I tired a few stones on the Darkside, and seem to be having a little scratching problem. The first few facets come in fine (not as fast as diamond on Batt), but then the scratches started. I was using Cerium and polishing beryl. I ended up switching to a spectra lap to finish the stone.
Same thing on the next stone.
Any ideas what I could be doing wrong? Too little polish? To much? Too fast or too slow? I was running around 20 on the Facette dial. I use a finger to kind of chase the water and polish around on the lap as I work it.
Joined: Tue Jun 12, 2007 6:41 pm Posts: 5534 Location: Massachusetts, USA
Quote:
I tired a few stones on the Darkside, and seem to be having a little scratching problem. The first few facets come in fine (not as fast as diamond on Batt), but then the scratches started. I was using Cerium and polishing beryl. I ended up switching to a spectra lap to finish the stone.
That's the first case I have heard of such a thing. Just for giggles, try spinning the lap with a brillo or SOS pad, wet, then rinsing it well with water and spin dry.
If that does not do the trick I will swap you another so I can study that one under the microscope. This is the kind of thing I jump onto like a duck on a Junebug. What seems peculiar to me is that it started after a few facets.
Joined: Sun Oct 23, 2005 8:10 pm Posts: 436 Location: Australia
Our Guys are still reporting great results a new report in today.
With Precision and Gearloose with there heads together who can guess whats next Two experts in the Game we are lucky to discuss private stuff out for all to see
Joined: Tue Jun 12, 2007 6:41 pm Posts: 5534 Location: Massachusetts, USA
As a point of general interest, one thing I did was to improve the machining so there is much less texture on the surfaces to retain dust or other environmental contaminants. There are no components or mineral fillers or anything like that present in the formulation that could scratch anything harder than Moh Hardness ~3 .
The surfaces are now silky smooth and require no break-in.
I was awaiting the arrival of the custom ground Single-Point Diamond tools I had ordered.
Every single lap in stock has been machined with them now- And that is quite a few, because in December I start building inventory for Tucson. They will be rolled out there by several dealers.
Joined: Tue Jun 12, 2007 6:41 pm Posts: 5534 Location: Massachusetts, USA
I think things are staring to make sense. One burning question is "Why are beginners getting good results?" I suspect it is because they use those plastic film things that do not tolerate high speeds or high pressures so are used to a slow light touch.
I went down to the shop and am cutting a Guererro Topaz and did some experimenting.
1: I can make the lap round the meets by applying too much pressure, and given my cutting style, that's easy to do.
2: I can overcharge and makes sleeky scratches.. These laps do not embed the polish in the same way BATT's do.
3: I can overspeed because it's my nature I tell everyone not to but sometimes my machine sounds like a turbine. Rounded meets, anyone? And I have a VERY rigid machine. Could be elasticity of the composite, but I would not be surprised if I never figured it out...
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I have been asking users about what they have been doing to get results. I just got this email in. I will only excerpt it till the guy gives me permission, but here are the essentials:
"Mine started scratching too. I had applied too much cerium oxide. I took it off and washed it with 409 and all is well again. The Darkside seems to take much less oxide slurry than a tin lap. I am also letting my cerium oxide mix settle and just taking a little off the top with a brush. I am using what is suppose to be the best cerium oxide you can buy.
I have tried between 200 and 500 RPM. 200RPM works best for me.
One more note: I turned off the water drip. I am just using a spray bottle like you use for diamond spray and spritzing ever now an then."
An earlier one:
"It is FLAT. This has to be the flattest polishing lap I own.
The best part: I am cutting a very nice amethyst now. I actually do not cut much quartz because of the low RI but this is a nice one. I prepolished on my BATT with 3K and it pitted. I don't know why this happens sometimes but it does. I would usually polish on a cerium Pol-A-Gem I have but it is very slow so I got out the Darkside. I cleaned it because I noticed when you first get it there is some black dust on it. I then applied a very thin slurry of cerium oxide. It must have a black hole in it because it just seemed to suck the pits out and I am left with the flattest sharpest facets I have ever had on any stone. I am probably not saying this right but you cannot see the edges of the facets. There was absolutely no edge tearout and there is no grooving because the Darkside does not have grooves. I am still experimenting with speed and dampness but it seems to be very forgiving."
Joined: Thu Jan 24, 2008 4:01 pm Posts: 1902 Location: Pine City, NY and Dothan, AL
Gearloose wrote:
"Mine started scratching too. I had applied too much cerium oxide. I took it off and washed it with 409 and all is well again. The Darkside seems to take much less oxide slurry than a tin lap. I am also letting my cerium oxide mix settle and just taking a little off the top with a brush. I am using what is suppose to be the best cerium oxide you can buy. I have tried between 200 and 500 RPM. 200RPM works best for me.
One more note: I turned off the water drip. I am just using a spray bottle like you use for diamond spray and spritzing ever now an then."
Add one more vote for this technique. That's exactly what I've found - when it looks like the oxide is all gone except for some that doesn't wash off, that's when it polishes best. I also went to the spray mist instead of drip.
Oh man! Are people going to make me buy ANOTHER polishing lap????
(Where do people get that white cerium anyway? I have used "optical grade 99.9% pure etc but it is still pink, not that I used it much anyways. Is the white better?)
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Joined: Tue Jun 12, 2007 6:41 pm Posts: 5534 Location: Massachusetts, USA
Quote:
Oh man! Are people going to make me buy ANOTHER polishing lap????
It could be worse. I got curious and ended my quartz boycott because of Starcut's stuff. I had a nice crystal tip of a rose d'France amethyst (A little deeper than most I have seen but not "Purple") and tried his #600-CeO/Darkside trick on the pavilion tonight. Well, damn. Just Damn. I mean, H...S..., a 2-lap stone. I used to claim that quartzes were not worth the effort per value.
I hope to finish it this weekend and shall put it up and let it speak for itself. Proves the Lapmaker does not know everything. Watch, I'll screw up the crown or something.
Quote:
(Where do people get that white cerium anyway? I have used "optical grade 99.9% pure etc but it is still pink, not that I used it much anyways. Is the white better?)
I got mine from Rob at Color-wright ages ago. He still stocks it. The tan stuff is used in the optics industry and once upon a time I used to be able to got big fibre barrels of it. Tumblers use it also.
Get the 99.9% Grade for faceting. There IS a difference.
Joined: Sun Dec 30, 2007 7:01 pm Posts: 50 Location: NW Washington St.
Yes John, you need yet another polish lap. But this one might just be the last one you'll ever need -- just like the last one.
I just finished a superpear96 that is 13.5 by 18.7mm and 12.3 ct. A light blue synthetic quartz no less. Polish was a pleasure with the DarkSide and cerium slurry (I use a few drop of Jetdry and distilled water along with the CeOx). I ran my norbide stick I use for polishes over the top of the lap before I started to polish just in case there were irregularities and mostly because it's just a habit. Lap was fine. I actually wiped most of the slurry off after a facet or two and then kept the lap barely moist with a water spray. I was given an empty spray container that had had "I can't believe it's not butter" in it and the very fine mist was just perfect for the job. Keeping the lap moist, not drippy wet worked really well. I'm always amazed at how fast CeOx moves facets (and their meets) around and the DarkSide is no exception. It's very fast (as fast or faster than my old standby, the CeOx Dynalap and much faster, for me, than the dynalaps) and is going to be my lap of choice for the CeOx. I'm reluctant to risk AlOx or diamond on the darn thing because I don't want to risk the way it's working with cerium. The only downside I see to the lap is that I now have several lifetime's supply of CeOx in my closet due to the very limited amount the lap needs.
Joined: Tue Jun 12, 2007 6:41 pm Posts: 5534 Location: Massachusetts, USA
#600 plated, directly to the Darkside with CeO. I may not finish this stone because I see a crack at the top corner-I would probably lose that corner at pavilion time. There's more in the rough drawer.
Here it is, still filthy with CeO on it. There was no work to this..no loss! shrug.
Joined: Thu Jan 24, 2008 4:01 pm Posts: 1902 Location: Pine City, NY and Dothan, AL
Gearloose wrote:
#600 plated, directly to the Darkside with CeO. I may not finish this stone because I see a crack at the top corner-I would probably lose that corner at pavilion time. There's more in the rough drawer.
Here it is, still filthy with CeO on it. There was no work to this..no loss! shrug.
Now, of course, I have to try it <g>. It probably won't be my regular method, though, because I need the pre-polish to fix the mistakes I make with the 600!
Joined: Tue Jun 12, 2007 6:41 pm Posts: 5534 Location: Massachusetts, USA
Quote:
Now, of course, I have to try it <g>. It probably won't be my regular method, though, because I need the pre-polish to fix the mistakes I make with the 600!
Yeah, that could have used a little work, seen (as usual) in the light of the next morning.
Plus, it seems abnormal, like "Cheating". But how could I just sit there when Starcut was doing those boulders on his Beer Day without trying it....
For me the capability to skip a 3 or 14 k prepolish is vital. I have almost all of my sequences down so that I go from a 1200 sintered at the finest direct to polish.
(There are some cases though when the 3k still seems necessary.)
Each time you have to revisit all the facets on a gem that is a big time consumer.
Will try the Darkside and see what it can do for me on the Quartzes.
Why Jet Dry? Does it really help? I understand that it is a surfactant etc but does it really make a difference? I like to keep things as simple as possible and still work well.
_________________ Gems are purchased because they are pretty, so they should be as pretty as possible!
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