View Full Version : baking fimo at lower temperature - need advice

25-10-2010, 07:35 PM
I'm doing some projects with fimo and resin. But the resin will turn yellow if baked at over 200F, and the fimo requires 230F. I googled and found something that said you can bake at lower temperatures if you double the baking time for every 18 degrees you lower. But how low can you go? I mean, eventually you'll get all the way down to room temp. What's the point where the clay will still bake properly? Does the thickness of the clay matter at all?

Or does anybody know of an epoxy/resin that won't turn yellow when heated?


25-10-2010, 07:46 PM
What are you making exactly? trouble is with fimo if you dont bake it for the correct minimum time it can become very crumbly. Could you use a clear casting resin at all which you could use after the fimo is baked? this air dries pretty quickly. Emma will be the one to ask, hope it goes well.

25-10-2010, 08:11 PM
My projects basically involve making a fimo base, baking it, setting a small decorative element on the base and applying resin over it (think paperwight, but with only a few millimeters of resin), letting the resin cure, then adding more fimo for frames and such (which I smooth onto the base in places and the clays bond), and then I bake the entire piece. I would just make the frame pieces, bake, and then glue them on, but that leaves ugly seems. I really need to smooth the new clay into the design on the base clay.

So my problems are the base getting baked twice, and the resin turning yellow. Although I've not noticed the base seeming more brittle or anything negative due to the second time through the oven.

25-10-2010, 08:30 PM
Ah i see! and see your point, fimo can be baked longer its only brittle if under baked. Theres got to be something on the market surely and if not there should be lol!

25-10-2010, 08:41 PM
Ah i see! and see your point, fimo can be baked longer its only brittle if under baked. Theres got to be something on the market surely and if not there should be lol!

Yep, there should be. But the only thing I found through googling was a mention of West System 207 & 105 being clear and handling high temps (but no mention of how high). So I e-mailed the company and just now got this reply:

The cured 105/207 should remain clear to 200F.
Above 200F to 300F you may see some discoloration.
300 - 400F you will see some discoloration.

I've not tried it yet. I'm trying to find out if you can use it the way I mentioned, or only for bonding two surfaces together. That part of my e-mail to them wasn't answered. I think I'll try calling the company.

25-10-2010, 08:46 PM
In my experience, Fimo does need to reach the correct baking temp for all the plasticizers to burn out and the particles to fuse together properly. Without reaching the right temperature, the clay may appear to harden, but it won't be strong and it could even re-soften over time, because enough of the plasticizer is left active.

Is there no way you can pre-bake your Fimo elements and then use a casting resin to put everything together after so the resin part doesnt end up getting baked?

You could also shop around for different types of resin, in case some suit your needs better than others or ask the manufacturers if they have any advice on how to make their resin withstand the higher baking temps.

25-10-2010, 09:08 PM
I would try experimenting with what resin you have already on scrap bits of fimo and see if it works out, otherwise you could spend a small fortune on resin ( i know i did with varnishes still have loads of different ones knocking around). I would def phone the company prior to buying any see if they answer all your questions then! Sorry not much help, all the best and would love to see pics of your finished pieces