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(01-11-2020, 06:42 AM)Robin Dobbie Wrote: So what do you do with it? Just mix it up with some mineral oil on lapping plates?
That swarf falls onto your clothes, is sucked into your lungs and ends up being red blood. So, wear a respirator and go to the hospital with anemia. I mean, no one puts nails into a pan of water for their tea anymore. They just park the nails in their mouths, forget them, swallow the nails and go to the hospital with something that's not anemia.
Ps. Oh, the Boron nitride. Never mind.....
PPs. I ordered diamond powder recently to supplement the pastes I use. Jury's out, but it could increase abrasiveness of the swarf on the steel plates. I get very impatient with grinding process on Japanese hard steels. I think the grit may not be uniform. I may need to spend more time cleaning up the mess. Maybe the stuff will work ok on axes....
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My "finest" stone is a 600 Medium India stone....after that, I go with the 3m Wet & Dry up to 2500 grit..then the strop. And that is it....works just fine for what I do..
YMMV
Very simple, very quick...then right back to work....
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(01-11-2020, 06:42 AM)Robin Dobbie Wrote: Boron nitride, that's the stuff on those CBN wheels I read about recently. So it's second place to diamond as far as absolute hardness, but I'm confused about its other differences. I saw that its thermal conductivity is higher than AO such that it absorbs 60% of the heat generated in grinding vs 10% with AO. This was when the CBN was sintered into cutting inserts for giant metal cutting lathes. But I guess that's how those CBN wet grinder wheels are sold as dry wheels. In fact they say absolutely do not run them in water... what I don't understand with that is where the swarf goes.
So what do you do with it? Just mix it up with some mineral oil on lapping plates?
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So what do you do with it? Just mix it up with some mineral oil on lapping plates?
I use petroleum jelly for more "body"..it "stays together" better...but you could use any type of oil or grease for the carrier.....Years ago when I was in the lapidary hobby, we used cheap lipstick for the carrier. mixed it with diamond powder...Using boron nitride or diamond powder and vaseline on a flat tile or a lapping plate, the hardest of steels cut like butter..Diamond powder is available from lapidary suppliers in .5 micron if you want to go that fine...And the harder abrasives cut the steel rather than just "burnish".......You can see that easily when you charge a leather power strop with it, and use it correctly...Boron can cost more than diamond powder......but it has certain advantages in grinding.....It "breaks down" differently as I understand it.
The swarf is thrown off when wheels are used dry, and when a carrier is used, the swarf is trapped in the carrier..When I strop, the build up of the swarf and abrasive sticks to the leather and builds up, and has to be scraped off occasionally... but some of it is thrown off by the movement of the wheel or the belt if you are power stropping as I usually do. Too much "build up" can actually impede the sharpening because the abrasive breaks down and gets blended with the swarf.
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(01-11-2020, 10:34 AM)hbmcc Wrote: PPs. I ordered diamond powder recently to supplement the pastes I use. Jury's out, but it could increase abrasiveness of the swarf on the steel plates. I get very impatient with grinding process on Japanese hard steels. I think the grit may not be uniform. I may need to spend more time cleaning up the mess. Maybe the stuff will work ok on axes....
I always wondered how effective pastes would be for setting a bevel or flattening. I wondered how much the steel and the lapping surface affected things, in addition to the abrasive. I noticed one of the fancy pants woodworking brands(veritas) offered steel honing plates for $25 or something like that.
(01-11-2020, 11:32 AM)bandit571 Wrote: My "finest" stone is a 600 Medium India stone....after that, I go with the 3m Wet & Dry up to 2500 grit..then the strop.
I never noticed those india stones are a nice 8"x3", come with a case just like the shaptons, and are only $20. Very tempting to get one just to play with.
What honing compound and surface material do you strop with?
(01-11-2020, 12:33 PM)Timberwolf Wrote: I use petroleum jelly for more "body"..it "stays together" better...
That probably makes more sense than mineral oil. More closely matches the consistency of the ready-made diamond pastes I've seen people use.
Quote:The swarf is thrown off when wheels are used dry, and when a carrier is used, the swarf is trapped in the carrier..
That's what I thought. And some people use those CBN wheels at 3450(the smaller 6" ones). That's why I like wet grinding. Sure, the water gets gross, but then it's in the water not your air or respirator(hopefully). I feel like if I ever get into CBN wheels I'd set up a dust collection port right there.
Quote:When I strop, the build up of the swarf and abrasive sticks to the leather and builds up, and has to be scraped off occasionally... but some of it is thrown off by the movement of the wheel or the belt if you are power stropping as I usually do. Too much "build up" can actually impede the sharpening because the abrasive breaks down and gets blended with the swarf.
Yeah I noticed that happens even with the waterstones.
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So other than powered abrasives, I'm still wondering if people make their own stones. Like choosing an abrasive(maybe even refining it), making a binder, then baking it.
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(01-11-2020, 11:19 PM)Robin Dobbie Wrote: I always wondered how effective pastes would be for setting a bevel or flattening. I wondered how much the steel and the lapping surface affected things, in addition to the abrasive. I noticed one of the fancy pants woodworking brands(veritas) offered steel honing plates for $25 or something like that. I don’t know about the LV plates. I use surface ground cast iron and diamond paste. With 15 micron paste I was able to flatten the very rounded belly on an E A Berg stone in 15 minutes. It works exceptionalities well.
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They're low-carbon steel, but they claim they last a lifetime. I just don't get how that works, how they, or even cast iron lasts that long.
15 minutes yeah, seems like I was able to put a very noticeable and unintentional skew on my half-inch chisel in about that time on the 1000 waterstone.
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01-12-2020, 04:33 PM
(This post was last modified: 01-12-2020, 04:35 PM by Bruce Haugen.)
(01-12-2020, 01:48 PM)Robin Dobbie Wrote: They're low-carbon steel, but they claim they last a lifetime. I just don't get how that works, how they, or even cast iron lasts that long.
15 minutes yeah, seems like I was able to put a very noticeable and unintentional skew on my half-inch chisel in about that time on the 1000 waterstone.
I neglected to mention that the chisel I flattened was 2” wide.
The diamonds become embedded in the surface of the iron. The diamonds do the work. The iron is not affected, except after years of use. I use 15, 3 and 1 micron diamond paste. The 3 micron is for general sharpening and the 1 micron gives a very fine finish.
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(01-11-2020, 11:27 PM)Robin Dobbie Wrote: So other than powered abrasives, I'm still wondering if people make their own stones. Like choosing an abrasive(maybe even refining it), making a binder, then baking it.
I tend to not get involved in sharpening threads, most of my currently used stones are from flea markets, some natural stone, some manufactured (think Norton), and I really have no idea of what grit they are, just course, medium and fine, but they get my edge tools sharp, so I'm a happy camper. Outside of extreme grain issues, sometimes good enough is good enough.
I also power strop with compound, the effectiveness of which cannot be underrated.
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From some of the threads I've read that's likely a safe strategy! lol It's just confusing since "fine" varies so much. Like bandit571's post. I went looking for what he had and for whatever reason assumed he was talking about the Norton 8 x 3 medium india stone. Well, those are actually 220, not the 600 medium that he has.
When you powerstrop, how do you do that? Are you taking like a 80rpm thing or 3450?
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