Zak wrote:
I'm in the Uk and I currently use a 25W Antex. It seems to "run out
of heat" all too often when I am soldering undemanding things like a
fine wires to small tag.

Get a regulated one like a Weller WTCPN(?), and you can choose you tip
size for the job, and select temperature by swapping tips.

$45 on eBay.