- Video Watch Time = 7 minutes
Question: What’s the best way to clean rust and dirt off of an old door lock? It’s seized and the outside is rusty right now, but it looks like a nice old lock with potential.
Answer: Good for you for wanting to salvage old hardware. There was some exceptionally beautiful hardware made in yesteryear, before the time when so many manufacturers began rushing to produce the cheapest possible products. I guarantee you that you’ll love that door lock all the more because of the work you put into it.
Clean & Lubricate
Step#1: Brush off all loose surface rust, then lubricate the mechanism with a thin machine oil.
WD-40 from a spray can works fine, but so will any other light, thin lubricating oil. such as 3-in-1 I have a big jug of sewing machine oil that I use for jobs like this. Given enough time you should be able to get the latch operational again, plus nice and clean. externally Wet/dry sand paper and synthetic rubbing pads are also a great thing to use to remove rust from oily metal. Just rub different parts of the lock, dry off the oil to see how the metal looks, apply more oil, then sand more.
Prevent Re-Rusting

Step#2: Prevent rust from reforming.
When you’ve got the lock looking good, give it a very light coat of boiled linseed oil, then let it sit for two days. Linseed oil is normally used as a wood finish, but it’s also superb at protecting metal. This little-known fact is valuable. The reason this works so well is because linseed oil hardens and forms a clear, durable skin. You get all the protection of oil, with none of the greasiness. Boiled linseed oil is also great for protecting steel shovels, rakes, axes and any other outdoor tool that could easily rust without protection.
TIP: If the hardware you’re working on happens to be brass (as opposed to steel), go gently. Brass is soft, and part of the attraction is developing a great surface shine by polishing. Don’t use a wire brush on brass, but rather an old tool brush and some paint remover to get rid of any paint residue. Brasso polish works great in my experience, once you get the initial layer of filth and corruption removed.
Boiled Linseed Oil
The best option I’ve found for preventing rust on steel tools and hardware used outdoors is boiled linseed oil. This seems strange since linseed oil is traditional used for finishing wood, not metal. But boiled linseed oil reacts with oxygen in the air, forming a clear non-oily surface that keeps rust at bay on shovels, hoes and other outdoor tools. The film left behind is not all that slippery, so I never use boiled linseed oil on stationary tool surfaces like table saws and jointers. But all of my outdoor hand tools get a coat from time to time, on the metal blades and handles.
The video below shows how I sharpen an old-time hand tool called a scythe, but the video also covers the use of boiled linseed oil as a protection for metal and wood that’ll see outdoor exposure. Linseed oil is great stuff, as you’ll see.