BATT ™ Cast Alloy Laps.

Lead? Pb? Are you NUTS??

Details and Ordering Information


As you have read from the Faceter's Digest, I love to facet. Originally, commercial 95%tin, 5% antimony solder was used to make leadless polishing and prepolishing laps, which retained the low coefficient of friction and nontoxicity of tin but was hard and rigid enough to be cast by the homebuilder. It was hoped that a manufacturer would soon offer laps made from this material, but to date none have. Perhaps the market niche is too small for them to bother with?

So I began making them, and continuing to experiment with improving the alloy, the casting process, the machining, and the surface characteristics. Many people have since made them, and have had good results. However, even the 95/5 alloy required fairly thick, heavy castings in order to be dimensionally stable. This consumed a lot of expensive alloy, and cost a lot to ship. I no longer cast 95/5, as it is available commercially everywhere as a lead-free solder. I continue to encourage people to make their own, if they wish.


The new alloy, which has completed its field trials by dozens of experienced faceters was named "BATT". Its casting and machining properties are superior to 95/5, and more importantly, perform better with oxide polishes.

Tuning the metallurgy:

Most high- tin alloys do not work-harden. About all that can be done with cast parts is to quench them. Below is a metallograph of 95%tin, 5% antimony. While the alloy makes a wonderful low-friction lap which holds diamonds well, and is substantially harder than pure tin, to give sharper facet meets, the laps can still bend if abused, or if a jam occurs.


Micrograph

In the following metallograph, note the highly ordered grain structure in "BATT" as various alloying components crystallize when the alloy cools.

New alloy

This is not a eutectic solution, but becomes more of a composite, with differing hardness domains, a finer grain structure, and results in a much stiffer alloy which does work harden, while retaining tin's low coefficient of friction and lack of toxicity. Another purpose of this alloy is also to provide better performance on water suspensions of common polishes, as well as with diamond compounds.






A novel class of polishes has been developed for use with these and other tin alloys as well as bronzes.

Polishes

From left to right: 0.05 micron Aluminum Oxide, Titanium Dioxide, Cerium Oxide, and 5 micron Aluminum Oxide (#4,000). The polishes will be offered for general sale after more extensive testing by actual faceters. Samples are being included with the BATT laps. Reports to date have been very promising. As is the case with the BATT alloy, the formulation is nontoxic.

Ordering Information

I will furnish these laps now that the prototypes have been finished and extensively field tested.

I will make a 6" for US$ 55, or an 8" for US$ 70. Shipping by Priority Mail in the US is $4 for the 6", $5 for the 8". Shipping by USPS Air to Europe or Scandinavia isUS $16.70

Send Check or Money Order to:

Jonathan Rolfe

PO Box 533

North Easton, MA 02356 USA.

Please e-mail me in advance so I will be able to respond more quickly. I have to make these evenings, but have so far been able to make them in a week or less after someone orders them.

>Let's Talk.



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How to charge a new lap.
"BATT is a Trademark used to describe a proprietary alloy, principally of tin, which contains alloying metals of low or no toxicity which harden and deoxidize the alloy and establish certain grain structures which are developed by a specific annealing and quenching process.