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Post by rockjunquie on Sept 12, 2016 18:08:36 GMT -5
johnjsgems recommended a video in this thread. I just got finished with it and thought a review might be nice. I hope this is a good place for it. I ordered the reasonably priced dvd video, Beginning Cabochon Cutting with Jim Barzee from Lapidarytutorials.com. I didn't get an email or anything and wondered if the order went through ok. But, I got it today, an acceptable 7 days later. The video begins where all cabs start... with finding a scene in a slab, marking it and cutting it with both a band saw and a trim saw. Pretty basic stuff. Then it goes on to dopping. Jim doesn't use a dop pot, which I do. It was nice to see another version of the procedure discussed. Then Jim gets right into cutting an oval cab in real time. At that point, I was a little disappointed because he didn't talk while doing it. No word about the girdle or angle of the girdle. (More on that later.) When the cab was finished, Jim did a whole chapter on cabochon cutting theory which was very, very thorough. He included a great deal of information about the expanding drum cabbing machine, which he used. He didn't cover the Diamond Pacific machines, but the same basic info applies. After going over cab cutting theory and the machines, including belt wear and water, Jim delves into a whole section devoted to girdles and bezels. I was really happy to see this because it is so rarely discussed. He discussed the angle of the girdle and why it was so important. He also discussed when to use a high or low dome. Jim concludes the video, by giving examples, at the wheel, of how a beginner can be more successful at cabbing and he includes troubleshooting. I have seen a few instructional cabbing videos. I must saw that this is the best one that I have seen. The information was well presented, was easily comprehensible, well filmed and thorough. I think this is well suited to the beginner or even someone who wanted to get a look at how someone else cabs (which is what I wanted it for.) Also, I think someone who is starting with an expanding drum would really appreciate this. Jim's manner was very easy going, it was almost like being in a buddy's shop.
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bsky4463
fully equipped rock polisher
Member since September 2013
Posts: 1,696
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Post by bsky4463 on Sept 12, 2016 19:50:50 GMT -5
Awesome review Tela...thanks for taking the time to post. I too have thought about getting that vid. Being self taught I know there are other ways. Cheers
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Post by rockjunquie on Sept 12, 2016 20:02:02 GMT -5
Awesome review Tela...thanks for taking the time to post. I too have thought about getting that vid. Being self taught I know there are other ways. Cheers Yeah, he and I cab differently, so it was nice to see how he does it. His way was pretty quick. It was done in real time and he posted the time on the screen. Not too shabby. I'd like to see an advanced video from him. |
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Post by Drummond Island Rocks on Sept 12, 2016 20:12:26 GMT -5
Nice of you to take the time to do a review. How in depth was polishing covered and what method was he using since he was not on diamond wheels?
Chuck
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Post by rockjunquie on Sept 12, 2016 20:17:57 GMT -5
Nice of you to take the time to do a review. How in depth was polishing covered and what method was he using since he was not on diamond wheels? Chuck He was using all diamond belts on the expando. He didn't do any polishing other than the wheels, but he went through to 14k. I'm figuring he needs to do a vol 2 to cover pastes and wooden wheels and such. I like his style. I would buy a vol 2 (advanced). |
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Post by Drummond Island Rocks on Sept 12, 2016 20:30:02 GMT -5
Nice of you to take the time to do a review. How in depth was polishing covered and what method was he using since he was not on diamond wheels? Chuck He was using all diamond belts on the expando. He didn't do any polishing other than the wheels, but he went through to 14k. I'm figuring he needs to do a vol 2 to cover pastes and wooden wheels and such. I like his style. I would buy a vol 2 (advanced). Yeah that's where the voodoo magic happens. I am still a complete newbie when it comes to some of those alternative old school polish methods. Chuck |
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Tommy
Administrator 
Member since January 2013
Posts: 11,806
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Post by Tommy on Sept 13, 2016 12:59:32 GMT -5
Thanks Tela! I may have missed it but what type of stone did he work on as his example?
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gemfeller
Cave Dweller 
Member since June 2011
Posts: 3,546 
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Post by gemfeller on Sept 13, 2016 16:19:00 GMT -5
I'd like to see the video Tela but it wouldn't do me much good without captions unless I could glean most of the info visually. I'm essentially deaf, as you know. I wonder if you'd personally follow up with more about your thoughts about girdle angles. I'm totally self-taught, with help from a few good books, and I've always cut girdles sloped properly for traditional bezel or prong angles. I usually cut with a jewelry design in mind and I've never had a problem setting stones in my self-made pieces. But I'm basically old-school and not totally up to date on current requirements.
As a wire-wrapper I suspect you're concerned with that and maybe other things I'm not aware of. I'm not a wire-wrapper and never will be due to worsening arthritis in my hands. But I'd like to understand better what wire-wrappers' needs are so I can incorporate those elements into some of my cabs. TIA.
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Post by rockjunquie on Sept 13, 2016 16:33:05 GMT -5
Thanks Tela! I may have missed it but what type of stone did he work on as his example? Good question.... As far as I can tell it was an olivine. It had a real nice pattern and took a great shine. |
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Post by rockjunquie on Sept 13, 2016 16:49:24 GMT -5
I'd like to see the video Tela but it wouldn't do me much good without captions unless I could glean most of the info visually. I'm essentially deaf, as you know. I wonder if you'd personally follow up with more about your thoughts about girdle angles. I'm totally self-taught, with help from a few good books, and I've always cut girdles sloped properly for traditional bezel or prong angles. I usually cut with a jewelry design in mind and I've never had a problem setting stones in my self-made pieces. But I'm basically old-school and not totally up to date on current requirements. As a wire-wrapper I suspect you're concerned with that and maybe other things I'm not aware of. I'm not a wire-wrapper and never will be due to worsening arthritis in my hands. But I'd like to understand better what wire-wrappers' needs are so I can incorporate those elements into some of my cabs. TIA. Part of the video is done on a chalk board, he does lots of work at the wheel with no talking or with onscreen notes and he uses a lot of visuals. I think you could follow a lot, but maybe not all of it. Funny you should mention the girdle.... As a wire wrapper, I like a straight girdle. He mentions in the video that that is what wire wrappers prefer, but that the angled girdle will suit both a silversmith and a wrapper. He says a 15 degree girdle, but I have also seen 12 degree. I had been cabbing for myself and did straight girdles for me, but when I started selling cabs, I put a 12 to 15 degree angle on it. As for wire wrapping cabs, as I mentioned, many people like a straight girdle. But, that came up on the board here sometime back and a lot of wrappers said they liked an angled girdle. So, I think you are safe with an angle. I (and probably any competent wire wrapper) can easily wrap with an angle. I just prefer it straight. I also like the bottom back edge to have a small polish line to take off chips but not enough to accommodate a messy solder join. There is no easy way for me to explain why I don't like the solder cut, but I don't. I also prefer a girdle versus a high dome type cab that goes straight to the back with no easily distinguish girdle area. I like a thin girdle, not too thick- for wire wrapping, that is. Hope that helped.  |
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gemfeller
Cave Dweller
Member since June 2011
Posts: 3,546
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Post by gemfeller on Sept 13, 2016 18:28:32 GMT -5
Yes, it helped. Thanks. But I wonder what you mean about the messy solder join stuff. What size bevel do you have in mind?
Bottom edge chipping drives me nuts, especially with my new 60-grit sintered metal wheel that's supposed to cut like an 80-grit but seems much more aggressive. I'm continually having to move to the 180 sintered to cut finished outlines. It cuts very smoothly, like a 220, but removes accidental chipping. In the end I cut only a very tiny bottom edge bevel, usually with a 600 Nova, which should allow plenty of room for an average solder join -- at least mine. I can't imagine solder jobs so messy they require anything more. Is that common in your experience?
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Post by rockjunquie on Sept 13, 2016 20:40:33 GMT -5
Yes, it helped. Thanks. But I wonder what you mean about the messy solder join stuff. What size bevel do you have in mind? Bottom edge chipping drives me nuts, especially with my new 60-grit sintered metal wheel that's supposed to cut like an 80-grit but seems much more aggressive. I'm continually having to move to the 180 sintered to cut finished outlines. It cuts very smoothly, like a 220, but removes accidental chipping. In the end I cut only a very tiny bottom edge bevel, usually with a 600 Nova, which should allow plenty of room for an average solder join -- at least mine. I can't imagine solder jobs so messy they require anything more. Is that common in your experience? sending a pm |
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Post by bobby1 on Sept 21, 2016 9:05:10 GMT -5
When I'm breaking in a new grinding wheel where significant chipping will occur on the back edge I transfer the outline to the back side and grind from the back. Any chipping will be removed when you are shaping the cab. This is especially helpful when working obsidian cabs where the chipping will occur at almost any grit grinding wheel.
I use diamond grinding wheels and silicon carbide sanding belts on a 8" expando drum. I'm old fashioned about cabbing and I learned cabbing back when expandos were first introduced, about 50+ years ago.
Bob
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gemfeller
Cave Dweller
Member since June 2011
Posts: 3,546
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Post by gemfeller on Sept 21, 2016 10:44:24 GMT -5
Hi Bobby. I almost never use outlines/templates except when I'm cutting calibrated, which is seldom these days -- I used to cut lots of them. Most of my cab shapes are "eyeball" only to maximize pleasing patterns in the stone. I grind from the bottom as you do but often find chipping's reduced considerably when I do most of my stock removal by holding the preform edge against the wheel instead of cutting from the top or bottom. I leave plenty of room for final "chipless" outlining on the 180 sintered.
I'm old-fashioned too. I cut my first cabs in the days before wet sanding was available. I've always been an opal nut. I remember dry-sanding opals using the "touch" system. I'd sand a little, then hold the stone to my cheek or lips to make sure it wasn't overheating. I usually had 3-4 stones dopped that I sanded in rotation so I didn't waste time waiting for a single one to cool enough to proceed. Ditto agates and jaspers. Lapidary technology has come a long way since then, especially with the tremendously reduced cost of diamond abrasives. I polished my first star sapphires using a maple wood wheel and the very first diamond paste that was commercially available. I was still using carborundum grinding wheels and I remember that preforming the sapphires ate up wheels at a remarkable rate since the wheels were about the same hardness!
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ChicagoDave
has rocks in the head
Member since June 2016
Posts: 720
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Post by ChicagoDave on Jan 2, 2017 16:44:56 GMT -5
I just purchased this video and watched it today (ordered on a Tuesday and it was here on Friday). As a complete beginner, I think it was full of useful information and agree with everything Tela mentioned. I think it could have used a little more editing, but that's a minor complaint. Now I just need to figure out how to use this knowledge on a flat lap since I don't have a wheeled machine.
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Post by johnjsgems on Mar 7, 2017 20:46:52 GMT -5
First time I noticed this post. Jim is a great guy and glad you liked the video. He actually does use a two wheel arbor for cabbing. He had a sintered 80 or something when I saw it and then went from 120 through 50,000 diamond belts on the 8" X 3" expando. He always had a 10 x 20 tent full of cabs he cut. He is more into faceting now. He had a video on polishing on wood discs that could be adapted to the spool polishers but it is a very slow process. His video on drilling holes is another maddeningly slow video with many useful tips and watching over his shoulder as he drills in real time. Anybody that watches the video can definitely drill holes.
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Bon Appétit 
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