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How thick is a sharpie mark?

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  • How thick is a sharpie mark?

    In this video we answer the burning question of just how thick a standard Sanford Sharpie mark is. We use our high resolution Johansson indicator and some ga...


    That answers that!
    Definition: Boat, a hole in the water you throw money into!

  • #2
    Makes sense to me that the thickness of a black mark is less than blue, which is then less than red. The Sharpie manufacturer is likely testing ink with an opacity test and the darker colors would tend to cover better.

    A fun experiment and now we know that a Sharpie mark is about a tenth thick - good info for anyone lapping or finish grinding a piece.

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    • #3
      Originally posted by HWooldridge View Post
      a Sharpie mark is about a tenth thick - good info for anyone lapping or finish grinding a piece.
      thanks for saving me a 10 minute vid and and a commercial

      I find black markers handy for picking up a diameter with a new tool - you know sometimes you have to bring the cutting tool and pick up an existing surface, a perfect example is a left then and right tool in a crank web. put on the black and carefully bring the tool in until it just scrapes the black off. Always worked perfectly but i hadn't quantified it
      Last edited by Mcgyver; 04-29-2016, 05:33 PM.
      in Toronto Ontario - where are you?

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      • #4
        Over ten minutes for the guy to "hmmm, haw, err, yeah, yeah...." and finally get to the punch line; about 0.00018" average black sharpie line ??? Or did I fall asleep and dream that?
        Gary


        Appearance is Everything...

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        • #5
          I use that little slider thing to skip to the parts of videos that interest me, and nobody has ever held a gun to my head and forced me to watch a youtube video.
          If he DIDN'T explain and show HOW he arrived at the various numbers, then they would be nearly meaningless. In fact, someone even commented that he should have gone back and rechecked zero with the gauge block, which he DID do.

          Blue Dykem is about 3 tenths and the red is almost a tenth thinner. To see just the results, skip to 8:20.
          Location: North Central Texas

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          • #6
            So the clear must be .00009? I like the clear the best cause it lasts longer or maybe I just don't know when it runs out

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            • #7
              Using Dykem I always scrape off on the inside of the top to get a thin coat . (Unless I want a real dark coat that I don't care how thick it is.)
              ...lew...

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              • #8
                Originally posted by Mcgyver View Post
                thanks for saving me a 10 minute vid and and a commercial

                I find black markers handy for picking up a diameter with a new tool - you know sometimes you have to bring the cutting tool and pick up an existing surface, a perfect example is a left then and right tool in a crank web. put on the black and carefully bring the tool in until it just scrapes the black off. Always worked perfectly but i hadn't quantified it
                Funny, just did that today blending in a barrel od. Got it so dead nuts the tool smeared the Sharpie mark!

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                • #9
                  So in normal language(metric )how many naughts is there ?

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                  • #10
                    Originally posted by Lew Hartswick View Post
                    Using Dykem I always scrape off on the inside of the top to get a thin coat . (Unless I want a real dark coat that I don't care how thick it is.)
                    ...lew...
                    That's why I love the foam top bottle like giant marker, much easier to keep it thin, mark on rods etc. Rarely break out the brush bottle.
                    Location: Jersey City NJ USA

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                    • #11
                      ten frick'en minutes!??

                      A sharpie mark is less than the surface error after a rough pass on the surface grinder. that's all I need to know.

                      information over load!

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                      • #12
                        It's thick enough to make a part stick to your surface plate.

                        JL...........

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                        • #13
                          fastfire - thanks for posting this video. I teach a machine shop class to physics university students which is rather basic but useful to the creation and maintenance of their research projects. Along with Dykem we also use Sharpies to establish the "touch" when making contact between the tool and the workpiece. I have often been asked how thick I imagined that the ink would be and I've always said less than a thou which would be far within the tolerances they are working to. Now I will be able to give them a definitive answer. I took a screen shot of the chart at the end just for the hell of it. It might make for interesting conversation some day.

                          Despite the complaints of some of our members I DID enjoy seeing the methodical approach he took to his experiment. If he had not explained each step he took, such as not touching the Jo block with his hands for example, the same people would be complaining that the test was flawed.

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                          • #14
                            I suppose along with that there's the question of surface finish, on rough surfaces the ink would fill in the voids and be thinner on the peaks, the troughs would be just that, troughs. The determination of atomic thickness experiment comes to mind where an oil drop was dripped onto a pond, the oil preadolescent was measured to determine the thickness and therefore the atoms dimensions.
                            On smooth surfaces surface tension pulls ink together, plastic film has to be corona discharge treated before ink will "stick", the outer electrons are ripped off to provide adhesion.
                            Will sharpy ink ball on a super finished surface to be thicker than an absorbent substrate?
                            All irrelevant btw just some thoughts on an experiment,
                            Mark

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                            • #15
                              Originally posted by CalM View Post
                              ten frick'en minutes!??

                              A sharpie mark is less than the surface error after a rough pass on the surface grinder. that's all I need to know.

                              information over load!
                              Who made you watch the video, as in what are you complaining?

                              I don't need to know what a Sharpie mark is thick, as I don't use Sharpies. Still the video showed how it was measured, how it can be measured and what the results are.
                              Amount of experience is in direct proportion to the value of broken equipment.

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