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FFC / Twistor2 results
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Author:  Jclimactic [ Tue Jan 09, 2018 8:56 am ]
Post subject:  FFC / Twistor2 results

I’ve been experimenting with the newest version of the Adamas cutting fluid additive, FFC. Plus the new Twistor2.

The fluid is added to the water drip (dilutes 20:1) when used with the sintered wheels (the 12m and 9m) - not the stock removal wheel (the 32m). It changes the dynamics of how I use the wheels a bit, with just water then behave best running at ~1000rpm (and plenty of water).

With the FFC the wheels seem to produce the best finish running at 400-500rpm, and a good drip flow. The additive slightly increases water viscosity, and slows lap clearing so the drip really needs to be adequate, and an occasional wipe of the lap is not out of order. (After finishing with a lap session, a lava soap treatment cleans it right up and is highly recommended.)

It’s hard (for me) to take a decent picture that shows the difference between the finish with just water, versus FFC - but there is a distinct improvement in finish. The first photo is with just water (I just cut in a couple of facets for the photo, rather than the whole tier). The second is the tier cut in with the use of FFC (same side of the stone, using the 12m lap since this is pink synthetic sapphire). The photo doesn’t really do it justice, the surface in improved, and pre-polish (I used 13k PCD on BATT) comes in faster on facets cut using FFC.

Attachment:
File comment: 12M sintered lap, water.
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Attachment:
File comment: 12M sintered lap, FFC.
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I’d recommend anyone using the Adamas sintered laps try out FFC, it definitely improved the starting point heading into the pre-polish stage.

So far the combination of FFC and the Twistor2 seems to be the real winner though. The FFC/Twistor2 produces (once I learned how to use it) a finish that’s not quite as good as 13k PCD on BATT, but meaningfully better than 3k on BATT (I’ve never used 8k PCD, so no comparison). It moves facets, doesn’t need charging, and doesn’t produce any black swarf, and does its work pretty quickly. The Twistor2 alone produces a pretty good finish with just water, but it’s meaningfully better with FFC.

The third photo shows a (syn. corundum) pear with facets laid in with the 12m sintered lap, then the first tier ‘prepolished’ with the Twistor2. I wouldn’t consider it polished, but the finish is really good. [The girdle is thick here, leaving room to experiment...]

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File comment: Twistor 2 results, synthetic colorless corundum.
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I did have some pretty bad initial scratching problems with the Twistor2, but that was largely technique related, and once I got that down the scratching issues went away. Technique particularly related to lap rotation direction relative to the facet - lap rotation direction into a facet point, not a facet edge; change direction as appropriate by tier or facet.

While I like my Adamas sintered laps a lot, the Twistor2 is simply awesome, particularly used in collaboration with the FFC additive.

[Lest anyone think otherwise, all the products I’ve commented on from Adamas are ones I’ve bought for my own use.]

Author:  Caedmon [ Wed Jan 10, 2018 1:50 pm ]
Post subject:  Re: FFC / Twistor2 results

Could you please elaborate on the technique you use to avoid scratching?

Also, any experience using the Twistor2 on quartz?

Author:  Jclimactic [ Thu Jan 11, 2018 9:00 am ]
Post subject:  Re: FFC / Twistor2 results

I haven't tried the Twistor2 with quartz yet so I don't have any insight on that. I've used it with hydrothermal emerald, and synthetic sapphire (a few different pieces). I'll give it a try on a couple facets with a piece of quartz this weekend and get back to you on that.

The scratching issue shows the same appearance with different material, at first I though it was just subsurface damage showing up, but I tested the same stone with another lap and it didn't show up. The picture below shows what I was seeing:

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IMG_0642.jpg
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Small scratches, very consistent in appearance and orientation, that did not decline with time, but got worse if I kept working on the same facet. Turns out though it was really easy to avoid, just reverse the lap direction, and the scratches disappear - again, that strategy worked on multiple pieces of material.

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Diagram.jpg
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Really looks like small pieces were being pulled off a leading facet edge, and then rolling across the facet and producing scratches. Very directional though, only happens if the facet orientation is at a narrow range of angles relative to the lap rotation - basically if the leading edge is almost perpendicular to the movement of the lap (which is the orientation for near maximum shearing force on the facet edge I suppose).

Break that orientation, by reversing direction (it's what worked for me at least so far) and the scratching went away. Now I just consider the facet orientation for each tier (usually, I guess it could be facet by facet in some cases) and change the direction of the lap as needed.

Author:  Caedmon [ Thu Jan 11, 2018 11:37 am ]
Post subject:  Re: FFC / Twistor2 results

Thanks for the detailed reply!
Your theory as to the mechanism of the scratching sounds reasonable enough, but I suppose the important thing is a working solution. I've seen a similar issue with other laps and haven't really bought into the subsurface damage idea for the most part. Not when continued prepolishing reveals and endless supply of scratches. I had a similar issue on a stone recently where I couldn't go from prepolish to polish until all adjacent facets were prepolished. Takes away much of the reason for a dual band lap :(

Author:  thomas.adamas [ Thu Jan 11, 2018 3:23 pm ]
Post subject:  Re: FFC / Twistor2 results

The Twistor2 has been formulated with a hard polymer-ceramic composite matrix to ensure flat facets and sharp meets. So, when you cut with it, you produce a sort of knife edge. Orienting the running direction across the facet towards this edge prevents chip-outs from dragging across the facet.

Author:  capcuadrate [ Fri Jan 12, 2018 6:45 am ]
Post subject:  Re: FFC / Twistor2 results

Hi,

I don't have a Twister but scratches :oops: Just for my understanding, where is the culet on the drawing ? Did you cut from the girdle towards the culet and after reversing from the culet towards the girdle. Do you ever cut perpendicular so that you would cut across the facet having a leading and a trailing edge ? Cutting mainly Quarz changing cutting/polishing direction by 90 ° often solved the issue.

Martin

Author:  thomas.adamas [ Fri Jan 12, 2018 7:36 pm ]
Post subject:  Re: FFC / Twistor2 results

capcuadrate wrote:
Hi,
I don't have a Twister but scratches :oops: Just for my understanding, where is the culet on the drawing ? Did you cut from the girdle towards the culet and after reversing from the culet towards the girdle. Do you ever cut perpendicular so that you would cut across the facet having a leading and a trailing edge ? Cutting mainly Quarz changing cutting/polishing direction by 90 ° often solved the issue.
Martin


After reversing, culet to girdle.
I have prepolished across the facet short distance and had few issues, but culet to girdle eliminates scratching. The exception would be on the culet facets of step cuts where no scratching occurs prepolishing towards the culet.

Author:  Duncan Miller [ Sat Jan 13, 2018 2:20 am ]
Post subject:  Re: FFC / Twistor2 results

thomas.adamas wrote:
The exception would be on the culet facets of step cuts where no scratching occurs prepolishing towards the culet.
Don't you then risk chipping the culet? I polish long culet facets at 3 o'clock, with the lap running nearly parallel to the culet to avoid chipping.

Author:  thomas.adamas [ Sat Jan 13, 2018 9:21 pm ]
Post subject:  Re: FFC / Twistor2 results

Duncan Miller wrote:
thomas.adamas wrote:
The exception would be on the culet facets of step cuts where no scratching occurs prepolishing towards the culet.
Don't you then risk chipping the culet? I polish long culet facets at 3 o'clock, with the lap running nearly parallel to the culet to avoid chipping.


Not if you have a keel facet.

Author:  DT gems [ Thu Jan 18, 2018 12:59 pm ]
Post subject:  Re: FFC / Twistor2 results

Jclimactic wrote:
I’ve been experimenting with the newest version of the Adamas cutting fluid additive, FFC. Plus the new Twistor2.


Hi,

I feel I need to shout out to anyone using the FFC additive. I have been using and experimenting with Tom's laps with the additive and I am sorting through similar scratches and lap rotation direction. My issue is something stranger and I probably should post under a separate heading. I am curious if anyone using the latest Ultra Tec drip tank has experience severe cracking and crazing to the plastic container. It appears that there is a chemical reaction after using the FFC to the plastic drip tank. I first discovered this one morning that my almost new Ultra tec drip tank had 3 major cracks in it. I stopped using it and several mornings later the cracks kept growing and multiplying.
I have talked extensively with Joe at Ultra Tec and he promptly sent another drip tank under warranty. That tank cracked also! This is when the chemical reaction became the dominant theory. Oddly, I also have a Graves brand drip tank that appears unaffected. I have also talked extensively with Tom of Adamas Facet. He suggested that there might be a difference in plastics as He was sure the Graves was acrylic and would be unaffected but a possible polycarbonate plastic could be affected. Ultra tec has assured me that they use acrylic. Joe with Ultra Tec is continuing to look into this issue. So far I am the only one that this has happened to. I would attach pics but I am having trouble reducing the file size. Anyone experiencing this problem??

DT

Author:  thomas.adamas [ Thu Jan 18, 2018 6:33 pm ]
Post subject:  Re: FFC / Twistor2 results

Hi Dave.
The Fine Finishing Concentrate and the dilution thereof will chemically react with polycarbonate. I was not aware of any drip tanks made from PC. The Graves and Polymetric drips tanks are PMMA (acrylic). I believe the Facetron is PVC. The Facette Gemmaster is aluminum alloy and the Omni/Patriot is 304 stainless steel. Adamas makes a drip tank from PET. None of these should react with the FFC dilution.
Last night I began extensive reading online about PMMA and found that there are PMMA copolymers with polystyrene or polyethylene. I suspect that a PMMA-PS copolymer would not be compatible with FFC dilution. The weak link being the styrene molecule. There can also be problems with the injection molding process itself:
https://plastics.ulprospector.com/gener ... leshooting
A faulty injection molding process can also produce an unstable product that could react with the FFC dilution.

Author:  Jclimactic [ Sat Jan 20, 2018 9:58 am ]
Post subject:  Re: FFC / Twistor2 results

Hi DT,

I use a Polymetric with an acrylic drop tank so unfortunately, on the plus side I haven't experienced any issues with the tank reacting with the FFC. On the downside I've go no insight to offer :?

Robert

Author:  thomas.adamas [ Sat Jan 20, 2018 3:42 pm ]
Post subject:  Re: FFC / Twistor2 results

I mentioned the UT drip tank issue to my business partner, Jon Rolfe, aka Gearloose, and his comment was that raising the temperature of the feed stock to increase parts per unit time, would degrade the polymer by molecular cleaving. Also, using a large percentage of regrind, recycled mold outflow, which is already degraded to some degree, would result in a product with lower chemical resistance. These are factors I had limited knowledge of in my previous post, but now I can state with greater certainty that these factors are likely the reason the UT drip tank, which may in fact be made from PMMA, would not have the expected chemical resistance that the other PMMA drip tank products on the market have.

Author:  DT gems [ Sun Jan 21, 2018 11:11 am ]
Post subject:  Re: FFC / Twistor2 results

Thanks All for your feedback and information. For now I will just stick with(drip tanks) that I know works. I will pass along possible solutions to UT. :)

DT :)

Author:  Duncan Miller [ Mon Jan 22, 2018 3:08 am ]
Post subject:  Re: FFC / Twistor2 results

DT gems wrote:
Thanks All for your feedback and information. For now I will just stick with(drip tanks) that I know works. I will pass along possible solutions to UT. :) DT :)
Perhaps one should stick with not putting a reactive additive in one's drip tank.

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