|Links to inlay projects:|
We initially tried putting my husband's turned wood bowls in the oven to cure the polymer clay inlays which was a huge disaster when the wood cracked. For the past ten years we've fired polymer clay inlaid into wood with a heat gun (actually a heavy-duty Bosch paint stripper gun).
Here's my method:
I've only had one failure - in a djembe (drum) that my husband made. The hardware for holding the head taut was drilled into the polymer and the polymer seemed to crumble in a couple of spots where it was stressed. Indeed, it hadn't been fired enough. I removed it, refilled and refired. Problem solved and ten years later he's still using the drum.
When we're inlaying wood bowls, my husband rigs up a turntable (meant for a microwave oven) and a heat gun mount so that I don't have to stand there firing. Looks odd but it works. You can't leave that high heat in one spot for long - the settings are 600 and 1000 degrees - or it will burn the clay. If I'm doing it by hand, I just keep turning the piece and sweeping the heat around much like hair drying.
You can see when the surface of the clay fires. It goes from shiny to dull, meaning the exterior clay has hardened. More time is required to fire it thoroughly. If I don't have time to do a full 20-minute firing, I do a quick firing just to solidify the top of the clay and come back later to finish.
(See the first steps in this latest project here and here.)