SOLID CAST POLISHING LAP!
THE BA5T Lap.
I hear and obey. The BA5T is now available in the 6" size.
The "BA5T™" was released at the end of January 2006.
Note the background on this page, a micrograph of BA5T's grain
structure. Compare it to the background of the BATT front page. The alloys are completely different in
structure. Some have described BA5T's feel in varying ways, such as "Creamy", "Smoother", etc.. These
descriptions result from the lower Coefficient of Friction and different Fractal Dimension (Surface
complexity of its microstructure) compared to other tin alloys, including BATT™. These
laps are intended for the experienced BATT user who requires a harder-finer-grained lap for HIGH
SPEED PRODUCTION POLISHING processes. The very complex alloy, having attendant casting quirks
requires a heavy ("Pro-Weight") 2.5 Kg casting, and extra machining steps. This of course allows more
resurfacings for a longer service life.
For someone slaving under a stopwatch for a living, they are cheap,
but the regular production "BATT™" will always remain the best
Price/Performance value for the hobbyist. BA5T™ contains silver and
other cost drivers that make it impossible for it to be a cheap product. Competition cutters want to win, some at any cost. They don't care about a few
Dollars. Commercial and Professional cutters know that "cutting tools" are fully tax-deductible and
depreciated in one year. Cutting hundreds of stones a year, a BA5T will polish better and faster, and pay
for itself quickly. So they don't care what the BA5T™ costs at all..which is, in their case, arguably,
"Nothing". First impression upon product release:
Thanks to Roger Dery for the disciplined and rigorous testing to qualify this new alloy and the product
produced, having tested several formulations under Production conditions..
The *new alloy* seems well machined and appears flatter than the BATT's we currently have in use. The *new
alloy* also seems to have a higher hardness than the standard BATT.... In comparison to using a standard
BATT [and this was using it's initial charge with 50K] polishing time was reduced considerably. From my
first observation I would say that polishing time is lowered by 30% to 40%. After several hundred hours of
use and experimentation, it is possible to enhance the time savings to a higher level still.... Please
consider that most faceters, especially the hobbyist, would move from 600 grit to a 3K or 8K pre-polish lap
prior to attempting the final polish. So my results may be slanted to my particular style. That being
for me - time is money. It may be possible with the *new alloy* [for most gem materials with hardness less
than 8] to move from the 600 bonded type - or - 1200 sintered/steel/plated type to 50K.
================================================= Ongoing Charge: [felt this was appropriate due to
reduced performance from the Initial Charge] Clean with WD40. Wipe down with paper towel to remove any
excess. Two drops of Crystalite's Crystalube Extender, spread evenly throughout the lap. Apply less-generous
amount of 50K diamond bort, not quite as much as the Initial Charge. Smear as consistently as possible until
it there is resistance in wiping fingers over the lap. Apply Norbide stick to lap with speed at about
200rpm. Reverse rotation as well; approximate total Norbide time: 4 minutes. I allowed a small remainder of
the charge to stay on the *new alloy* lap. Comments: Working on 2ct. Tourmaline em/cut..... Running the
*new alloy* slowly [80 to 100 rpm] we arrived at a polish from 1200 Sintered lap. It required 45-60 seconds
per facet - all facets were large. When running the lap fast [600 to 700 rpm] we arrived at a commercially
appropriate polish much more quickly [10 to 12 seconds - all facets were relatively large]. After
acquiring the commercial polish using the higher speed, we wiped away the ridges of the original
[commercially acceptable] polish by going over the same facets slowly [80-100 rpm] with four sweeps of the
lap. [By sweep, I am referring to edge of lap to center-nut]. I am certain this is significantly faster than
most, if not all of my previous BATT operations. In comparison to using the standard BATT's, polishing
time was reduced considerably. I again would estimate that polishing time is lowered by 30% to 40%. To note:
I moved from 1200 Crystalite Sintered running at full speed to *new alloy* with 50K. [I know it's
unconventional to not use a pre-polish lap]. ================================================= Ongoing
Charge (4th, 5th, 6th - using the usual routing shown below): Cleaning with WD40. Wipe down with paper towel
to remove any excess. Two drops of Crystalite's Crystalube Extender, spread evenly throughout the lap. Apply
generous 50,000 diamond bort, still not quite as much as the Initial Charge. Smear as consistently as
possible until there is resistance in wiping fingers over the lap. Apply Norbide stick to lap, speed at
about 200rpm, reverse rotation as well. Approximate total Norbide time: 3-4 minutes. Allowed the small
remainder of the charge to stay on the lap. Comments: Working on several Tanzanites'. Running the *new
alloy* slowly [60 to 100 rpm] we arrived at a polish [small star facets], it took a short time, 4 to 6
swipes [10-15 seconds per facet]. Ran the *new alloy* fast [600 to 700 rpm] for the larger facets, one swipe
to prepare the facet - similar to what you would do with a pre-polish lap, then 4 to 6 swipes slowly to
finish. Produces a mirror shine reminiscent of Alumina Oxide on Tin.
Working on 4ct Tourmaline oval..... Cut facets using the 1200 Sintered lap. Running the *new alloy* fast [600
to 700 rpm] we arrived at a commercially appropriate polish quickly [10 to 12 seconds, usually two swipes].
Then, final finish was acquired by going over the same facets slowly [80-100 rpm] with four sweeps of the
lap. This creates a great look. ================================================= ***Performed by my
apprentice*** Recut of 5ct Blue Zircon round.... All facets were cut in with 600 Dyna lap. Began pre-polish
with 3000 on Copper. 'Orange-peel effect' was visible. Didn't complete the pre-polish. Changed to 50K on
*new alloy* lap. Running the lap slow [60-100 rpm] we arrived at an awesome polish [20 to 25 seconds per
facet]. No 'orange-peel effect' visible. ***Comments from apprentice*** Not knowing all the particulars
regarding the *new alloy* lap, he stated "why would anyone bother with a BATT if they can use one of these".
Final thought.... if there's too much WD40 or Extender Lube left on the lap, it reduces how much "drag"
is created by the laps normal use. Seems as if the facet "skips" or "hydroplanes" on top of the lap - and
therefore little polishing action takes place. There is a fine line of not enough - and - too much lube.
I'll be paying closer attention to this because to the new user of the *new alloy*, this could be an area of
frustration. ================================================= Comments: We were trying an
alternative at this point. We changed from the two-lap process of going from a cutting lap straight to
polish. This format included using either a 325, 360 or 600 to cut in the facets, then pre-polish with 8K
on a standard BATT lap, then finishing with 50K on the *new alloy*. Have polished: Tanzanite, four
Tourmalines, six Rhodolite, two Almandite, three Zircons - majority were over 5ct sizes Began with
standard BATT charged with 8,000 mesh as a pre-polish on all the above. Ran the lap medium-fast [300 to
400 rpm] for all the facets, usually one swipe to prepare the facet, sometimes two for larger facets. From
time to time I may add more swipes with the 8,000 to 'move a facet' closer to its meet. Running the *new
alloy* lap slowly [100 to 150 rpm] we arrive at a polish fairly quickly on small facets - either one or two
swipes. For larger facets it is a slightly longer time, 4 to 6 swipes [10-15 seconds per facet].
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