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Post by jasoninsd on Apr 30, 2021 0:26:15 GMT -5
So, I'm wondering why scratches are being caused by my 8000 and my 14,000 grit wheels? I need you to trust me when I say with 100% certainty the scratches are NOT there prior to these two stages. I have looked at the cabs through the loupe to ensure the scratches are gone at the 500 stage, the 1200 stage, and the 3000 stage. I have an idea it has to do with the types of disks I'm using, but I'd like to understand WHY this is happening... I have a Hi-Tech Diamond 8" Slant Cabbber. The 80 grit and 180 grit are Electroplated Diamond Laps (https://hitechdiamond.com/collections/diamond-discs/products/electroplated-diamond-laps)  The 220 grit, 325 grit, 600 grit, 1200 grit, and 3000 grit are the Hi-Tech Diamond Smoothing Disks (https://hitechdiamond.com/collections/diamond-discs/products/diamond-smoothing-discs)  I purchased the 8000 and 14,000 grit Eastwind Diamond Discs from Kingsley North (https://kingsleynorth.com/eastwind-diamond-disc-8-psa-backing.html)  All the smoothing disks and the Eastwind Diamond Discs have a sponge pad backing on them. I have broken in the disks with Brazilian Agate and Blackskin Agate to no avail. I contacted Eastwind, who sent me a dressing stick. I dressed the disks accordingly, but that did not work. I still get scratches on my cabs! Eastwind is saying there is nothing wrong with the disks and the diamonds are not clumped nor are they high. They are stating I can't use their particular disks after using the Hi-Tech Diamond Smoothing Disks. It makes no sense to me why an 8000 grit disk would be creating scratches SO DEEP that I have to take the cab back down to the 500 grit in order to get them out. I did try the 1200 to remove them, but they were too deep for the 1200. Can anyone explain to me if I just wasted $140 (plus) for 8000 and 14,000 that I can't use? Or, is there something I should be or could be doing differently? |
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Post by rockjunquie on Apr 30, 2021 6:31:14 GMT -5
Sounds to me like contamination. I'd take a scrub brush and dish soap to those puppies and give it another go. That might just work.
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Post by jasoninsd on Apr 30, 2021 6:52:50 GMT -5
Sounds to me like contamination. I'd take a scrub brush and dish soap to those puppies and give it another go. That might just work. That's definitely something to consider. I'll give that a go...but... My gut is telling me it isn't cross-contamination. I ran so much water on this while using the dressing stick, it almost filled up my 5-gallon waste bucket. Well, maybe not that much...LOL...but I had the water pouring out onto the disk while dressing it. I will clean them up though, just to see one way or another.  It's just gnawing at me wondering if there is an issue moving from the 220-3000 grit "smoothing" disks and going back to 8000 and 14,000 Diamond Disks? In my mind, the move from 3000 to 8000 of any kind of disk shouldn't be an issue...but with the two different types of disks, is that where there's an issue...and if so, I'm wondering why? |
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Brian
fully equipped rock polisher
Member since July 2020
Posts: 1,512
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Post by Brian on Apr 30, 2021 7:52:27 GMT -5
Eastwind is saying there is nothing wrong with the disks and the diamonds are not clumped nor are they high. They are stating I can't use their particular disks after using the Hi-Tech Diamond Smoothing Disks. Did they give any reason why you cannot use their disks after using the Hi-Tech disks? Assuming there is no contamination, it seems like the only other explanation would be in how the diamonds are bound and how they are exposed. For example, if the diamonds are embedded deeply in one disk but more surface bound in the other disk, it seems plausible that the smaller grit could expose more of the diamond for cutting compared to a larger grit that is more deeply embedded. Another possibility could be in the shape/sharpness of the diamonds used by different companies. If Eastwind is using diamonds with more aggressive cutting edges than Hi-Tech, that could also make a difference. Sort of like going from SiC to AlOx in tumbling where you could use the same grit and get much different results. That’s my uneducated guess anyway, but I am curious why they said they cannot be used. |
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Post by jasoninsd on Apr 30, 2021 8:28:17 GMT -5
Eastwind is saying there is nothing wrong with the disks and the diamonds are not clumped nor are they high. They are stating I can't use their particular disks after using the Hi-Tech Diamond Smoothing Disks. Did they give any reason why you cannot use their disks after using the Hi-Tech disks? Assuming there is no contamination, it seems like the only other explanation would be in how the diamonds are bound and how they are exposed. For example, if the diamonds are embedded deeply in one disk but more surface bound in the other disk, it seems plausible that the smaller grit could expose more of the diamond for cutting compared to a larger grit that is more deeply embedded. Another possibility could be in the shape/sharpness of the diamonds used by different companies. If Eastwind is using diamonds with more aggressive cutting edges than Hi-Tech, that could also make a difference. Sort of like going from SiC to AlOx in tumbling where you could use the same grit and get much different results. That’s my uneducated guess anyway, but I am curious why they said they cannot be used. Thanks for chiming in Brian.  Here's an excerpt from the email communication I had with Eastwind: "After talking with Joe about the disks you are having an issue with scratching and what steps you are taking prior to using our 8 Inch Disks 8,000 & 14,000 Mesh. He advises that the High Tech Diamond Disks are non aggressive compared to our disks so when you go from non aggressive disks to a disks that are more aggressive you are going to have an issue. He suspects that there were most likely scratches that may not have been visible prior to using our disks so that when you transferred to our disks they are exposing the scratches." It bothered me that the "solution" was stated that scratches were being "exposed" when going to the 8000 disk. I know that is NOT what's happening. I know the 8000 and the 14,000 are CAUSING scratches in the cabs. I guess I'm trying to make educated guesses myself, I just can't fathom how an 8000 grit disk from Eastwind can be "more aggressive" than a 500 grit disk from Hi-Tech. I just assumed the levels of "grit" would be somewhat uniform across the spectrum of manufacturers (give or take a little as the grits get finer - as in plus or minus 100 grit as the grits get into the thousands)...somewhat similar to sandpaper grits. "60 grit sandpaper is 60 grit sandpaper - and 220 grit is 220 grit, etc. regardless of who's producing it" kind of mentality... |
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Post by mohs on Apr 30, 2021 8:40:20 GMT -5
Very precise descriptions & you have your technique down agree Eastwind analysis is less than satisfying Mohs solution would be Quit looking through the loupe  Am interested in what type of dressing stick they sent Could you post a picture of it ? |
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Post by rockjunquie on Apr 30, 2021 8:40:30 GMT -5
I don't get their convoluted answer- AT ALL. You are right. It doesn't make any sense. BUT, a soft wheel will conform to a stone- if you picture it, the diamonds can NOT dig as deep by the very nature of the soft base. The diamonds on a hard disc, which has no give, will dig deeper, right? Seems like it anyway. But that shouldn't at all matter because of the difference in the grit sizes. So, I am agreeing with you- something ain't right.
How do you store your discs? (Individually, I'm sure.) I had to put that out there for anyone reading. ALWAYS store separately.
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Post by jasoninsd on Apr 30, 2021 8:56:39 GMT -5
Very precise descriptions & you have your technique down agree Eastwind analysis is less than satisfying Mohs solution would be Quit looking through the loupe Am interested in what type of dressing stick they sent Could you post a picture of it ? Thanks Ed. Heck, the new scratches are deep enough to be seen with the naked eye... I've included a pic of the dressing stick. I don't get their convoluted answer- AT ALL. You are right. It doesn't make any sense. BUT, a soft wheel will conform to a stone- if you picture it, the diamonds can NOT dig as deep by the very nature of the soft base. The diamonds on a hard disc, which has no give, will dig deeper, right? Seems like it anyway. But that shouldn't at all matter because of the difference in the grit sizes. So, I am agreeing with you- something ain't right.
How do you store your discs? (Individually, I'm sure.) I had to put that out there for anyone reading. ALWAYS store separately.
Thanks Tela. The disks from Eastwind are backed by a sponge pad...they're not solid like the 80 and 180 disks. So, they should be conforming to the dome the same as the Hi-Tech disks... I actually use a dish drainer for storage, so each of the disks are not touching each other (like plates in the dish drainer)...  |
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standles
spending too much on rocks
Well all I got was a rock ... Cool!
Member since February 2021
Posts: 325 
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Post by standles on Apr 30, 2021 8:58:03 GMT -5
Have you taken the loupe to the disc themselves to see if there is an issue with them. Maybe something got under the disc when applied to pad but u think the dressing would have gotten that.
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Post by mohs on Apr 30, 2021 9:05:34 GMT -5
 thanks for posting that those are good dressing sticks they are the ones that was sent sent w/ my diamond wheel on the twice as sharp something wrong.... something not quite right 
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Post by jasoninsd on Apr 30, 2021 9:10:20 GMT -5
Have you taken the loupe to the disc themselves to see if there is an issue with them. Maybe something got under the disc when applied to pad but u think the dressing would have gotten that. Good thoughts. No, I haven't taken a loupe to the disks. I can do that here in a few minutes. I would've thought the sponge pad underneath the disks would solve any issue if something were to have somehow gotten underneath the disks when being applied. Again, these aren't "rigid" - they're backed with that spongy pad... |
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Post by jasoninsd on Apr 30, 2021 9:22:35 GMT -5
Have you taken the loupe to the disc themselves to see if there is an issue with them. Maybe something got under the disc when applied to pad but u think the dressing would have gotten that. So I just inspected the 8000 with the loupe, and see no irregularities in the surface. I'm assuming I'd be likely to see a "high" diamond, or a clump of diamonds, and I saw nothing that resembled that... thanks for posting that those are good dressing sticks they are the ones that was sent sent w/ my diamond wheel on the twice as sharp something wrong.... something not quite right I figured it was a pretty decent one since it came directly from the manufacturer...so I know the dressing stick "shouldn't" be to blame... |
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Post by mohs on Apr 30, 2021 9:25:59 GMT -5
what kind of pressure are you applying
when fine grinding on the wheel's give ?
on the Nova wheels I really get on that stone
into the give of the wheel
then lighten up towards the the end of the cycle
under pressure to figure this out ....
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Post by jasoninsd on Apr 30, 2021 9:32:23 GMT -5
what kind of pressure are you applying when fine grinding on the wheel's give ? on the Nova wheels I really get on that stone into the give of the wheel then lighten up towards the the end of the cycle under pressure to figure this out .... I tried to use a light/moderate touch...got scratches. I used a heavier pressure...still get scratches... I've tried running the cab with moderate amounts of water...I've tried it with tons of water...scratches happening both ways. |
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Post by hummingbirdstones on Apr 30, 2021 9:38:52 GMT -5
I have used the Eastwind discs after the Hi-Tech ones and I have only had a problem once, I think. That was contamination and Vince got it out.
What Eastwind is talking about is subsurface damage. I know I posted a link to it before, but it is, in fact, a real thing. Here are a couple of articles regarding subsurface damage by Steve Attaway. These are with regards to faceting, but stones are stones and they should also apply to cabbing.
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Post by HankRocks on Apr 30, 2021 9:40:04 GMT -5
It almost sounds like an oversized renegade diamond(s?) infiltrated the manufacturing process and you now have a corrupted wheel.
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Post by hummingbirdstones2 on Apr 30, 2021 9:48:17 GMT -5
Robin shared a trick from the faceting world with me that has seemed to work in the past.
Get a white gum eraser and run it over the laps. I used one with the machine turning just fast enough to keep the motor from bogging down.
We keep our laps in individual plastic bags, and I still had that same problem a while back. The eraser was the last step in a vigorous cleaning that included the usual scrubbing with a denture brush, etc. Something finally worked, and the eraser was the only new addtition to the process.
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Post by mohs on Apr 30, 2021 10:00:05 GMT -5
Interesting article Robin
What little I could peruse
this busy morn
Quick thought
Perhaps some stones
Have a higher chance
To undercut with finer grits>
In example
the finer grits have a tendency to rip out
looser micro grains in the stone ?
time to ride
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Post by jasoninsd on Apr 30, 2021 10:02:57 GMT -5
I have used the Eastwind discs after the Hi-Tech ones and I have only had a problem once, I think. That was contamination and Vince got it out.
What Eastwind is talking about is subsurface damage. I know I posted a link to it before, but it is, in fact, a real thing. Here are a couple of articles regarding subsurface damage by Steve Attaway. These are with regards to faceting, but stones are stones and they should also apply to cabbing.
Robin, thank you! I remember reading that second article you posted and it totally stuck with me. In fact, that's when I started getting a better polish on my cabs was after understanding the issue with "subsurface" fracturing. I started spending a bit more time in each stage of grit in order to make sure I was removing enough surface layer to proceed to the next step. I know this is not a subsurface issue. There is something on these disks that is "gouging" into the cab... It almost sounds like an oversized renegade diamond(s?) infiltrated the manufacturing process and you now have a corrupted wheel. Thanks Henry. When I spoke with Eastwind, they stated they had not had any other complaints from anyone else about any corrupted disks...which doesn't mean I didn't get a couple though. Robin shared a trick from the faceting world with me that has seemed to work in the past.
Get a white gum eraser and run it over the laps. I used one with the machine turning just fast enough to keep the motor from bogging down.
We keep our laps in individual plastic bags, and I still had that same problem a while back. The eraser was the last step in a vigorous cleaning that included the usual scrubbing with a denture brush, etc. Something finally worked, and the eraser was the only new addtition to the process.
Thanks Vince. I will do this. I'm going to clean the disks really well (per Tela's original advice), and will have my wife pick up a white gum eraser when she's downtown today. I don't have any cabs ready at the moment to try to use these disks, so I'll try to make a couple cabs later today and will try to see if the issue still persists sometime this evening. |
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Post by jasoninsd on Apr 30, 2021 10:06:42 GMT -5
Interesting article Robin What little I could peruse this busy morn Quick thought Perhaps some stones Have a higher chance To undercut with finer grits> In example the finer grits have a tendency to rip out looser micro grains in the stone ? time to ride Good thought Ed. I have experienced the "undercutting" on cabs...but I really don't believe this is an undercutting issue. The scratches are linear - they're following the spinning of the disk...I can change the direction of the scratches by turning the cab 90 degrees. That's how I knew "something" in the disk itself was causing the scratching... |
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