On 03/09/2020 10:20, john west wrote:

In a house built in 1936 on an ancient fuse board it has huge copper U
shaped plugs that act as fuse holders.
They are unbelievably stiff to pull in and out, so only those with the
strongest fingers can manage it.
Is there some kind of lubrication that could be thinly smeared on the
copper prongs that would be safe to do?

You can get purpose made contact cleaners, and contact lubricants / greases.

e.g.

https://cpc.farnell.com/electrolube/...ct%20lubricant

or

https://cpc.farnell.com/electrolube/...ntact%20grease

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/