Help regarding copper laps and other questions

[Debbie K]

Hello all:

I'm new here, and I'm primarily a gemstone carver. I've recently started faceting and today received a set of 6 copper topped, corian backed laps. They're marked 180, 260, 600, 1200, 3000, 14000. The man who gave them to me said they've never been used, but they look like they may have been. It appears that they have at least been charged.

Is there a way to clean these? I doubt that there is, but thought I might as well ask. I'm a little spooked about cross-contamination but I guess the only way to find out is to try cutting a stone. I've been reading about how to charge these, but to tell you the truth, I can't afford the brayer right now. Can a brayer be cleaned and used on other grits? I have some tool steel and access to a lathe so I can make one if it's necessary. How often will I need to recharge and with approximated how much diamond?

I have plenty of diamond powder in a large variety of grit. I've been using plated laps up to 1000, and after that using 1200, 3000, 8000 and cerium on corian laps that I made myself. I put turtle wax on them and then smear some diamond grit and work it in with a agate burnisher. I've been cutting quartz to learn on before moving over to more expensive rough. I have found that the turtle wax only holds up to facet one stone, after that it needs to be redone.

I've been reading about copper laps, and one site said that you use water up to 1200, and oil on 3000 and above. Is this what you guys do? There also seems to be a debate about what kind of oil or grease: almond oil, synthetic lube with teflon, etc... to tell you the truth, I'm confused. Should I aggressively clean these things after using them, or just rinse them with water? I only use water to clean the corian laps; maybe this is why I have a few mystery scratches occasionally.

My machine is an ancient Graves Mark I. It has one speed and one direction and a 64 index. It's one step up from a jamb-peg faceter. It's cranky and inaccurate, but it's what I have. I've replaced the bearing, belt and switch. It's an adventure every time I facet a stone; nothing stays level. I'm just grateful to have it, and a friend lent me a 96 index a few days ago, and I'm looking forward to being able to cut some different stones.

Sorry for all the questions, it's hell being a newbie.

Debbie K

 

[Mr Magoo]

I'm new here, and I'm primarily a gemstone carver. I've recently started faceting and today received a set of 6 copper topped, corian backed laps.They're marked 180, 260, 600, 1200, 3000, 14000. The man who gave them to me said they've never been used, but they look like they may have been. It appears that they have at least been charged.

I've never heard of a copper topped, corian backed lap. Love to see a photo. I have heard of people using the copper boards used in electronic circuit boards. If they look as if they have been charged I would treat them as so, especially since the grit size has been written on the lap.
You can clean them using soap under a running tap or wipe down with something like WD40 but you will never remove impregnated grit without machining the lap.

I can't afford the brayer right now. Can a brayer be cleaned and used on other grits?

Not sure what a 'brayer' is. Are you referring to a knurling tool? If so, some knurl, some don't. I don't.

I have plenty of diamond powder in a large variety of grit. I've been using plated laps up to 1000, and after that using 1200, 3000, 8000 and cerium on corian laps that I made myself. I put turtle wax on them and then smear some diamond grit and work it in with a agate burnisher. I've been cutting quartz to learn on before moving over to more expensive rough. I have found that the turtle wax only holds up to facet one stone, after that it needs to be redone.

I find making a paste up and using a dab as required. I am at the moment using a vasoline and grit mix. Although when I rub it around the lap I also add a drop of WD40 to thin it down. Thick paste results in rounded facets.
I would also practice on some other lab created stone as well - Sapphire, Spinel. For a few reasons. It's cheaper than quartz, unless you're finding your own but it's worth ten fold more than quartz once cut. It gives you experience on how different materials behave. You don't want to learn on decent Sapphire, how to polish a Sapphire. You will see how different laps behave. You'll have a prettier looking stone. And quartz is notoriously awkward to polish. Some days are good and some are bad. You'll figure it out.

I've been reading about copper laps, and one site said that you use water up to 1200, and oil on 3000 and above. Is this what you guys do? There also seems to be a debate about what kind of oil or grease: almond oil, synthetic lube with teflon, etc... to tell you the truth, I'm confused. Should I aggressively clean these things after using them, or just rinse them with water? I only use water to clean the corian laps; maybe this is why I have a few mystery scratches occasionally.

On laps where the diamond is part of the lap, diamond topper laps, sintered laps, etc, which is usually 1200# and below use water.
On laps, where you add the diamond I would use WD40. Some don't like the smell and may use almond oil. But the thicker the lube the more likely you will round facets also the stone is more likely to 'aquaplane' reducing cutting efficiency. Even baby oil is to thick in my opinion. When using oxides to polish use a slow drip of water.
I generally only wipe my laps down that have had an oil based lube only, all polish and prepolish laps placed into their own bag.
And those scratches you are talking about could just as easily be part of the quartz's behavior.

My lap range that covers most stones is:
A sintered 800# from 'Rough2cut' a forum member. A excellent lap but expensive and will hopefully out last me. But I would suggest you get a couple of topper type laps such as: Note 8"
https://www.aussiesapphire.com.au/i...d=1021&zenid=9a2368c0292c1a11e35527981912a85f
along with
https://www.aussiesapphire.com.au/i...d=1024&zenid=9a2368c0292c1a11e35527981912a85f

I also have a couple of copper laps, https://www.aussiesapphire.com.au/i...id=654&zenid=9a2368c0292c1a11e35527981912a85f one with #3000 loose grit and the other with #8000.

A 'Darkside' for quartz (love hat relationship with that one )
A Tin laminate lap with #100,000 for polish. Not sure where you would get one from.
A Typemetal lap for use with Aluminium Oxide. Not sure where you would get one either. Rough2Cut would know, he may sell them.
A couple of 'Dominatrix' laps from Gearloose. Don't like them. Partly because both arrived with bad runout and have had to be machined. Rough2Cut dues excellent machine work also.

HTH.

 

[Debbie K]

For lack of any other name,

Mr. Magoo:

Here's a picture of all the laps, a side view and a oblique view of one of the copper laps.

It seems as if they were glued together at one time; all but this one have separated. The copper is a little more than 3 mm thick; actually measures 1/8 of an inch. Pardon my ignorance, but isn't Australia metric? I think we in the U.S. is about the only ones stubborn enough to not have converted.

Yes, I think a knurling tool and brayer would be the same thing. I wasn't really looking forward to making one, so I think I'll go with your method. I have vaseline and WD40, so I'll be good to go.

They look like they need a little clean up; I was thinking a nylon scrubber with some soap and water. If they don't sit level, I'll have to soak them in acetone to get any residual epoxy of the back and I'll use my corian master lap for them to sit on.

Since I carve gemstones, I have a bunch of citrine, amethyst, smoky and clear quartz; and I mean many pounds. Have a few synthetics; a couple of cz's, a ruby half boule and a spinel boule. I have quite a bit of topaz; blue and imperial, lots of peridot and garnet. Most of my rough is good because if it's too included it is unsuitable for carving, so the majority is "faceting grade". I have some good stuff, too, but I'm not touching it until I get a lot better at everything. I'm struggling with proportions and polishing, but since I discovered cerium oxide I feel like I've died and gone to heaven.

I have some bur oil which is very thin which I can try if the WD40 stinks too much. It's from Rio Grande and I used to use it all the time with diamond for carving, but switched to mineral oil which is a little thicker which is better for carving as it seems to stick to the stone better.

Thank you so much for your help; I guess you figured out I'm kinda flying blind here. All I know is from what I've read on the internet; I do understand critical angles and polishing as I am interested in gemology and have been carving for many years. But this faceting stuff is new to me; my first five stones were horribly bad but the last four are pretty decent. I see everything wrong with them but no one but a jeweler or faceter would.

Thank you again!

Debbie K

 

[Mr Magoo]

Love that lap box!

Yes, metric. My Copper lap is 5mm thick after being machined. I haven't seen anything that type of lap before. Interesting. But what concerns me is that the have delamination. Personally I'd be tempted to throw the corian section in the bin, not as a master, and clean up the back and use straight on the platen as Copper only.

Re cleaning: I have read somewhere the nylon scrubbers contain an abrasive within the nylon that can contaminate a lap. But since these are cutting/prepolish laps that may not be an issue. I have used them before without problems. I now use stainless steel wool.

Enjoy.

 

[Lefty]

Hi Debbie.

I agree with Mr Magoo - if a laminated lap is separating I would ditch the backing part. If you try to peel it off and re glue it it will never run perfectly true. Like MM says, clean it up and run it straight on the platen.

I've personally never had much of a problem polishing quartz though many people say it can be fiddly at times. Amethyst in particular typically has a property called "polysynthetic twinning" where the crystal is composed of many layers sandwiched together, each layer has the crystal grain running the opposite direction from the layer above and below it. While it isn't usually visible to the naked eye, you can sometimes see this through the loupes while polishing quartz, an infitismally thin layer appears to have "peeled" off the surface of the facet. I cut a fair bit of amethyst and smoky and in my opinion, cerium oxide seems to be about the best all round polish for quartz, though I have also succeeded using #60 000 and #100 000 diamond and zirconium oxide. There are others as well that I haven't tried.

I have succeeded in polishing quartz on a Darkside lap (available over your way from Gearloose), old typemetal and even a Matrix which is a ceramic-type lap (again from Gearloose) but the one I keep going back to is nothing more than a perspex disc I bought for a few bucks at a local gem show years ago. It needed to be scored with box cutters before it would work but I would have to say it is about the best quartz polishing lap I have ever owned - it polishes reliably, reasonably quickly and without agglomeration scratching. Contrary to what many people have insisted, I have found that it does not round the facet edges to any noticable degree, certainly not to the naked eye and it isn't even that easy to see with loupes.

this faceting stuff is new to me; my first five stones were horribly bad but the last four are pretty decent. I see everything wrong with them but no one but a jeweler or faceter would.

Many of the little defects that drive us nuts are often not as bad as they seem at first - things that loom large through a 10x loupe can be all but invisible to the naked eye.

My wife has the first stone I ever cut - a smoky - set in a pendant. It was an atrocity when first finished but after about a year's experience, I re-cut it to a much neater stone

 

[Debbie K]

Thanks you guy for the advice and information! I cleaned the epoxy off the backs of the copper today and gave everything a good scrub with with soap, water and a scrub brush. The ones that had verdigris I cleaned with the lap on the running machine and my finest steel wool and washed them again.

It appears that only two of them have been used, but I'm going to test them all before charging them. I'm excited about having such nice laps, though deep down I'm convinced that my faceting troubles are caused by operator errors.

I'm having trouble posting; this is the forth time I've tried to reply and I hope that this one goes through.

Again, thanks for your help!

Debbie K

 

[Debbie K]

So I tried the laps out today on a piece of faceted glass; three of the six were charged. One was a 180 grit and I was amazed that it seemed to cut as quickly as my plated lap. The others seem to be 360 and 600.

Thanks again for your help, I've been looking at what you guys are faceting and I feel like I'm making mud pies; some amazing faceting and designs! Thanks for helping the newbie!

Debbie K

 

[rough2cut]

Hi Debbie,
I make tin laminated and solid laps, type metal(making some next week) as well as bronze laps solid cast and a new special quartz polishing lap. I also make special polishing kits which make a crappy lap work good again. My first machine was a grave left hand and they can be cleaned up and remotored with variable speed controllers.
Im restoring one very soon so i will take notes for you on how to tune it up.

 

[Debbie K]

I would very much appreciate hearing about your restoration.

I've been reading about the idiosyncrasies of Graves machines, and one article mentioned a set screw on the pivot bearing on the head which could be adjusted to help eliminate wobble. So I went to my machine and looked for the set screw to see if tightening it up would help; Surprise, I'm missing the set screw!

Don't know if it will make a difference, but I certainly intend to get one before I start another stone. I maintain that most of my problems stem from operator error, in other words, me. As I take just a little more time and look a little more carefully to see if my facets are polished, my stones get better and better. As a carver, at least I understand the problems cross-contamination can cause, so I don't think that's an issue.

As crappy as everyone is telling me my machine is, I'm beginning to get attached to it. It's doing the best it can do, and it is MUCH better than a jamb peg. The platen runs pretty true, not perfect, but not too bad. The motor seems good and I plan to determine some true angles to transfer to the protractor since they are always inaccurate, especially 45 degrees. The mark on the protractor at 45 is actually somewhere around 43.5, which can make a table really difficult to do.

I don't think I'll ever be a great facetor or ever participate in competition, I'm just having fun. I like making it up as I go along, cutting the stone to fit the rock. As an illustration, here is my first faceted stone. It was a six sided quartz crystal and all I had was a 64 index. You can imagine the fun I had with that.

Thanks again for the warm welcome and all the help you guys have given me. I appreciate it very much.

Debbie K

 

[Lefty]

That looks awesome Debbie! :Y:

You're essentially creating a piece of art there from the stone so faceting principles like critical angles need not apply in that particular case. My father has ended up with a whole bunch of stuff that belonged to my sister-in-laws's late grandmother. She didn't facet but she cabbed, made jewellery (she finally laid down the tools aged 92, hope I can keep going that long!) and did carving. There are some partly-finished carvings among all the other stuff, they look like New Zealand greenstone (which is nephrite jade I believe?) and other things. There is a near-new flex shaft and a whole bunch of bits, burrs, bobs etc. I would like to have a go at using it sometime, when I am not so busy faceting.

 

[Debbie K]

Lefty:

Yeah, but the meet points and polish still matter, and right now they need work. I want to learn to facet; I have a lot of imperial topaz, peridot, garnets, citrines, amethysts, etc. that are too small to carve but would make some nice faceted stones. Once I master polishing quartz, I really want to do one of the topazes; it's from Guerroro, Mexico and it's a deep orangey-red color and I think it would a lovely faceted stone, the color is so unusual. The perfect cleavage spooks me a little; and I've heard 5 degrees to 15 to off-set, so I figure I'll do a clear or blue topaz to practice on before I mess up a really good one.

Since you facet already, along with what you already have, you're good to go if you want to start carving. If you start in on jade; and I don't recommend it because it's a bear to polish without the dreaded "orange peel"; I'd get diamond files and moldmaker stones, too. I'm doing a carving right now in polar jade and I wonder why I ever started it; it's not that hard of a stone but it's tough and what's easy to carve in quartz is twice as hard in jade.

If you start to carve, post here and if I can help anyway I'd be more than happy to assist you anyway I can. I've been carving for a long time and carved many different materials and learned a lot from bitter, bad experience. I posted a picture of my most recent "big" piece on the introduction page. For some reason, I can't link to my website and I don't like to overwhelm folks with pictures.

Some of the greenstone is nephrite, some of it isn't. In that culture, like in China a long time ago, practically anything green was called "jade". I've carved a lot of the Australian black jade, it's a delight to work with. Hard, but not that difficult to carve and takes a fantastic polish.

The reason why I've taken up faceting is to have something to do when my right index finger is stressed from too much carving. I nicked the tendon on it and when I do anything very labor intensive, I have to take a few days off for it to recover. The hand work is what really gets to me; the stoning and sanding and polishing. Opal and jade are particularly hard on it as a lot of the work ends up being hand-done. Since my faceting machine is left-handed, I can at least work on something while my right hand recovers.

Your "Cleopatra's Eye" is absolutely fantastic. I didn't comment on your thread because all I could think to say was "WOW".

Debbie K

 

[Lefty]

Cheers Debbie.

I've never had much of a problem with the cleavage in topaz but most of my topaz has been self-collected from a site where the stones are only just weathering to the surface and so are not rounded or stream-worn and the crystal shape - and therefore cleavage direction - is easy to discern. Despite what an old faceting book I have says, I have often just put the cleavage plane basically plumb through the stone - vertical from table to culet. The book says "this is not ideal as a sharp blow on the crown may split the stone". Topaz is hard and I doubt you would easily split a topaz in a ring if you punched a brick wall (assuming a person was silly enough to punch a brick wall ). I've never managed to split one anyway.

If you end up with the table on the cleavage plane you may have difficulty polishing it as tiny bits keep flaking off. Is your topaz stream-worn or does it have a definate crystal shape?

 

[Debbie K]

Lefty:

I've got Guerrero topaz, which is crystal, some clear and irradiated blue, both tumbled and crystal. So I've got plenty to choose from. I even have some really pale pink and yellow topaz.

You know, you got me wondering and now I'll have to pull out the polariscope soon to see if the C axis in topaz behaves the same way quartz does. If so, it might be fairly easy to determine where the planes are on the tumbled ones and cut accordingly.

It's good to know that the topaz isn't all that tricky. Knowing me, I should aim for the cleavage plane to be level with the table; I start with the pavilion and once I transfer, it seems the stones always have to have the table adjusted. Just joking, but I will have to be mindful about how much I adjust.

I messing about with the "new" old machine and the cheater is driving me crazy. It seems to only move not at all or way too much. I'm trying to figure out a way to make it more sensitive. I found that the bed isn't quite level, and spent some time adjusting that. My Graves was a left-handed machine, and this one is right-handed. I find that I can't easily adapt and I want to use my left hand to facet, and it's awkward.

The copper plates, on the other hand, are working out great. I have three left that I'm saving for yet to be determined grit. And, the bonus is that I have 6 corian laps, too!

Debbie K

 

[Lefty]

Unless the stream-worn piece of topaz is completely flawless, you can often discern the cleavage direction if you examine it really closely. If you have some refractol, coat the stone with that or aniseed oil or even baby oil can help make a clearer view into the rough. Check for any little cracks - if you see two or more cracks/flaws that are dead straight and running perfectly parallel to one another, that's the direction of the cleavage plane. Sometimes there might be one or two tiny, bright, shiny flat faces on the surface of an otherwise irregular stone that help give it away as well.

Cheers