I have always used Amiga explorer to make adf floppies but thought this method would be quicker, what am I doing wrong!?
When using Workbench if you drag the adf to the floppy it will try to copy the adf as a file. You instead need to write the adf directly to the disk. There are numerous tools for this, for example
tsgui.
It's quite easy to assume Workbench would work the same way as Amiga Explorer does, but here it doesn't.