Joseph Meehan wrote:
Daniel Prince wrote:
In your opinion, what is the best lubricant for an outdoor padlock?
I live in a humid area about six miles from the ocean. Thank you in
advance for all replies.

There are two totally different parts of a lock. One is the tumbler
(the part where you put the key). That you don't want to lube as much as
you want to keep it clean. A zero residue cleaner is best. I like to use a
little graphic when done. NOTE: WD40 is an oil and is not zero residue. It
will leave a thin film of oil that will in time collect dirt as will any
oil. There is a product call lock ease that works well. I will also
suggest that the Teflon based lubes often work well.

The other part of the lock is the part the actually holds the thing
shut. That also needs to be kept clean, but it also often needs some
additional protection from the elements. For that I would agree with most
of the suggestions make. A lithium based product may be best. It will
likely need cleaning and re-lubrication often where you live.

--
Joseph Meehan

Dia duit

Well, yet another opinion:
I would think even 30 weight oil, let alone various greases, would
promote sticking of the teeny weeny internals of the lock. That's why
they never recommend 3 in 1 oil. WD40 is thin to begin with, and at
least evaporates leaving no gunk behind, but by the same token long
term corrosion protection might need to be reapplied now and then.

So you want something light/thin, that evaporates without leaving a
residue, but not too quickly. Maybe dunk it in kerosene? Silicone oil?