Hi
I've just tried slumping a 6mm thick piece of glass into a new mould – it's a dish mould 9x9x3.5cm
http://www.warm-glass.co.uk/extra-small-square-slumper-with-flat-base-9-x-9-x-35cm-p-2979.html
I followed the basic slump schedule on warm glass but it has barely started to slump at all
– BASIC SLUMP
Runtime = 12 hrs
RATE TEMP HOLD
Segment 1 167°C ( 300°F ) → 663°C (1225°F ) 10 min
Segment 2 999°C ( AFAP°F ) → 482°C ( 900°F ) 60 min
Segment 3 56°C ( 100°F ) → 371°C ( 700°F ) End
Would I be better off using Elaine's schedule posted up for slumping bottles ...
Seg. Rate Temp Hold
1 278 593 10
2 139 704 0
3 Full 804 5
4 Full 554 60
5 56 399 0
Thanks x
hi trudi,
Im sure someone with more knowledge than me will follow me on here, but i will try and help.
What glass are you using? if its bullseye then they have good slumping schedules online somewhere in their technotes.
If it were me i would try changing one variable but keeping the others the same on your original cycle, maybe take the top temp up 20degrees and try that first, if you piece started to slump then you are close.
i would be worried about using a bottle slumping cycle for non bottle glass as you may end up with a puddly mess.
the other thing that may affect it is if you have blocked up your air holes at the bottom of the mold with your battwash or thinfire, as this can cause you to trap a bubble which will stop slumping.
Hope this makes sense :)
Trudi, if you look on the same page as the mould is on, there is general mould instructions to download - you should find your answer on there. ;)
Ah ha .... thank you for that ..... will have another go x
My note book and schedules are at the unit but I had this on my pc so this would be what I started with before I tweaked them to suit my kiln.
SLUMP with BULLSEYE (6mm)
1. Initial Heat (Process Soak) 155/hr to 704C 0.20
2. Rapid Cool AFAP or 9999C/hr to 516C 1.30
3. Anneal Cool 26C/hr to 371C 0.00
5. Cool to room temp. AFAP or 9999C/hr to 25C 0.00
You certainly don't need to go as high as you do for bottles so why not try the above. I have the same mould and have stumped successfully into it in one go so the above schedule won't be far out
Suex
Here's my slumping schedule for 6mm thick Bullseye glass into a mould deeper than 1cm:
Seg Rate Temp Hold
1 200 520 25
2 300 680 10
3 Full 482 60
4 60 370 0
I tweak Temp 2 and Rate 2 according to the thickness of glass and depth of mould, but 680 is the temp that I usually use, although I've also used 690 on a couple of occasions. Hold 2 can be from about 5 to 20 minutes. Sometimes I watch the slump and skip to the next segment when it looks ok.
For a shallower mould (< 1cm) I drop T2 down to 638.
i haven't tried slumping 6mm thick glass but the schedule I use is
Rate - Temp - Hold
200 - 520C - 25 mins
330 - 660C - 20 mins
full - 516C - 50 mins
60 - 370C - 0 mins
Not sure if I'm helping or confusing with so many other schedules !!!
Oh wow - thank you for all the replies!!
I put the kiln on this morning using the link from the website (Thanks Dawn .. trust me not to see that one). Fingers crossed.
It's cooling down now - currently on 250°C
If that doesn't work I'll be checking out some of your other suggestions!
Hi Trudi
Hope it works this time. When I went to liquid glass they gave us a handout with firing schedules for bullseye, full fuse, tack, slumping, fire polishing, small jewellery pieces and some for float, I could type it up and send it to you if you like. Janet
Ah bless you Janet
I'll see how I get on first - save you all that work!
Thank you xx
Hmmmm - well it slumped about half way - so I'm going to have to have a little think!
Same temp for longer?
This time I tried
200-520-25
330-650-20
AFAP-516-50
60-370-0
100-40-0
as opposed to
RATE TEMP HOLD
Segment 1 167°C ( 300°F ) → 663°C (1225°F ) 10 min
Segment 2 999°C ( AFAP°F ) → 482°C ( 900°F ) 60 min
Segment 3 56°C ( 100°F ) → 371°C ( 700°F ) End
Trudi, when I referred you to the sheet, it wasn't for the firing schedule. Below the sample schedule it says:
Variations of slumping temperatures depending on size and shape
(Small deep moulds need higher temperatures than large shallow moulds).
Hi I don't know what kiln you have but is it possible to view the bowl while it is slumping? I put a long soak time when I first fire a new bowl and open the kiln periodically to see what it looks like and if it has fully slumped. I then not how long it took so I can program the kiln the same another time.
Hi Sarah
I have an SC2 with a bead door, so I can't really see how it is doing till it's done!
It was 3rd time lucky ... I tried Sue's schedule (thank you Sue) and it has worked!!! I'll take a picture in the daylight and will post it up in the next few days!
Thank you all for your posts, really appreciate it!
Well done Trudi :) - i am lucky enough to have a hobby fuser but never peep - problem with fusing is in my opinion it's all about the programme and waiting to see if your lovely design is intact ;D
looking forward to pictures
Yay
Trudi, you can open the SC2 door for a quick peek. A few seconds only and you should be wearing kiln glasses in theory to protect your eyes. If I'm making a large bead, say a rose, that won't go through the bead door, I just open the large door and pop it in that way with no problems.
never thought of that - I don't have kiln glasses, would diddy's be ok?
Not sure Trudi. You'd better wait for a full time fuser to come along.
No I dont think so, you need protection from infra red when looking in the kiln, I think diddys protect against flare which is not the same. I know you can't use the welding ones for the kiln to lampwork, so it's a different spectrum I suppose or something technical like that. They aren't expensive from warm glass or ask a friendly welder for their mask.
Edit: looked on warm glass and diddys do both infra red and the flare so should be ok. Hurrah!
At last a picture of the trinket dish!!
(http://farm9.staticflickr.com/8517/8472813119_b8d2ffdd91_n.jpg) (http://www.flickr.com/photos/glitteringprize/8472813119/)
Briar Rose Trinket Dish (http://www.flickr.com/photos/glitteringprize/8472813119/) by Glittering Prize - Trudi (http://www.flickr.com/people/glitteringprize/), on Flickr
I'm so pleased! ;D
That is very pretty Trudi.
Thanks Pat, it was my first time using decals too!
Hi Trudi, Glad that you got it to work in the end, nice colours. Janet
lovely and so is the chain, did you do that too?
Trudi you need special glasses for looking in the kiln when fusing. They have green lenses.
Hi Pauline, yes I did make the chain, it was from a Dragonfly Lynn kit!
Now I did have some of those green lense glasses ..... where oh where did I put them .......
Hi Trudi
When I bought my initial kit, liquid glass made it up for me and for opening the kiln they sent me a huge yellow helmut with a visor, looks like part of a fancy dress costume.