johnthor1963
starting to spend too much on rocks
Cattle dogs rock
Member since June 2023
Posts: 236
|
Post by johnthor1963 on Sept 1, 2024 14:33:05 GMT -5
I’m just kinda curious how everyone is polishing it. Early today I had a 8000 grit res wheel have a melt down. It scratched the two pieces I was working on. Took 30 minutes for me to find the colpert of the scratches lol. I also think I have some lower grade material. I normally go from 3000 grit to 80000 then 14000 grit wheel. I us sapphire powder on a canvas pad at the end. Looking for maybe some thing different. Thx for looking
|
|
gemfeller
Cave Dweller 
Member since June 2011
Posts: 4,068 
|
Post by gemfeller on Sept 1, 2024 15:13:41 GMT -5
I’m just kinda curious how everyone is polishing it. Early today I had a 8000 grit res wheel have a melt down. It scratched the two pieces I was working on. Took 30 minutes for me to find the colpert of the scratches lol. I also think I have some lower grade material. I normally go from 3000 grit to 80000 then 14000 grit wheel. I us sapphire powder on a canvas pad at the end. Looking for maybe some thing different. Thx for looking I think you may be right about lower grade material. Looks to me like your procedure should result in a great polish. I've found Lapis varies a lot in hardness and density. It's a rock, made of several minerals, and the specific composition can affect the polish quality. Some is quite porous and won't take a good polish. |
|
|
|
Lapis
Sept 1, 2024 20:45:37 GMT -5
Post by jasoninsd on Sept 1, 2024 20:45:37 GMT -5
I've only worked a few pieces of Lapis...but like Rick mentioned, different sources of rough can result in good or "ok" polishes depending on the composition. The pieces I worked refused to take a high shine...more of a satin/matte type finish...
|
|
johnthor1963
starting to spend too much on rocks
Cattle dogs rock
Member since June 2023
Posts: 236
|
Post by johnthor1963 on Sept 2, 2024 6:50:40 GMT -5
Thx for the replies, the material I have after closer examination it is rather open grained for a lack of a better word has a lot of silver speckles in it.
The 8000 grit rez wheel really left scratches on the surface of the material I went back 3 wheels and gently removed them. I’ve got a new one ordered. If it leaves scratches on an agate is just best to replace or can you refresh it with something? Hard to believe that 8000 grit can leave scratches lol.
Thx for sharing your knowledge, appreciate your time
|
|
|
|
Lapis
Sept 5, 2024 16:01:26 GMT -5
Post by jasoninsd on Sept 5, 2024 16:01:26 GMT -5
Thx for the replies, the material I have after closer examination it is rather open grained for a lack of a better word has a lot of silver speckles in it. The 8000 grit rez wheel really left scratches on the surface of the material I went back 3 wheels and gently removed them. I’ve got a new one ordered. If it leaves scratches on an agate is just best to replace or can you refresh it with something? Hard to believe that 8000 grit can leave scratches lol. Thx for sharing your knowledge, appreciate your time ...I had an 8000 flat lap disk that kept leaving scratches...I never could find the issue. After a bunch of debate on here about the problem, the general consensus was "high diamond clumping"...but even after every attempt to find them and knock them down, I never could fix the problem. You can try and run a hard agate (not worked) over the surface and see if that solves the problem...but it's a crapshoot as far as I'm concerned... |
|
johnthor1963
starting to spend too much on rocks
Cattle dogs rock
Member since June 2023
Posts: 236
|
Post by johnthor1963 on Sept 5, 2024 18:11:24 GMT -5
Jasoninsd lol I think I remember that I have since ordered a new wheel. I inspected the wheel on my bench looking for rogue diamonds nothing, I did put and agate across it th see if it would leave scratches and it did. My next thought was a rough agate that failed. New wheel time lol.
The short time that I have been doing this and trying to grind slow to achieve a consistent girdle all the way around the stone and when scratches show up like that you just never think take pictures of it. Thx for the comments looking forward to seeing more of your work
|
|
|
|
Post by jasoninsd on Sept 5, 2024 18:24:20 GMT -5
Jasoninsd lol I think I remember that I have since ordered a new wheel. I inspected the wheel on my bench looking for rogue diamonds nothing, I did put and agate across it th see if it would leave scratches and it did. My next thought was a rough agate that failed. New wheel time lol. The short time that I have been doing this and trying to grind slow to achieve a consistent girdle all the way around the stone and when scratches show up like that you just never think take pictures of it. Thx for the comments looking forward to seeing more of your work This was me after I couldn't figure out the problem! LOL  |
|
lapidary1234
spending too much on rocks
"If you like rocks you can't be all bad!!" ~ old timer quote
Member since October 2021
Posts: 325
|
Post by lapidary1234 on Sept 13, 2024 0:23:22 GMT -5
That is unfortunate. I still have a hard time believing that resin matrix discs or wheels can get contaminated. Maybe I'm wrong but no one has explained it in a satisfactory way to me.
I'm much more in the camp of uneven height of diamonds or even worse an uneven distribution of grit particles. For example it seems entirely possible to me that a small portion of the disc (even miniscuke) might have more of say something like a 1200 grit patch of diamonds rather than an uneven distribution of 8,000 grit. Thats my theory at least.
If someone believes they can explain how a resin disc could be contaminated please do so. I do understand if using a copper or tin master lap where you add loose grit that could cause contamination but nowadays folks don't seem to use those kind of laps as much.
Anyway, that's my thoughts!
|
|
... to the New Guys from The ChatBox V.2 Crew