Lubricate Metal and Inhibit Rust With Moly.




Introduction: Lubricate Metal and Inhibit Rust With Moly.

About: I'm a born tinkerer who's always enjoyed hands on activities. I'm into 3D printing, CNC carving and milling, woodworking, and many other trades and crafts. I'm always coming up with ideas for new inventions an…

All of my tools live in a garage that isn't temperature or humidity controlled. I run space heaters or a rolling room air conditioner whenever I'm working out there, which means that the majority of the time, my tools are exposed to the humidity of the outside air. This makes iron rust.

I've found rust removing products that will return surfaces to bare gray iron, but I've struggled with ways to keep the rust away permanently. In another Instructable, I stripped the rust from an old table saw, and treated it with Johnson's Paste Wax. This provided a nice smooth surface that didn't interfere with paint and finishes like some oils can, but in the environment that my tools were stored in, it wasn't as permanent of a solution as I'd hoped. The comments section of that Instructable turned into a war about moisture and WD-40 (please don't let that happen to this one!) and everybody and their grandmother prescribed a different home brewed solution for stopping rust.

One commenter brought a new kind of product to my attention, a spray on molybdenum based film lubricant, so I gave it a try. Thanks Lion of Love!

Moly lube is more properly called Molybdenum Disulfide, and one of its many forms is a dry film lubricant that you apply like spray paint. Basically, you clean the metal, spray it on, let it dry, and wipe off the excess. It provides a beautiful graphite like finish, and it's widely purported to be a more permanent rust fix, because it's a dry coating instead of a semi-liquid film that is permeable and easier to wear away.

Here is the step by step of how I applied this dry film lube for the first time.

Step 1: Remove the Rust.

I recently acquired a semi-rusty wood lathe that I needed to clean up, so it became the focus of my moly experiment. If you look at the picture of it, you can see the orange and brown rust on the lathe bed.

I've been using a Rust-Oleum rust stripping product that my local auto parts store sells. You apply it to the clean, rusty metal, and let it foam away the rust. Wipe off the sludge with the dissolved rust and lather, rinse, repeat until you get the results that you're looking for.

A few applications of the product, and you'll have a nice, bare, gray iron finish.

Step 2: Clean the Iron Surface.

Next, I wiped the iron rails down with rubbing alcohol until the cloth came up clean. This is to remove particulate material from the surface, and to remove the rust stripping chemical itself.

It took me about 3 thorough wipes with a clean cloth and alcohol to get everything nice and clean.

Step 3: Mask and Spray on the Moly Lube.

I found a CRC branded moly spray that I used for this project. Many other options exist, but this one was convenient to buy, and is a brand that I trust.

I sprayed a section of my work surface with the lubricant, and noted that it laid down an opaque, paint like layer.

Because of this, I thought it best to mask off the edges of the lathe bed so that I didn't get overspray on the motor and body of the lathe itself.

Then, I sprayed the lube on the bare metal of the lathe bed. Nice, thin, and even coats are the way to go so that you don't end up with drips and runs. The same rules apply from paining anything else.

Step 4: Let It Dry, and Wipe Off the Excess.

The instructions on the moly lube said to let it dry for 10-20 minutes, so I did. The wet and glossy gray finish slowly dulls, and you can visually see when it's dry.

With a clean cloth, I wiped off the powdery excess lubricant, and lightly burnished the surface to clean it.

Since this was the first time I've ever applied moly to this surface, I elected to apply a second coat, followed by the same dry and wipe steps.

Step 5: Inspect and Admire.

After everything dried and was cleaned up, I gave everything a close visual inspection to make sure that I hadn't missed any spots or forgotten to wipe anything off.

It is worth noting that I also sprayed the lube on the underside of the tailstock and tool holder. I coated everything that was bare iron, or that would slide metal on metal with the moly.

If you do get overspray on any surfaces, it cleans up easily with alcohol. Be careful though, it's just as easy to remove the moly from the bare metal where you want it as it is to remove it from the painted parts that you don't.

Step 6: Reassemble the Machine, and Test It Out!

After cleaning up everything and removing my masking tape, I put the machine back together. Everything slid nice and smooth, and I could definitely feel the difference before and after the moly treatment.

Now I've got a nice, clean, lubricated, and rust proof wood lathe to enjoy!! (And it works very nicely, even if I do say so myself)

I'll report back on how the finish holds up over time.

Thanks for reading!

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    8 Discussions

    Arnold Ziphle
    Arnold Ziphle

    3 years ago

    Thank you for taking the time to experiment with this, and bring it to our attention. I am not a fan of rust. I collect whatever information I can about it, to find better ways of dealing with it, than I currently employ. To date the best best form of dealing with rust prevention came from someone that likes the patina of lightly rusted metal, an Instructable titled: "Preserve the Beauty of Raw or Rusted Steel & Iron Surfaces" by BrianJewett. A link to it:

    I am not sure if your method will work, I have my doubts based off several hours of research. A report from a NASA study implies it won't: Lubrication and Failure Mechanisms of Molybdenum Disulfide Films. A link to the PDF:

    Another paper produced by a company in the lubricant industry gives hint that Moly isn't a viable option. Comparison between Molybdenum Disulfide & Tungsten Disulfide A link to the PDF:

    However this last report gives hint that Tungsten Disulfide may have some promise in rust prevention. Good luck on your lathe and table saw.


    3 years ago

    I recently had some storm damage that punched a hole through my garage ceiling and let in water, directly on top of my lathe! It didn't seem to rust from moisture in the air, but when it came into contact with water, it instantly flashed orange. So... I just re-treated the lathe ways like I did in this instructable. Because of the flash rust, I decided to use the moly lube again, but to put a coat of paste wax on top to seal it in. So far so good. It slides noticeably smoother than before, so I'm happy about that. If this treatment holds up, it's probably what I'll do to my tablesaw, as well. Fingers crossed that this is a bit more water resistant if that ever happens again.


    3 years ago

    Excellent work?


    Reply 3 years ago

    Excellent work!


    3 years ago

    "I'll report back on how the finish holds up over time."

    Thats the bit I'll be waiting for


    3 years ago

    I have this at home. I'll give it a try. Thanks.


    3 years ago


    I've never seen it used for rust prevention before, but I've used it in both spray and most often as moly grease. Molybdenium is extremely good with large loads (it's like having a huge amount of microscopic ball bearings) and I've used it from door hinges, bicycle and motorcycle chains to the steering knuckles in cars (and everything in between) and never had any issues with it.

    I'm looking forward to hear how the spray holds up as a rust shield, as I absolutely hate to apply oil to my tools after use.

    Nice run down!

    Have a nice day :)