Removing Grit after Lapping Ways

[Men IfrParticipant @menifr84251]

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?

[Men IfrParticipant @menifr84251]

How to do this?

[ZanParticipant @zan]

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 CordellParticipant @petecordell95786]

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)
Or use a soft lap, abrasive gets embedded in the lap then not the work

Only thing i can think of to get it out is have it hand scraped

[OldironParticipant @oldiron]

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 PooleParticipant @mikepoole82104]

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 RimmerParticipant @peterimmer30576]

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 LickfoldParticipant @neillickfold44316]

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 CordellParticipant @petecordell95786]

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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