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DaisyDaisy
01-06-2011, 08:03 AM
Hello everyone, I'm new to the forum but I'm hoping someone may be able to give me some advice about firing art clay silver.

I've only just started working with it and I'm looking to do fingerprint/artwork jewellery. I'm practising with getting the technique and the look right before I offer any of my work for sale. I've not gone to the expense of a kiln yet, need to make sure I'm carrying on with the silver jewellery first, so I'm firing my pieces with a butane torch. All is going fine until I fire pieces....they aren't curling completely at the sides but ending up dipped in the middle so when I come to polish the piece it's making it very difficult as it's not flat. I'm very careful when preparing the pieces, sanding them down the get them even etc.

I'm wondering if firing the pieces in a kiln would solve the problem? Any advice would be greatly appreciated.

Thanks.

DaisyDaisy
10-06-2011, 10:49 AM
83 views of my post but no advice/tips.

Thanks.

Kwant
10-06-2011, 12:19 PM
Hi I am one of those 83 and do not fully understand your problem, particularly this part "they aren't curling completely at the sides but ending up dipped in the middle". I would not want my PMC to be curling at all, as sometimes happens if you dry it out too quickly.

As for polishing awkward shapes this can be achieved with a pendant drill and some 3M radial discs such as these http://www.cooksongold.com/Jewellery-Tools/Radial-Disc-Kit-6-Each-3-Grades--3-Mandrels-prcode-999-1967 , the rubbery types that come in a variety of colours depending on their coarseness, they get into all sorts of nooks and crannies, tumbling also helps to get into awkward places. I have made many PMC pieces and do not have a kiln, though kiln firing does produce a more resilient piece, tumbling also helps to compact a piece that has been torch fired.

ps_bond
10-06-2011, 12:26 PM
I don't use the stuff, personally, so while I've read your post, I've nothing constructive to offer beyond the observation that you aren't going to get an even heat across anything large with a butane torch.

snow_imp
10-06-2011, 02:12 PM
I don't have a kiln either, but I fire my pieces on my gas hob rather than with a torch so can't offer any advice I'm afraid.

medusa
11-06-2011, 05:17 PM
I think it's possible they are too thin? Maybe if you post some photos, we can get an idea of what you have done and are trying to achieve.

DaisyDaisy
12-06-2011, 06:49 PM
Kwant, I don't want my piece curling, the fact that it's curling is the problem. I leave it to dry naturally so I doubt it's down to drying it out too quickly.

I have made 4 round fingerprint charms in varying thicknesses from around 2mm to 5mm so I doubt the thickness is the problem - they have all curled. I want them to remain flat but after firing they're ending up a concave shape, the outside edge slightly curled up. As I'm firing a piece I can see the edges starting to curl. I've tried backing off with the flame slightly, turning the piece over part way through firing but nothing seems to be working.

Hopefully I've explained this a bit better.

caroleallen
12-06-2011, 09:27 PM
Is it possible to flatten the piece with a hide mallet?

medusa
14-06-2011, 06:52 PM
2mm is really thin, I think, for PMC. I would have thought 5mm would be ok. maybe fire it on a mesh platform and use two torches, one top and one underneath?

could try a hide mallet, like carole suggests, but it might break. not sure how flexible PMC is.

Joe
14-06-2011, 10:11 PM
I do very little PMC - just for fun. I have made a few thin - 2mm ish - pieces. Yes, they curl up markedly at the start of the firing and then, of their own accord, flattened out in the kiln.

I suspect that the pieces are under-fired and you are suffering torch firing blues. You wont want the advice of buying an expensive kiln...

MuranoSilver
16-06-2011, 09:29 PM
Use your tweezers to flip them over (as soon as the curling starts) :)
It's because with torch firing (and sometimes hob firing) the heat can be uneven
and cause uneven scintering which pulls the piece out of shape...
Hope that helps & let us know how you get on

Nicola x

DaisyDaisy
17-06-2011, 11:50 AM
I'll try that, Nicola, thanks. I have tried turning the piece over but not as soon as the curling starts. I thought it may be to with the fact that the heat with a torch is uneven.

madamcc
30-08-2011, 09:50 PM
if the piece starts to curl as it sometimes does when it starts shrinking, depending on the design of your piece, try turning it over mid fire and firing it from the other side also, this has worked for me.
:~: