Home shop uses for graphite

Alright... I will keep you posted... I kind of like the cabinets too, I may replace some of my crappy shelves with these cabinets. Maybe or or both.

Cavities for zinc alloy casting

Best regards, Spehro Pefhany

Not exactly rocket motors, but the nozzles for them. Any rods about 2.25" in the bunch?

Jason

I once turned a complicated graphite part on the lathe and incorporated it into a casting pattern, pouring brass around it. Then, i knocked it out with a centerpunch.

I will find out. I was under impression that graphite burns, if so, how an nozzles be made of it?

Very nice. Looks like most uses center around two facts, one is that it is easy to machine, and another is that nothing sticks to graphite.

They're a nice worksurface for silverbrazing small objects.

You could make a diamagnetic levitation demonstrator and amaze your kids or grandkids.

Jeff

Graphite is pretty resistant to burning. Which is why its good for electrodes, rocket engines, etc.

You might be thinking of how pencils burn fairly easily. I believe this is the binder burning.

Nah...Alumina clay burns a whole lot less easily than graphite; in fact, not at all. Technically, it's already "burnt" (Al2O3).

Graphite burns just fine -- it's just difficult to supply it with oxygen, because it is pretty dense, only the surface few molecules are actually burning, and the CO2 evolving from that interface prevents more oxygen from getting in to the surface.

LLoyd

Works for lead, too. A coworker and I cast some enormous 10 oz. sinkers in a homemade graphite mold. These were wedge shaped and were the best I've ever seen in the surf with a current running, as good as spiders, easier to retrieve, and enough mass to launch a couple of big slabs of cut mullet into the wind. Took a hell of a stiff rod with slow action to work.

I think I still have a couple of those weights down in Texas. These were made ~30 yrs. ago.

Pete Keillor

I think you're right, graphite can burn, but it takes a nuclear melt down to start the fire.

No, not really. Graphite burns at about the same temperature as paper, or any other carbon-based material.

The problem with graphite is that it doesn't sustain combustion because of the issues I stated earlier.

Now... heat graphite in the absence of oxygen, chlorine, bromine, or fluorine, and it won't burn... just like anything else won't burn without an oxidizer. The difference is that you have to get pure carbon (graphite) damned hot to vaporize it (it doesn't have a liquid phase), and wood, plastic, etc doesn't have to be very hot before it begins to break down.

LLoyd

So, you're saying that in order to get graphite to burn, you have to vaporize it so that the O2 can get to the flame. You also state that it must get really hot to vaporize. Therefore, my statement about a nuclear melt down (think Chernobyl) to start the fire really wasn't out of line.

Short answer is they don't. I have some with multiple (10 or so) firings on them and they have shown virtually no signs of erosion. These were low/no metal content motors. A Sparky would erode them some I would think.

A burning nozzle would be a bad thing indeed! :)

Jason

No, no... I said it won't burn in the absence of an oxidizer. It ignites at something under 700F, easily obtainable from an ordinary fire. The problem is getting oxygen to its surface, and the fact that it tends to burn slowly. But, you don't have to vaporize it to ignite it.

It begins to sublime at 3675C (roughly) and boils at about 4200. That's about 6600F and 7600F, approximately.

LLoyd

Hmmmmm.

I got some salt peter laying around, and a whole shop full of graphite...........

I am now recalling having seen some Soviet nose cones from used nuclear warhead re-entry vehicles. Our mathematical physics professor (I was a student) did some classified research on air flow around them.

Thise cones were made of graphite and had plenty of evidence of erosion, but they seemed to have held up. The ones I saw were after they were actually tested.

So, I think, graphite burns but not as a single piece -- only in a pile.

My most immediate use would be to use them as electrodes for derusting.