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Polishing in the lathe

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  • Polishing in the lathe

    I was polishing up a mill arbor bearing/ journal in the lathe on the weekend. Normally I just use a couple of bits of 120 grit emery strip (one new and one old and blunt - cheap bastard...).
    Anyone do anything more sophisticated? In particular I was wondering whether anyone uses a holder or something other than fingers to hold the paper. After my efforts the surface was nicely shiny and smooth, but my fingers were filthy and got warmer than I would have liked.

    Michael

  • #2
    Originally posted by form_change
    I was polishing up a mill arbor bearing/ journal in the lathe on the weekend. Normally I just use a couple of bits of 120 grit emery strip (one new and one old and blunt - cheap bastard...).
    Anyone do anything more sophisticated? In particular I was wondering whether anyone uses a holder or something other than fingers to hold the paper. After my efforts the surface was nicely shiny and smooth, but my fingers were filthy and got warmer than I would have liked.

    Michael
    "Warmer"? How did your fingers get warm holding the ends of the strip? It sounds as though you are doing something dangerous here. Many, many lathe accidents are due to holding the strip wrong. How were you doing it that got your fingers dirty and hot?

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    • #3
      I glue emery strip to 1" x 1/4" wooden strips with PVA glue then use those.

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      • #4
        Originally posted by tdmidget
        It sounds as though you are doing something dangerous here. Many, many lathe accidents are due to holding the strip wrong.
        About forty years ago I blackened a thumbnail when the paper grabbed and pulled My thumb in. That was a close call that resulted in My thumb looking and feeling like I hit it with a mallet. Taught Me a lesson that I have not forgot.

        Steve

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        • #5
          Listen to the guys about holding sandpaper/emery strips on the lathe.

          Hold it so if it grabs, it will slip out of your fingers and not pull them in.

          If you are sanding or polishing a ball and have a hard time keeping the paper straight, glue it to a wood strip as suggested above.

          Give a metal lathe due respect. Like I told a woodworking friend when he told me how much more dangerous woodworking tools (table saw and radial arm saw) are than metalworking tools, I told him a saw will cut your arm off. A metal lathe will rip it off. Your choice.

          Brian
          OPEN EYES, OPEN EARS, OPEN MIND

          THINK HARDER

          BETTER TO HAVE TOOLS YOU DON'T NEED THAN TO NEED TOOLS YOU DON'T HAVE

          MY NAME IS BRIAN AND I AM A TOOLOHOLIC

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          • #6
            I usually hold a strip 6-12 inches long in my finger tips and around the work. Works fine, no heat. Rarely have any problems, but if the paper snags the chuck, it just pulls away. While it's tempting to leave the strip connected to the roll - that's just asking for trouble.

            Yes, I've been guilty of pushing very fine paper onto the work with finger pressure. Been lucky, so far.

            To me it's like using a hand held grinder without guard - dangerous but I do on some work - recognizing it as so is important.
            Last edited by lakeside53; 08-08-2011, 01:11 AM.

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            • #7
              Always run the lathe in reverse. It is much better to be pulled over the top than under the bottom. It also prevents stubbed fingers if they get too close to the chuck jaws.
              Free software for calculating bolt circles and similar: Click Here

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              • #8
                Polishing? On a lathe? I do all the time. Problem is it scatters abrasive on the machine. You gotta practice safe polishing. Use protection. Lay down plastic to catch it otherwise you're in for a long clean-up. When you take up the plastic roll it from the edges into the center, fold and try to capture all the dust and swarf you can.

                A shop vac can be used for dust pick-up but you still need to go over the machine with rags damp with solvent to pick up any residue before you move the carriage.
                Last edited by Forrest Addy; 08-08-2011, 03:30 AM.

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                • #9
                  For those concerned about my personnel well being I am being careful when I use a lathe this way - the work is mounted on a mandrel with around 6" to the chuck - this is one of the reasons that I like collet chucks - there are less things to catch on them.
                  I am using my fingers to apply pressure because while a strip of emery works well for a cylindrical surface, less regular surfaces need another way of applying some pressure. The strip of wood sounds like the way to go.

                  Thanks,
                  Michael

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                  • #10
                    As I see it, the dangers of polishing work held in the lathe include getting knuckles rapped by a whirling chuck and getting fingers trapped in the work.

                    Fingers get trapped when the polishing material starts to wind around the work, easiest way to avoid this, in my opinion, is to only use tiny pieces. An alternative is to use a long strip held by two hands, one in front of the work and one behind but I dont like that as it means leaning over the work and there is always the risk of clothing getting picked up and wrapped around which could be much worse than getting the fingers nipped!

                    Whatever you do, do not loop the polishing material around the work unless you have a way of holding it so that there is no way you can get hurt when it get wound around the work, note I said when because it surely will.


                    I have a very strict rule that rags are not allowed near any machine except at clean up time when everything is turned off.

                    Just my humble opinion, but I am a newbie at all this and subject to further education.

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                    • #11
                      I use a file to back up the abrasive cloth. A strip a bit longer than the file can be wrapped over the end and held with the hand holding the tip of the file as you normally hold the file when filing work in the lathe.

                      As with any work around rotating machinery, be aware of all the hazards, where the chuck jaws are, no loose clothing, etc. If just using the strip alone in shoeshine manner, use a long enough piece and grip only with the thumb amd forefinger.
                      Jim H.

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                      • #12
                        I remember reading somewhere (Frank Ford's site?) you could use a small piece of leather to prevent your finger from burning.
                        (of course this has to be combined with using small pieces of abrasive to prevent grabs)

                        edit:
                        Yes, right here http://www.frets.com/HomeShopTech/ShopTips/398.html

                        Igor

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                        • #13
                          on protecting the lathe and yourself, protect the lathe with paper towels held down by pot magnets.....if something snags paper towel will have the least strength to pull you in with it. Cloth/rags, for this reason, are a no-no. The magnets make it quick & easy to set up.
                          Last edited by Mcgyver; 08-08-2011, 09:22 AM.
                          in Toronto Ontario - where are you?

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                          • #14






                            Ed P

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                            • #15
                              Originally posted by Ed P

                              Ed P
                              "Sanding Paddle" is what i was thinking, not as fancy as what you posted, more like this:




                              school woodshop maybe is where I saw these? The ones I am thinking of had several pieces of sand paper stapled on and when one wore out you just tore it off.

                              Is there a name for those?

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