HISTORY:
The Development of the BATT™ Lap.
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I have been cutting gems since 1958, and from the very first built my own equipment. Working after school wielding a shovel at a dairy farm, there was little other choice.
As with us all, the quest for a perfect polish, and the equipment with which to achieve it, was a lifelong activity. I had always been comfortable with cast iron, bronze, and copper laps, and diamond compounds. There was something especially forgiving and easy to use with the tin alloys, pure tin, and the various solder and type metal lead alloys.
After a few decades it appeared the benefits of tin made it the essential ingredient in these alloys. Combining a resistance to work hardening with a low coefficient of friction against most gem rough materials, it generated little heat. Tin was soft enough so that the polish compounds would become embedded in the lap surface, and tin had a natural affinity for diamond; Some diamonds are actually dopped with solder! I used to make my laps from commercial grade tin ingots, purchased from Grainger's or McMaster-Carr.
I did not like the short service life of pure tin. It seemed as soon as they really became charged, their thickness or uniformity would begin to vary across the lap.
The solders were often better, but as time passed, the dangers of lead became more apparant. Since tin was really the essential ingredient, the lead was not contributing as many benefits as it was contributing to inhalation risks from the dusts and mists that would come off the polishing lap.
As concerns about lead mounted, several agencies began regulating the use of lead alloys. Factories and foundries that had been processing lead, solders, old pewters, and leaded bronze were being shut down. Lead scrap and dross were now regulated toxic waste. Lead solders were no longer used in plumbing. The National Sanitation Foundation began approving lead-free solders. At this time, there arose on the Internet the original Faceters' Digest, and on it, as anywhere, the discussions often concerned the Quest for the Perfect Polish. The NSF had approved 95% tin/5% Antimony solder for potable water plumbing, and it was obvious to try to make some laps from it. These were quite successful, but not "there" yet, and I felt that 5% antimony was too high. This alloy was much harder than pure tin, and delivered flat facets with sharp meets.
I am aware that the inventor always considers his idea to be a good one. Therefore, I began supplying them for below cost to various Faceters' Digest members. Many had more gemcutting experience than I did, and some were full-time commercial cutters! These were the people whose opinions mattered.
Reports started to show up. E-Mails began coming in. People began writing about them. People began winning competitions with them.
Since that time, the formula for the BATT™ alloy has been modified and fine-tuned. The casting procedure was difficult to develop because the as-cast grain structure of the alloy required a precise cooling rate, and the cooling rate at the center of the lap had to differ from that at the edges. Special ceramic molds with forced directional cooling are now used.
The machining process was another matter that was difficult to develop. Expensive tooling was needed to achieve the accuracies needed for polishing laps, and holding these tolerances in this mechanically horrible alloy was another challenge. BATT™ also has a dispersed oxide phase that cheerfully wears out cutting tools!- Some people have actually polished fluorite without bothering to charge the lap. Making faceting supplies can be exasperating, because we all have our own favorite habits of speed, pressure, coolant quantities, and polish application. That is why there are always so many differing opinions about the "Best" polishing laps. A few people, for example, master the ceramic lap, and have perfect award-winning results on stone after stone. Some people never get one to work at all. (I was one of those!)
On the newsgroups and mailing lists, we have seen good products pilloried, and bad product praised, because it all depends on who used which lap on which stone, and how they used it.
So, it is always difficult to make something that everyone likes. It must be forgiving, and easy to use for the beginner. It must be fast and have a long service life, for the production cutters. It must be affordable to hobbyists, many of whom live on fixed incomes...The latter, I can understand, because when I finally retire, THEN I will have the time at last to be a really good gemcutter!
To meet all these conditions is something that would give migraines to any manufacturer.
BATT™ continues to be improved. I have other alloys in development which are even harder, but some of these are at present prohibitively expensive. The "secret" if there is one, is that hardness as measured by the Brinell System is more a measure of stiffness, and this is not always predictive of a successful lap alloy.
for cutting everything else.
THOUSANDS of BATT™ Laps have been sold. There is nothing left to do but make them with polycrystalline diamond tools. Always sharp and true-cutting for a hundred laps or two, they produce finishes that are frequently complimented.
The BATT™ lap is the "Right tool for the Job", and it takes the right tools to make them. |
