Acid etching: fingernail polish or wax?

Discussion in 'Replica Props' started by kiddo, Apr 19, 2012.

  1. kiddo

    kiddo Active Member

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    Hey guys, Ive recently started a build (i still need to buy the materials) for the tomahawk from the patriot. If you're familiar with this tomahawk, then you know that it has intricate acid etching on its blade:
    [​IMG]

    Ive been reading up on acid etching, not having much experience in this area. I believe i found a suitable acid, but am not sure what to coat the part I dont want etched with. It seems like there is two main materials used: wax and fingernail polish. Since I need to coat the majority of the head, I thought to melt candle wax over the whole thing and then scratch the part I want off with a needle or something. It also looks like many people use fingernail polish as well though. Does anyone have any experience in this kind of situation?
     
  2. MadMike

    MadMike Well-Known Member

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    AT LAST! A topic on the RPF where I can help due to my experience!!! :lol

    I've tried it with wax and it worked pretty well. The best thing is to melt candles in a pot and then apply the wax with a brush (a throw-away brush, it won't be very useable afterwards).
    After the way cooled down, you can scratch it off just as you said. But be careful, the more filigree the design you scratch off is, the more likely the wax is to break. AND you should pay attention that you apply the wax very thoroughly. If you have any air-intrapments under the waylayer that touch the scratched off areas, the acid can flow underneath the wax leaving some nasty etched areas you don't want.

    My advice: try it with some scrap-metal first until you get an idea of how much wax should be applied and so on. Then you can also use fingernail-polish instead of wax, just to see which one works better.

    Oh, and another thing, how do you want to apply the acid?
    I asked my chemistry teacher before I tried some etching, he said it would be best to dip the metal into the acid, then dip it into water, and repeat if depending on how deep you want the etched areas to be. It you want to lay the metal down and apply the acid (with a brush, for example) and just wait (i.e. not dipping it into the water), it could happen that the etching becomes uneven.

    Hope that could help.
     
  3. kiddo

    kiddo Active Member

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    Thanks! I was planning on dipping the metal in, but then again, I would need alot to dip that head in though....do you think I could build a contaier that would almost perfectly fit the head so that I would not waste acid? or would that not produce enough of a chemical reaction...ill have to experiment though, and see what works best
     
  4. cheech9898

    cheech9898 Sr Member

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    From years ago when my parents did outdoor craft festivals we had a smith/knife maker 2 booth's down from us. He used a stiff bee's wax-asphaltum compound and a 50/50 nitric acid/acetic acid wash.
     
  5. LeMarchand

    LeMarchand Sr Member

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    another great and relatively easy way to etch is with photoresist laminate, especially if you plan to do more than one of the same pattern.

    you can see the stuff here, i use it for my constantine lighters. Works just as good for acid etching as electro etching. for protecting large areas, plastic sticky tape will probably work too.

    Making the most accurate "Constantine" lighter movieprop replica - YouTube
     
  6. kiddo

    kiddo Active Member

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    hmm, that looks promising! Do you have any tutorials you would recommend that show all the steps in a detailed manner?
     
  7. Jaruemalak

    Jaruemalak Well-Known Member

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    I'm gonna agree with Cheech9898. A mix of beeswax and asphaltum is perfect because it sticks to metal, resists the acid very well and you can scratch very fine detail through it without it breaking up. I used it for etching knife blades all the time, although I used a 50/50 mix of nitric acid and sulfuric acid for the etch.

    I am about 90 percent sure I have some here in the shop. If I find it in the next day or so, I can send more than enough to you to do your project... no charge (hey, fellow propers have to help each other out!)
     
  8. kiddo

    kiddo Active Member

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    Hey, that'd be great! If you cant find it, still thanks anyways for the thought!
     
  9. LeMarchand

    LeMarchand Sr Member

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    here is a link i found helpful when i started using photoresist laminate:

    Suchý fotorezist doma? - Nu pro

    it takes some practice but the results are overall good and sharp. The dry transfer photoresist can be bought on ebay these days
     
  10. kiddo

    kiddo Active Member

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    Thanks LeMarchand, but I dont think I will do photoresist laminate due to the cost of materials, as well as the many things that go into it. I plan on using acid. I would like to keep the project simple; the way I see it, the less things that have to be done, the less chance of messing up. But thanks anyways though, it may be something I look into in the future. The constantine lighter looks awesome, by the way!
     

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