EUR/USD - Watching. May give short this week.
GBP/USD - Moved stop on long 2.0141, stop 1.9768, limit 2.0978. Some indications that this will not hit my limit and I'll have to offset. Question: move stop real close?
USD/JPY - No change on long 116.61, stop 112.05, limit 121.84. Based on my other trades with this pair, I will stop watching it if it doesn't trade well.
AUD/USD - Limited out on long 0.8300. Profit diff 463. Should have set limit higher (7+ grid points up from 8/12 bar). Watching.
USD/CAD - Watching
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Thursday, September 27, 2007
The 220 grit wheel arrived
Yay!
I found the technique I used with the 100 grit stone to be frustratingly slow. But considering how alarmed I was at the speed the 100 grit cut when the stone was to form, this wasn't a bad thing.
I'm now sure that a sanding step is needed. I was able to get rid of most of the ridges but not all. Even if the cutting was slower, I found that if I persisted at trying to eliminate the ridges on the 220 wheel, I ended up making more ridges and taking off more than I wanted.
Use of the 220 wheel and a lighter touch prolonged the lifespan of the carbide sanding disks, but not by much.
I found the 400 grit to be too aggressive. I attribute this to all the grinding on the 220 wheel. In general, the closer to form I get the rock the faster any given grit will cut. The 400 grit disk was not anywhere this aggressive when it was dealing with much more carry over work from the 220 grit sanding disk. I have a few more 400 grit disks to test this assumption.
The 600 grit disks worked well. I suspect that they may work better when they are not correcting the problems introduced with the 400 grit disks. I'm irritated that I screwed up my last order and only bought two disks. I will have to get some more.
My question now is: Do I test a grit somewhere between 400 and 600 grit? Or try something between 600 and 1000 grit?
I'm well pleased with the tripoli. After finishing with it last night I brought out a finish similar to the cerium oxide finish I got on my first stone. When I moved to the cerium oxide after the tripoli I achieved a finish that displayed a pleasing depth in the stone. One stone in particular shows clear layers of cream with a window into a transparent center. I can only imagine what these stones would look like if I had worked the bottoms.
So, what is my progression like?
1st stone: Some rounded facet like tables all over the cab with a nice shine
2nd through 3rd: No faceting but not symmetrical. Some stones have a dome that have a full curve on one side and a shallow one on the other. One's edge is a nice oval on one side and has sort of a fatter bottom on the other. Nice polish on all.
4th stone: This was a problem stone that I didn't think I'd do well on but still wanted to try. It was some grayish white soft material with mica throughout. I tried working it from the edge as this caught all the mica chips on the edge giving a glittery appearance. The soft stone cut alarmingly fast and I was only able to bring up a soft luster on the dome. The attractive glitter does not show up in the finished product. The next time I find a rock with many mica chips in it, I'll work it from the side where the full face of the mica chips show as those edges took a better polish.
As I'm concerned about the state of my 100 grit wheel, further grinding will have to wait until my dresser arrives. However, my templates (from a different supplier) have arrived and I'll try my hand with the trim saw.
Update:
After looking around it appears that the finer carbide sanding pads come only in 400 and 600 grit.
So I'm going to order a bunch of 600 grit.
Considering how it is looking like I will be able to get away with one sanding step, I'm also going to order "How to Use Diamond Abrasive" by Riggle.
Hmm, that reminds me, I should mention the books I picked up along with my grinder.
"Cabochon Cutting" and "Advanced Cabochon Cutting" by Cox
"The Art of Gem Cutting" by Dake
All of these books are quite dated (especially the Dake book). However, what modern books I've found on this subject tend to have a great deal of fluff. Even if they are dated they still have useful hints and pointers. I'd have to say both of the Cox books have more useful info on cabs.
The real issue on cab books is that beyond a few specifics, the actual act of cutting and polishing cabs appears to vary greatly between cutters. An example I've seen several times is how cutter A claims one polishing agent is the best for whatever stone. While cutter B is unable to get any luster from cutter A's polishing agent, but gets wonderful results from a different agent.
So it would appear that anyone who wants to learn to cut cabs must put in time and effort actually cutting stones in order to discover what works best for him.
I found the technique I used with the 100 grit stone to be frustratingly slow. But considering how alarmed I was at the speed the 100 grit cut when the stone was to form, this wasn't a bad thing.
I'm now sure that a sanding step is needed. I was able to get rid of most of the ridges but not all. Even if the cutting was slower, I found that if I persisted at trying to eliminate the ridges on the 220 wheel, I ended up making more ridges and taking off more than I wanted.
Use of the 220 wheel and a lighter touch prolonged the lifespan of the carbide sanding disks, but not by much.
I found the 400 grit to be too aggressive. I attribute this to all the grinding on the 220 wheel. In general, the closer to form I get the rock the faster any given grit will cut. The 400 grit disk was not anywhere this aggressive when it was dealing with much more carry over work from the 220 grit sanding disk. I have a few more 400 grit disks to test this assumption.
The 600 grit disks worked well. I suspect that they may work better when they are not correcting the problems introduced with the 400 grit disks. I'm irritated that I screwed up my last order and only bought two disks. I will have to get some more.
My question now is: Do I test a grit somewhere between 400 and 600 grit? Or try something between 600 and 1000 grit?
I'm well pleased with the tripoli. After finishing with it last night I brought out a finish similar to the cerium oxide finish I got on my first stone. When I moved to the cerium oxide after the tripoli I achieved a finish that displayed a pleasing depth in the stone. One stone in particular shows clear layers of cream with a window into a transparent center. I can only imagine what these stones would look like if I had worked the bottoms.
So, what is my progression like?
1st stone: Some rounded facet like tables all over the cab with a nice shine
2nd through 3rd: No faceting but not symmetrical. Some stones have a dome that have a full curve on one side and a shallow one on the other. One's edge is a nice oval on one side and has sort of a fatter bottom on the other. Nice polish on all.
4th stone: This was a problem stone that I didn't think I'd do well on but still wanted to try. It was some grayish white soft material with mica throughout. I tried working it from the edge as this caught all the mica chips on the edge giving a glittery appearance. The soft stone cut alarmingly fast and I was only able to bring up a soft luster on the dome. The attractive glitter does not show up in the finished product. The next time I find a rock with many mica chips in it, I'll work it from the side where the full face of the mica chips show as those edges took a better polish.
As I'm concerned about the state of my 100 grit wheel, further grinding will have to wait until my dresser arrives. However, my templates (from a different supplier) have arrived and I'll try my hand with the trim saw.
Update:
After looking around it appears that the finer carbide sanding pads come only in 400 and 600 grit.
So I'm going to order a bunch of 600 grit.
Considering how it is looking like I will be able to get away with one sanding step, I'm also going to order "How to Use Diamond Abrasive" by Riggle.
Hmm, that reminds me, I should mention the books I picked up along with my grinder.
"Cabochon Cutting" and "Advanced Cabochon Cutting" by Cox
"The Art of Gem Cutting" by Dake
All of these books are quite dated (especially the Dake book). However, what modern books I've found on this subject tend to have a great deal of fluff. Even if they are dated they still have useful hints and pointers. I'd have to say both of the Cox books have more useful info on cabs.
The real issue on cab books is that beyond a few specifics, the actual act of cutting and polishing cabs appears to vary greatly between cutters. An example I've seen several times is how cutter A claims one polishing agent is the best for whatever stone. While cutter B is unable to get any luster from cutter A's polishing agent, but gets wonderful results from a different agent.
So it would appear that anyone who wants to learn to cut cabs must put in time and effort actually cutting stones in order to discover what works best for him.
Monday, September 24, 2007
My first grinder
So, what to do with this rough stone?
Well, in googling around I found out a few things:
Low end cab equipment costs a few hundred dollars (under $400 if you look around). The all metal models have ok resale values if you find you can't cab very well. The main issue with low end cab equipment is inconvence. If you go with the plain arbor unit you'll have multiple wheels (two in the smaller units) to move to without slowing down, but no trim saw (trim saws save wear and tear on your wheels and can carve up small slabs). Units with a built in trim saw tend to be cramped in front of the wheel and allow only one wheel at a time (meaning you have to take time to switch wheels/sanding pads when you're ready for them).
I decided on the "Rock Rascal" model TM. It comes with a trim saw, 100 grit carbide wheel, 220 grit sand pad, felt polishing pad, mounting head for the pads, and a rubber backer for the pads.
Note on distributers: spend some time in pricing your equipment. You will find very large price differences for the same item at different sites (sometimes by several hundred dollars). I went with the cheapest I could find. That was a mistake. The invoice indicated that they were doing a week long inventory and wouldn't ship. Then it was back ordered. In the end it took about a month to get my grinder. It is near two months now and the last parts of my order have not arrived (a loupe, scribe, and templates). So if you do go with the cheapest distributer, you may just get what you get.
I had ordered some rough moonstone on ebay to go along with what was found at the public mines. Here too, don't go super cheap. Find common rough (like moonstone) that is pretty cheap to begin with and then be willing to pay a bit more. Two examples: #1 I first bought a pound of cheap moonstone for a little over $10. It had little flash or much usable stone. #2 I then bought 500ct of moonstone for the same price. Nearly all of it has nice electric blue flashes and is very usable.
But now that I had my grinder I didn't want my first attempts to be with my bought stone or the public mine stone. Luckly I had a substitute. My daughter has taken to bringing me stones that she finds. NC is pretty neat in that there are all sorts of interesting rocks just lying around. So I had a number of feldspar looking pebbles (translucent creamy colored stones that look stream smoothed).
My first grinding attempt was a learning experiance. Specifically, carbide sanding pads have a *very* short lifespan. I had bought some 400grit and 600grit sanding pads to go along with the base rock rascal. Every pad was spent before I was done with the stone. Around 5 minutes of useful life.
Now considering that the 100 grit wheel is used to get the stone formed roughly into shape and the 220 grit (sandpaper or wheel) is where the real work is done (all other work is smoothing in preparation for polishing), this would have me buying a ton of 220 grit sandpaper. Not to mention that the grinder only came with one 220 grit paper. I simply had no idea how very short a lifespan they had.
So, a 220 grit wheel is an absolute must with a rock rascal type setup.
Something I didn't like about the carbide sandpaper is that when the grit wore out in one area it was still ok in another. This caused some facet like aspects on my first stone. I'm pretty sure that using a 220 grit wheel will help with this, but it still bothers me. There are two other options available: diamond grit on a pad or diamond sandpaper. I'm going to use the carbide sandpaper again when my 220 wheel arrives. If I continue to have issues I'll look into the diamond grit. The diamond sandpaper is awful expensive and I have no idea if it can be recharged.
I had bought several grits of sandpaper the first time around thinking the coarse wheel and sandpaper would leave gouges. This wasn't the case. All grinding left smooth areas. Also, the closer I got to the desired form the faster the grit cut. Sometimes too fast. This left me thinking that I might want to try to get as much of the work done on the wheels as possible and then try just one sanding ~600 grit. If I can get down to one sanding I'd feel better about the costs of using diamond grit. But I just won't have a good idea until my 220 grit wheel arrives.
I used cerium oxide for my first stone and it worked pretty well. This time around I'm planning on prepolishing with tripoli. Tripoli has a grit of somewhere around 1000-1200.
So, if I had it to do over again:
Rock Rascal TM
Trim saw lubricant
220 grit carbide wheel (must have)
400 grit carbide sandpaper (not sure if needed)
600 grit carbide sandpaper (compare with diamond grit if this is the only sanding)
Tripoli with additional felt pad (haven't used at the time of this writing)
Cerium oxide (I suspect any general polish would work)
Carbide wheel dresser (needed with carbide wheels)
Dop wax (didn't use the first time which resulted in limited control)
Dops - various diameters of dowel 3-4" long (pretty much anything can be used)
1" wide paintbrush (for polish... get one per type of polish)
Dop wax preparation (I use old cans on the stove)
Templates (to form stones for commercial settings (not needed at first))
x10 Loupe (not needed at first)
Note on the wheel dresser: I suspect I used too much pressure on my first attempt as some uneveness has developed. This makes it hard to grind well. Remember - light pressure on the wheels.
At present, I've ground four other stones on the 100 grit wheel and am waiting for the 220 grit wheel to arrive. I think I'm catching on to working the coarse wheel as I can get the stone near to sanding ready. The thing that threw me off was how fast the coarse wheel ate into the stone when only ridges were left. I caught myself from cutting away too much, but I did cut more than I wanted on a couple of the new stones.
Well, in googling around I found out a few things:
- As mentioned the other day, public mines are like a lottery and should really be approached as a family fun activity.
- Faceted stones do the best in general (i.e. More setting options and does well unset) but adequate rough is very pricey to just practice on. Synthetic is more reasonable but doesn't sell well.
- Cabochon (aka "cabs") cuts use cheaper rough and is generally thought of as "easy".
- Faceting equipment is very pricey. Generally the price goes along with precision. A skilled faceter can work around imprecise equipment but a rank amateur (i.e. me) can not.
- Cabbing equipment is pricey, but not as bad as faceting equipment. Looking at the lower price range there appears to be some junk mixed in with adequate equipment. The adequate equipment is cheap because it is inconvenient. By that I mean that the work zone in cramped, the wheels are thin, or only one wheel can be mounted on the arbor at one time.
- It is generally thought that, at the very least, a hobbist cutter will be able to pay for their hobby with what they make.
Low end cab equipment costs a few hundred dollars (under $400 if you look around). The all metal models have ok resale values if you find you can't cab very well. The main issue with low end cab equipment is inconvence. If you go with the plain arbor unit you'll have multiple wheels (two in the smaller units) to move to without slowing down, but no trim saw (trim saws save wear and tear on your wheels and can carve up small slabs). Units with a built in trim saw tend to be cramped in front of the wheel and allow only one wheel at a time (meaning you have to take time to switch wheels/sanding pads when you're ready for them).
I decided on the "Rock Rascal" model TM. It comes with a trim saw, 100 grit carbide wheel, 220 grit sand pad, felt polishing pad, mounting head for the pads, and a rubber backer for the pads.
Note on distributers: spend some time in pricing your equipment. You will find very large price differences for the same item at different sites (sometimes by several hundred dollars). I went with the cheapest I could find. That was a mistake. The invoice indicated that they were doing a week long inventory and wouldn't ship. Then it was back ordered. In the end it took about a month to get my grinder. It is near two months now and the last parts of my order have not arrived (a loupe, scribe, and templates). So if you do go with the cheapest distributer, you may just get what you get.
I had ordered some rough moonstone on ebay to go along with what was found at the public mines. Here too, don't go super cheap. Find common rough (like moonstone) that is pretty cheap to begin with and then be willing to pay a bit more. Two examples: #1 I first bought a pound of cheap moonstone for a little over $10. It had little flash or much usable stone. #2 I then bought 500ct of moonstone for the same price. Nearly all of it has nice electric blue flashes and is very usable.
But now that I had my grinder I didn't want my first attempts to be with my bought stone or the public mine stone. Luckly I had a substitute. My daughter has taken to bringing me stones that she finds. NC is pretty neat in that there are all sorts of interesting rocks just lying around. So I had a number of feldspar looking pebbles (translucent creamy colored stones that look stream smoothed).
My first grinding attempt was a learning experiance. Specifically, carbide sanding pads have a *very* short lifespan. I had bought some 400grit and 600grit sanding pads to go along with the base rock rascal. Every pad was spent before I was done with the stone. Around 5 minutes of useful life.
Now considering that the 100 grit wheel is used to get the stone formed roughly into shape and the 220 grit (sandpaper or wheel) is where the real work is done (all other work is smoothing in preparation for polishing), this would have me buying a ton of 220 grit sandpaper. Not to mention that the grinder only came with one 220 grit paper. I simply had no idea how very short a lifespan they had.
So, a 220 grit wheel is an absolute must with a rock rascal type setup.
Something I didn't like about the carbide sandpaper is that when the grit wore out in one area it was still ok in another. This caused some facet like aspects on my first stone. I'm pretty sure that using a 220 grit wheel will help with this, but it still bothers me. There are two other options available: diamond grit on a pad or diamond sandpaper. I'm going to use the carbide sandpaper again when my 220 wheel arrives. If I continue to have issues I'll look into the diamond grit. The diamond sandpaper is awful expensive and I have no idea if it can be recharged.
I had bought several grits of sandpaper the first time around thinking the coarse wheel and sandpaper would leave gouges. This wasn't the case. All grinding left smooth areas. Also, the closer I got to the desired form the faster the grit cut. Sometimes too fast. This left me thinking that I might want to try to get as much of the work done on the wheels as possible and then try just one sanding ~600 grit. If I can get down to one sanding I'd feel better about the costs of using diamond grit. But I just won't have a good idea until my 220 grit wheel arrives.
I used cerium oxide for my first stone and it worked pretty well. This time around I'm planning on prepolishing with tripoli. Tripoli has a grit of somewhere around 1000-1200.
So, if I had it to do over again:
Rock Rascal TM
Trim saw lubricant
220 grit carbide wheel (must have)
400 grit carbide sandpaper (not sure if needed)
600 grit carbide sandpaper (compare with diamond grit if this is the only sanding)
Tripoli with additional felt pad (haven't used at the time of this writing)
Cerium oxide (I suspect any general polish would work)
Carbide wheel dresser (needed with carbide wheels)
Dop wax (didn't use the first time which resulted in limited control)
Dops - various diameters of dowel 3-4" long (pretty much anything can be used)
1" wide paintbrush (for polish... get one per type of polish)
Dop wax preparation (I use old cans on the stove)
Templates (to form stones for commercial settings (not needed at first))
x10 Loupe (not needed at first)
Note on the wheel dresser: I suspect I used too much pressure on my first attempt as some uneveness has developed. This makes it hard to grind well. Remember - light pressure on the wheels.
At present, I've ground four other stones on the 100 grit wheel and am waiting for the 220 grit wheel to arrive. I think I'm catching on to working the coarse wheel as I can get the stone near to sanding ready. The thing that threw me off was how fast the coarse wheel ate into the stone when only ridges were left. I caught myself from cutting away too much, but I did cut more than I wanted on a couple of the new stones.
How I found out about stone cutting
In my daughter's fourth year she started to become interested in rocks. Very interested.
Mrs. Bear and I took this to be simple curiosity at first, but it wasn't so.
I suggested we find a museum with a large crystal exhibit and Mrs. Bear agreed. However, once she started poking around she found that NC is a gemstone dense state. She noted that there were several public mines in the state. So we picked a little one that was nearby and headed out.
My girl was enraptured. Generally, I'm lucky to get 10-15 minutes of good focus from her. That first day of sluicing the rocks... she was intent on the task for a full three hours. Amazing.
I became interested in how to make money on the stones. Heh.
To make a long story short, we hit a few public mines near to the house but generally just for my girl. Reading up in the archives here it became clear that #1 most public mines are "enriched" (operators introduce outside stone of little value to the dirt) and #2 that it is a lot like a lottery. By "lottery" I mean that it is highly unlikely that you'll find anything of real value (otherwise the mine wouldn't be public).
Still, my girl loves it and it got me interested in lapidary.
Next up, my first grinder.
Mrs. Bear and I took this to be simple curiosity at first, but it wasn't so.
I suggested we find a museum with a large crystal exhibit and Mrs. Bear agreed. However, once she started poking around she found that NC is a gemstone dense state. She noted that there were several public mines in the state. So we picked a little one that was nearby and headed out.
My girl was enraptured. Generally, I'm lucky to get 10-15 minutes of good focus from her. That first day of sluicing the rocks... she was intent on the task for a full three hours. Amazing.
I became interested in how to make money on the stones. Heh.
To make a long story short, we hit a few public mines near to the house but generally just for my girl. Reading up in the archives here it became clear that #1 most public mines are "enriched" (operators introduce outside stone of little value to the dirt) and #2 that it is a lot like a lottery. By "lottery" I mean that it is highly unlikely that you'll find anything of real value (otherwise the mine wouldn't be public).
Still, my girl loves it and it got me interested in lapidary.
Next up, my first grinder.
Sunday, September 23, 2007
Monday, September 17, 2007
EUR/USD - Moved stop on long 1.3671, stop 1.3452, limit 1.4104
GBP/USD - Moved stop on long 2.0141, stop 1.9680, limit 2.0978
USD/JPY - No change on long 116.61, stop 112.05, limit 121.84
AUD/USD - No change on long 0.8300, stop 0.7850, limit 0.8763
USD/CAD - Watching. Starting to look like I could have gone short on the 8/12 bar
GBP/USD - Moved stop on long 2.0141, stop 1.9680, limit 2.0978
USD/JPY - No change on long 116.61, stop 112.05, limit 121.84
AUD/USD - No change on long 0.8300, stop 0.7850, limit 0.8763
USD/CAD - Watching. Starting to look like I could have gone short on the 8/12 bar
Tuesday, September 11, 2007
Sunday, September 09, 2007
EUR/USD - Moved stop on long 1.3671, stop 1.3387, limit 1.4104
GBP/USD - Moved stop on long 2.0141, stop 1.9635, limit 2.0978
USD/JPY - No change on long 116.61, stop 112.05, limit 121.84. This may end up a loser. Need to check on my CCI.
AUD/USD - Moved stop on long 0.8300, stop 0.7850, limit 0.8763
USD/CAD - Watching.
GBP/USD - Moved stop on long 2.0141, stop 1.9635, limit 2.0978
USD/JPY - No change on long 116.61, stop 112.05, limit 121.84. This may end up a loser. Need to check on my CCI.
AUD/USD - Moved stop on long 0.8300, stop 0.7850, limit 0.8763
USD/CAD - Watching.
Sunday, September 02, 2007
I'm thinking I'm going to try some entry stops next time around as well.
EUR/USD - No change on long 1.3671, stop 1.3220, limit 1.4104
GBP/USD - No change on long 2.0141, stop 1.9435, limit 2.0978
USD/JPY - No change on long 116.61, stop 112.05, limit 121.84
AUD/USD - No change on long 0.8300, stop 0.7725, limit 0.8763
USD/CAD - Thought about it some more and the monthly chart won't work as trades span years. Watching.
EUR/USD - No change on long 1.3671, stop 1.3220, limit 1.4104
GBP/USD - No change on long 2.0141, stop 1.9435, limit 2.0978
USD/JPY - No change on long 116.61, stop 112.05, limit 121.84
AUD/USD - No change on long 0.8300, stop 0.7725, limit 0.8763
USD/CAD - Thought about it some more and the monthly chart won't work as trades span years. Watching.
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