Polishing Troubleshoot

[rough2cut]

Ok heres what a pro does to get a good polish.
3000-8000 pre-polish on a special alloy(you can get this lap from Gemcuts, Robilt and Glen Huntley QGRS) Its a very low scratch lap made here in Australia.
The compound I use is my own special formula mixed with 3 drops of aniseed oil and 1 drop of baby oil. Normal diamond will work with this. As for speed I like 1500 RPM
which is fast but the faster the better from my experience. The same is repeated in 50,000 to 100,000. The special alloy is also available in an 8 inch split lap for a pre-polish and final polish in one lap.
As for quartz, I ordered the final component today to make a trouble free plug and play sort of polish that is used exactly the same way as diamond. The only problem is quartz doesn't like and diamond loaded lap so a dedicated lap is needed.
I started with a Graves machine so I feel your pain. You can re-motor this with a 3 phase motor run off an inverter with an external pot to variable the speed.

I don't use many laps these days and find some laps not commercially viable for a pro cutter. I have made a new polishing compound for metal only laps and will be selling all my items soon on my website which is near completion. I mostly earn a living by cutting stones and manufacture on the side so I can justify having a factory but if I was to make laps alone then I would be evicted within a month.

I just love to play in my faceting manland.

 

[Lefty]

So many variations. All right and all wrong. smile

Yep, such is faceting

There often seems to be nearly as many approaches to faceting as there are facetors and most of them work. And just because something didn't work for you doesn't mean someone else won't be able to make it work fast and efficiently. So many factors can come into play.

I might try charging that unused BATT with 3k and cutting facets in with it, just to get a feel of how to do it when the noise is not so obvious. The finish is definitely superior to fixed-grit plated types.

I still prefer the listening method because it has never failed me - when cutting is in progress, the ear can hear what the eye cannot see and there is no need for frequent visual inspection on anything other than the first facet in the row. Once that one is established to the correct depth, I cut the remainder in that row without stopping to look at the facet until the sound is a faint tic-tic, since the sound - or lack of it - does not lie, the stone will tell you if it is making contact with the lap or not and whether it is heavy contact or just barely touching. I do check it at that point just in case of some minor discrepancy.

A mate came down the other week to have a go at his first ever stone and I taught him the listening method - the finished stone was good enough to go straight in a setting with only very small innacuracies.

But ultimately, there are multiple approaches that can lead to success and you will find the ones that work best for you

 

[Mr Magoo]

I think a lot of it is fashion/hype based approaches also. I remember about 15 years ago of reading about how awesome ceramic laps were and it was impossible to get a good finish on a saph without one and everybody should have one. Maybe one could get a awesome flat facet on a saph using them but now the love has gone as apparently user friendly and ceramic lap is rarely seen in the same sentence.
The 'Darkside' may one day join that rank.

I've never used a 3K topper because the 3K on copper gives such a good finish for a pre-polish but cuts fast enough to nudge facets in. If you are used to the listening method it may take a bit of getting used to.Sometimes it is difficult to even hear if you have touched down or not, so it's a lot of looking until you get used to the performance. But I imagine you have already discovered that.

 

[Mr Magoo]

@ rough2cut.

Thinking about a 600 sintered. And with a few reports of over sized arbor holes, divots, balance problems of one brand, the GemPro is looking like an option.

The copper is softer than a normal sintered lap so care needs to be taken not to introduce the facet too aggressively to the lap

Is that for the 3000 only as the rest are bronze. Not that I intend to jam it in. Just curious?

And what kind of cutting lap would a pro use when using his pre former?

 

[rough2cut]

That happens when you out sourse your manufacturing to somewhere with lower standards. I have done a side by side with an American cutter who has a lap of mine and they are both very close in performance and finish. The difference is they claim a lot of things like ten times the concentration of diamond etc while mine is just a well made lap to Australian standards.
I don't like using anything over 800 for preforming as it scratches the bronze. The way to counter this is to increase the diamond concentration. It will give a courser finish but wont deteriorate the disc surface. I preform on my 800 but only after a 360 grit. It still scratches.

 

[Mr Magoo]

I'm assuming they are your laps - GemPro????

These two quotes are from the 'GemCuts website regarding the GemPro.

The copper is softer than a normal sintered lap so care needs to be taken not to introduce the facet too aggressively to the lap

and

USE ONLY FOR FLAT FACETING AVOID ROTARY ACTIONS LIKE BY A GEMMASTA PREFORMER OR FREE- HAND GRINDING

That's why I was asking what you would use as the website YELLS about avoiding it. Not that I own a preformer, but if I did (and I am considering at times) should I use a cheap topper instead?

Also you mention using wet 'n' dry on glass to dress it. What grit/grade would you use on a 600 sintered lap.