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Post by hummingbirdstones on Jun 4, 2020 8:56:15 GMT -5
I'm also learning now how to polish the backs properly. I have a friend that swears he can do it on his 8” CK. Vince can polish a back on wheels, but I can't. It's tricky and takes a certain skill and technique which I apparently lack. I've tried a couple of times, but I was not successful. So I said to myself, "Self, this is why G_d made flat laps. You have one, use it!"
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Post by Drummond Island Rocks on Jun 4, 2020 10:05:46 GMT -5
Well, this doesn't look dead yet, so I'll add my 2 cents. As a wrapper, I can wrap a straight or angled girdle, so I cut with an angled girdle to make silversmiths happy. I think gemfeller is right. An accomplished, old school silversmith will prefer an angled girdle. I don't generally like the look of the bezel wire being turned over the top of the cab and would rather see a stone set with an angled girdle and the wire below the top. I have set both as a silversmith and prefer the angle. It doesn't need to be much. To me it isn't that difficult to do. I simply watch the angle of my dop stick. Grinding an angle is not hard to do but all of my cabs are calibrated shapes and or symmetrical shapes. If that angle is not 100% the same all the way around it messes with the shape at the front of the stone. For me the only way to accomplish it is to use an angled cab rest. I have not sold cabs in years and I only smith about 1/2 of a percent of my cabs so I generally do not bother with the angle. Chuck |
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Post by rockjunquie on Jun 4, 2020 10:14:05 GMT -5
Well, this doesn't look dead yet, so I'll add my 2 cents. As a wrapper, I can wrap a straight or angled girdle, so I cut with an angled girdle to make silversmiths happy. I think gemfeller is right. An accomplished, old school silversmith will prefer an angled girdle. I don't generally like the look of the bezel wire being turned over the top of the cab and would rather see a stone set with an angled girdle and the wire below the top. I have set both as a silversmith and prefer the angle. It doesn't need to be much. To me it isn't that difficult to do. I simply watch the angle of my dop stick. Grinding an angle is not hard to do but all of my cabs are calibrated shapes and or symmetrical shapes. If that angle is not 100% the same all the way around it messes with the shape at the front of the stone. For me the only way to accomplish it is to use an angled cab rest. I have not sold cabs in years and I only smith about 1/2 of a percent of my cabs so I generally do not bother with the angle. Chuck I wasn't singleing you out. Your bezel wires are always neat. Not everyone can say that.  |
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Post by rockjunquie on Jun 4, 2020 10:17:26 GMT -5
The use of a cab rest while grinding the girdle is key to keeping your shape from the template, maintaining the exact same angle all the way around the stone is the only way you’ll get that perfect round or oval. I like to sharpen my brass before I trace my template design leaving the thinnest line I can possibly deal with, for me this leave less room for error in grinding through part of the line and losing that perfect shape. I also sharpen my brass and draw my girdle line before dopping, keeping the girdle height exactly the same around the entire stone is equally important in getting that perfect shape on the face of the cab. I use a pencil for a thin line. Works for me. I dop on the back of the cab. I know a lot of people do not and I don't know how much of a difference it makes. I have never used a cab rest and don't intend to, but I have very consistent girdle lines and angles and I can cab a calibrated cab and do circles and ovals just fine. Everyone is different.
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julieooly
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Post by julieooly on Jun 4, 2020 10:36:21 GMT -5
I go back and tidy up my girdle height after I'm done with the 3,000. I use a sharpie paint marker to create a layer of paint on the top of the edge cab and the topmost part of the girdle line. Then, I eyeball the highest point in the girdle and set my calipers to that height and lock them. Then I very carefully drag the side of my metal calipers against where the top of the girdle should be and get a little fine line at the perfect height, this was difficult to perfect and so I'd love to hear more ways of doing it. The cab is not damaged as the point of the dragging is just to remove the paint, and in the off chance the cab is scratched this line becomes a part of the girdle anyway so that's not an issue. Keep in mind my cabs are on dopsticks at this point, any advice?.
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gemfeller
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Post by gemfeller on Jun 4, 2020 11:04:02 GMT -5
I have a friend that swears he can do it on his 8” CK. Vince can polish a back on wheels, but I can't. It's tricky and takes a certain skill and technique which I apparently lack. I've tried a couple of times, but I was not successful. So I said to myself, "Self, this is why G_d made flat laps. You have one, use it!" I do it routinely on my Genie but the technique's easier to do than explain. Vince and I share a background in opal cutting and I think that experience may be key. Learning how to manipulate the stone with your fingers without damaging your delicate digits is part of the opal-cutting learning curve. And that's what's needed to learn how to polish cab backs on wheels I think. |
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Post by stardiamond on Jun 4, 2020 11:14:46 GMT -5
Well, this doesn't look dead yet, so I'll add my 2 cents. As a wrapper, I can wrap a straight or angled girdle, so I cut with an angled girdle to make silversmiths happy. I think gemfeller is right. An accomplished, old school silversmith will prefer an angled girdle. I don't generally like the look of the bezel wire being turned over the top of the cab and would rather see a stone set with an angled girdle and the wire below the top. I have set both as a silversmith and prefer the angle. It doesn't need to be much. To me it isn't that difficult to do. I simply watch the angle of my dop stick. Grinding an angle is not hard to do but all of my cabs are calibrated shapes and or symmetrical shapes. If that angle is not 100% the same all the way around it messes with the shape at the front of the stone. For me the only way to accomplish it is to use an angled cab rest. I have not sold cabs in years and I only smith about 1/2 of a percent of my cabs so I generally do not bother with the angle. Chuck When I grind the preform, I don't try to make the edges square. When I am done doming through 280 soft, I square the girdle line. I grind vertically to remove most of the material and then horizontally watching the shape on the top. It helps me do a better job on the shape of the top. The bottom is easy because I just have to stay outside the pencil line an even amount. |
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Post by rockjunquie on Jun 4, 2020 13:43:29 GMT -5
Vince can polish a back on wheels, but I can't. It's tricky and takes a certain skill and technique which I apparently lack. I've tried a couple of times, but I was not successful. So I said to myself, "Self, this is why G_d made flat laps. You have one, use it!" I do it routinely on my Genie but the technique's easier to do than explain. Vince and I share a background in opal cutting and I think that experience may be key. Learning how to manipulate the stone with your fingers without damaging your delicate digits is part of the opal-cutting learning curve. And that's what's needed to learn how to polish cab backs on wheels I think. I have gotten close, but I have never gotten a truly uniform polish on the back with a wheel. SO, I got myself a spin-on 600 for the right hand. |
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Post by stardiamond on Jun 4, 2020 14:07:23 GMT -5
Figure eights. I can sand and polish relatively flat. I can't get absolutely flat doing figure eights on the 80 grit, so I ordered and 80 grit end lap and it is currently somewhere in China. I have a few finer end laps but don't use them.
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Post by hummingbirdstones on Jun 4, 2020 20:17:45 GMT -5
Vince can polish a back on wheels, but I can't. It's tricky and takes a certain skill and technique which I apparently lack. I've tried a couple of times, but I was not successful. So I said to myself, "Self, this is why G_d made flat laps. You have one, use it!" I do it routinely on my Genie but the technique's easier to do than explain. Vince and I share a background in opal cutting and I think that experience may be key. Learning how to manipulate the stone with your fingers without damaging your delicate digits is part of the opal-cutting learning curve. And that's what's needed to learn how to polish cab backs on wheels I think. Um, Rick? I coached Vince on opal cutting when he was first learning.  |
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Post by rockjunquie on Jun 4, 2020 20:43:12 GMT -5
I do it routinely on my Genie but the technique's easier to do than explain. Vince and I share a background in opal cutting and I think that experience may be key. Learning how to manipulate the stone with your fingers without damaging your delicate digits is part of the opal-cutting learning curve. And that's what's needed to learn how to polish cab backs on wheels I think. Um, Rick? I coached Vince on opal cutting when he was first learning.  A girl can never get a break. LOL!  |
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Post by knave on Jun 4, 2020 20:44:06 GMT -5
Now if you girls protest, please do it peacefully.
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gemfeller
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Post by gemfeller on Jun 4, 2020 20:44:30 GMT -5
I do it routinely on my Genie but the technique's easier to do than explain. Vince and I share a background in opal cutting and I think that experience may be key. Learning how to manipulate the stone with your fingers without damaging your delicate digits is part of the opal-cutting learning curve. And that's what's needed to learn how to polish cab backs on wheels I think. Um, Rick? I coached Vince on opal cutting when he was first learning.  Well how come you can't polish cab backs on your Genie wheels?  I knew you were both opal cutters but several times you've posted about Vince's dexterity on the wheels when cutting, and when you said you'd resorted to a flat lap I drew the wrong conclusion. Mea culpa! |
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Post by hummingbirdstones on Jun 4, 2020 21:14:13 GMT -5
Um, Rick? I coached Vince on opal cutting when he was first learning. Well how come you can't polish cab backs on your Genie wheels? I knew you were both opal cutters but several times you've posted about Vince's dexterity on the wheels when cutting, and when you said you'd resorted to a flat lap I drew the wrong conclusion. Mea culpa! No worries - I was teasing you. I just can't move my fingers like Vince does to do that. Especially now with some arthritis setting in. I just use my flat lap (which is what I started cutting opal on). Lots easier for me. |
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