There are a lot of reasons why you would want to bake polymer clay twice or even more than that. For example, if you want to create a very complex sculpture and you need parts of the sculpture to be hardened already before you can continue to work on it or you simply didn´t bake the clay enough the first time around and you want to bake it a second time to harden it properly. So it is not surprising, that one question, that I get all the time, is if it has any negative impact on the clay itself if it is baked multiple times. So I decided to put that to the test and see if there are any side effects of baking polymer clay more than once.
In short, polymer clay can be baked twice or even more times than that without any complications. It’s only important, that the clay cools down completely before it is baked again and the temperature has to be correct. Some brands of polymer clay can react poorly if they are baked multiple times.
So there you have the short answer. If you just wanted to bake your regular polymer clay a second time because you did something wrong the first time or because you added something to the existing already hardened sculpture then you can simply go ahead and bake it a second time without any issues.
If you are using a special kind of polymer clay though, then you should read on because they may be a little harder to bake more than once.
The two things that you should be careful about are the correct temperature and that the sculpture has already cooled down completely before you bake it again.
You can find the right temperature for your polymer clay brand on the package or you can check out my polymer baking guide where I list the baking times of the most common polymer clay brands.
If you want to bake your polymer clay more than twice though, then you should maybe read on because depending on the type of clay and the brand things may be a little more complicated.
And if you have a special kind of clay-like effect clay (glitter for example) or if you are using translucent clay, then you may want to read on as well because these clays can be a little harder to bake more than once as well.
Baking Regular Polymer Clay More Than Twice
Baking regular polymer clay twice is almost never an issue. But if you want to bake it more than twice, then things start getting a little more complicated.
Generally, you don´t need to worry, that your sculpture melts. Polymer clay is a type of plastic, that is true, but it is a thermosetting plastic. Meaning that the temperature will harden it but it will not get soft in any way whatsoever.
You can see how I made a polymer clay sculpture of Link from the legend of Zelda where I baked several pieces of the sculpture multiple times in this video.
But Polymer clay can be scorched quite easily if you are not careful. This is normally not an issue as long as you follow the instructions on the package but if you want to bake it more than twice then this can become a little bit of a problem.
Especially if you have a lot of thin parts on your sculpture or if your sculpture is generally a little smaller. To avoid any scorching it is important, that you keep a close eye on your sculpture while it is in the oven.
If you see any smoke or if a part of the sculpture is starting to get darker then you should take the sculpture out right away.
You can also try to use a little less heat, then write on the package for your third or fourth bake. This will ensure, that when the clay begins to show signs of scorching that you have more than enough time to react and take it out of the oven.
The heat in ovens is a lot of the time not evenly spread. A lot of the time most of the heat will come from the top of the oven. You can try to disperse this heat and protect your sculpture by putting a little aluminum foil or baking paper tend over your sculpture.
Make sure, that the paper or the foil does not touch the polymer clay in any way. You also don´t have to cover it from all sites. It is enough to fold a U-Shape out of the foil or the paper and then put it right over your sculpture to protect it from above.
Be especially careful if you are using Sculpey or Sculpey III. These Brands can burn especially fast if you are not careful enough. Translucent Clays and special effect clays like Fimo Glitter, for example, can get scorched quite fast as well.
If you are using Premo or Cernit, then you don´t have to pay that much attention. These brands are very resistant to getting scorched. I found that you can easily bake them multiple times without any issues and with very little care or protection.
Baking Special Effect Polymer Clay More Than Once
There are quite a lot of special effect polymer clays out there and unfortunately, I just couldn´t test them all but I found, that most of these special effects clays are behaving similarly bad to repeated baking.
Special effect Polymer Clay is every kind of Polymer Clay, that has some special gimmick to it, like glow in the dark clay, glitter clay, translucent clay, and so on.
Most of these clays are from the company Fimo but there are other companies, that have similar products.
I found, that these clays can be baked multiple times but you should be a heck of a lot more careful when baking them more than once.
I personally look after the sculpture every minute when I bake them a second time because these clays can get scorched quite fast.
So I would recommend looking after these clays a lot when baking them for a second or third time and take them out of the oven when you see any discoloration.
You should also bake them at a lower temperature but for slightly longer and I would highly recommend building an aluminium foil or baking paper tend for them, as described above.
You should also put your polymer clay on some folded baking paper to protect it from the heat coming from the bottom. This will also secure, that your clay does not get scorched on the bottom side.
You can use the translucent effect if you are not careful. I saw that happening when I baked Translucent Fimo a second time. It started yellowing a little bit and when I took it out the translucent effect was greatly reduced. It had become very fogy.
So as long as you pay close attention to the polymer clay while it is in the oven and as long as you protect properly, as long as you do that you will be fine and you will be able to bake your polymer clay multiple times.