Announcement

Collapse
No announcement yet.

Bore Polishing ideas?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Bore Polishing ideas?

    Evening all,
    I need to polish to a good, if not mirror finish a (1 to start, but several actually if all goes well) long thin bore.
    The bore will be upto about 12" long, and 4.5mm dia. Material is 316L stainless.
    Any scratches / machining marks must run the length of the bore, not round it.
    Best I can come up with is to pump some sort of abrasive slurry through the nearly finished bore, but that will be messy and Im not certain it would actually work.
    A long thin lap mught do the job, but Id have to actually do it, whereas the pump idea I could setup and leave only lightly attended whilst it was going.


    Any other ideas?

    cheers
    Dave
    Just south of Sudspumpwater UK

  • #2
    Polish an 0.177" ID x 12" long bore leaving only longitudinal marks, if any.

    Is it necessary to hold a tolerance along the ID?

    .

    Comment


    • #3
      Maybe electropolishing. Not something you want to do at home, real nasty chemicals.

      Comment


      • #4
        How is the bore put in to begin with? Or is it manufactured tubing?

        Comment


        • #5
          Bore Polishing

          Look up a company that does "Electropolishing". It should be a good solution to your problem.

          JRW

          Comment


          • #6
            finished bore needs to end up at 4.5 and shiny, but the initial rough start is 4mm, so any combination of drill, ream polish will be ok.

            Electro polishing sounds nasty from the very quick read Ive had.

            Dave
            Just south of Sudspumpwater UK

            Comment


            • #7
              I would start with a drill motor and a mandrel with emery first, then scotchbrite, working your way finer and finer, until it's close. Then use a ramrod with rag and various compounds to remove the roundy round scratches and finish.

              Comment


              • #8
                Originally posted by lbhsbz
                I would start with a drill motor and a mandrel with emery first, then scotchbrite, working your way finer and finer, until it's close. Then use a ramrod with rag and various compounds to remove the roundy round scratches and finish.
                And read up on lapping a rifle bore. They cast a short lead lap around a rod placed in the bore. Then withdraw it and roll it in abrasives, then place it back in the bore and slide it back and forth. Make new laps as needed.
                Dennis

                Comment


                • #9
                  Originally posted by small.planes
                  finished bore needs to end up at 4.5 and shiny, but the initial rough start is 4mm, so any combination of drill, ream polish will be ok.

                  Electro polishing sounds nasty from the very quick read Ive had.

                  Dave
                  It is, that why you have someone else do it.

                  Comment


                  • #10
                    Electropolishing can't remove any deep scratches, but can make them nice and shiny.

                    Comment


                    • #11
                      My thought was of a material like sash cord carrying an abrasive and passed
                      back & forth by some reciprocating mechanism.

                      I'd have no illusions about holding a precision tolerance, however. I suspect
                      at a minimum, there would be an hour-glass taper or waisting effect in
                      the middle of a twelve inch section. It is speculation, but I would try more
                      rather than less reciprocating motion in the hope of lessening this effect
                      by ensuring that abrasive passed all the way through.

                      It will be interesting to hear what actually works.

                      .

                      Comment


                      • #12
                        Make up whatever sort of lap/cannon swab/bore snake-rod you wish. Attach it to a reciprocating saw motor (like a Sawzall). Move swab in and out of bore while using the saw motor to reciprocate it at speed.

                        Bob's yer uncle.
                        My cup 'o plasma: https://www.youtube.com/watch?v=H1vMfmhM9fg No dialog, just ten minutes of dancing plasma and music. Turn on, tune in, space out.

                        Comment


                        • #13
                          You might explore ball sizing or ballizing. You force a ground carbide ball of appropriate diameter once through the bore. Any radial tooling marks are mushed over in the linear direction of the ball travel.

                          Might be hard to come up with a long slender pusher, maybe force it through hydraulically with a grease gun.
                          Weston Bye - Author, The Mechatronist column, Digital Machinist magazine
                          ~Practitioner of the Electromechanical Arts~

                          Comment


                          • #14
                            +1 for Weston. ( good to have you back). If not that then hone to a mirror finish (that'll cure you from want to hone,EVER) and electro if necessary. I think it can be honed but a chore. Especially on 316. The slurry won't work. It will form a boundry layer of slow moving fluid and the vast majority will travel in a helix through the center. If honed right there will be no visible scratches. They will be there but too small to see. Why must they be length ways?
                            Last edited by tdmidget; 12-02-2011, 10:14 PM.

                            Comment


                            • #15
                              Start with a highly polished hardened steel ball bearing a little bigger than the bore. Push it through the bore. this will get you 80-90% 0f the way there. use lube.

                              Comment

                              Working...
                              X