On Fri, 29 Nov 2019 14:00:38 +0000, Chris Green wrote:

Sounds a good approach, I'll get my (relatively) new gas blow torch
onto the job.

Alternatively, use cold.

There's a variety of "rust shock" sprays that combine oil and some gas that
cools on contact. Even if the ally gets tighter on steel with cold, it may help
as it may stretch, and then be looser as it warms up again, IYSWIM.

And less chance of melting the nearby plastic...

Thomas Prufer