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Electroplating/Anodizing without sulfuric acid???

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  • Electroplating/Anodizing without sulfuric acid???

    Is it possible?

    Where I live sulfuric acid is hard to come by(even if I were to go the route of cracking open a used car battery I would have to buy it from a scrapyard), I can get reagent grade but the thought of a liter of sulfuric acid in a glass bottle in my pickup for 20 min of very bumpy roads is less than appealing.

    I don't want anyone to tell me that I'm better of just buying the reagent grade as I already know that is an option and one I would avoid if possible, shouldn't it be possible to electroplate/anodize with a different acid such as nitric/hydrochloric(or some other) acid???

    Anyone here with knowledge in electro-chemistry that can answer this?

  • #2
    Well, the 18 Mol sulfuric acid I order via the Internet arrived in a well packed, densely foam surrounded plastic bottle. If you look at how they ship wine bottles via email or UPS, you'll see what I mean. I don't think you'll have any problems whatsoever with your road.

    As far as the chemistry goes, the acid is really an electolyte. Sulphuric is used because it is A cheap and B plentiful. I don't think there is any chemical reason other than that. When doing electropolishing, I use a mixture that is almost 70% phosphoric acid. I got mine from the same chemical supplier, but want to test DPSOA(?) fertilizer as it has a much longer shelf life.

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    • #3
      Depending on the strength of the Alternative acids, they probably wouldn't be any safer and possibly more dangerous. Take reasonable precautions (cushion the bottle) and there shouldn't be any problem.
      The shortest distance between two points is a circle of infinite diameter.

      Bluewater Model Engineering Society at https://sites.google.com/site/bluewatermes/

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      • #4
        What is DPSOA?

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        • #5
          Can't you haul it in a heavy plastic jug inside a well padded plastic tote?
          Really, hauling it in a glass jar on you lap will make you the most careful driver of your life or beat the Hot McDonalds coffee story all to h*ll.
          "Let me recommend the best medicine in the
          world: a long journey, at a mild season, through a pleasant
          country, in easy stages."
          ~ James Madison

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          • #6
            Originally posted by flylo View Post
            Can't you haul it in a heavy plastic jug inside a well padded plastic tote?
            Really, hauling it in a glass jar on you lap will make you the most careful driver of your life or beat the Hot McDonalds coffee story all to h*ll.
            "And then, I got 3rd degree acid burns on my lap. So I sued them"
            Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

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            • #7
              Here's a link from the Homebuilt Airplanes forum...

              http://www.observationsblog.com/4/po...tery-acid.html

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              • #8
                I do both anodizing and zinc plating at home, and yes, some of the chemicals could be dangerous if mishandled, but no more so than many other things around us every day. In many ways, something like gasoline is as or more dangerous than sulfuric acid. For transportation, just put the glass bottle in a plastic cooler.

                Having said that, many plating solutions don't require acid. My zinc bath has none.
                For just a little more, you can do it yourself!

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                • #9
                  try your local auto parts store for battery acid.

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                  • #10
                    If there were a milder acid that worked anywhere near as well it would be in use. There isn't. Any substitute will be even harder to obtain and more dangerous. I have done a lot of anodizing and it requires a pretty weak solution that lasts a long time. Ordinary battery acid works fine diluted about 1 to 1 parts acid to water. It also keeps a very long time when well sealed in the container, usually a poly bag for 25 litre lots for battery filling. I paid $25 for 25 litres. I still have some left and it is still good.
                    Last edited by Evan; 03-30-2013, 01:16 AM.
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                    • #11
                      Originally posted by Evan View Post
                      If there were a milder acid that worked anywhere near as well it would be in use. There isn't. Any substitute will be even harder to obtain and more dangerous. I have done a lot of anodizing and it requires a pretty weak solution that lasts a long time. Ordinary battery acid works fine diluted about 1 to 1 parts acid to water. It also keeps a very long time when well sealed in the container, usually a poly bag for 25 litre lots for battery filling. I paid $25 for 25 litres. I still have some left and it is still good.
                      You are kind of correct... To be specific, you want 10-15% sulphuric acid by volume. Most (but not all) battery acid comes as a 50% acid/water solution. This acid to water ratio will affect current, which in turn affects your maximum oxide thickness and how long it takes for the oxide to form. If you're just going for looks, you can be a little under or over this ratio.

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                      • #12
                        Fresh battery acid is 30% in 70% water. Cut that in half and you have the correct dilution for anodizing.
                        Free software for calculating bolt circles and similar: Click Here

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                        • #13
                          Not sure about anodizing (never done it), but there is a whole line of "plating" products by Caswell that doesn't require electricity to plate. I know that for a long time I have wanted to do some plating (chrome, nickle and tin for PC boards), but standard electroplating gets expensive and can get me in a lot of trouble (Where I am, if someone was to complain I would have the authorities all over my ass asking for "proper disposal papers" for the chemicals used.
                          Things are not the same as when I was a kid, so the Caswell stuff seems promising (plus dont need expensive nasty Cyanide based chemicals for plating "chrome like" coatings.)

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                          • #14
                            Originally posted by tdmidget View Post
                            What is DPSOA?
                            I think it's DiPhosphoric organic. Dry, little black and white grains. Crush, saturate water with them and it turns a mild green. That's phosphoric acid. About 2-2.3 ph.

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                            • #15
                              The nice thing about anodizing is that it produces no toxic waste at all. The chemicals used are sulphuric acid and lye for stripping the parts before anodizing. The resulting waste solution from the anodic bath is weak acid with dissolved aluminum. That can be safely poured on the ground. Aluminum is the 3rd most common element in the Earth (and universe) making up an average of 8% of the Earth's crust. Putting a little back where it came from is not a hazard to anything. The acid will quickly neutralize leaving sulphur traces. You can use the lye to neutralize the acid bath before dumping and it makes a pretty show with massive amounts of shiny aluminum tinted bubbles. It is also safe to put down the drain when neutralized and is not toxic to fish or insects either.

                              The gas products of the reaction are just dissociated water, namely hydrogen and oxygen. It is a process that is best carried on outside since there will be traces of atomized acid in the air which will promote instantaneous corrosion of all bare steel surfaces in the general vicinity. If done inside it should be in a separate space with good outside air exchange such as a fume hood to remove the acid mist though plastic pipe to well outside.

                              This is the setup I have used:

                              Free software for calculating bolt circles and similar: Click Here

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