Firing PMC

[Fi Wilson]

Hi everyone,

I'm new to the forum and have been impressed with all the help and advice you have all been giving to each other. A brilliant resource for any jewellery maker.

I was just wondering if anyone came across the same annoying thing that sometimes happens to me when firing PMC on a gas hob. After the binder has burned off the piece sometimes starts to curl. It's usually not much of an issue if it's a one off piece as it becomes part of the character of a handmade piece, but this happened when I made the top piece for a cufflink which really should be as similar to the other one in the pair as possible. Does anyone have any advice on how I can stop this subtle curling at the edges. I'm afraid I can't afford a kiln so that solution is out for me.

Thanks, Fi

[bustagasket]

Hi Fi i am afraid all i can offer is a welcome to the forums, but we have a lot of pmc users here so i am sure one of them will have a little gem of advice for you

[MuranoSilver]

Ahh this one I can help with
Use some of those cross lock tweezers (cooksons have a set of two in their latest mini-brochure) and turn the piece over shortly as soon as you see any curl. It should flatten itself out

[Fi Wilson]

Thanks for the warm welcome Su.

Nic, thanks, you're a star! I knew it would be a simple solution. I've actually got three pairs of cross-lock tweezers (I think they're breeding in my jewellery box) so I can get to it straight away.

Thanks again!
Fi

[EmmaRose]

Happens in a kiln sometime too. Thinking maybe I should put a weight on top (a kiln brick??) any ideas Nic??
Em

[MuranoSilver]

Hmm never had it happen in a kiln...things naturally try to flatten to the shelf.
(I'm often firing in vermiculite to stop them slumping when I don't want them to)
Were the pieces layered or flat?
If they were flat, I guess you could turn them over and refire, which might straighten them...or I'd bash them flat with my hide mallet (provided they were fired at 850 or above so were dense enough).

[EmmaRose]

would that it were that simple!
Where did you get your vermiculite? I have alumina hydrate but now hear scary things so wondering if I should swap....
E

[MuranoSilver]

Think it was from Petra over at silverclay...maybe?
The stuff lasts for Ages and I've had mine about 2 years

[mizgeorge]

Lampworkers buy vermiculite from the garden centre. I can't imagine it's any different!

[Lindyloo]

Am I right in thinking you can fire your piece resting in plaster of paris powder too?