Well, after finding out that sanding with diamond is pretty easy and cost effective, I'm willing to look at additional sanding steps.
The reason this is coming to mind again is because of all the ridges in my last batch of stones. Yes, if I had worked smaller batches I'd have been able to get rid of the worst of the ridges, but not all.
Looking though Riggle's diamond abrasives book again I noticed that he suggests sanding with near the same grit size as the fine grind (280). He states "The cutting action, however, is not the same because the smoothing wheel or disk has the cushioned surface, which has a gentler effect. With this grit, the scratches, plus any bumps or tiny flat spots that may have been left by the grinding wheel are smoothed away". That right there describes my complaint.
So not only have I ordered 220 grit diamond paste (closest to 280) but I'm going to try out a dura-tex pad. I can't tell from the descriptions if it is more laplike (stiff and flat) or more like a pad. However, it appears to hold the diamond grit better which might translate to more aggressive sanding.
If that works out, I'll replace the other sanding disks with dura-tex pads as they wear out.
I'm curious about polishing with diamond, but I don't see the point in the additional cost before I'm able to sell my end product.
Custom Search
Monday, October 29, 2007
Sunday, October 28, 2007
Checking out MB trading. It is an ECN which means that they won't take the other side of your trade. Not liking their software all that much, but that they are a ECN is very appealing.
EUR/USD - No change on 1.4202, stop 1.4442, limit 1.3847. Looks like a loser.
GBP/USD - I did get out too early. Watching.
USD/JPY - No change on long 116.61, stop 112.29, limit 117.25.
AUD/USD - Watching.
USD/CAD - Watching.
EUR/USD - No change on 1.4202, stop 1.4442, limit 1.3847. Looks like a loser.
GBP/USD - I did get out too early. Watching.
USD/JPY - No change on long 116.61, stop 112.29, limit 117.25.
AUD/USD - Watching.
USD/CAD - Watching.
Trial and error is useful but frustrating
My diamond grinding book arrived and I bought 360 and 600 grit diamond paste and two uncharged disks. The diamond worked as advertised. I sanded eleven stones before I had to recharge the disk. After eighteen stones it does not look worn. I'm well pleased about that.
However, I'm less than pleased with three errors I made:
Very frustrating.
Re: #2 -- Dopping stones is a bit of work... especially a large number of stones. Normally, it is easier to grind while holding the stone in my fingers. But once the stone gets to be under a centimeter, it is very difficult. Plus I manged to grind away around a third of the fingernails on my index and middle fingers of both hands. In the end my smaller stones had many ridges.
Re: #3 -- I had read that faceters sometimes mixed their diamond grit in petroleum jelly instead of oil. I had been mixing my polish in water and painting it onto the felt pad. As that was a bit messy I thought mixing it with petroleum jelly might be better. It wasn't. Best as I can tell, once the water drys up on a given polishing run the polish acts like it is bonded with the felt. This makes the polishing action much more aggressive. When the polish is mixed with petroleum jelly it never gets aggressive and the stone never gets a proper shine.
So, I now have eighteen stones with a crummy polish and thirty more with the error mentioned above.
grr
Might as well write down my current method (which is nothing more than a hodgepodge of what I've read).
#2 -- Dop small stones! While holding the stone so that its bottom is on top, grind to around half a millimeter of the outline then flatten the bottom. Then grind the edge flat (about a 1/4mm from the outline). Measure and mark off the top of the bezel, which should be one third the height of the stone. "Mark the top of the stone in thirds from end to end and side to side"*. Then make a dot in the center of that marking. While continuing to hold the stone with the bottom on top, grind to around a quarter millimeter of both the bezel line and the line drawn on the top of the stone. Once the entire top of the stone has been ground that way, grind to the dot at a lesser angle. Lastly remove any large ridges or facets before rinsing off the stone.
#3 -- Lightly grind all over the sides and top of the stone to improve later polishing. Remove all ridges, facets, and bumps because sanding/smoothing will not remove them. If there are any major errors found at this stage (like an asymmetrical shape), go back to the 100 grit.
#4 -- Being careful to avoid the bezel line, sand all over the stone to improve later polishing. It is at this point ridges that were missed during steps 2-3 will begin to stand out. If you find them, go back to the 220 wheel.
#5 -- Same procedure for both tripoli and cerium oxide: mix polish with water and dab onto pre-moistened felt pad. Starting on the outside while the pad and polish are wet, use moderate pressure and twist and rock the stone. As the pad drys move towards the center of the pad. When you feel the pad tugging at the stone pay attention to heat and stay near the center of the pad. Do this all over the stone for a dull shine with the tripoli and a good luster with the cerium oxide. Note: if you are too near the outer edge of the pad when it starts to dry, you will get pitting and an odd "flow" of stone in the area worked. The only way to get rid of that is to go back to the sanding step.
At this point I'm going to try batches of five stones and finish off the eighteen stones that have been rough formed. Then I can test out grinding to both bezel and top markings.
* Cabochon Cutting by Jack Cox
However, I'm less than pleased with three errors I made:
- I tried to do a huge batch at a time
- I insisted on trying to work little stones in my fingers instead of dopping them
- I experimented with my polishing
Very frustrating.
Re: #2 -- Dopping stones is a bit of work... especially a large number of stones. Normally, it is easier to grind while holding the stone in my fingers. But once the stone gets to be under a centimeter, it is very difficult. Plus I manged to grind away around a third of the fingernails on my index and middle fingers of both hands. In the end my smaller stones had many ridges.
Re: #3 -- I had read that faceters sometimes mixed their diamond grit in petroleum jelly instead of oil. I had been mixing my polish in water and painting it onto the felt pad. As that was a bit messy I thought mixing it with petroleum jelly might be better. It wasn't. Best as I can tell, once the water drys up on a given polishing run the polish acts like it is bonded with the felt. This makes the polishing action much more aggressive. When the polish is mixed with petroleum jelly it never gets aggressive and the stone never gets a proper shine.
So, I now have eighteen stones with a crummy polish and thirty more with the error mentioned above.
grr
Might as well write down my current method (which is nothing more than a hodgepodge of what I've read).
- Trim saw
- Rough forming
- Fine forming
- Sanding/smoothing
- Polishing
#2 -- Dop small stones! While holding the stone so that its bottom is on top, grind to around half a millimeter of the outline then flatten the bottom. Then grind the edge flat (about a 1/4mm from the outline). Measure and mark off the top of the bezel, which should be one third the height of the stone. "Mark the top of the stone in thirds from end to end and side to side"*. Then make a dot in the center of that marking. While continuing to hold the stone with the bottom on top, grind to around a quarter millimeter of both the bezel line and the line drawn on the top of the stone. Once the entire top of the stone has been ground that way, grind to the dot at a lesser angle. Lastly remove any large ridges or facets before rinsing off the stone.
#3 -- Lightly grind all over the sides and top of the stone to improve later polishing. Remove all ridges, facets, and bumps because sanding/smoothing will not remove them. If there are any major errors found at this stage (like an asymmetrical shape), go back to the 100 grit.
#4 -- Being careful to avoid the bezel line, sand all over the stone to improve later polishing. It is at this point ridges that were missed during steps 2-3 will begin to stand out. If you find them, go back to the 220 wheel.
#5 -- Same procedure for both tripoli and cerium oxide: mix polish with water and dab onto pre-moistened felt pad. Starting on the outside while the pad and polish are wet, use moderate pressure and twist and rock the stone. As the pad drys move towards the center of the pad. When you feel the pad tugging at the stone pay attention to heat and stay near the center of the pad. Do this all over the stone for a dull shine with the tripoli and a good luster with the cerium oxide. Note: if you are too near the outer edge of the pad when it starts to dry, you will get pitting and an odd "flow" of stone in the area worked. The only way to get rid of that is to go back to the sanding step.
At this point I'm going to try batches of five stones and finish off the eighteen stones that have been rough formed. Then I can test out grinding to both bezel and top markings.
* Cabochon Cutting by Jack Cox
Sunday, October 21, 2007
EUR/USD - No change on 1.4202, stop 1.4442, limit 1.3847.
GBP/USD - Limited out on long 2.0141. Profit diff 284. But I think I got out too early. Not sure.
USD/JPY - Moved limit on long 116.61, stop 112.29, limit 117.25. This is looking like a bad trade. Even if I had used a limit entry, the exit signal happened on a big reversal. Update: I've removed the limit on this. Looking at it a bit more, the price may be fixing to jump very high... or not.
AUD/USD - Watching.
USD/CAD - Watching.
GBP/USD - Limited out on long 2.0141. Profit diff 284. But I think I got out too early. Not sure.
USD/JPY - Moved limit on long 116.61, stop 112.29, limit 117.25. This is looking like a bad trade. Even if I had used a limit entry, the exit signal happened on a big reversal. Update: I've removed the limit on this. Looking at it a bit more, the price may be fixing to jump very high... or not.
AUD/USD - Watching.
USD/CAD - Watching.
Sunday, October 14, 2007
Tuesday, October 09, 2007
Some thoughts on sanding
Still waiting for my diamond grinding book to arrive. So, I started googling around and pondering sanding disks, pads, and grit.
It makes sense that the 6" carbide sanding disks wear so quickly. Only out on the edge is there 6" of running space. All in all, sanding disks have very little surface area and must wear out quickly.
So, if a sanding belt can make use of its entire length, I think it reasonable to think the belt will last at least twice the time that a disk would. Ignoring that the old timers sanded dry, I think this explains why they used equipment with very long belts. I think the belts got shorter once diamond got more popular.
Something interesting I read on sanding with diamond is that as the diamond sanding belt is used up, it cuts slower but not finer. That's something that makes carbide difficult to sand with. It becomes finer as it is worn down.
Another thing I read was that diamond grit is cheaper than a diamond belt but is harder to work with. Considering that diamond belts are pretty pricey, I think I'm willing to work harder.
Last thing I found while googling around -- the reason that a soft backing is used when sanding cabs is to avoid making facets. So, in using such a light touch on the 400 grit, did I make an artificial flat lap? Thing is I can't push too hard either or else the carbide is used up in under two minutes and I risk hitting the backing plate and making facets that way.
It makes sense that the 6" carbide sanding disks wear so quickly. Only out on the edge is there 6" of running space. All in all, sanding disks have very little surface area and must wear out quickly.
So, if a sanding belt can make use of its entire length, I think it reasonable to think the belt will last at least twice the time that a disk would. Ignoring that the old timers sanded dry, I think this explains why they used equipment with very long belts. I think the belts got shorter once diamond got more popular.
Something interesting I read on sanding with diamond is that as the diamond sanding belt is used up, it cuts slower but not finer. That's something that makes carbide difficult to sand with. It becomes finer as it is worn down.
Another thing I read was that diamond grit is cheaper than a diamond belt but is harder to work with. Considering that diamond belts are pretty pricey, I think I'm willing to work harder.
Last thing I found while googling around -- the reason that a soft backing is used when sanding cabs is to avoid making facets. So, in using such a light touch on the 400 grit, did I make an artificial flat lap? Thing is I can't push too hard either or else the carbide is used up in under two minutes and I risk hitting the backing plate and making facets that way.
Monday, October 08, 2007
Seems there is a window of use with the carbide wheels
Starting sometime after 1.5 hours I noticed a good deal of green clay coming off of the wheel.
I suspect that the water gets too far into the wheel around that time and it starts eating away at a much faster rate.
I suspect that the water gets too far into the wheel around that time and it starts eating away at a much faster rate.
Sunday, October 07, 2007
EUR/USD - Set a short limit at 1.4202, stop 1.4442, limit 1.3847.
GBP/USD - Moved stop on long 2.0141, stop 1.9855, limit 2.0978. Some signals are indicating that I should offset and others are saying to hold o.O
USD/JPY - No change on long 116.61, stop 112.05, limit 121.84. Hmm, seems like it wants to go long now.
AUD/USD - Watching. May give a short this week.
USD/CAD - Watching. May give a weak long this week.
GBP/USD - Moved stop on long 2.0141, stop 1.9855, limit 2.0978. Some signals are indicating that I should offset and others are saying to hold o.O
USD/JPY - No change on long 116.61, stop 112.05, limit 121.84. Hmm, seems like it wants to go long now.
AUD/USD - Watching. May give a short this week.
USD/CAD - Watching. May give a weak long this week.
Thursday, October 04, 2007
I think I need to use diamond grit for sanding
My next stones showed me something interesting.
I used a very light touch on the 400 grit sandpaper and used only one disk for all six.
Well, when I tried to sand on the 600 grit and went through three pads on one stone I realized what was wrong. I was too tired when I thought I was finished with the 400 grit but ended up leaving many ridges and tables. So, I went back to the 400 grit and finished up.
This tells me that I do need two sanding steps.
Also, considering one sanding pad is only good for 1-2 stones, carbide sanding pads aren't cost effective.
I'll know more after I go through the diamond abrasives book.
I used a very light touch on the 400 grit sandpaper and used only one disk for all six.
Well, when I tried to sand on the 600 grit and went through three pads on one stone I realized what was wrong. I was too tired when I thought I was finished with the 400 grit but ended up leaving many ridges and tables. So, I went back to the 400 grit and finished up.
This tells me that I do need two sanding steps.
Also, considering one sanding pad is only good for 1-2 stones, carbide sanding pads aren't cost effective.
I'll know more after I go through the diamond abrasives book.
Tuesday, October 02, 2007
I find a lot of truth in this link
It's frustrating.
I found some things I didn't like with Bush after his first term, but when Kerry came up as the Dem candidate I felt I had no other choice (like this time around if it's Hillery). Except now, the Republicans seem to have fully joined with the Democrats in only fielding people from the ruling class. By ruling class I mean people that have little to no connection to the middle class. Any connection displayed to the middle class is nothing more than smoke and mirrors designed only to get votes and money.
In my amateur's view of history I've seen this before. Both parties like the lower class because it is easily controlled with incentives. The lower class lacks the ability/desire to be free actors in life. The upper class does everything in its power to keep more households from joining its ranks as that would mean its influence would become watered down. The upper class *hates* dealing with direct competition.
That leaves the middle class. It is what moves society forward. The middle class, in effect, is society/culture.
What I've seen in other countries that have done well for themselves only to up and die in under a century is the ruling class (aristocracies, theocracies, and plutocracies) kills off (literally or through sanctions) the middle class.
In the US and too many other countries, I'm seeing the middle class having less and less of a say in how things get done. I'm seeing in the US the ever increasing debt load carried by people who should know better. I'm seeing the middle class killing itself through manufactured need for shiny toys that have no use beyond limited entertainment.
Bread and circuses.
Makes me worry.
It's frustrating.
I found some things I didn't like with Bush after his first term, but when Kerry came up as the Dem candidate I felt I had no other choice (like this time around if it's Hillery). Except now, the Republicans seem to have fully joined with the Democrats in only fielding people from the ruling class. By ruling class I mean people that have little to no connection to the middle class. Any connection displayed to the middle class is nothing more than smoke and mirrors designed only to get votes and money.
In my amateur's view of history I've seen this before. Both parties like the lower class because it is easily controlled with incentives. The lower class lacks the ability/desire to be free actors in life. The upper class does everything in its power to keep more households from joining its ranks as that would mean its influence would become watered down. The upper class *hates* dealing with direct competition.
"Competition is sin." - John D. Rockefeller
"If one understands that socialism is not a share-the-wealth program, but is in reality a method to consolidate and control the wealth, then the seeming paradox of super-rich men promoting socialism becomes no paradox at all. Instead, it becomes logical, even the perfect tool of power-seeking megalomaniacs. Communism, or more accurately, socialism, is not a movement of the downtrodden masses, but of the economic elite." - Gary Allen, author
That leaves the middle class. It is what moves society forward. The middle class, in effect, is society/culture.
What I've seen in other countries that have done well for themselves only to up and die in under a century is the ruling class (aristocracies, theocracies, and plutocracies) kills off (literally or through sanctions) the middle class.
In the US and too many other countries, I'm seeing the middle class having less and less of a say in how things get done. I'm seeing in the US the ever increasing debt load carried by people who should know better. I'm seeing the middle class killing itself through manufactured need for shiny toys that have no use beyond limited entertainment.
Bread and circuses.
Makes me worry.
My wheel dresser arrived
Worked nicely.
Now that I'm using light pressure on the wheel I notice no real wear.
I made my first attempt at using my templates. My thinking is that if I get that down, symmetric cutting will soon follow.
I found this to be very difficult. The four I tried ended up smaller than the template. I tried leaving one millimeter but working the bulges took too much off. I'll try leaving more space next time.
Waiting on the 600 grit paper and the diamond book to arrive. With a light touch I'm able to make the sandpaper last longer, but I keep running into little facets when the paper is near worn. I'm leaning towards sanding with diamond at this point.
Now that I'm using light pressure on the wheel I notice no real wear.
I made my first attempt at using my templates. My thinking is that if I get that down, symmetric cutting will soon follow.
I found this to be very difficult. The four I tried ended up smaller than the template. I tried leaving one millimeter but working the bulges took too much off. I'll try leaving more space next time.
Waiting on the 600 grit paper and the diamond book to arrive. With a light touch I'm able to make the sandpaper last longer, but I keep running into little facets when the paper is near worn. I'm leaning towards sanding with diamond at this point.
Sunday, September 30, 2007
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
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
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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