How to do this?
Men Ifr | 11/12/2018 12:34:57 |
119 forum posts 10 photos | Is any special method(s) required to remove grit after lapping? After lapping the column on my small mill it was cleaned by rubbing with paper tissues until they came out clean then applying isopropyl alcohol and re-rubbing. I now *think* the oil on the Z column is blacker than it should be which I wonder if that is an indication of either cast iron grit or lapping grit still present? I wonder if post lapping rubbing over dry with a very fine wire brush maybe brass or something maybe better at dislodging any remaining small particles or is there a standard way to do this?
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Zan | 11/12/2018 13:43:00 |
356 forum posts 25 photos | That’s why you don’t lap slideways, use a scraper. Some of the grit will embed itself into the metal and some will get into the pores. Always use a non- embedding abrasive for lapping if you must do it. C I is dirty and it will darken the oil |
Pete Cordell | 11/12/2018 13:59:59 |
20 forum posts | I believe you are saying your abrasives have embedded in the cast iron Next time it may be worth consider using Timesaver or Garnet lapping compound (supposed to break down) Only thing i can think of to get it out is have it hand scraped |
Oldiron | 11/12/2018 17:25:52 |
1193 forum posts 59 photos | Lapping is definitely not he way to go on machine ways. They should be scraped to allow oil to get between the ways and the table/compound etc. :Lapping makes for a much too smooth a surface that will scrape the oil off. Leading to rapid wear. As said elsewhere they need to be rescraped to fix the problem. regards |
Mike Poole | 11/12/2018 17:50:51 |
![]() 3676 forum posts 82 photos | Cast iron is a popular material to make a lap from so you may have dug a bit of a hole for yourself. Mike |
Pete Rimmer | 11/12/2018 18:20:43 |
1486 forum posts 105 photos | A lapped finish is not a desirable condition for machine ways as it creates too much stiction and leaves no room for oil-bearing pockets. I don't think you have to worry about embedded grit from the lapping as much as trapped grit/dirt/iron in the form of microscopic particles. The blacker oil is most probably from accelerated wear that you're now getting from the lapping you did. Make or get a simple scraper and run a couple of opposing passes of scrapes across the surface. Not only will the ways run smoother but the shallow pockets created by the scraping will hold the oil that lapping the surfaced will cause to be squeezed out. |
Neil Lickfold | 11/12/2018 20:09:27 |
1025 forum posts 204 photos | What lapping grit did you use? Like been said scrapping or flat filing will help. Stones and lapping compounds seem to always embed into cast iron. Unless it is hardened. Seldom these days is the cast iron hardened anymore. If soft iron, it is best to just re scrape the surfaces. Things like break clean and microfibre cloths do help. If you see black oil coming from the slide, you know that there is still some abrasive working in there somewhere. Ground slides can have the same issue, particles caught and embedded into the surface. Especially from a fresh dressed wheel that has not been cleaned correctly after dressing. Neil |
Pete Cordell | 11/12/2018 21:03:18 |
20 forum posts | Ultrasonic Cleaning looks promising What Ultrasonic Cleaning Can do Its Cleans Oil, grease, polishing compound, waxes, cutting fluids, lapping compound, dirt, swarf, residues, resin, silicones, carbon deposition, scale, finger prints, solder flux, plating salts, blood, ink, photoresist, lacquer, paint etc
ref: saisonics |
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