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i won this little chunk of Yowah boulder opal and want to try and make a cab out of it. I know it tends to be quite a bit softer so I'll start on the 220 and go up from there, but I wondered if I should cut it so this is the 'face' of the cab? So this side would be the top of the slab? I had to battle this auction to the last minute so I really don't want to ruin it. I watched a video on someone making a cab out of this material, so I think I can do it, but am worried about cutting it wrong. Thanks!
It looks like the face you are showing is a good one. I would most likely split it before deciding on which is the front, assuming it's thick enough to split. Opal that has been out of the ground for awhile can have the fire fade a little, so what you find in the middle may be even more flashy. Of course, when you grind in a little ways it's all fresh material anyway. I have a 4 and 6 inch saw, both use water based coolants, so hand splitting nuts and boulder opals is not an issue for me.
“You preachers of equality, the tyrannomania of impotence clamors thus out of you for equality: your most secret ambitions to be tyrants thus shroud themselves in words of virtue. Aggrieved conceit, repressed envy—perhaps the conceit and envy of your fathers—erupt from you as a flame and as the frenzy of revenge.” —Friedrich Nietzsche
Post by opalpyrexia on Mar 7, 2024 10:44:23 GMT -5
It looks like the best area is reasonably flat or slightly convex, which should make this rough fairly easy to work.
What I would do is gently begin to lightly work it with 600 grit, checking it frequently. If it starts to reveal more/additional opal, then continue. Slow down or stop if you begin to see the opal seams starting to shrink or disappear. If you work slowly you don't have to worry about "ruining" it.
Chasing opal fire is a lot of fun, even when it's stressful!
It looks like the face you are showing is a good one. I would most likely split it before deciding on which is the front, assuming it's thick enough to split. Opal that has been out of the ground for awhile can have the fire fade a little, so what you find in the middle may be even more flashy. Of course, when you grind in a little ways it's all fresh material anyway. I have a 4 and 6 inch saw, both use water based coolants, so hand splitting nuts and boulder opals is not an issue for me.
Great! Thank you! I think I can split it without issue. Its smaller than it looks here, and a little weirdly shaped, but I have a 5" trim saw that I could use. Thanks!!
It looks like the best area is reasonably flat or slightly convex, which should make this rough fairly easy to work.
What I would do is gently begin to lightly work it with 600 grit, checking it frequently. If it starts to reveal more/additional opal, then continue. Slow down or stop if you begin to see the opal seams starting to shrink or disappear. If you work slowly you don't have to worry about "ruining" it.
Chasing opal fire is a lot of fun, even when it's stressful!
thank you so much! It has a little bit of a strange shape, but this face seems to be the best. Start on 600? Soft wheel? I only have 80 and 220 electroplated, but I should skip those altogether? I love the peeks of color and have seen some amazing finished pieces - excited to try my hand here. Thanks very much!
It looks like the best area is reasonably flat or slightly convex, which should make this rough fairly easy to work.
What I would do is gently begin to lightly work it with 600 grit, checking it frequently. If it starts to reveal more/additional opal, then continue. Slow down or stop if you begin to see the opal seams starting to shrink or disappear. If you work slowly you don't have to worry about "ruining" it.
Chasing opal fire is a lot of fun, even when it's stressful!
thank you so much! It has a little bit of a strange shape, but this face seems to be the best. Start on 600? Soft wheel? I only have 80 and 220 electroplated, but I should skip those altogether? I love the peeks of color and have seen some amazing finished pieces - excited to try my hand here. Thanks very much!
I don't know what you use for finer grits, but using the 220 with a very light touch would be OK to explore and potentially reveal more of the opal.
Never use 80 on opal. I thought you were working on a 6 wheel cabbing matching? Am I missing something
I am, the cabking - I was going to start with the 220 electro, until Opalpyrexia mentioned starting with the 600. I knew the 80 would chew right through that stone.
thank you so much! It has a little bit of a strange shape, but this face seems to be the best. Start on 600? Soft wheel? I only have 80 and 220 electroplated, but I should skip those altogether? I love the peeks of color and have seen some amazing finished pieces - excited to try my hand here. Thanks very much!
I don't know what you use for finer grits, but using the 220 with a very light touch would be OK to explore and potentially reveal more of the opal.
I just have the 80 and 220 electro (I think the flat lap on the side is 300 ish, but more difficult to use IMO), then the 280 soft. Maybe I'll start with the 280 soft and see - it's a new wheel so it should be a little more aggressive than a worn 280. I'll move up to 600 if that's too much. Thank you!!
Post by hummingbirdstones on Mar 7, 2024 12:28:15 GMT -5
Peta, exactly how big is that rough? It's kind of hard to ascertain from the picture because it's so big. opalpyrexia gave you good advice as did Rockoonz. I would start with the 600 and drop down to the 220 if the ironstone matrix is harder than you think it might be. The hardness of ironstone can really differ. Usually the more yellow it is, the softer and more porous it is, but it looks like the yellow on yours may be just a rind in places. I'm seeing what I think is brown under it, but it's really hard to tell.
The opal cutter's mantra is: Cut a little, look a lot. Rules to live by when you're cutting any type of opal with fire. Go slow, look a lot and you will be fine. It's really not as scary as everyone says (unless it's a black opal that you can't see in to at all - then all bets are off and you need to wear depends when cutting).
Robin
"Of all tyrannies, a tyranny sincerely exercised for the good of its victims may be the most oppressive. It would be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated; but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience."
Robin said what I was thinking: that yellowish matrix looks like it could be very soft. Some I've cut just melted away under the wheel. That's why I think opalpyrexia is about starting with nothing coarser than 600 grit. If you use the 220 use a VERY light touch until you can gauge the hardness.
Peta, exactly how big is that rough? It's kind of hard to ascertain from the picture because it's so big. opalpyrexia gave you good advice as did Rockoonz . I would start with the 600 and drop down to the 220 if the ironstone matrix is harder than you think it might be. The hardness of ironstone can really differ. Usually the more yellow it is, the softer and more porous it is, but it looks like the yellow on yours may be just a rind in places. I'm seeing what I think is brown under it, but it's really hard to tell.
The opal cutter's mantra is: Cut a little, look a lot. Rules to live by when you're cutting any type of opal with fire. Go slow, look a lot and you will be fine. It's really not as scary as everyone says (unless it's a black opal that you can't see in to at all - then all bets are off and you need to wear depends when cutting).
It's about 2" from that top to bottom, maybe a little smaller. Not a super big chunk. Thank you for the comments - I will definitely go slow and look alot. I think I'll start on the 600 too and dip down to 280 if needed. Thank goodness it doesn't appear to be a black opal lol - I would need to make a drug store run if so Thank you!!
Robin said what I was thinking: that yellowish matrix looks like it could be very soft. Some I've cut just melted away under the wheel. That's why I think opalpyrexia is about starting with nothing coarser than 600 grit. If you use the 220 use a VERY light touch until you can gauge the hardness.
Thank you! I will definitely start with the 600 and go from there - if I need to go to coarser, I will, but for sure want to start with the least aggressive I can. Thanks!!
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Welcome to the Rock Tumbling Hobby Forum where we share a love of rocks and a sense of community as enduring as the stones we polish.
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