Making diamond glass cutter

I have used spelter to secure a diamond into a shank for a grinding wheel trueing tool. As I remember the spelter did not do well at wetting the diamond. Silver brazing would be another option. Might work better at getting a bond to the diamond.

Dan

That sounds good, but I wonder if I can get away with something less drastic for a glass cutter. I think the specific load is much less than what you needed. Does soft solder wet diamond?

What I have now is a really crude device, with a large piece of bort mounted in the end of a dowel with epoxy. It works, but I'd like to use a little chip and mount it in a pencil-sized steel handle.

-- Ed Huntress

Ed,

As a WAG - th>> I have a few carats of diamond bort here and I've wanted to make a

That sounds good, but I wonder if I can get away with something less drastic for a glass cutter. I think the specific load is much less than what you needed. Does soft solder wet diamond?

What I have now is a really crude device, with a large piece of bort mounted in the end of a dowel with epoxy. It works, but I'd like to use a little chip and mount it in a pencil-sized steel handle.

-- Ed Huntress

You could probably use epoxy in a pencil sized steel handle. As far as using something less drastic.........I was concerned with that when I use the spelter. But I used an oxy/acet torch and the diamond did not seem affected by it when I put the hottest part of the flame right on the diamond.

Dan

I saw a short film once of burning diamond, it said the activation energy was so high it was necessary to heat the diamond to white heat with OA then place it in liquid oxygen for it to sustain combustion. Looked much like the usual demo of sodium being added to dish of water and it fizzing around on top. Probably why they can braze diamonds into diamond dressing sticks.

Well, JB Weld is basically epoxy with filler. That works, although the big stone I'm using now probably contributes to the strength of the joint.

But it's a possibility. This is not a big tool I'm talking about and I'm not using it to make long cuts for window glass. I find that a regular roller wheel works better for that, especially with a little bit of caustic solution applied to the scratch. But the diamond is nice for small pieces, especially in thin glass.

-- Ed Huntress

Yeah, maybe that's the easiest, and it probably will hold. There's no harm in trying it; if it doesn't work, I'll just clean it off and try to join it with solder or braze.

Very interesting. I always wondered how much heat you could apply to diamond.

-- Ed Huntress

I don't think the alloy actually wets the diamond surface, it's more of a mechanical capture. I've read several old machinist's manuals where they just took a rod, thinned the end down, cut a small cavity in it to fit the stone, then burnished the edge down over it. The stone was then shaped on a rotating copper disk charged with diamond dust and olive oil.

I'm not sure a diamond would be any better than a sharpened tungsten carbide scriber for glass cutting. Either is much harder than the glass itself. Most of those old books predate the common availability of tungsten carbide.

Stan

Holy cow. Somehow I had the impression that it burned just like coal, but I realized that couldn't be the case because of brazed diamond tools.

-- Ed Huntress

Carbide is used for wheels, but commercial glass cutters sometimes use a diamond scratch tool. They're available commercially for around $8. I don't know how the pros decide when to use which but my experience is that I get a cleaner and better cut with a wheel-type cutter. The wheel just isn't convenient for very short cuts, or for curves. I want something that's pencil-like for those curved cuts.

I have one carbide-wheel cutter and it's lasted me for years. But I prefer the steel-wheel cutters that have five wheels on a rotating holder, which you just turn to replace a wheel when it gets worn. The steel cutters seem to be smoother-cutting than the carbide. Or maybe it's my technique.

-- Ed Huntress

Ed I was a little 'Ole sapphire cutter (gemstone type). We used hard wax. If a hole is close to the size of the stone and then hard wax is poured in to close the gap and fitting - it might lock it in for the little pressure needed.

This isn't candle wax - this wax is used to attach stones on holders and then they are ground using the holder as the handle.

Martin

Mart>> >>> I have a few carats of diamond bort here and I've wanted to make a

If that hard wax will hold it in there, then I'm surely OK with epoxy. OK, tomorrow I'll give it a try. Thanks to all.

-- Ed Huntress

Jewelers often re-tip prongs with the diamond in place. They'll take a serous amount of heat, but occasionally one will get slightly oxidized, or even break. If they have inclusions, that can encourage breakage. Don't know any of this from experience, just from talking with my old refining customers, most of whom became close friends through the years.

Harold

I'm not following. What's a "prong"?

-- Ed Huntress

Braze it! Silver (brazing) solder works too.

Steve R.

I have a commercially made diamond glass cutter, and the diamond is brazed. The tool is older than I am (67) and is blunt now. An attempt to sharpen it will be made, using a diamond mill in the dremel, and a bit of soapy water as coolant. It will have to wait until I get a roundtoit though.

Steve R.

"Ed Huntress" wrote in news:FQJZi.1228$nt7.1091 @newsfe10.lga:

Paint the diamond with a suspension of titanium hydride powder and then you can solder it with almost anything. plus you don't have to bury it to get it to hold.

Oh, that's interesting. I see there are some suppliers here in NJ, although I'll probably have to coerce the quanitity I'd need. I might want to try making a diamond dresser that way. I probably have 8 carats or so of bort, bought back in the 1930s by my uncle, who used it for lapping gages.

Thanks, Dan. I see that article dates from the early '50s. Is that the way it's done in industry today?

-- Ed Huntress

Somewhere in my good things down in the jun er shop I have a section of rim from a diamond saw blade that I picked up after a labourer who didn't know any better ran it dry cutting pavement on one of the paving jobs. It works great as a glass cutter - just wish I had picked up a few more sections. Gerry :-)} London, Canada