The best product I've found for lock lubrication is a good spray oil like Mr. Moly spray grease with a MoS2 in tenacious oil.

The easiest available decent-quality spray oil is IMO 1-Lube from the people I otherwise despise: the Slick-50 guys (ironic, isn't it). 1-Lube is a good tenacious oil in a spray can, might have some Teflone/PTFE in it (don't remember), and unlike WD-40 (AKA: starting fluid) the oil sticks around. I use it in my shop on production parts, available at Menard's and other places.

True IMO that graphite has the ability to get into locks, impact the void behind the tumblers, and make the lock inoperable.

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Gone to the dark side

- Jeff