How strong is polymer clay? Advice please

I was thinking of making polymer clay brooches and pendants. But when I was working on a ‘cooked’ piece of Fimo, it seemed quite crumbly and Sculpey pieces were quite brittle. I hate the thought that something I sell might easily break. Would they need to be reinforced somehow? Any advice appreciated! Thanks!

Years ago as a kid I used to make ornaments out of fimo and found them very robust and more recently when I used some sculpey it stayed slightly flexible after I had baked it so I would have no qualms about using either to make jewellery. Have you checked the temperature of your oven to make sure it’s not inadvertantly over baking them?

I did wonder about that, Sasha. I have a gas oven so there’s never any “official” temperature printed on the clay packaging. Perhaps I’ll just have to experiment. I still have some Fimo things that my kids made in the eighties and they seem quite strong…

Some of the big buttons I use have been made from polymer clay, Fimo I think. Read the instructions carefully and bake at the right temperature for the right amount of time and they are fine. You might need to buy yourself a thermometer from a cooking shop. Most important not to cook at the same time as or just before food as it gives off nasty gases.

I used to use Fimo and used to reinforce some delicate items with perforated aluminium sheet they use for car repairs. Fimo can be quite brittle unless thick and chunky, but curing it in an oven helps. Make sure you use the correct temperature. Did send some quite fragile dragon models to Australia once, with the reinforcement, and they arrived safely.

Made the mistake of asking my partner to “cook” some Fimo models I had made, while I had a bath, and came down to see the kitchen full of smoke. She had misheard the temperature setting I gave her, and dialled- in almost double the correct temperature, and the oven was never the same again ! I think the fumes were toxic too at high temps.

Hi Christine @coatimundi

Polymer clay is amazingly durable and very strong if the correct clay is used for the specific task.

I use only Sculpey Premo now its my firm favourite over others. I have many prototypes which have stood up well to testing where other clays have failed. I really dislike Sculpey iii as its just too crumbly and won’t withstand much pressure for delicate work.
Fimo is my second favourite but so much harder to condition…

I have a special oven dedicated for my clay with a thermometer inside as underbaking or overbaking can weaken your finished piece.

Hope this helps abit

Karen :blush:

Thanks, everyone! Lots of good advice here! I’ll have a play around with various methods and try to find out what works best… (and get an oven thermometer as I don’t think my thermostat’s very accurate)…