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WD-40 causes rust ??

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  • WD-40 causes rust ??

    I see Mac vs PC arguments, Right vs. left disagreements here in the states.
    A lot of people hate WD-40 lube (?).

    Co-worker told me it had water in it and would rust his guns in 2 days.
    I had to blow that comment off.

    I love the stuff. Sure, it has problems. A weak lube at best, not a super penetrating oil, or an outdoor rust preventive.
    On the good side, it's low odor, good solvent/cleaner, for me it leaves a clean film on indoor metal that has some protection qualities. It's cheap by the gallon. Cleans up out side of the stainless bar-b-q nicely, great for cutting lube on aluminum. Kind of smells good too, decent hand cleaner.( If my skin takes a bath in it, a little soap takes the odor off)
    I use a lot of it.

    Whats to hate about the stuff if you take it for what it is?

  • #2
    From wiki:

    WD-40 is the trademark name of a United States-made water-displacing spray. It was developed in 1953 by Norm Larsen, founder of the Rocket Chemical Company, San Diego, California. It was originally designed to repel water and prevent corrosion,[1] and later was found to have numerous household uses.

    WD-40 stands for "Water Displacement – 40th Attempt". Larsen was attempting to create a formula to prevent corrosion in nuclear missiles, by displacing the standing water that causes it. He claims he arrived at a successful formula on his 40th attempt.[1] WD-40 is primarily composed of various hydrocarbons.

    WD-40 was first used by Convair to protect the outer skin of the Atlas missile from rust and corrosion.[1][2] The product first became commercially available on store shelves in San Diego in 1958.

    The long-term active ingredient is a non-volatile, viscous oil which remains on the surface, providing lubrication and protection from moisture. This is diluted with a volatile hydrocarbon to give a low viscosity fluid which can be sprayed and thus penetrate crevices. The volatile hydrocarbon then evaporates, leaving the oil behind. A propellant (originally a low-molecular weight hydrocarbon, now carbon dioxide) provides gas pressure in the can to force the liquid through the spray nozzle, then itself diffuses away.

    These properties make the product useful in both home and commercial fields; lubricating and loosening joints and hinges, removing dirt and residue, and extricating stuck screws and bolts are common usages. The product also may be useful in displacing moisture, as this is its original purpose and design intent.
    No water, protect missles sitting in a silo. (controlled envirnoment?)

    I don't like that it turns to a sticky mess. Otherthan that, it has kept my drill bits and craftsman tools from rusting in the garage for years. I plan to use Starrett Tool and Instrument oil for my precision tools because it doesn't turn gooey. Local tool amker has been using starrett oil for a long time, his 30 year old mic's still spin free...good enough for me.

    I have no problems with WD.
    If the women don't find ya handsome, they should at least find ya handy


    • #3
      It was never meant as a lubricant as a matter of fact it leaves a residue after it dries. It does do a great job of what it was designed to do- displace water.


      • #4
        In the UK it was marketed as "Rocket WD-40"
        "Patriotism is the last refuge of a scoundrel"


        • #5
          Huh- yeah, I thought that PREVENTING rust was one of the few things it was really pretty good at...

          rusting in Seattle


          • #6

            When it dries it leaves a varnish that attracts moisture in the air. That is what leads to rust. I have seen guns sprayed with WD-40 then stored away for a year or so that were one solid mass of rust, completely ruined. It does displace moisture until it dries out.


            • #7
              Only a fool would use WD40 on guns and locks. It does good as a short term surface protection and should never be used for a lubricant.
              It's only ink and paper


              • #8
                I've found the trouble with WD40 is it emulsifies quite easily and also attracts dust, which in turn absorbs moisture.
                Paul Compton


                • #9
                  WD-40, the product claimed to do everything. Except work well at anything.

                  Ok, So maybe the cutting fluid for aluminum it does work well at... Other then that.. Havent used my can once.

                  Need a penetrating lube? .. Buy some penetrating lube.
                  need a rust protector? Buy some LPS (1 2 or 3 depending on how long you want it to last)
                  Need a hinge lube? Use way oil.

                  'The product also may be useful in displacing moisture, as this is its original purpose and design intent'
                  'May be useful' hahaha.

                  I can see it 'displacing' moisture in a crack/crevis, where the object is then put into a controled low humidity envorment so the varnish does not attract more moisture, I can't see it being used to coat a surface to any useful effect.

                  Other then that.. Not a product you want to use!
                  Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.


                  • #10
                    Originally posted by Carld
                    Only a fool would use WD40 on guns and locks. It does good as a short term surface protection and should never be used for a lubricant.
                    Guess I'm a fool then. I use it liberally after scrubbing my muzzleloader barrel in hot soapy water. Never had a bit of rust, but then I store it in a safe, not under my truck seat or in a barn.


                    • #11
                      When in the USN working aviation it was not legal to use on aircraft due to it not preventing corrosion.

                      For what its worth the only thing that I use it for is taking road tar off my fenders and bumpers on my car.


                      • #12
                        I also use it liberally on firearms and the like BUT never spray it on - the spray will pick up moisture out of the air and actually force it into tiny cracks and crevices. Instead, spray it on to a rag or cloth, and apply it with that.


                        • #13
                          I find it works well at what it was designed for. If you have wet or damp metal remove the water with WD-40, however if you need long term rust prevention then you need to follow up with something else either a coat of oil or LPS-3 etc. I also find its good as a cleaner and it smells better than K-1. Other penetrating oils such a PB Blaster should never be used to displace water. I've seen PB Blaster trap water and cause rust spotting on tooling.


                          • #14
                            I have never had a "sticky" problem with it.

                            I don't expect long term storage with it. Seems good for 6 months or better if the metal is stored very well.

                            Maybe the way I use it. I always shake it up. Like Tel, I also spray on a rag, or smear it around with one.


                            • #15
                              The best spray/lube/penetrant I have every used is, Penetro 90.
                              We use it at work and I have to say, it is awesome.