I’m 68 years old and recently retired. I started to learn by self study how to facet around 3 months ago. I’ve cut about 7 stones so far, mostly round brilliant but also an amethyst oval. I’ve only worked with amethyst, quartz, and Nanosital so far. I struggle with the polishing. I’ve tried cerium and aluminum oxides ultralaps but just can’t achieve a polish that I’m truly happy with. PrePolish is with 1200 and 3000 grit laps. I’m using a vevor faceting machine with digital upgrade. (6”).
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Hi Bob, I have polished most gems over time with 50,000 diamond grit and have had little problem with getting a good polish on any gemstone from 7 to 9 hardness, you can go to 100,000 but that is mainly used for faceters who are entering competitions
thanks.
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Thanks for your suggestion. what kind of lap do you use (hopefully at a reasonable price). is all of your finished, final polishing performed on a lap, or do you do post polishing with the grit with a rotary tool? my polishing looks smooth when done on an ultra lap, but looks like a fog on the face. I can’t seem to get that glass look without using a polishing pad on a rotary tool using the 50,000 diamond grit.
Hi Bob I use diamond impregnated laps for rough shaping medium and fine then I use a master tin lap with 50,000 diamond grit that I put on myself.
go to this website https://www.aussiesapphire.com.au/batt-polishing-lap-from-gearloose
BATT Polishing Lap from Gearloose .fancybox-margin{margin-right:0px;}
The BATT™ is the standard for tin alloy laps. With more than 8,000 sold, it has established itself in Commerce and Competition time and again. Select from 6 inch or 8 inch from the options above.
A BATT™ lap charged with 3,000 diamond (Or 8,000) provides a perfect pre-polish after cutting with 600, with a surface good enough to allow subsequent polishing in record time, on stones from Fluorite to Sapphire.
A BATT™ lap charged with 50K or finer, or an oxide/ Darkside for the quartzes, promptly finishes the stone.
A great, solid, cast tin alloy lap designed for prepolishing and polishing. This hard tin alloy allows the casting to be rigid enough to serve as a solid lap, without bonding to a baseplate or being excessively heavy. It provides sharper meets and higher speeds than are possible with laminated laps, and does so without the use of toxic metals such as lead and cadmium. The new BATT ™ alloy is now used by everyone from beginners to award-winning gemcutters. Its casting and machining properties are superior to 95/5 solder and other tin alloys, and more importantly, performs better with oxide polishes. Being solid castings, finished on both sides, BATT™ laps are more versatile than the one-sided laminated laps.
Thank you again, I placed an order for a batt lap.
no problem good luck happy faceting
Quartz is usually tricky to get a good polish on in the first place! If your getting a slightly clouded finish, you may be overheating your stone. (too much pressure or not enough lubricant).
Having said that, if you may want to try Lightning Laps, also named LL D Lite. They are Very fast working, you don’t have to charge them. (for the beginning faceter, over charging a lap with diamond can also cause polish problems or the dreaded hairline scratches when polishing.
Lightning Laps come in 600, 3000, 50,000 and 100,000 sizes. They also have a Cerium Ox. lap for fine polishing…for Oregon Sunstone, this lap is truly lightning fast!
When using quartz or Oregon Sunstone…(which I do a lot of). I usually start with a 600 diamond then use 600 lightning lap, (for maybe 5 - 10 seconds per facet. Then I use 3000 as pre-polish then cerium ox. lap. Each lap only takes seconds to finish a facet. For small stones and facets I can use just the 600 LL lap then go to pre-polish, saves time as I am using fewer disks.
If taken care of these laps will last a very long time and are fairly priced at around $55.00 each.
The LL laps I am using now, I have have for over a year and they are just like new. When they start to get glassy or shiny on top, rub them with pumice soap and a stiff plastic brush to get them back to new shape.
Another nice thing about these laps is you use a very very light touch or pressure between stone and lap and it only takes seconds for the lap to do its work so there is no overheating of the stone.
Hope that helps!
Hello Bob,
And welcome to the weird and wonderful world of faceting. I have to take issue with a lot of what’s been said about polishing quartz. There isn’t anything wrong with upgrading to a BATT lap or to a Lightning lap…both will probably give you flatter facets than an Ultralap. Ultralaps—cerium oxide or spectra—work quite well on quartz and a lot of people find them easier to use than other laps, and the main knocks on them are that they wear out fast and that they can give rounded facets. You can combat this by using very little water or just using WD40 to stick them down to a smooth master lap and by having a good prepolish and then using not a lot of pressure to polish. Cerium oxide, and not diamond, is actually considered to give a better polish on quartz than diamond. This is true for some other species below Mohs 8 in hardness, too. Cerium or chrome work better than diamond for them.
The typical problems with polishing quartz seem to be balling up of slurry if you use that (you aren’t) or subsurface damage from your prior cutting laps making it hard to get a good polish. It’s important that if you rough out with a coarse lap (180-325) that you take off enough material during your next cutting phase (600 grit) to remove any subsurface cracks and damage. You can actually go from a good 600 surface to a polish on any of the various cerium oxide laps. Ultralap, BATT with the Gearloose cerium BATTstik, a Lightning Lap cerium or some other coated cerium lap. The crayon or the coating make it possible to avoid using a slurry, which is problematical and can scratch unless you get it just right. If I were you I would listen carefully to my cutting lap and make sure you are getting a nice smooth sound and not some kind of tick-tick as you are starting your cutting. Some kind of tick-tick at the start of cutting or some kind of tug would indicate that something is scratching your stone. Tick-tick at the end point of polishing is different and means you are coming up against your hard stop, if you are using one.
If you are doing enough cutting at 600 to get a nice evenly frosted surface and then doing the same to get a nice finer frosted surface at 3K or 8K, a polish should come up on small facets that are face on to the polishing lap correctly in about 10-15 seconds or so. A table or very large facet will take longer. If you are taking much longer than this, you are having to polish out scratches from the 600 or 325 or your facet is not hitting the polishing lap all over at once and you need to cheat it in so that it polishes all at once.
The only other thing I can think of that would be a problem with polishing quartz on cerium would be a defective lap or perhaps too little water. If you are using a medium amount of water and a medium to slow polishing speed 100-500 rpm, you should be OK.
If you can’t solve this by yourself, look for a mentor from the local gem and mineral society, an experienced faceter, or maybe if there isn’t anybody local, find someone to talk you thru it on Skype. You can certainly PM me if you think I can help you further. Best of luck! -royjohn
Problems with
Thanks so much for the feedback. I did purchase a batt lap. It arrived today and I went to put it on my facet machine. The lap is a 6” but doesn’t have a 1/2 in. mounting-hole. It’s very slightly less. Does anyone know if I can drill the mounting hole with a metal bit without damaging the lap?