Lapidaryforum.net
Rock Art => Cabochons, Intarsias, Cameos => Topic started by: Mossagatemac on February 13, 2020, 09:05:17 PM
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Hi everyone, I'm still getting the hang of cabbing and would appreciate some advice. When I do my final polish, if the stone has some pitting or maybe some undercutting, the stone seems to picks up some of the polish. It shows up as little white dots and doesn't wash off very well.
Any techniques to avoid this? Or how to clean it off after it happens?
I'm using micro alumina on leather. Specifically Covington gold #2.
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That can be hard to remove. A fine brush and soap; try something fizzy, maybe carbonated water. I hate it when that happens.
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If mechanical cleaning like fine brushes or soda water doesn't work... maybe Sodium Hydroxide cleaner? I know it attacks aluminium, but it's nasty stuff and you should wash everything it touches with detergent after using.
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Also if going the chemical route - depending on the stone, rub in some sodium bicarbonate and add pour on a little vinegar. If desperate, some ink or watercolor, rub in, rinse surface. Lol
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A classic case for an ultrasonic cleaner.
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Thanks I'll give some of those a try.
Can you recommend any techniques to prevent this? Maybe use a different polish or technique or something?
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Stop using oxide polishes.
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Stop using oxide polishes.
What would you recommend?
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Rub the stone with a bar of soap before pre polish the soap will fill the cavities,polish stone and wash clean. :brushteeth:
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i was going to say wax would do similar. Another option is seal the pores prior to 1200 grit with either Super glue or other sealant (hxtal, Opticon etc..) Stones like Sagenite and Rutilated Quartz that are famous for picking up ozides in the ends of the needles often need this type of treatment.
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ultrasonic cleaner
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from Rock&Gem June 2019 "Bench Tips":ultrasonic with dish soap and ammonia. Also from the article: not for opal or porous stones.
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Definitely the ultrasonic. It just takes a few seconds to get the polish out but you must not let the polish dry out before you start any cleaning activities. I wrote the article.
Bob
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I would use a ultrasonic cleaner as a first choice but a dry cleaning spot cleaner might also work. The spot cleaner was about $50 a few years ago.
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Luckily for me my darling wife lashed out and bought herself a new ultrasonic for her jewellery workshop, and gave me her old one....definitely is the go!
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If mechanical cleaning like fine brushes or soda water doesn't work... maybe Sodium Hydroxide cleaner? I know it attacks aluminium, but it's nasty stuff and you should wash everything it touches with detergent after using.
I would not advise sodium hydroxide. First of all it is quite caustic so not really safe to be playing with unless you know what you are doing.
Secondly it will attack aluminum metal forming aluminum hydroxide, not aluminum oxide that is the dry version of aluminum hydroxide.
Third, sodium and potassium hydroxide can dissolve silica forming sodium silicate and potassium silicate respectively. Therefore there is a high probability of damaging the stone itself.
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Thanks I'll give some of those a try.
Can you recommend any techniques to prevent this? Maybe use a different polish or technique or something?
I fill pits with a mix of mud from cabbing and epoxy to help match the color of the stone or fill the pits with baking soda then hit it with super glue. The baking soda will instantly harden the super glue.
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Let's suppose that one were an idiot (and I am) who at one point let this stuff dry on some druzy stones (and I did). What then? I have some gorgeous tiny green diopside druzies and pink cobalto calcites. Fortunately, they were smallish stones and I didn't pay much for them. Are they lost forever?
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Let's suppose that one were an idiot (and I am) who at one point let this stuff dry on some druzy stones (and I did). What then? I have some gorgeous tiny green diopside druzies and pink cobalto calcites. Fortunately, they were smallish stones and I didn't pay much for them. Are they lost forever?
What dried on them?
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Not really polish. Just was using the nova wheels and I guess sediment from the matrix dried on the druzy tops even though I tried to get it off. I did not have an ultrasonic so just washed them after cutting to shape. Now they look dusty.
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If mechanical cleaning like fine brushes or soda water doesn't work... maybe Sodium Hydroxide cleaner? I know it attacks aluminium, but it's nasty stuff and you should wash everything it touches with detergent after using.
I would not advise sodium hydroxide. First of all it is quite caustic so not really safe to be playing with unless you know what you are doing.
Secondly it will attack aluminum metal forming aluminum hydroxide, not aluminum oxide that is the dry version of aluminum hydroxide.
Third, sodium and potassium hydroxide can dissolve silica forming sodium silicate and potassium silicate respectively. Therefore there is a high probability of damaging the stone itself.
Oh thanks, I didn't know about it attacking silica!
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Was looking through the new (toy) catalog from Rio Grande and saw a new type of cleaner, an ionic cleaner. Supposed to be safe even for opal and pearls. Also, on line, found instructions for for making your own from an a/c adapter. Just need an electrolyte. That you can't make yourself, probably. I imagine you could do the battery version just as easily.
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I was watching a video from black opal direct, like his videos, and he was "putting some myths to bed about opal". One of the things he said was cleaning in Ultrasonic cleaners was just fine and put a black Opal in a cleaner. I don't know if he addressed Doublets and triplets vs a solid nobby opal and whether the bonding agents could be affected by the ultra sonic. In the Vid he also put the opal in various cleaning chemicals to show they wouldn't harm the opal.
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I was watching a video from black opal direct, like his videos, and he was "putting some myths to bed about opal". One of the things he said was cleaning in Ultrasonic cleaners was just fine and put a black Opal in a cleaner. I don't know if he addressed Doublets and triplets vs a solid nobby opal and whether the bonding agents could be affected by the ultra sonic. In the Vid he also put the opal in various cleaning chemicals to show they wouldn't harm the opal.
Maybe it depends on the opal and the aluminum oxide content. There area about 300 types of opal and they can vary in aluminum oxide content. The higher the content the more stable the stone becomes.