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Post by stardiamond on Aug 26, 2014 22:30:33 GMT -5
I am self taught and have a problem getting a sharp clean line between the face and the girdle.
I grind the shape and then mark the girdle line. My girdles tend to bow out to the face. I grind to the girdle line and then when the face is domed to the girdle line at 280 grit, I square off the girdle. Sometimes my cut girdle line is ok and sometimes it is a little wavy. What is worse is that sometimes there are scratches where the face meets the girdle that I can't see until I'm done polishing. I have two cabs that I made the third attempt at fixing. I thought it was because I don't dop, but even though I superglued dopsticks to these cabs, I had the same issue. One thing I learned today was to run a pencil along the edge and the scratches and other flaws really stand out. This is going to save me a lot of time having to go back after polishing, I also ordered a 2x visor with a 10" focal length so I might see better when cutting.
It seems with the visors the more magnification the shorter the focal length so I had to figure out how close I stick my face to the wheels. I decided that 10" 2x was the best compromise. My wife bought a lot of cabs way back when and I studied the finished product. I noticed that a lot of cabs had the girdle line rounded. This helps smooth out the waviness. I think my strength is composition but my cutting ability is C+ to B-. Maybe a B on a good day.
Like everyone else I'mm looking to improve. A critique would be helpful. Everyone has limitations on their skill level but I don't think I have reached my limit.
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Post by parfive on Aug 26, 2014 22:46:13 GMT -5
Get a 10x loupe.
Do not leave the 280 wheel until the cab is flawless.
That’s it.
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Post by Drummond Island Rocks on Aug 27, 2014 7:50:29 GMT -5
Cabs with a rounded over girdle may have been cabbed then tumble polished. I run a lot of my agate and jasper cabs through the vibe tumbler after cabbing to get a uniform polish front to back but then I go back to the genie and sharpen/polish the girdles. A rounded over girdle is difficult to wire warp because the wires keep wanting to slip over the edge.
Chuck
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QuailRiver
fully equipped rock polisher
Member since May 2008
Posts: 1,634
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Post by QuailRiver on Aug 27, 2014 10:34:48 GMT -5
Maybe I misread but it seems like you're intending to use the visor to examine the stone while cutting the girdle with your face close to the wheel? If I am reading that correctly please keep in mind that the mist coming off the wheels will have stone residues including silica that shouldn't be breathed. I few years back I developed a rare eye condition called Central Serous Retinopathy in my dominant eye. Fortunately I was one of the 20% who recovered without surgery but it left me with mild distorted vision in that eye. When faceting I was having to wear magnifying visors and cut with my face close to the lap to be able to see well enough. Even though mist wasn't really that visible I noticed that after cutting for a while I would begin tasting the rock swarf so I knew I was breathing it. Having been a potter too I was aware of the dangers of silicosis. So I had my eye doctor write me a prescription for a pair of low magnifying bifocals that have focal ranges at 18" for use while cutting, and 6" for close-up examinations. On a normal pair of bifocals the shorter range of focus is on the lower half of the lenses and the long range at the upper half which would be awkward for gem cutting. So the optometrist who made the glasses was able to calculate the prescription where the longer 18" range was on the lower half of the lenses and the 6" range on the upper half. These work well for what I need but when doing any lapidary work that kicks up a lot of mist I still wear a disposable dust mask. I like these the best: www.zoro.com/i/G0660974/?gclid=CJKErvbhs8ACFa_m7Aod2HEABg
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Post by stardiamond on Aug 27, 2014 11:15:58 GMT -5
I cut everything with a lot of water. My face won't be significantly closer wearing the goggles than it was before. I always cut with eye protection and the goggles should be better than the readers I currently use.
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Post by pghram on Aug 27, 2014 14:02:09 GMT -5
I don't have a girdle line, I bring the dome all the way to the bottom of the cab, with the appropriate angle.
Rich
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Post by gingerkid on Aug 27, 2014 18:55:06 GMT -5
Hi, stardiamond, are you cabbing on a flat lap or wheels? If you're cabbing using wheels, do you use a cabbing armrest?
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Post by stardiamond on Aug 27, 2014 19:10:15 GMT -5
Hi, stardiamond, are you cabbing on a flat lap or wheels? If you're cabbing using wheels, do you use a cabbing armrest? All my cabbing is done with wheels. My stardiamond machine has a steel bar that I need to reach over, but I wouldn't consider it a rest. My hands ares steady, but my vision isn't great and my touch is just ok. Also, not dopping can make moving the stone awkward.
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