blank should be. I would start with one that’s the full 25 cm circle in width. Over time you may find that you can get away with a narrower blank, but if you make it too narrow, the glass may slide off the ring. My wife and I have done that a couple of times.

We always do a full fuse on the blank before we drop it. We find that this helps get most of the bubbles out of the blank. The more bubbles, the more likely it is that you’ll have some of them exposed at the lip of your vase. Dirt will get into these open bubbles when you’re sanding and polishing it, and it’ll look weird.

You asked what will happen to the layers. The layer of glass on the bottom (closest to the ring) will stretch the most (become the thinnest) when it drops, because it is trapped against the ring. The layers on top of the blank stretch the least, because they are free to flow into the vase. So at the bottom of the vase you will see your bottom layer of glass, as the glass stretches toward the top of the vase you will see your inner layers. You can get some very interesting color effects by taking advantage of this.

We use COE 90 glass, so you will have to adjust your firing schedule from this. But here’s what works for us:

Heat the kiln 150c/hour to 670c. Based on what you wrote, your blank is going to be very close to the heating element, so you might want to heat a bit more slowly so you do not crack the blank (I have done that one too). Hold at 670c. Check the glass once it reaches 670c degrees, and every 15 minutes after. The glass will take a long time until it starts to drop, and then it will drop faster and faster. So you have to check it more and more frequently as it drops. Toward the end, you need to check every few minutes. We usually need about an hour and a half at 670c to get a 15-cm drop.

The narrower your ring, the higher your temperature will need to be. For an 18cm ring, with an 8 cm hole, we hold at about 700c.

You can make the glass drop faster if you hold at a higher temperature, but it will be very difficult to control the drop because it’ll go so fast.

Once you like the shape of the vase, skip to your annealing temperature. Bullseye says not to vent the kiln, but I usually lift the lid to drop the temperature a little bit (maybe 10c) at the start of cooling. The idea is to stop the vase from dropping more. Warning: if you do too much flash cooling, the surface of the glass may become rough.

I hope this is helpful. Good luck!

Mike
Jan de Jong
Posts: 114
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Location: The Netherlands

Re: Drop with Dropring

Post by Jan de Jong »

Sorry for late respons. Thank you Michael Stevens and michaelmace ! In the past there was a notification when there was a new mail, but now not anymore (or have I done something wrong ?) Jan
jim simmons
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Joined: Sun Mar 09, 2003 10:37 pm
Location: Hillsboro Oregon
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Re: Drop with Dropring

Post by jim simmons »

No, Jan you didn't do anything wrong. That link was supposed to show you how to do a drop with only one firing.
That post and the firing schedule were first posted by me, and I do not seem to find it either.
I will look and see if I can find a link that works, and if I can. I will post it here.
The Other Jim
Jan de Jong
Posts: 114
Joined: Sun Mar 09, 2003 3:31 pm
Location: The Netherlands

Re: Drop with Dropring

Post by Jan de Jong »

Hello, with your help I was able to make a good drop, but this was with only blank and transparent glass. Now I wish to make a new drop with opal glass and then a good design is a must. Michaelmace wrote: " You asked what will happen to the layers. The layer of glass on the bottom (closest to the ring) will stretch the most (become the thinnest) when it drops, because it is trapped against the ring. The layers on top of the blank stretch the least, because they are free to flow into the vase. So at the bottom of the vase you will see your bottom layer of glass, as the glass stretches toward the top of the vase you will see your inner layers. You can get some very interesting color effects by taking advantage of this." Most of this I understand, but for me is better to see an example (it is difficult for me to see how it work) How is the plate composed and what is the result (vase). I hope someone can give me some examples. P.S. I realise that my knowledge of the English language becomes bad, so I hope I have explain what I mean. Jan (from Holland)
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