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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Fri Jul 09, 2010 5:53 pm 
Hi mhuynh,

Thanks for taking the time to break that down step by step.....faceting for dummies...like me...haha.

Sometimes I don't know if it is just me having the difficulty comprehending what is written, and EVERYONE else in the world who is normal gets it, or if my questions are valid, and something really does need expanding on. It's a challenge I face daily with my disability. Brain injuries are very strange, I can still do advanced Boolean algebra, or calculate the resonant frequency and RF signal radiation pattern of a ultra high frequency antenna, but then I can't follow the instructions to make a TV dinner properly, as I've forgotten one of the steps, or did not understand one of them.....lol.

I hope I haven't made you do more work than you needed to to explain this, if it is already written in plain English that everyone SHOULD be able to understand!

Those steps you've written REALLY clarify this whole cutting and polishing process for me though, so thanks once again, one thing however I'm still unclear about, (sorry about that), where is says "Change to the polishing lap with an appropriate polishing agent. Polish all the crown facets except for the table changing the angles.", does the "appropriate polishing agent" mean the FINAL polish in diamond paste for example? I just wanted to know if that mean to polish to the final stage as if that part of the gem is finished, I'm "assuming" it does, but wanted to confirm this with you.

Thanks again for doing that, the page is great how it is, and has very good pictures for reference on it.

I DO plan on purchasing books such as the "learn to facet" one posted in the link here, but was also hoping to have a similar "free" online reference for now, (I know, it's ONLY 20 bucks!) as I'm sure they are out there somewhere, I just don't know where they are!

Thanks again!

Chris ;)


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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Fri Jul 09, 2010 6:19 pm 
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does the "appropriate polishing agent" mean the FINAL polish in diamond paste for example?


Yes, it is one example. I usually use one of most commonly used agents, i.e., fine grit diamond (50,000-grit or 100,000-grit) and oxides such as cerium oxide and aluminum oxide. I use it on a tin alloy lap or a composite lap. There are excellent products on the market, especially manufactured by one of our members. (Meow! :wink: ) And yes, it is the final stage of faceting.

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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Fri Jul 09, 2010 7:22 pm 
I have a Corian material lap, are they any good??
Kindof a white plastic nylon type of material.


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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sat Jul 10, 2010 2:16 am 
Ok, now these are way kewl!

I can maybe do away with that crappy manual protractor all together, and just mount this little device on the quill, and then simply put a right angle square or something from quill to mast to calibrate it, and then I'll know "exactly" what angle I'm at all the time, with a fairly good degree of accuracy (pardon the pun), probably more accurate than manually looking at the needle on the protractor wouldn't you think?

http://www.harborfreight.com/digital-an ... 95998.html

I could also aet it on the top of the cutting plane of the polishing disk or the lap, and then use that to level the base when installing it, at least to a point where I can fine tune it with the very fine adjustments anyhow.

Do you think these are a good idea? They also have the digital protractors with an arm on it, but you would have to mount one on the quill arm and the other on the part that holds it in place.

I noticed alot of faceting machines have digital protractors on them, I'm thinking this might bring my level of accuracy up on this cheap and dirty device of mine, what do you think?

;)


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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sat Jul 10, 2010 2:16 am 
Ok, now these are way kewl!

I can maybe do away with that crappy manual protractor all together, and just mount this little device on the quill, and then simply put a right angle square or something from quill to mast to calibrate it, and then I'll know "exactly" what angle I'm at all the time, with a fairly good degree of accuracy (pardon the pun), probably more accurate than manually looking at the needle on the protractor wouldn't you think?

http://www.harborfreight.com/digital-angle-gauge-95998.html

I could also set it on the top of the cutting plane of the polishing disk or the lap, and then use that to level the base when installing it, at least to a point where I can fine tune it with the very fine adjustments anyhow.

Do you think these are a good idea? They also have the digital protractors with an arm on it, but you would have to mount one on the quill arm and the other on the part that holds it in place.

I noticed alot of faceting machines have digital protractors on them, I'm thinking this might bring my level of accuracy up on this cheap and dirty device of mine, what do you think?

;)


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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sat Jul 10, 2010 2:25 am 
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NovaScotiaCreations wrote:
Ok, now these are way kewl!

I can maybe do away with that crappy manual protractor all together, and just mount this little device on the quill, and then simply put a right angle square or something from quill to mast to calibrate it, and then I'll know "exactly" what angle I'm at all the time, with a fairly good degree of accuracy (pardon the pun), probably more accurate than manually looking at the needle on the protractor wouldn't you think?

http://www.harborfreight.com/digital-angle-gauge-95998.html

Those are SuperCool! I think I'll get one myself. You will, however, still want the mechanical protractor with the bracket thingy to provide a hard stop. You would not believe how easy it is to cut past the desired angle without one.

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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sat Jul 10, 2010 2:35 am 
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The faceting procedure Mitch describes is, of course, correct. I think it probably gives the most precise final results, especially on the better faceting machines.

Chris and I, however, have faceting machines that are regarded as "imperfectly precise." In other words, once you change the faceting angle, you have the Devil's own time trying to reproduce it for the prepolish or polish step. Personally, I find that I get better results if I cut, change laps, prepolish, change laps, and polish a complete course of facets before changing the angle and starting over with the next row.

That electronic angle sensor will undoubtedly help with the precision of the angle, though, so I may change back to the sequence Mitch described after I get mine installed.

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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sat Jul 10, 2010 2:51 am 
Well, I'm glad that I contributed something positive to other people out there like yourself Steve!

I didn't plan on removing the mechanical protractor or anything for that exact reason, I need to put that stop in place. I only had it clamped in the position it is in just so I wouldn't lose it, that's why it is where it is in the pic, I have to put it "beneath" the brass pointer for the stop to work at the angle I want to to stop at.

When I bought the thing, nobody told me I'd need a stop, I just could not wrap my brain about how it wouldn't cut past the angle that I wanted it to stop at if I was just trusting my hand to do that, no way I'm THAT good with my hands!

I was just thinking about how I could make this thing more precise, and it doesn't get better than digital, I think I might even attach a digital caliper to the mast and the unit that slides up and down it, so I can ensure I measure the height precisely as well.

I'm glad that you also answered the question about when to switch laps, and if you have to go back and reset all the angles all over again, as all I could think of is how could i EVER get it back to the SAME angles I had it on before if I MOVE it!

So now I know that it CAN be done the method where you polish one set of facets right from start to finish without changing the angle, what I thought might happen in that case would be that where the finished very first set of facets you polished right to the finished stages interface with the next facets you do after you change the angle, there might be uneven or chipped edges that you would have to polish a bit deeper in the next set of facets to get rid of all those deeper chips or scratches where the facets intercept if that makes sense, but I'm not sure if that would even happen, and I guess that the next set of facets you made would just simply polish out the edges where the facets meet.

At least I know it CAN be done both ways, so now, I have to get this thing mounted and take it from there, although I might just finish the other flat lap machine instead of mounting it on this one, as it was specifically being built as a faceting machine, I just didn't have the proper arbor for inside it, but now that I do, I think I'll just finish that other one that this faceting unit would just mount on the metal deck of it in a slot, just like a commercial one.

Glad I could help you out with something Steve, now I don't feel so useless...lol.


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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sat Jul 10, 2010 4:54 am 
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NovaScotiaCreations wrote:
So now I know that it CAN be done the method where you polish one set of facets right from start to finish without changing the angle, .... there might be uneven or chipped edges that you would have to polish a bit deeper in the next set of facets to get rid of all those deeper chips or scratches where the facets intercept if that makes sense, but I'm not sure if that would even happen, and I guess that the next set of facets you made would just simply polish out the edges where the facets meet.

You do get some pretty nasty looking facet edges when you cut the next row with the rough lap, but it smooths out nicely with the prepolish, and goes away entirely when you polish. You just don't cut all the way to the meet point until the prepolish or polish step. There are some exceptions, but usually it all works itself out. 8)
NovaScotiaCreations wrote:
Glad I could help you out with something Steve, now I don't feel so useless...lol.

BWAHHH-hahahaaaaa! Even those who contribute nothing contribute something, whether they intend to or not! :lol: It's just the nature of a forum like this.

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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sat Jul 10, 2010 5:58 am 
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Chris, you asked about the Corian laps. Now I don't know if my old one is a Corian, the chap I got it from said it was Perspex, quite thick. A few lines were scored into the lap with a blade and cerium and Alox/ lindeA stuff were used on this for polishing. Don't think you can use diamond on it but don't quote me.
I have bought myself a Darkside lap for final polish now. It is very versatile and you can use diamond and oxide on the one lap. Very much worth saving for, over there it should be fairly cheap.

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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sat Jul 10, 2010 11:52 am 
mehoose wrote:
Chris, you asked about the Corian laps. Now I don't know if my old one is a Corian, the chap I got it from said it was Perspex, quite thick. A few lines were scored into the lap with a blade and cerium and Alox/ lindeA stuff were used on this for polishing. Don't think you can use diamond on it but don't quote me.
I have bought myself a Darkside lap for final polish now. It is very versatile and you can use diamond and oxide on the one lap. Very much worth saving for, over there it should be fairly cheap.


I HOPE you can use diamond on it, as the person basically sold me a "kit" at Sierra gems, she sold me the mast/quill/yolk faceting assembly, a couple tubes of diamond paste (14,000 & 60,000, which I am currently using on my opals instead of it's original purpose which was for the faceting!), the table adapter, transfer block, a brass dop set, a few other necessary nick knacks, and also threw in some of the brown wax for mounting for free, which was really nice of her. I don't get the feeling that she led me astray at ALL, in fact, I recommend dealing with her as she was ULTRA helpful to me, and VERY kind to deal with, and even gave me a big discount.

So it BETTER be able to be used with diamond paste!

She explained to me that this corian lap was WAY better than phenolic, was super long lasting, and VERY durable, and told me TONS of production houses were switching to them, instead of the old standard tin or copper laps, as metal was way too expensive these days.

Here is a link to one of Sierra gems ebay auctions for a corian lap, perhaps now that I've posted the EXACT lap I'm talking about, someone out there can comment about it:

http://cgi.ebay.ca/New-6-Corian-Polishing-Faceting-Lapidary-Master-Lap-/180401268780?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2a00c0e82c

Thanks mehoose!

Chris ;)

PS, in case you don't want to go to the link, here is the written description for the corian lap:

New 6" Corian Polishing Lap - 1/2" Arbor Hole

The Corian Polishing lap is a solid, non-porous lap that polishing compound doesn't become imbedded in, unlike copper, zinc, tin or epoxy compound laps. The advantage of this is that you can wash the lap and change polishing compound from one mesh to another or if your lap becomes contaminated it can be washed with dish detergent in the sink or even in the dishwasher.

Corian is Dupont's trade name for a very dense mixture of acrylic plastic and other compounds that is formed under high pressure and temperature. It is similar but softer than Hi-Macs by LG.

The biggest advantage of using Corian as a polishing lap is aggressive way it can move facets around and the quick polish it gives. We are commercial cutters, we cut thousands of stones in our shop every year. We cut many stones like sunstone that can be problematic when polishing, and even softer stones like fluorite and apatite. These stones can be tricky to polish and every faceter is looking for a reliable way to quickly and easily polish their difficult stones.

For us Corian was the answer, it worked so well on the feldspar group we were soon trying it on other stones and found it worked well on stones from fluorite to danburite and everything in between. We were able to reduce our polishing time and at the same time improve meets. Some faceters even use it on stones 8 to 9 in hardness, and it will work, however there are other laps like zinc that are better suited for that application.

With this fast cutting polishing lap facets are easily cheated in if necessary using Voodoo polish or diamond pastes. Washing thoroughly with dish detergent removes old charge or contamination and the lap may then be re-charged with the same or different compound or grit. Diamond sprays aren't sticky enough to remain on the lap very well and soon your stone is in contact with the lap surface and Corian is soft enough that you don't want this to happen. For this same reason you need to go very easy on small facets and on girdles, they will cut through the polishing compound and can damage the surface of the lap if you don't have a light touch. We recommend using only paste type polishes, they work best and John Bailey's Voodoo Polish is probably the best of the best.

The lap does build heat if too much pressure or on a large surface like a table so easy does it, especially on heat sensitive stones.

This is a very aggressive lap, surprising in a polishing lap and once you get used to it you'll start polishing (almost) everything on it.


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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sat Jul 10, 2010 12:56 pm 
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Quote:
I have a Corian material lap, are they any good??
Kindof a white plastic nylon type of material.


Hi, Chris,

I don’t have a Corian lap. So I can’t give you an answer as my experience. But I found this video by John Bailey who sells VooDoo diamond polish.



I think this will answer your question.

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Mitch

I am a slave to cutting a stone completely free of chips and very much enjoying it.


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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sun Jul 11, 2010 1:35 pm 
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NovaScotiaCreations wrote:
snip

I HOPE you can use diamond on it, as the person basically sold me a "kit" at Sierra gems, she sold me the mast/quill/yolk faceting assembly, a couple tubes of diamond paste (14,000 & 60,000, which I am currently using on my opals instead of it's original purpose which was for the faceting!), the table adapter, transfer block, a brass dop set, a few other necessary nick knacks, and also threw in some of the brown wax for mounting for free, which was really nice of her. I don't get the feeling that she led me astray at ALL, in fact, I recommend dealing with her as she was ULTRA helpful to me, and VERY kind to deal with, and even gave me a big discount.

So it BETTER be able to be used with diamond paste!

She explained to me that this corian lap was WAY better than phenolic, was super long lasting, and VERY durable, and told me TONS of production houses were switching to them, instead of the old standard tin or copper laps, as metal was way too expensive these days.
snip [/b]


Yes, of course you can use diamond on it...paste, spray, loose bort with lube, it works pretty well on corian. So do the oxides. I have one around here somewhere that I used to use before I figured out what I was about with other products. I did in fact polish everything from apatite to sapphire on it. The sapphire took a while, but eventually polished nicely with 60k diamond. I don't think it would be my lap of choice for the harder stones, 8-9 Mohs range, although it obviously works. There are faster options though.
One thing to keep in mind is that it's a type of plastic, and so will gouge if you're not careful. I have a slight groove in mine from an indexing mistake. Also, it will slightly round your facet edges if you press too hard. In my experience, it's very much like phenolic in use, though its certainly more dense. It will cause some heat if you use much pressure.

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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sun Jul 11, 2010 2:44 pm 
Thanks Kevin, hopefully I will get this thing together and be able to see for "myself" how it polishes....lol.

I think the quicker road however is to not mount it on the lap I first started thinking about mounting it on, but rather finishing building the other lap that is more suited for a "faceting" configuration. That way I don't have to mess about so much in making the mount and can concentrate on making the lap to fit the faceting device instead. It just makes more sense.

I've figured out how to remove the height adjustment and replace it with my own external mechanism instead, I still can't figure out exactly HOw they intended that mast setup to work straight out of the box, everything is fine until you try to use the table adapter, which is way to long and makes it all way too high to work, i think someone on the design team flubbed something on that one!

I'm shortening the table adapter dop arm that mounts onto the quill, and making it so the dop with the gem in it only protrudes a bit out of the bottom of the table adapter, rather than the whole length of the dop.

Thanks!

Chris ;)


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 Post subject: Re: New to faceting, need help mounting mast!
PostPosted: Sun Jul 11, 2010 10:34 pm 
Well, here is the table mount that I've modified to finally work properly, it was too long where it plugs into the quill and also I couldn't push a dop all the way into it as it was not drilled properly, now that dop can slide in far enough like it is supposed to, and hopefully, it is completely parallel with the proper angle it need to be, otherwise I can see some adjustments in my near future, or additionally a flying table adapter going out the window...lol

;)
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