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Availability of Chemicals

  1. Jan 20, 2005 #1

    DocToxyn

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    I'm looking to get the following: concentrated hydrochloric and nitric acid and powdered asphaltum. The book I'm getting this from suggests hardware stores or pool chemical dealers, but its dated back to the 1970's, so I'm not sure of the current availability outside of a commercial chemical dealer. Also, if chemical houses are the only place to get them, do they sell to the common man?
     
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  3. Jan 20, 2005 #2

    Gokul43201

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    Conc. HCl and conc. HNO3 are restricted chemicals with most commercial suppliers. You must be affiliated with a school, university or industry that requires such chemicals. Haven't ever tried a hardware store for chemicals, so no clue about that.

    You can get liquid asphaltum from most any art supply store. No luck finding asphaltum on websites of standard Chemical Supply houses. If liquid asphaltum is allowed to dry, it will harden into a solid layer, which can be scraped and ground to a powder. I'm sure you have better things to do with your time ! :biggrin:
     
  4. Jan 20, 2005 #3

    Moonbear

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    I doubt any hardware store would sell concentrated HCl or nitric acid. Those are really strong acids and far too dangerous to sell in concentrated form to just anyone. Do we dare ask what home use you had in mind for these things? :eek:
     
  5. Jan 21, 2005 #4
    H2SO4 and HNO3

    Legally I think it's quite difficult to obtain these 2 mineral acids esp. in the concentrated form. You can try your luck by asking to private or public (chemical) laboratory nearby or high school/university laboratory.

    H2SO4 at approx. 25% (d= approx 1.2g/mL) strength is readily obtainable as an acid soln. for your lead cell car battery.
    Traditionally, long long time ago, HNO3 is synthesized by distilling conc. H2SO4 with Potassium nitrate (salpeter)...KNO3 + H2SO4 -> HNO3 + KHSO4
    But this is an very archaic method and too troublesome to do unless you have other way of getting HNO3
     
  6. Jan 21, 2005 #5

    DocToxyn

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    The acids, when mixed at 4:1 HCl:HNO3, form a mixture called Aqua Regia which is used to etch steel. The asphalt is mixed with beeswax and when coated onto the steel provides the resist to the acid into which you carve the design you want the acid to "bite" into the steel. As I said the source for this is rather old and perhaps there are better, safer solutions for etching steel than this rather caustic mix. I'll search around for alternatives or if anyone here does such work, clue me in.
     
  7. Jan 21, 2005 #6
    Well, depending on the amount you need and your available equipment, you could just synthesize it ...
     
  8. Jan 21, 2005 #7

    Moonbear

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    Don't they have commercially available etching solutions now? I don't know if they are for steel or just glass. I know I've seen them for glass etching in craft stores. You might want to try an art store.

    Not sure if this is the sort of thing you're looking for...
    http://www.permanentmarking.com/etch-electrolyte.php
     
    Last edited: Jan 21, 2005
  9. Jan 21, 2005 #8

    Gokul43201

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    A common etchant for most types of stainless (I know it works for 304 and 316) is ferric chloride - which I'm quite sure is sold in a decent art supply store. If you have an appropriate light source, I would suggest you use a mask and commercial photoresist as an etch stop, else you could try most enamel basd resists. In fact, regular paint, might work. The advantage of using a photoresist is that you can design the mask on your computer and print it onto a transparent (OHP) sheet...but this requires the correct lamp and reflector.

    Don't art supply stores sell etch and resist kits ? I would imagine they do. I'm sure you wouldn't have to look too far for one.

    Surely you do not require aqua regia to etch steel. HCl alone will do (though at a slower etch rate - which might to good or bad for you). A lower etch rate gives you better control but takes more time.
     
  10. Jan 24, 2005 #9

    DocToxyn

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    I found a method using ferric chloride/citric acid or copper sulfate/sodium chloride for etching steel. These should be more readily available and considerably safer :biggrin: . Thanks.
     
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