On Sat, 29 Aug 2020 12:41:13 +0100, Chris Green wrote:

ss wrote:
Image below is the cross drive for a mini lathe. It is rusted solid.
I have soaked in WD40 for a couple of days and still stuck.

WD40 isn't necessarily the best thing for freeing rusted joints,
'proper' penetrating oil such as Plus-Gas may do better and/or other
even more specialised formulae.

Plus Gas and all those kind of products are pretty useless TBH, esp if
they've been on the shelf for a while. Best results come from freshly
mixing isopropyl alcohol with a thin hydrocarbon oil and giving that
mixture time to penetrate.
A heat gun is far too puny and not worth bothering with IMO.