On 2/9/2018 8:42 PM, Ed Huntress wrote: > On Sat, 10 Feb 2018 08:59:37 +0700, John B. > wrote: > >> On Fri, 9 Feb 2018 13:29:20 -0700, Bob La Londe >> wrote: >> >>> I'm finishing up some details embossing press dies in steel, and I'd >>> like to do a little bit nicer job. They flat part of the plate is >>> pretty easy. I go over it with a diamond hone, then some fine grit >>> paper, and finally hit it with the buffing wheel and some polishing >>> compound. Comes out looking fairly decent. >>> >>> The embossing part looks looks pretty good, but I'd like to make it look >>> better. The finish pass with the smallest ball end mill leaves a pretty >>> good looking finish, but there are fine tool marks if you look close. >>> The big old buffing wheel just won't fit down in all the fine details so >>> I was thinking of maybe making a tiny soft cloth wheel to fit a rotary >>> hand piece mandrel and having a go at it some polishing compound. >>> >>> I have a few failures from the project on my bits and pieces shelf I >>> could test it out on, but I'd like to know if I am just chasing my tail. >> >> Perhaps not want you want but I might mention that hand engraving, >> guns for example, are polished surfaces with hand cut depressions. The >> actual engraved portions are not polished or smoothed in any way. > > If you really *do* need a polish, the traditional way to do it is with > slips (shaped hand stones) and die grinders equipped with points > (cylindrical buffs, longer than they are wide, made of felt and > available in a variety of end shapes) The last handwork I saw of that > type, over 30 years ago, was being done with die grinders and > rubberized abrasive Cratex points, and polished with felt points. > > A lot has to do with how fine and complex the details are. But a > complex coining die might require 30 hours or more of handwork. Often, > depending on the machine finish, it starts with jeweler's files and > diemaker's rifflers, which are like woodworker's rifflers but with > very fine teeth. > > These are traditional moldmakers' and diemakers' skills. They've been > largely replaced with advanced ram-type EDMs. It's a lot easier to get > that finish on a piece of graphite or tellurium-copper electrode than > on steel, and the finish you can achieve with today's EDMs, using > copper or copper-alloy electrodes, amounts to a medium-high polish. >
Thanks Ed. I am not quite ready to step into EDM, so polishing tricks may be the ticket. I didn't pickup the graphite mold job, so I have not dedicated a machine to being destroyed by cutting graphite just yet.
I probably have a "good enough" finish, but I'd like to do better.