On Mon, 3 Jul 2017, Rob Jarratt wrote:
All I could do was prop open the tape door with a paper clip. 45C in my fan oven worked for me. 55C in my oven seemed to mostly demagnetise the tape. Other ovens may be different, so it is best to experiment with something that doesn't matter.
You can not demagnetize tapes at 55°C, that must be another effect, like crosstalk (which is an issue, especially with audio tapes) or something like that.
Christian
