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Post by holajonathan on Nov 24, 2021 14:14:56 GMT -5
I spent a long time on the 220 hard wheel with a very light touch, and the 280 soft wheel with a heavy hand. With RIJ, I sometimes struggle with tiny sub-surface fractures caused by the hard wheels. These little fractures looks like tiny scratches, but they don't show up until the 1200 or 3000 resin wheels and you can't sand them out with a 280 soft wheel. I have a 140 grit soft wheel that is helpful in this regard, but I don't usually have it mounted. Another option that I want to explore is a 400 or 500 grit hard wheel to remove something like 0.1-0.2mm of material over the entire face of the cab after finishing up with the 220 hard wheel. Does anyone have experience using such a fine grit hard wheel for cabbing? Here's the cab:   Cat approved  |
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Post by rockjunquie on Nov 24, 2021 14:25:28 GMT -5
That is really beautiful.  Great specimen and great cab.
I have no experience with the finer grit hard wheels. Do you use the 220 soft?
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Post by knave on Nov 24, 2021 14:30:44 GMT -5
That is very lovely.
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Post by Starguy on Nov 24, 2021 16:22:41 GMT -5
holajonathan I’ve got a 600 grit hard wheel on my old 6” arbor. It’s pretty handy. I use it mostly for the final shaping on garnets. I also like to use it for beveling the bottom edge of cabs.
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nik
spending too much on rocks
Member since May 2019
Posts: 315
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Post by nik on Nov 24, 2021 16:53:44 GMT -5
I've got 400 and 600 grit hard wheels for the occasional soft or fragile stone. They usually just live on a hook under the bench, but when you need them they are nice to have in the progression.
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Post by jasoninsd on Nov 24, 2021 18:03:15 GMT -5
Beautiful cab Jonathan. I like the way you chose to follow the pattern for the perimeter of the cab. I don't have the selection of wheels (disks), so I can't comment with regards to your questions...well...I can...but it wouldn't be based on any factual evidence.  |
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Post by holajonathan on Nov 24, 2021 18:35:09 GMT -5
That is really beautiful. Great specimen and great cab.
I have no experience with the finer grit hard wheels. Do you use the 220 soft?
I have a 140 soft and a 280 soft. The 140 is great for really hard materials, in which case it performs like a 280 performs on somewhat softer material. The 140 would have been great for the Royal Imperial Jasper, but I don't have it mounted most of the time. My original Nova wheels are still going strong after at least a couple hundred cabs. The 280, 600, and 1200 don't have much texture left on the surface, but they still have the original color and they still sand. I actually like how they feel better now that they are well worn. It makes sending silky-smooth and more precise. I can see why 220 soft is ideal, but unfortunately DP stopped making them. I would try a third-party 220 soft if I can find one as soft and flexible as the Nova wheels (and even half as durable). Any recommendations? I have tried all 3 grades of the Baltic Abrasives (Lithuanian) soft wheels. The quality and durability are fine, but none are as flexible as a Nova wheel. |
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Post by holajonathan on Nov 24, 2021 18:40:13 GMT -5
I think part of my problem is that I am using a textured 220 wheel from Baltic Abrasives. It was so aggressive when I got it that I must have domed 20 Montana agate cabs entirely with the 220 textured wheel just to break it in. I've gotten it broken in to an extent, but it is still much more aggressive than a 220 Galaxy or my 220 sintered. Maybe 220 textured is just a bad idea.
Baltic Abrasives must use a high concentration of high quality diamonds on their hard wheels. They cut fast compared to Galaxy wheels. I've got one of their 100 grit textured wheels as well, and it still grinds like a 60 after trying my best to break it in with heavy handed grinding on numerous Montana agates.
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Post by holajonathan on Nov 24, 2021 18:48:34 GMT -5
Beautiful cab Jonathan. I like the way you chose to follow the pattern for the perimeter of the cab. I don't have the selection of wheels (disks), so I can't comment with regards to your questions...well...I can...but it wouldn't be based on any factual evidence. With Royal Imperial Jasper the nature of the rock doesn't leave much choice but to follow the pattern of the rock. The outside of the nodules is really soft and chalky, and it gets harder and you approach the colored jasper. To grind a preform, I basically just spin the girdle edge against a hard wheel until all of the chalky rocks comes off like mud. Once I've hit decently hard material on all edges, I stop. At that point the cab shape automatically follow the pattern, if that makes sense. The fact that the edges of the dome remain a little softer than the colored jasper in the middle is kind of nice because it makes it easy to grind a really precise girdle line. |
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Post by rockjunquie on Nov 24, 2021 18:58:06 GMT -5
That is really beautiful. Great specimen and great cab.
I have no experience with the finer grit hard wheels. Do you use the 220 soft?
I have a 140 soft and a 280 soft. The 140 is great for really hard materials, in which case it performs like a 280 performs on somewhat softer material. The 140 would have been great for the Royal Imperial Jasper, but I don't have it mounted most of the time. My original Nova wheels are still going strong after at least a couple hundred cabs. The 280, 600, and 1200 don't have much texture left on the surface, but they still have the original color and they still sand. I actually like how they feel better now that they are well worn. It makes sending silky-smooth and more precise. I can see why 220 soft is ideal, but unfortunately DP stopped making them. I would try a third-party 220 soft if I can find one as soft and flexible as the Nova wheels (and even half as durable). Any recommendations? I have tried all 3 grades of the Baltic Abrasives (Lithuanian) soft wheels. The quality and durability are fine, but none are as flexible as a Nova wheel. I tried a Baltic soft wheel and didn't like it, at all. Johnson Brothers does have what they call Super Novas. I didn't want to shop with them again, but I won't be without a 220 soft, so with knave's good recommendation, I went ahead and got their 220 soft. Now, take this with a grain of salt because I haven't mounted it or used it... but I can't tell the difference between it and a Nova. It is nice and squishy and feels rubbery like a Nova- unlike the Baltic I had. From what I can tell, I'll be happy. I have a newish 220 Nova already, but I wanted to get ahead of the curve in case it isn't there when I need it.
I'll attach a picture in my next post.
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Post by rockjunquie on Nov 24, 2021 18:59:20 GMT -5
I'm applying moderate pressure. Hope you can see that it is indented a bit- as much as a Nova would.
ETA- I have nail psoriasis, so don't judge my funky nail.
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Post by holajonathan on Nov 24, 2021 19:25:55 GMT -5
I'm applying moderate pressure. Hope you can see that it is indented a bit- as much as a Nova would.
ETA- I have nail psoriasis, so don't judge my funky nail.
It does look just like a Nova. I'm going to buy one right now. I have two-toned hands (vitiligo) and dirty nails half the time (no good excuse). Your hands make beautiful cabs which is good enough for me. |
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Post by holajonathan on Nov 24, 2021 19:29:31 GMT -5
Johnson Bros says it's made in the USA. If so, it is very possible likely that it is either made by a company that makes the Nova wheels for DP, or at least some of the components (foam / resin belt?) come from the same supplier. That seems far more likely than Johnson Brothers sourcing wheels from an entirely different USA company. I can't imagine there are more than one or two companies in the country making resin lapidary wheels...
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Post by rockjunquie on Nov 24, 2021 19:31:42 GMT -5
Johnson Bros says it's made in the USA. If so, it is very possible likely that it is either made by a company that makes the Nova wheels for DP, or at least some of the components (foam / resin belt?) come from the same supplier. That seems far more likely than Johnson Brothers sourcing wheels from an entirely different USA company. I can't imagine there are more than one or two companies in the country making resin lapidary wheels... I wouldn't be surprised if they do it. They do recoating, after all. |
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Post by rockjunquie on Nov 24, 2021 19:32:59 GMT -5
Can't beat their price on it, either. I got free shipping, too. Sweet!
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Post by holajonathan on Nov 24, 2021 19:38:39 GMT -5
I just got a 220 and 600 Supernova. I can't believe DP lets them sell a resin wheel called a Supernova. Maybe DP doesn't have the Nova name trademarked. My basic understanding of intellectual property law is that you can't just add the word "Super" to a competitor's trademarked name.
At checkout, I was reminded why I have mixed feelings about JB: "please allow 5 days for order processing."
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Post by rockjunquie on Nov 24, 2021 19:45:31 GMT -5
I just got a 220 and 600 Supernova. I can't believe DP lets them sell a resin wheel called a Supernova. Maybe DP doesn't have the name trademarked. At checkout, I was reminded why I have mixed feelings about JB: "please allow 5 days for order processing." 5 days? Really? I got mine pretty quick. At least, they don't charge for credit cards and Paypal payments, anymore. |
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Post by Pat on Nov 24, 2021 19:48:15 GMT -5
Your cab is lovely, and your cat is darling. 🙂
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Post by Son Of Beach on Nov 24, 2021 20:09:09 GMT -5
I know you are striving for perfection, but I think you have an excellent cab going already.
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Post by hummingbirdstones on Nov 24, 2021 20:21:55 GMT -5
When you get that soft 220 from Johnson Bros., please post a review.
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Great specimen and great cab.
