BATT™ Owners' Instructions.
BATT™ Cast Alloy Laps:
The laps are hard enough to ring like a bell when struck, unlike pure tin or tin/lead...but they WILL bend if force is used to pry them off a spindle, or if they are dropped or stepped on, etc. (One person rolled over one in his chair. Things happen.) Their unique grain structure is grown from the melt. Dropping them onto a hard surface can damage the grain structure of the metal so that if the "bump" is dressed or machined to a true surface, the damaged area may show different wear properties.. So handle them with as much care as your other laps. The laps are cast and machined as simple disks. This way, they can be turned over for a second grit size, or can be resurfaced many times. Some faceters prefer using one side for diamond and the other for oxide polishes.
Choice of Polishes:
The new BATT ™ alloy has been tested with many aluminum oxide and cerium oxide suspensions. Originally developed for diamond, the BATT has been proven superior for use by "Oxide Fans". A light touch and low concentration is recommended, because many of these polishes, and the aluminas in particular, can be fast and aggressive and can quickly overheat the stone if allowed to run dry.
Charge the lap before cutting a first stone with diamond. If you are patient, you can skip the charging step, by simply applying diamond compound frequently.
As the diamond continues to sink into the lap, less and less will be used. The presence of metal deposited on the facet surface always means there is not enough diamond present! The diamond does the cutting or polishing, NOT the lap itself.
Load the lap well with diamond compound, or, preferably, diamond powder and a little oil to make a stiff paste. Polish a scrap piece of quartz, topaz, sapphire, etc, sweeping the lap to insure uniform spreading and abrasive loading. After a minute or two you will see the finish begin to improve as diamond is taken into the softer domains of the alloy. Metal being smeared on the stone, (or on any facet during cutting) is an indication that the lap is "seeing" the stone..Apply more polish (diamond, Cerium oxide, whatever you are using.) You can see an illustrated example, including a VIDEO on the Web
General tips for use with BATT™ Laps:
If using diamond compounds, charge before using for quickest benefits.
SWEEP THE LAP. When polishing a facet, move the stone from the inside of the lap to the outside. It is a good habit to develop for the following reasons: First, it spreads wear uniformly so the lap will break in and burnish well. Since the laps are made on a lathe, when new they have microscopic annular grooves, like a phonograph record. If the lap is swept, these grooves will not create an impression on the facet. Sweeping any metal lap allows it to break in better and last much longer.
USE LITTLE OR NO WATER. BATT ™ laps are designed for their low frictional value. Only a thin film of "dew" is needed for adequate cooling and swarf removal. Too much water wastes polish and wears the lap faster.
In recent years, users have found that BATT™ laps can be used for cutting! When charged with 220 or 325 grits, much water needs to be used to remove the swarf quickly generated...It comes off looking like milk. One user called the Coarse charged BATT™ a "Stump grinder". (The BATT™ was originally designed to be a polishing lap, and polishing is the process that used to give users the worst headaches, so these instructions are focussed on polishing.)
There has been an increasing trend in recent years not to use water on BATT™ laps at all. Users report the use of WD40™ prevents lap fouling by quartzes and allows much faster polishing.
The best tip for fast and superior polishing is, after the lap has been broken in on a few stones, to wipe the lap almost dry, removing swarf, "Black Stuff", and excess compound. Try for a "Monolayer" or remaining compound. Four sweeps with 50K after a 3K prepolish usually produces a finely polished facet on most 1-2 carat stones.
Developed for HIGH SPEEDS! Users report that speeds of 800-1,000 RPM on 8" BATT ™ laps produce excellent finishes without overheating. The User's transition from tin or tin/lead laps to BATT ™ is fairly easy. If you have never used a metal lap, experiment!
Transfer of metal to the stone:
Usually when any new lap transfers a metal film to a stone being polished, it means there is not yet sufficient polish into the surface. It took me a while to figure this out, and the first stone I did was an emerald. The flaws in the emerald were PACKED with metal! However, by the third stone or so, it never did it again. Another thing is that these -do not use as much water coolant...Do not flood the polish off. It is the polish which does the work, not the metal. It sounds simple, but it is not that obvious. Do NOT use vinegar. There is no need for it, and it will shorten the charge life. The metallurgy and surface characteristics have been optimized for oil or water, not acids. The oxides which normally form in use are hydrophilic already. If you continually etch them away with acids, the lap may not break in as well.
Like most metal laps, BATT ™ is softer than gemstones, and by itself, cannot scratch. However, it will "do its job" and hold abrasive particles. The following is drawn from case histories that have been solved by working with BATT owners:
Case 1: A worn 1200 grit plated prepolish lap was throwing out diamond particles, contaminating the machine, the faceting head, and the dops. These particles were taken up by the polishing lap, and produced fine "Cat Hair" scratches in the finished facet.
Case 2: Cooling water in the drip tank was taken from a faucet during a drought. The well pump was pumping SAND.
Case 3: A person was cutting green Cubic Zirconia. Some synthetic materials are not well strain relieved. Tiny chips and flakes were coming off the CZ, and embedding in the lap.
A particular type of "Horsetail" or "Comet-like" scratch will form if the lap is overloaded with diamond. Under shear and pressure at the lap-stone interface, agglomerated lumps of polish break up under the facet.
Use an artgum or similar rubber eraser on the dry rotating lap (Not the common red type, which contains mineral abrasives!). Like graphite, diamond has a great affinity for rubber. The excess diamond will be plucked from the lap and will leave with the "eraser crumbs".
If you use a #170 grit to shape or preform the stone you will have to remove a MILLIMETER of material to get below the scratches, scores, and strains!!! The stone will look fine, all the way through prepolish, but when you begin to polish, you will see a particular type of scratch that is a line with an occasional "starburst" or fracture mark.-------*-----**-------*
Think of how they cut glass in the hardware store! They score it with a cutting wheel or a diamond scribe. The strain on this line is so great the glass breaks cleanly all the way through. Look at such a scored line! Familiar? Doesn't it look JUST LIKE the scratches you are seeing from using a coarse grit early on?
If you have a #170 or a #180/220 "split grit" lap, and are not prepared to take off a lot of material with a #600 or #1200, THROW THE COARSE LAP AWAY or give it to a cabber. Often you may be surprised to find that a finer lap in good condition can actually cut faster because there are more diamond particles bonded to the lap per unit area.
ABOUT CHEMOMECHANICAL POLISHING:
There are many theories floating around about polishing.
There is solid research from the Optics Industry on oxide polishing in water based systems indicating complex processes in addition to the simple "Finer and finer scratches" of diamond polishes. This research is valid for glasses and quartzes, because the industries and government agencies that funded it were focussing on these materials.
Other theories involved lithium ion roles in polishing kunzites, pH modification of drip tank water with vinegar, or extremely basic aluminum oxide dispersions.
All these issues can be ignored and discounted if one follows the trend of using nonpolar oils for cutting: They become irrelevant.
BIELBY LAYER: This phenomenon has been noted in polishing metals and possibly glasses. Attempting to apply it to tourmaline, etc. reminds one that the year it was published was the year before the Marijuana Tax Act was passed. Followers have been wandering away since.
Because gem polishing is a technique-dependent operation, endless theories about "What worked for me once" will always be cropping up.
When you hear these, remember this:
In a Third-World country, somewhere, at this moment, is a guy who never thinks about these things. He has no fancy equipment. He is sitting there, and will cut and polish several hundred carats of Kunzite today, getting paid some piecework rate, and the polishes look very good. He has never heard or thought about lithium ion stabilization, micelle dispersion, or pH adjustment, Bielby Layers, or anything else other than going home and feeding his chickens.
All the endless debates, all the bullshit, ends with this guy in the jungle, polishing stone after stone.
We have no excuses, do we?
New Charging Video
Here is a movie clip of the new EASY charging process. I started with a piece of CZ (Since a few people think it is hard to polish).
This CZ was sawn, and then ground to a #600 finish.
The camera original runtime was 1:45 seconds.
Yes, 1:45 seconds to charge the new lap and 3K prepolish a piece of CZ. I edited it down to the essentials so it is only about 3Megs.