NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on May 7, 2019 14:35:29 GMT -5
I have a couple of hours free time on my hands today, so I decided to see if I could cut small slabs using the 7" trim saw I had. Here is what I came up with:    After some frustration, this did end up netting me a few small slices of rock. But I kept hearing this voice in my head. It sounded like it was coming from far far away, in a recessed and seldom accessed portion of my brain. I think it was Intellect. I felt like I was breaching new boundaries and attaining new levels of stupid. I kept waiting for the explosion or expected failure in my execution where sharp parts would go flying everywhere at high speeds. Luckily it didn't happen. My first question to the experienced is whether this is smart and safe. I am also open to any variations or other creative techniques of getting small slabs from a small trim saw. Thank you. |
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Post by MsAli on May 7, 2019 14:44:49 GMT -5
I can tell you one thing from personal experience : Make sure that baby is grounded, keep your body away from the metal and stand on a rubber mat. Getting electrocuted is not fun
The others here are way better at giving other advice o
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Post by aDave on May 7, 2019 14:51:18 GMT -5
I'm definitely not experienced, but my biggest concern is the use of only one clamp. Can you get a second one next to it to make two points of contact? With only the one clamp, there may be a potential for the rock to rotate on the axis you created. Having the rock rotate could cause it to dislodge and be thrown, or it might bind and damage your blade. ETA: NevadaBill , the other problem will be your potential inability to get parallel cuts for your slabettes since you'll have to unclamp and move the rock for each cut you make. The raised ruler on your table sets you up nicely to be able to clamp and use a fence across the table, as long as your fence has an end that's square. Simply butt the square end against the ruler, and you should be parallel to the blade. To do your slab, just make an end cut on the rock to create a flat surface and then hold that surface along the fence to cut your slab. With such a setup, parallel cuts are more likely, and you'll be able to use the ruler to make accurate incremental movements of the fence to get consistent slab thickness. |
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Post by stardiamond on May 7, 2019 15:25:18 GMT -5
I can't tell from the picture if you have a moveable table and what you are lacking is a vise to hold the rock.
In 2002 I bought a Genie that came with an almost free trim saw attachment. In 2007 my wife told me to buy a slab saw, so I bought a Covington 16" combo saw. I had a full time job, had little leisure time and chose to spend it cabbing instead of cabbing and slabbing. The Covington sat in the box until 2014 when I retired. I used the Genie trim saw for over 12 years to slab small rough.
The trim saw has an 8" MK303 .032 blade or the equivalent. I hold the rock in my hand and push it through the blade. I bought another plastic Genie trim saw table and attached some heavy aluminum L stock with wing nuts as a saw guide. It didn't work any better than cutting without the guide. I mark the first cut with a marking pen and start cutting around the line. When the cut is straight I just continue to push the rock through the blade. When the rock is too large to push straight through I rotate it as it is being cut and end up with a small nub in the middle.
Many people here use the rotating technique. Since I use the slabs to cut cabs, they don't have to be perfectly even. With years of practice I do a pretty good job. The biggest downside to cutting rough is I wear out blades much faster then trimming. A slab saw advances the material much slower than me pushing it though.
My next significant lapidary purchase will be a 10" slab saw. The smaller blade chews up less material and most of my remaining rough is small.
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Post by greig on May 7, 2019 16:15:19 GMT -5
I don't use a clamp and just hold the rock firmly in my hand. I still have all of my fingers. If a rock jams or breaks, it will fly away from you because to the spin direction of the blade. On a few of my cuts, I would not want to be standing on the other side with the table at waist height, awaiting a hunk of rock at baseball pitcher's speed .
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on May 7, 2019 18:12:42 GMT -5
I'm definitely not experienced, but my biggest concern is the use of only one clamp. Can you get a second one next to it to make two points of contact? With only the one clamp, there may be a potential for the rock to rotate on the axis you created. Having the rock rotate could cause it to dislodge and be thrown, or it might bind and damage your blade. ETA: NevadaBill , the other problem will be your potential inability to get parallel cuts for your slabettes since you'll have to unclamp and move the rock for each cut you make. The raised ruler on your table sets you up nicely to be able to clamp and use a fence across the table, as long as your fence has an end that's square. Simply butt the square end against the ruler, and you should be parallel to the blade. To do your slab, just make an end cut on the rock to create a flat surface and then hold that surface along the fence to cut your slab. With such a setup, parallel cuts are more likely, and you'll be able to use the ruler to make accurate incremental movements of the fence to get consistent slab thickness. Thanks Dave. Yes, actually the rock did rotate some. I have another clamp, and will use both together if I try this setup again. Yes, the blade kind of does not like to be completely immersed inside a rock. It is too much heat and friction. So, yes, I have to cut from various sides, and angles become an issue. I like the fence idea. I have to think about how to design one. The ruler does not offer as much surface area as I like though. Originally I had the clamp on it, but it kept coming off. I like the end cut idea to create flat surface. I thought about it, but had a rock that was kind of flat this time. Next time, I will do that. I appreciate it. |
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Post by stardiamond on May 7, 2019 18:21:51 GMT -5
I created a slot with a drill and attached with wing nuts. Even though the L seemed firm, I had trouble maintaining even presuure.  |
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on May 7, 2019 18:22:48 GMT -5
Yes, stardiamond, it has a movable base. The side with the rock on it, is on wheels. And the ruler in the back can also possibly be used to help brace the rock, or clamp the rock to the movable base. In the past months (since owning the saw), I have used the cut-by-hand (rotating technique) method to slowly work 360 degrees around larger rocks to make longer cuts. Mine come out sloppy. But you are right, they don't have to be perfect. I guess I was trying to come up with something where I wasn't holding the rock in my hands so much, as the forces behind the saw are great, and it only needs to bind just a bit, to pull the rock right out of your hands and shoot it across the room. Even with that ruler / fence to hold it against. It's happened twice and scared the snot out me. I really appreciate your input. Some day I would like a slab saw too. I just don't have any place to put it yet. |
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on May 7, 2019 18:25:33 GMT -5
I don't use a clamp and just hold the rock firmly in my hand. I still have all of my fingers. If a rock jams or breaks, it will fly away from you because to the spin direction of the blade. On a few of my cuts, I would not want to be standing on the other side with the table at waist height, awaiting a hunk of rock at baseball pitcher's speed . Yes, I have done this "rock firmly in hand" method. A lot. Great advice to stand on the opposite side of the saw. I do this too. I just wish I had hands of steel. My weakling hands get tired though. |
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on May 7, 2019 18:28:14 GMT -5
I created a slot with a drill and attached with wing nuts. Even though the L seemed firm, I had trouble maintaining even presuure. Great picture of the solution. I appreciate you taking the time to show me this. I am going to use something like this, and might combine it with Dave's idea, to perhaps create some kind of support. Going to have to think about this. |
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on May 7, 2019 18:37:12 GMT -5
Thanks for the suggestions so far, all. I received a PM from another RTH member, who has just suggested using a standard yellow wood type of glue, to actually glue the rock to a small section of 2x4, which is a couple inches long. Then, the 2x4 could be clamped, fenced, or what have you, a lot easier to the saw (or in my case, the movable base). The only concern is that yellow wood glue will disintegrate in water somewhat, and the stone might become dislodged prematurely. Perhaps if some of the rock is ugly and won't be used, a sufficient portion of it could be epoxied to a piece of wood. And make the glue permanent. When done, just cut back the 2x4 right behind where the rock is glued. Odd, I just came across an article like this, just now when searching for this.  Haven't read the article yet, but I imagine he is trying to do something similar. |
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Post by stardiamond on May 7, 2019 18:51:05 GMT -5
I use water glass. It dissolves in water after a while much better than wood glue. My slab saw uses oil. I don't know how long the water glass would hold cutting with water.  |
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Post by opalpyrexia on May 7, 2019 21:06:25 GMT -5
I use water glass. It dissolves in water after a while much better than wood glue. My slab saw uses oil. I don't know how long the water glass would hold cutting with water. After you're done slabbing, about how long does it take for the water glass to dissolve in water? A day? A week? A month? |
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Post by stardiamond on May 7, 2019 21:54:47 GMT -5
Less than a day. I toss the end cuts with the boards in a large bucket of water.
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Post by opalpyrexia on May 8, 2019 19:29:45 GMT -5
I have one more question about water glass, stardiamond. I have a polished end cut that is thick enough to yield 3-4 slabs. Will water glass form a strong enough bond with a polished surface, or is it necessary to rough up that surface to 600 or 1000 grit? |
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Post by stardiamond on May 8, 2019 19:39:55 GMT -5
I don't know if I have done this. I have glued thick slabs slabs to the board. I had a thick polished piece of Stefoinite that I cut a bunch of slabs from but probably glued the back and cut toward the front
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on Jun 7, 2019 11:43:11 GMT -5
It's been a month since I've been able to visit this thread, so I apologize for orphaning the conversion. I wish I had seen the water glass post before. I also found this video a few weeks ago, by random, on youtube. This person is using Water Glass? to glue rocks to the wood. I don't know what Water Glass is, really. But it looks pretty easy to store and use in this video. I bought some yellow glue and some gorilla glue. If the yellow glue idea does not work so great, then I will try this Water Glass idea, or Epoxy (which I have no problem using either). I might PM you stardiamond (#stardiamond) for details. I talked with Walt about this briefly, and he sent me a recipe for making water glass. www.thoughtco.com/make-sodium-silicate-or-water-glass-608271But i am not so sure I understand, really. And as opalpyrexia mentions, the tricky part might be retrieving your stone from the wood block once you are done with it, and still would like to use the block (or the rock chunk) again. Thank you. |
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Post by stardiamond on Jun 7, 2019 12:22:00 GMT -5
Water glass should is not expensive and you can buy it on Amazon or a hardware store. I reuse my blocks.
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Post by rockjunquie on Jun 7, 2019 12:46:47 GMT -5
stardiamond, could you post how you make it? I am interested, too. I bought some sodium silicate for something else, so I have some to try. I'm not sure, but I think I have seen easier recipes than the one linked to.
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NevadaBill
fully equipped rock polisher
Member since January 2019
Posts: 1,332
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Post by NevadaBill on Jun 7, 2019 13:23:57 GMT -5
Water glass should is not expensive and you can buy it on Amazon or a hardware store. I reuse my blocks. Oh, I did not know that you could buy it. This kind of changes things. I was worried that creating it might be more of a science experiment than I could handle. But if I can buy it, and keep it in a jar, then this might be a solid choice. I have to see if the wood glues which i bought will fit the bill. They have to hold up to constant water (from saw), and not have a chunk fly off. If this does not work, then I will try the water glue next. I'll update my progress here. |
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