Forums Beginner Questions Contaminated Lap?/Over Cutting Facets During Polishing

37 replies, 8 voices Last updated by Gregory Hays 2 months, 2 weeks ago
Viewing 15 posts - 16 through 30 (of 38 total)
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  • #6596

    scottwkelley
    Participant
    @scottwkelley

    i get that @Lowjiber. But, i get different results, i get to 8k and after that 50k doesn’t touch it. I was blaming pre polish. i decided to ask, learn and try again. it finally came off the dop, thats when i stopped.

    #6597

    Alan Balmer
    Keymaster
    @alanbalmer

    Scott, you can buy Lightning Laps directly from Marsh Howard, the manufacturer. Other good info on his website, https://shop.lightninglap.com/
    Marsh is a good guy, always helpful.

    #6601

    scottwkelley
    Participant
    @scottwkelley

    @alanbalmer yes he is and has helped me many times. The prices and guarantee’s are the same, kingsly north offers much more too. Their steel laps and blades are great and I have had great experience with them. Like a 6″ trim saw blade for $5. The 10″ saw blade for $12 works well to.
    Again thanks for all you do!

    #6635

    hray
    Participant
    @hray

    Hi again,

    I have a few questions about charging a BATT lap. I followed David’s advice and purchased 2 BATTS and a Matrix along with 3K, 60K Diastiks and a Cerium Battstik. I think I have a decent idea about what I need to do to get the BATTS charged and broken in, but I want to run it by the experts before I do anything. You have all been so helpful! As I understand it I need to apply a thin layer of WD-40, baby oil, olive oil or something comparable to the surface with a paper towel. Then draw a few lines on with the Diastik and spread it around with my finger while the machine is running. After this is it necessary to break the lap in? A few articles I have read have said to use a piece of corundum or Cz for this. I have quite a few tiny Montana sapphires that are too small or fractured to cut. Would it work to just hold on to one of those and run it across the lap a few times? I guess I have just been worried a small chip will break off and contaminate my new lap. This brings me to my next question. I am pretty paranoid about contamination. I know to wash my hands between handling laps, but what is the best way to clean the stone, mast, etc before moving to a finer grit? Do I have to clean out the splash pan? How should I clean the lap before storing it?

    Lastly, Is the process similar for charing the Matrix with Cerium? This is probably a pretty silly question, but do I charge the Matrix with diamond and cerium or just cerium? Thanks so much for the help!

    #6636

    duncanmiller
    Participant
    @DuncanMiller

    I would not use a small piece of sapphire to embed diamond in a Batt lap. It may score the lap. Apply the Diastik lightly or use a clean finger to spread the diamond thinly, and grind or polish away. When black swarf builds up on the lap or the stone, wipe the lap with a piece of paper towel dampened with WD-40, and reapply some diamond – sparingly. Clean the stone and dop with alcohol on paper towel before polishing. I give Batt laps a cleaning wipe after use. Sometimes I clean the splash pan before polishing, but not always, and I avoid touching it. After cutting a few stones I clean the machine as best I can, but without being obsessive. The Matrix laps are also given a wipe with dampened paper towel to clean them. If you are going from an oil-based diamond to a water-based oxide, or vice versa, on the same lap wash it with water and some household detergent. (I use separate laps for oxides and diamond polish.) Most of my Gearloose laps live in the original cardboard covers they came in, just with a clean piece of paper towel on the working surface to protect it.

    The main thing is to use minimal diamond or oxide when polishing. If you get scratches it usually means the lap needs a wipe to remove excess polishing medium. If scratching persists change polishing direction through 90 degrees. Check your prepolish. Has it removed all previous grooves and pits? Clean the polishing lap thoroughly. If it is a Matrix+oxide lap scrub it with water and detergent. If it is a diamond lap wash it, dry it, and apply a synthetic rubber eraser to the lap running in reverse. Try different lap and polish combinations. If all that doesn’t work try a different stone. Resurfacing a lap is the very last resort.

    #6641

    hray
    Participant
    @hray

    @DuncanMiller, thank you for all this info. Im glad I didn’t try the tiny sapphire for breaking in the lap! Do you think WD-40 has significant advantages over the other oil options? I have my machine setup inside my house and two young kids, so I am trying to avoid fumes if possible. Thanks again for your help!

    #6643

    Frankwood
    Participant
    @Frankwood

    I do the same as Duncan and use different laps for different polishing agents. They live on those plastic office trays meant to store A4 paper, they stack on top of each other and stop on a shelf in a cupboard.
    I used to use WD40 before someone on this forum said baby oil was good with diamond, I agree with that and used it ever since.
    I have three liners for the inside of the pan, one for normal use, one for 3000 grit and one for polishing.
    As I mentioned before every time I touch anything with 3000 grit on it I wash my hands.

    #6644

    duncanmiller
    Participant
    @DuncanMiller

    You want to be able to clean the facet easily to inspect the surface you are working on. WD-40 is thin and wipes off easily with paper towel dampened with alcohol. Both produce fumes, the alcohol being worse than the WD-40. You could avoid both by using Gearloose Pandemonium Universal Base Diastiks, which can be used with water as a lubricant. (I am still using up my old stock of oil-based Diastiks.)

    #6652

    hray
    Participant
    @hray

    Thanks to everyone for all this great input! I gave it a try today and had some pretty rough results. I ended up charging with baby oil and a 3000 DiaStik. First off I got major scratching and some nasty black buildup. I tried wiping some diamond off, then got bits of metal. I added more diamond and things improved a little, but still a lot of scratching. At one point I was able to get two facets that look more frosty instead of scratched so I think I might be heading in the right direction. This didn’t last long though, and I soon got metal again. After recharging I was back to scratches, worse near the culet. I am not sure how much of this has to do with the amount of diamond I am using, or if maybe partially due to the fact that it is a new lap. I am including some pictures, so if anyone has suggestions I would appreciate it! The first two are of the scratched pavilion facets, then I have one with the two frosty facets that I think might be improving. The last is a pic of the lap. In it I am guessing the area I have been using is due for a recharge. Oh, and when I took the lap off the spindle I realized I had the sticker side face down ,I don’t think this should matter though since BATTS are double sided right?

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    #6662

    Lowjiber
    Participant
    @Lowjiber

    Yes, the Batt is a solid lap… both sides are the same.

    #6664

    Alan Balmer
    Keymaster
    @alanbalmer

    Hard to guess what’s going on without actually watching. Generally, if you get metal from a BATT lap, it isn’t charged enough. BATT can absorb a lot of diamond when first put in service. I did have a stone a few years ago which scraped metal off the lap at a particular angle, but that turned out to be my fault.
    I always found baby oil to be too viscous. I like WD-40, though some people can’t stand the odor. There are lots of choices for lubricant. Trombone oil is reputed to be very good. Gearloose’s Snake Oil (approved by Professor Ignatius) is great, though pricier than common oils.

    #6667

    hray
    Participant
    @hray

    The problem of picking up metal seems to improve (at least temporarily) if I add more diamond. At this point I am more worried about the scratching. Is it possible that the lap just needs breaking in? I have only ever polished with cerium oxide ultra laps after pre polishing on a very worn 1200 grit Crystalite, so I am not really even sure what a pre-polish with 3000 should look like. Will the facets be mirror-like at all or still pretty frosty? I had two facets that didn’t show the big scratches as much as an overall frostiness.

    I have been shying away from the WD 40 due to the fumes and the fact that I am set up inside near my kids. Maybe I will look into the trombone oil or the Gearloose product. I have heard others have had luck with baby oil though, so I might not give up on it just yet. Thanks for the help!

    #6668

    Lowjiber
    Participant
    @Lowjiber

    I use WD-40 in a liquid form, vice the aerosol version.

    WD-40 Liquid

    #6669

    Frankwood
    Participant
    @Frankwood

    Never knew you could buy WD40 in liquid form, anyway I couldn’t tell any difference between it and baby oil as far as a carrier for diamond was concerned.
    Looking at the photo of your BATT lap it’s in a terrible state, the inside 1/3rd is what it looks like new and after a few uses the same but grey in colour from the diamond imbedded in it.
    No massive grooves and certainly not producing scratches like on your stone. I would suggest you join your local club for advice as its something your doing wrong with the lap.
    The finish with 3000 grit on corundum for example looks close to a final polish.

    I recharge mine with two drops only of baby oil (and that’s heaps), small amount of 3000 diamond powder, all rubbed in a circular motion till the lap is covered. Just checked the speed I run the lap at and its slower than I thought, it’s only 200rpm. Don’t know why this mixture ends up going black but it does. I wipe an ink marker over the first facet of that set and wipe it over a stationary lap to make sure its flat on the lap. No significant pressure on the stone when cutting. That’s it.

    #6671

    Alan Balmer
    Keymaster
    @alanbalmer

    Don’t know why this mixture ends up going black but it does.

    Swarf is always black, in my experience – nothing to do with a particular lubricant. Probably because nanoparticles of stone in lubricant don’t reflect light.

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