Rust Removal

Discussion in 'The Garage' started by JimVonBaden, Jun 4, 2013.

  1. danfmc

    danfmc Adventurer

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    Hello to all.
    Recently I bought an old motorcycle, and it has small rusty spots on frame, near some original welding.
    What can I do to get rid of this rust without dismantling the whole bike? I have a bottle of phosphoric acid and I was thinking of getting a rag soaked in acid and cover the rusty part with it, and then paint the part with a small paintbrush with oem color. I'm not thinking about getting rid of the rust with something like sandpaper because it might weak the frame, don't you think? And will phosphoric acid corrode the painted part?
    Thanks.
    #41
  2. H96669

    H96669 A proud pragmatist.

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    You'll be fine. One good product is Krud Kutter, the one thay says "The must for rust" on it does contain Phosphoric Acid and does neutralize the rust for maybe a year according to the claims on the container.

    But I like the rust converters made out of Tannic/gallic acids. They are usually milkish white in color unlike the clearish Phosphorics. And convert the rust to a darker black polymer. The phosphorics are more like a clearish varnish. I wonder how much snow is over my test piece???....been outside for a couple years I should look for it if just to show the difference between the two products.
    #42
  3. danfmc

    danfmc Adventurer

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    But can I apply it soaking a rag and applying it for a few hours to the rusty surface, with a solution with phosphoric acid suitable for remove rust? And will it ruin the paint job? The part I need to remove rust is this
    [​IMG]
    #43
  4. H96669

    H96669 A proud pragmatist.

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    ^^^ Remove the privacy setting on your pic.
    #44
  5. Treadless

    Treadless seeking adventure

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    If ruined paint to you is stained or etched then yes it will ruin it. If ruined is blistering-pealing then no it likely won't. Best to test a spot that is somewhat out of sight to be sure.

    Locktite has a product (can't recall the name right now) that is easy to use and is applied to surface rust and piant bonds well to. Taking a route like this might be safer for you and the bike and produce a better result than using an acid.
    #45
  6. H96669

    H96669 A proud pragmatist.

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    Most of them products are sold there and there are application sheets available/MSDSs etc etc for all of them:

    http://www.theruststore.com/Rust-Removers-C1.aspx

    And they have tannic acid based rust converter and them won't do nothing to paint but stick to it, you have to remove it with water before it dries. But wear gloves the stuff will stain hands. I think my "new" bottle by another brand, Corroseal "Gallic Acid based" but Gallic/Tannic are closely related will last a long time.

    Phosphoric Acids etching paint???....may depend on the concentration. I think I have some deck cleaner here, that's pretty high % maybe up to 60%. Higher than the typical Phosphoric "rust cleaner/converters" for sure, what I have here is in the 20% range and so far hasn't touched painted surfaces but does say on the instructions: "DO NOT let dry on painted surfaces", easy enough to do, just keep it wet.
    #46
  7. RFVC600R

    RFVC600R SAND EATER!

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    Damn, I got a cherry tank for my XL but it is rusted inside. I gotta go to the store. :eek1
    #47
  8. H96669

    H96669 A proud pragmatist.

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    My friend just did a very rusty tank.Very very nasty, I was the first to open that gas cap for years and peek in there.:eek1 Step one was "cleaning vinegar" for a week or so with screws in the tank. Higher Acetic acid content vs regular vinegar the "cleaning/strippng" types. That took about 80% of the crap out.

    Step two....good old CLR and a few screws for a few days.Shake shake once in a while. Took everything else out, tank looked like new but did flashrust pretty quick.

    Step three was "Eastwood" metal prep, that's some kind of etcher and most probably Phosphoric Acid based, sure smells like it.I'll look it up when I go visit and dig up the MSDS or product sheet. Will prevent the flashrust and make the tank ready for your choice of liner.
    #48
  9. Plaka

    Plaka Brevis illi vita est

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    Phosphoric acid will convert the rust to Iron Phosphate. Called phosphating. The phosphate itself will not prevent further rust. But it's porous. It holds oil and paint very well. This is why you see those black oilb bolts in the hardware store. Phosphated and oiled to prevent rust in storage. Not a durable coating but it's something and good for storing metals. You want durable you paint or plate.

    Things like Rust desolver or the jelly stuff are phosphoric acid preparations. You can get a gallon of the strait stuff cheap in the paint isle. Clean rusty area to remove oil/grease and rinse well after to remove all trace of acid.

    As mentioned, test on paint. Using the jelly stuff costs more but it's easy to control---put on with a flux brush.

    Sanding is good too.


    If the guy had used phosphoric on his chain it would have taken 5 minutes. Then he could have oiled it to help keep the rust from returning. Storing the chain in an oiled canvas bag helps too. Reuse the phosphoric acid until it doesn't work anymore.
    #49
  10. linkin

    linkin n00b

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    The best way to remove rust from parts is using electrolysis.
    It's cheap and easy and the results are absolutely fantastic.

    As you can see in the link, I have derusted succesfully my fuel tank with electrolysis. The tank was completely rusted inside after standing outside for decades. After two days, the tank was completely new :clap
    #50
  11. D.T.

    D.T. Difficult but useful

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    We have some metal cooling platens at work and we are trying to get the rust out.

    Pressure washer is the only thing that seems to work to at least get some flow through the platens. Tried some Numetal phosphoric acid last night with an air pump, could not force it through.

    Anyone have any better ideas?
    #51