Observation about sharpenability - nomi

They are a common machine shop stone

Bill Tindall, E.Tn.

Well they used to be before CNC machining and insert bits. I have several silicon carbide stones that stay in my old fashion metal working area for all the reasons you listed. A long time ago a particles shed from one of these shedding stones and embedded in a piece of wood. It milled a nice scratch across the bottom of a near new LN plane, through the blade and beyond. I can imagine that they cut quick immersed in oil, but who has that set up in their shop. Again, I used to see this set up in machine shops but I will bet no more.

who has the IM 313?

David Weaver

I'm not sure - I have one in my shop. The reason I got one is because someone else got one and told me it'd be the last piece of sharpening gear that ever left their shop.

Lee Richmond probably sold quite a few of them as he had the stones changed to options that would be more sensible or grinding to finish of woodworking tools. When I got mine, the oilbath with three stones (the finish stone as a norton translucent) was about the same price as any of the sets of boutique waterstones.

I don't like a translucent in it, so I sold that and put a cheap dan's "hard" (their second finest stone grade) in it, which made it a $200 gadget instead of $300.

For filthy people like me, the oil bath and lid are very useful. Even if you get filth on a stone, as it rolls around, the oil will flush off the filth (metal dust, whatever), leaving it in the bottom of the bath.

Re: who has the IM 313?

Jack Dover

I used to think it's a gimmick. Then I've seen you using it on YT for the very first time and now I want one. Or rather something like it, but for arbitrary sized stones.

I have a Norton crystolon stone btw. The Norton crystolon stone has to be cleaned thoroughly and frequently, because it goes from fast to medium-slow as soon as there's even a little bit of slurry developed. I read somewhere that it's supposed to be soft and dish fast, but it hasn't been a problem so far: it's soft, but it doesn't dish that readily. It is used to remove a unicorned edge when a grinder can't be used (too late at night). I still wouldn't consider it a substitute for a grinder, I don't think any stone can be a decent substitute for even a cheapest grinder.

I also have a worn grinding wheel from an old grinder, it's below 60 grit and from an unidentified manufacturer, had a label that said "Carborundum". I wanted to use it as my coarsest stone before I knew about different binders. It's super hard and predictably stops cutting within seconds. Freshening it with a diamond helps for a bit, but even freshened it's marginally faster than a diamond plate, so it's literally a door stop now.

carborundum grinder wheels...

David Weaver

..not sure where they're used if the binder isn't friable because the silicon carbide crushes to bits right away.

I can't remember what I said earlier in this thread, but the IM-313 carries all of that oil so that just a rotation around if it starts to cut slow and everything is flushed out. A couple of swipes and all of the loose stuff floats away into the bottom. It's wonderful as long as you're not sharpening something that carries the oil off of the stone too far (past the side of the tub).

I would never give it up. I've made at least 6 irons this week now, and it's gotten heavy use. re: the carborundum stone in the IM 313, it may be close to grinder speed, but hollow grinding only is more accurate. i guess the virtue of the crystolon in the oil bath is that it could be used for 20 seconds in each cycle and no grinder would ever be needed (still like the grinder, though) - but beyond that, when you bring a knife to it and set the bevel of the knife, it's so few strokes for it to set the bevel, and it's set in the shape then that you freehand sharpen (so it's not like belt grinding a secondary and then finding that it doesn't quite match your hand sharpening shape).

My guitar teacher when I was a kid had a saying, but i'll just have to say..."the IM-313...if I was a bull, I'd say it's udders".

Re: carborundum grinder wheels...

Jack Dover

The wheel came with a hand cranked grinder, this and the looks of a label (which I've scrapped off already) kinda tells it could be one of very early wheels. The wheel is about 5" in diameter, maybe a hard binder is why it's not worn - it just didn't cut, generated lots of heat and was put aside.

I was thinking about an oil bath because crystolon is porous, so everything just soaks right through and and then this slurry — it get really messy really quick. Also that Pike brochure recommends cleaning stones as soon as there's swarf, so the idea of a stone suspended in oil comes to mind. Kinda like people do water ponds for waterstones, just with oil. Too bad my primary stones are glued to a wooden base, so I have to figure something else.