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Easy mill scale removal from hot rolled steel

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  • #31
    Originally posted by grzdomagala View Post
    Reaction with lye (Natrium hydroxide?) is also quite useful to remove aluminium from endmils. Don't ask why i know...
    Nice to come here and learn. I never heard of Natrium. So I looked it up. Are you really old Thanks for the new word. JR

    http://www.vanderkrogt.net/elements/element.php?sym=Na

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    • #32
      Originally posted by JRouche View Post
      Nice to come here and learn. I never heard of Natrium. So I looked it up. Are you really old Thanks for the new word. JR

      http://www.vanderkrogt.net/elements/element.php?sym=Na
      Sodium in English, French and Spanish, Natrium in most? other languages.
      I have to check every time that I'm not talking about Wolfram instead of Tungsten.
      Location: Helsinki, Finland, Europe

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      • #33
        Originally posted by Edwin Dirnbeck View Post
        Here it is


        Sent from my iPhone using Tapatalk
        "My Grandmother was a slave"? You have some internet history up on that image. JR

        Oh. And I love the paint pen description of you computer. Looks to be a pretty nice setup.

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        • #34
          will Evaporust work on mill scale?

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          • #35
            Originally posted by quasi View Post
            will Evaporust work on mill scale?
            wont touch it. JR

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            • #36
              Originally posted by Jim Stewart View Post
              Heh. Some years ago I was heavily into two-stroke sportbikes - it's possible to get surprisingly high power out of small engines (250-400cc). In the process, of course, you transform a decently reliable bike into a rolling hand grenade that's lots of fun while it runs.

              A common failure mode is piston seizure, which leaves a smear of aluminum strongly bonded to a cast iron cylinder sleeve. Many mechanics would routinely hone the cylinder until the smear was gone, leaving a sloppy fit for the piston. Bad idea, particularly in a two stroke.

              Instead (at the suggestion of a long-time tuner) I applied a few drops of muriatic acid (HCl) to the smear. It would bubble away, eating away the aluminum and leaving the cast iron entirely alone.

              I discussed this method on a very popular two-stroke list and had "experts" insist that this couldn't work, the HCl would attack the iron and leave a pit. Explanations with diagrams of chemical reactions were posted as proof.

              So I took pictures - before, during and after. Good pictures, where you could see exactly what was happening. This was followed by backtracking from some of the experts and disappearance of others.

              Funny how a chemist could forget the basic premise of the scientific method: observation first, then theory.

              As the psychologists sometimes say, "the rat is never wrong".

              -js
              I've done the same for removing aluminum from iron dirt bike cylinders; it works well and is fairly well known in some circles.

              I completely agree on the scientific method though. Seems like way too many people put theory before observation/experience these days. Or they observe, but don't understand what they observed and misinterpret the results.

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              • #37
                Originally posted by MattiJ View Post
                Sodium in English, French and Spanish, Natrium in most? other languages.
                I have to check every time that I'm not talking about Wolfram instead of Tungsten.
                Plumbium, Argentinum and Aurium too no doubt. Anyone who has taken a bit of chemistry should have no problem with any of the original names even if they are in the US or other countries that have adopted the newer names. ( Silly "Spell Checker" doesn't understand any of them. ) :-)
                ...lew...

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                • #38
                  Originally posted by Yondering View Post
                  I've done the same for removing aluminum from iron dirt bike cylinders; it works well and is fairly well known in some circles.

                  I completely agree on the scientific method though. Seems like way too many people put theory before observation/experience these days. Or they observe, but don't understand what they observed and misinterpret the results.
                  You need both.

                  You use theory to identify things that should have an effect of the type you want. (A hard steel hammer, not one made of ordinary soft wood, should drive steel nails better)

                  You then rank them, and test the most likely first. Observation then decides if you need to go further down the list, or even make a new list. If the theory is wrong, or misdirected, then observation should show that. But you need to be ready to re-think things, and accept what you see. Accepting does not mean you know what is going on, it may mean that you need to examine closer, if it does not agree with what you think should be happening.
                  Last edited by J Tiers; 11-04-2017, 12:03 AM.
                  CNC machines only go through the motions

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                  • #39
                    Originally posted by Lew Hartswick View Post
                    Plumbium, Argentinum and Aurium too no doubt. Anyone who has taken a bit of chemistry should have no problem with any of the original names even if they are in the US or other countries that have adopted the newer names.
                    ...lew...
                    Perhaps you meant "plumbum'?

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                    • #40
                      Originally posted by Lew Hartswick View Post
                      Plumbium, Argentinum and Aurium too ) :-)
                      ...lew...
                      "Anyone who has taken a bit of chemistry should have no problem with any of the original names even if they are in the US or other countries that have adopted the newer names."

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                      • #41
                        Originally posted by bobw53 View Post
                        As for grinding scale off... I HATE that, it makes such a mess and you get that nasty metallic taste in your mouth, black crap all over
                        the place...
                        I earnestly suggest a respirator! If nasty is getting in your mouth then nasty is getting in your lungs! Lee Cordochorea's Short List Safety Rule #3: "It's usually a bad idea to breathe anything other than fresh air."

                        Originally posted by Jim Stewart View Post
                        I don't see a problem disposing of acetic acid. If it's stronger than vinegar, so what? Just dilute it - pour it down the sink and run cold water after to rinse it down.

                        -js
                        If you have blueberries, rhododendrons, or other acid-loving plants, you can dilute the used vinegar iron-oxide solution and call it "fertilizer."

                        --

                        Edwin D., THANK YOU for the tip! I'll be trying it out soon!

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                        • #42
                          Originally posted by Lee Cordochorea View Post
                          If you have blueberries, rhododendrons, or other acid-loving plants, you can dilute the used vinegar iron-oxide solution and call it "fertilizer."
                          It'd also make a good moss killer and greener-upper for grass if you suffer from lawn problems
                          Location- Rugby, Warwickshire. UK

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                          • #43
                            I will probably catch some flack for this but, I tend to use a thin cutoff wheel on a grinder for removing scale on weld prep. You do need to be very careful not to side load it very much. It will cut through the scale quickly but doesn't gouge the material like a standard hard wheel will. The outside of the wheel will start to degrade after a little and want to throw pieces off, at this point I plunge the wheel into some scrap material(like you would for cutting off something), clean the edge up and then carry on.

                            Ear protection should be on anyways when using a grinder, but it seems extra loud when using the side of a cutoff wheel like this.

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