small dish with flat bottom

Started by anditsinthefish, September 21, 2015, 05:06:20 PM

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anditsinthefish

I am looking for a small (12-15cm) dish mould that has a flat bottom. I have this one from Warm Glass http://www.warm-glass.co.uk/small-spherical-bowl-mould-8146-135cm-diameter-x-33cm-p-2528.html?cPath=96_189 and its great but all of my dished have a round bottom and spin on the table. I'd ideally like to avoid having to grind them flat.

Has anyone seen one anywhere? I only have an SC2 at the moment, so am quite limited.

Sarah xx
Sarah xx
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Blue Box Studio

Not got the mould, but was having the same as you, the bottoms weren't getting flat or large enough.  I ended up double slumping and it seemed to do the trick (which probably means tweak my schedule but that's advanced stuff on my pre-programmed Skutt so they go in twice).
Sue
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anditsinthefish

Quote from: Blue Box Studio on September 21, 2015, 06:35:07 PM
Not got the mould, but was having the same as you, the bottoms weren't getting flat or large enough.  I ended up double slumping and it seemed to do the trick (which probably means tweak my schedule but that's advanced stuff on my pre-programmed Skutt so they go in twice).

Surely as the mould itself doesn't have a flat bottom even by re slumping it, it wont make any difference...

Sarah xx
Website. Blog. Flickr.

Zeldazog

Quote from: anditsinthefish on September 23, 2015, 12:06:15 PM
Quote from: Blue Box Studio on September 21, 2015, 06:35:07 PM
Not got the mould, but was having the same as you, the bottoms weren't getting flat or large enough.  I ended up double slumping and it seemed to do the trick (which probably means tweak my schedule but that's advanced stuff on my pre-programmed Skutt so they go in twice).

Surely as the mould itself doesn't have a flat bottom even by re slumping it, it wont make any difference...



I thought I had posted a comment similar - the mould you're using doesn't have a flat bottom.  There is a another small square slumper that I've had issues with, similar to Sue - in that my normal slump isn't hot enough for it - but I think the Warm Glass/Bullseye slumping tips advise this.  Slumping (even more than fusing!) is not an exact science

Could you use coaster bumpers, or would that spoil the look?

anditsinthefish

Quote

Could you use coaster bumpers, or would that spoil the look?

It would spoil the look and to be honest, the bottoms are so rounded I'm not sure they would stick. They are pretty much spherical.

I'm sure there must be a mould... if not I will just have to wait for a bigger kiln and a bigger mould :(
Sarah xx
Website. Blog. Flickr.

Moira HFG

How about a circle of fibre paper in the bottom of the mould to create a flat base?
Or some dry shelf primer? This will give you a texture which you may like, or may not want

Or, you might consider one of the small square moulds Warm Glass do? Nothing to stop you slumping a circular piece in a square mould. They are shallower, though.

Fluffstar

Yes, that mould won't give you a flat base even if you slump all year...  

Zeldazog - is it this one? http://www.warm-glass.co.uk/extra-small-square-slumper-with-flat-base-mould-9-x-9-x-35cm-p-2979.html?cPath=96_73 ?

I have 8 of them I used to churn out dishes for the xmas fairs last year so I didn't want to double-fire everything. I found that using a slightly higher holding temperature worked best, and holding for double the time (if not more).  Counterintuitively (well, I thought so anyway) smaller slumps are generally slower than bigger ones, as there's less mass of glass without support to pull down, or something.  
Kathy

anditsinthefish

oh my gosh... that is genius... thank you Fluffstar and Moira.

Sarah xx
Website. Blog. Flickr.

Zeldazog

Quote from: Fluffstar on September 23, 2015, 03:50:53 PM
 

Zeldazog - is it this one? http://www.warm-glass.co.uk/extra-small-square-slumper-with-flat-base-mould-9-x-9-x-35cm-p-2979.html?cPath=96_73 ?

I have 8 of them I used to churn out dishes for the xmas fairs last year so I didn't want to double-fire everything. I found that using a slightly higher holding temperature worked best, and holding for double the time (if not more).  Counterintuitively (well, I thought so anyway) smaller slumps are generally slower than bigger ones, as there's less mass of glass without support to pull down, or something.  

Yes, that's the one, and I did alter my slumping schedule to suit, and it's not just about size of slump, its about the depth.  Whilst that dish is only 3.5cm deep, it's a little deeper than say the 25cm square slumper, but it's the proportions really - and yes, a smaller dish has less glass therefore less weight.  A larger piece of glass will be heavier and the forces of gravity will come into play as soon as it's softened a little.

If you look at the profile of say, that small dish to a larger one, the angle is much steeper, so the glass needs to be softer (And therefore requires more heatwork) to move


Fluffstar

Quote from: Zeldazog on September 23, 2015, 07:44:36 PM
Yes, that's the one, and I did alter my slumping schedule to suit, and it's not just about size of slump, its about the depth.  Whilst that dish is only 3.5cm deep, it's a little deeper than say the 25cm square slumper, but it's the proportions really - and yes, a smaller dish has less glass therefore less weight.  A larger piece of glass will be heavier and the forces of gravity will come into play as soon as it's softened a little.

If you look at the profile of say, that small dish to a larger one, the angle is much steeper, so the glass needs to be softer (And therefore requires more heatwork) to move



=) I think that's what I like about that mould - you can do fun stuff on the outside of it and it can be seen as well as the inside. I do find I sometimes get faint 'stretch marks' (not sure if it's devit - doesn't look like normal surface devit) around the top of that one which I thought was because I was slumping it too fast.  I used to sell them as seconds but customers said they couldn't see a difference so I stopped worrying about it for quick fair makes.
Kathy

anditsinthefish

Only issue I have is my round pieces are slightly too big I have realised. I have 10cm pre cut circles from studio supplies and they are just that little bit to big for that square mould....

Back to the drawing board :(
Sarah xx
Website. Blog. Flickr.