The funnel has become completely stuck. Let’s give it a try.
After lubricating thoroughly, I applied thread compound spray to soak in. It’s aluminum to aluminum, so I’ll heat it in the oven just to be safe.
The problem is that the funnel can’t be held in a chuck.
In the end, I made an attachment like this, held the funnel by hand, and used a plastic hammer on the attachment, repeating ‘loosen—tighten, loosen—tighten’ until it came free.
All’s well that ends well.
