meviva
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Post by meviva on Oct 22, 2015 19:35:09 GMT -5
Capt, I cut Rio Grande agates all day long, day after day, with a porcelain blade (MK 225). It has been in service for nigh onto 3 years and still going strong. Porcelain tile is tough stuff, and a good porcelain blade should stand up to lapidary uses. I'd go for judging the culprit as a bad blade. Its hard to imagine someone twisting the stone enough to break outa chunk like that so its probably materials defect. Tom As to whether porcelain tile is just a thin hard layer on a crumby base, . . . maybe my wife only knows how to buy the expensive stuff, but a bathroom remodel a few years back required my contractor to buy a special blade for his tile saw, the regular tile blade wouldn't cut it. Just saying. I was just looking at the Lowe's website and the saw came with an MK 225. That's the one that broke. So maybe it was a bad blade. The Rio cut pretty easily....just a few minutes for each slabette. I need to get another blade...still doing some research but I'm not finding anything else that can be cooled with only water. Andrea
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Deleted
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Post by Deleted on Oct 22, 2015 19:56:05 GMT -5
It should be fine to use that blade. But agate seems to be very hard on even high end blades. Order a 303 from johnjsgems
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Post by Deleted on Oct 22, 2015 20:00:54 GMT -5
I'll take you word for it that porcelain is a 6-7, never considered it's hardness. But, I can cut a porcelain tile with a screwdriver, and tile is probably what your saw was intended to cut. Porcelain tile (most tile) is basically a kiln fired, or pressed, piece of clay or dust made out of pulverized rock. The "porcelain" is a thin glaze coating on top of the base material. I'm not saying that a tile saw can't cut some types of rock, many here only use tile saws. Just that the tile saw has it's limits. What sized blade are you needing for your saw? I'm sure folks here won't mind throwing out some suggestions for a proper lapidary blade. Please check the color of the raw side of the tile in is discussion. I have sincere doubt you are using a screwdriver to cut porcelain. You are probably cutting ceramic tile. Ceramic is clay tile and matches your description above. Some porcelain tile will scratch a Quartz crystal. A standard masonry drill will cut a hole in ceramic tile and will skid on the surface of porcelian. Ceramic tile is pink from iron content of the clay. Porcelain is white, no iron.
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meviva
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Post by meviva on Oct 22, 2015 20:13:50 GMT -5
It should be fine to use that blade. But agate seems to be very hard on even high end blades. Order a 303 from johnjsgemsThe only problem is that the 303 needs coolant added to the water, the one broseph82 mentioned is $50 a gallon and is to be mixed 1 part coolant to 10 parts water. I'm not sure it's meant for a tile saw.....would be very costly. Andrea
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Post by Deleted on Oct 22, 2015 20:14:53 GMT -5
Doesn't NEED it. Performs better with it. But not required.
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meviva
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Post by meviva on Oct 22, 2015 20:43:33 GMT -5
Doesn't NEED it. Performs better with it. But not required. That's good to know because that probably would be the best blade. Andrea
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Post by mohs on Oct 22, 2015 20:54:40 GMT -5
I agree water should be just fine especially at the rpm of a tile saw
Oil is definitely more beneficial on slower rpm saws
I hope you figure out what you did somehow that rock tweaked in the cut of that blade
mostly
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Post by paulshiroma on Oct 23, 2015 9:13:53 GMT -5
x2 on the dud blade comments above. That looks like a manufacturing defect in the blade. Good thing you didn't catch a finger in there. Dang ...
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Post by catmandewe on Oct 23, 2015 11:11:31 GMT -5
Blades for porcelain have a harder core and finer diamonds, it will work but it will take longer. Lapidary blades have a softer core and coarser diamonds, works good for hard rock but will chip porcelain. You can use either one for either job but life of the blade will depend on how it is used.
Tony
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Post by mohs on Oct 23, 2015 12:18:29 GMT -5
that harder core, w/hard rock, may equal more fragility in the rim of the blade ?
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Post by catmandewe on Oct 23, 2015 13:57:10 GMT -5
Very possible
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Post by Peruano on Oct 23, 2015 14:14:44 GMT -5
I always suspected my success with this blade (12" MK 225) rested on several factors: 1. I'm using a porcelain blade (high speed design) at a lapidary speed (slower rpms). 2. I'm using it with a mechanical feed (slow and steady). Probably about 1" in 7 minutes or so. 3. I'm using it with oil (covered and contained); I suspect the slots carry more lubricant up to the cutting surface, which might be messy if you were not covered or hand holding. 4. I'm cutting a variety of stuff, but mostly hard = still never seem to need to dress the blade. 5. I've never dished or dinged the blade due to its strength (thicker core). Sure I have a rock slip once in awhile, but nothing that has affected the blade. If anything I think its cutting better now than when I first put it on years ago. Its a happy blade even as a lonely little onion in a petunia patch. I'm still puzzled that it crapped out so quickly for you. Tom
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Post by Rockoonz on Oct 23, 2015 14:40:28 GMT -5
I see two things on your pic: 1] the edge of your sintered cleat looks very rounded, it normally takes a lot of use to do that to a blade. 2] The outside of your blade looks discolored, brown orangish and bluish. If that's true then the blade got real hot. Did you lose water while cutting? If my observations are accurate you may have been forcing the rock through too quickly. I still agree with Tony that since part of the blade disc came off with the cleat that it could also be a faulty blade. DON'T get a 303, a tile saw spins way too fast for it, especially with untreated water. Get a 225, it's made for straight water and high RPM. Don't push hard, cutting rocks by hand is a meditative action that builds patience
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meviva
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Post by meviva on Oct 23, 2015 17:44:16 GMT -5
I see two things on your pic: 1] the edge of your sintered cleat looks very rounded, it normally takes a lot of use to do that to a blade. 2] The outside of your blade looks discolored, brown orangish and bluish. If that's true then the blade got real hot. Did you lose water while cutting? If my observations are accurate you may have been forcing the rock through too quickly. I still agree with Tony that since part of the blade disc came off with the cleat that it could also be a faulty blade. DON'T get a 303, a tile saw spins way too fast for it, especially with untreated water. Get a 225, it's made for straight water and high RPM. Don't push hard, cutting rocks by hand is a meditative action that builds patience I did lose water for a little bit. I had the pump in a bucket of water with the hose on just a little but it was filling up too fast so I turned off the water and the bucket emptied. Maybe that's what I did wrong. I will be sure to find a balance with the pump/hose to keep the water in the bucket full at all times. I ordered a 303, the one that broke was a 225 but I may get another one and see how it goes. I will slow down and not push too hard. Is there a way to tell if I'm pushing too much or not enough? Andrea
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Post by Peruano on Oct 23, 2015 17:56:27 GMT -5
I occasionally cut slabettes with my 8" trim saw, but not liking rust or daily cleanup of that saw, I run oil. Maybe you can't slow a tile saw, but if you push too hard on my saw you can hear the motor slow down. Ditto if you don't push through in a totally straight line (the rock rubbing on the blade body, not just the diamond on the perimeter and immediate side) results in a lot of friction. That scarring on the side of your blade (central to the diamond) may suggest you were jamming the rock through at a less than straight line. The sawing should be relatively effortless with the main task being a gentle pressure and not deviating from a straight line. Noise and rpms are two factors you want to pay attention to in avoiding going too hard, too fast, and ruining a blade. I hope this helps. Tom
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Post by stephan on Oct 26, 2015 17:02:39 GMT -5
The Moh's hardness scale has two issues. One, it is ordinal, not cardinal. This means that values do not mean anything precise for which one could have meaningful unit. This means that things that are hardness 7-ish, are harder than 6, and softer than 8, but you do know how much. Also, the hardness is only a measure of well an item resists scratching. While this is essentially what the blade is doing (gradually scratching through your rock), there is also toughness to consider, which is completely different, so hardness doesn't tell you everything. Think of porcelain as more akin to sandstone,in that it is composed of many tiny grains that are held together by a glue, whereas an agate has a much more uniform crystal lattice. An imperfect explanation, but it should give you an idea of the difference
Also, I agree that I would not hand-hold a rock while sawing it (unless I'm trimming a slab). Too easy to move and apply uneven pressure. If you think you have steady hands, try taking a long-exposure photo without a tripod. Also, there is the safety factor of bits of rock (or blade) breaking off, and being potentially flung into your face.
Sorry you lost your blade.
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meviva
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Post by meviva on Oct 26, 2015 17:44:56 GMT -5
The Moh's hardness scale has two issues. One, it is ordinal, not cardinal. This means that values do not mean anything precise for which one could have meaningful unit. This means that things that are hardness 7-ish, are harder than 6, and softer than 8, but you do know how much. Also, the hardness is only a measure of well an item resists scratching. While this is essentially what the blade is doing (gradually scratching through your rock), there is also toughness to consider, which is completely different, so hardness doesn't tell you everything. Think of porcelain as more akin to sandstone,in that it is composed of many tiny grains that are held together by a glue, whereas an agate has a much more uniform crystal lattice. An imperfect explanation, but it should give you an idea of the difference. Sorry you lost your blade. Isn't a toilet made of porcelain? That doesn't seem to be grainy. Although I've never seen what it looks like if sliced. Just curious. Andrea
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