Product Review of the BATT lap by R. Walker.
Published in the March, 2000 issue of "Facets", the Columbia-Willamette Faceters' Guild Newsletter.
A New Polishing Lap The magic bullet perhaps?
I am always interested in new polishing laps or techniques that are devised or rediscovered. My curiosity was aroused by several comments made on the "Faceters Digest", an Internet based faceters symposium singing the praise of a new and exciting polishing lap. I decided to purchase of one of these new laps after visiting the producer's website, which is www. gearloose.com/batt.This website is very informative for the faceter whether or not you intend to order one of his laps. I e-mailed him, him being Mr. Jonathan Rolfe, and informed him of my intent to place an order and stated that my check would be in the mail. My lap arrived in just a couple of days via priority mail. The laps cost at this time ...(ed.note: Check dealers or BATT page for current pricing) If you read price lists, you know that this lap is moderately priced by today's standards.
On receipt of my new lap, I noted that the lap is solid BATT, not just a thin layer on some form of backing. This allows for several refacings before the lap is worn out unlike many metal laps on the market. The "BATT" metal, is a proprietary alloy that was developed by Mr. Rolfe specifically for the polishing of gemstones. This material has several properties that should endear it to the faceter from the start.
When rated against other polishing lap materials other than ceramic, the BATT Lap is very hard. For instance, a standard tin lap has a hardness of 5.3 on the Brinell Scale whereas the BATT Lap has a hardness on the same scale of 32.5; hard enough to ring like a bell when struck.
This lap is an alloy containing Tin and several other metals, but NO "0" lead minimizing the potential for toxicity problems when used according to the guidelines set forth in the instructions that come with the lap and the explanatory documentation on his web site.
Due to its' crystalline structure this alloy will polish a very broad range of gemstone hardnesses with diamond. It can also be used very effectively using either cerium oxide or alpha alumina (commonly referred to as "Linde A"). It can be used with either an aqueous (water) based extender or an oily base and extender such as light mineral oil.
I decided to charge my new lap, complete with serial number, with 50,000 mesh diamond. I might mention that Mr. Rolfe provides good instructions for preparing and charging the BATT lap on a sheet included with the lap as well as on his web site. I used a piece of nondescript aquamarine to finish charging the lap. Surprisingly the charging process was very trouble free, the aquamarine taking a fine polish in a very short time. I decided to see just what this lap would do. In order to do this, I prepared dopped preforms of the following gemstones, a Montana sapphire, a large CZ, a blue topaz, an aquamarine, a peridot, a bicolor Oregon sunstone, and an orange Mexican opal. These stones ranging from 9 in hardness for the sapphire to about 5 for the opal.
The lap proceeded to polish all of the above stones to a fine commercial polish with no problems. If a competition polish is desired on the softer materials, the use of alpha alumina, cerium oxide or a finer grade of diamond on a BATT lap is suggested.
When polishing using a light mineral oil as suggested in the lap instructions, it is best to use only a very minute amount of oil. If too much oil/extender is used, the stone tends to skate or ride on the lubricant. After application of the lubricant it is best to wipe most of it off with a tissue leaving only an oily sheen on the lap. The oil remaining on the lap will rapidly turn dark. The metallic oxides produced by the polishing process cause this discoloration.
All in all I am very excited by the potential of this lap for polishing a very wide range of natural and man made gemstones. An additional benefit from polishing with a lap of this hardness is the nice sharp facet edges and flat facets.
I might add that I have ordered a second BATT lap to experiment with using oxide polishes such as alpha alumina (ex. Linde A) and cerium oxide, perhaps a review will follow.
If you are not on line you can write to Gearloose at the following address: Mr. Jonathan Rolfe P.O. Box 533 North Easton, MA 02356
The appropriate e-mail address for Mr. Rolfe is BATT@gearloose.com. I sincerely hope that those of you that choose to acquire a BATT Lap will become as enthusiastic about it as I am.
