I was at my locksmith's the other day and noticed a spray can of lube. He told me that the stuff was the only thing they use for locks. He went on to say that graphite turns to "concrete" and that WD-40 turns to "gum" after a while.

The name is the stuff is Houdini. On it's label it lists a ton of things that are not in it but never says what is in it. The locksmith didn't know either.

Anyway, I bought some and put some in my door lock key holes. It works very well but it hasn't been long enough to know about long term.

bliving7

 

I puffed a small amount of graphite powder into front door and boot locks a month ago. They have got smoother and smoother, and easier to turn since then.
I await others' opinions..

 

An old trusted favourite WD-40 Company and Product History and its available everywhere on the planet

 

always used and always will use WD40

 

I use silicone spray works just fine no residue.

 

Same here.

 

For decades graphite has been a long time staple for locksmiths; however, times have changed. Wd-40 is a great product and many say it will gum up, I have not seen it! I have however, seen a dry spray lubricant that is suppose to the answer. I have not used it but hope to give it a try soon it might be worth looking into.

 

I picked up a 4 oz bottle of "Liquid Teflon Penetrant" (they had a version sans penetrant) from Lowe's and it worked wonders on the siezed-driver's-door-lock on the 2003 S-Type. Key would only go in halfway, and never turn. Now works 4.0. I went round and applied a bit to ALL the vehicle door and boot keyholes.

By Eyeballing it, I'd say I still have 3.8 oz....