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In quest of the best material for vibration control. There are so many schools of thought on this it is pointless to insist that one solution is best. There have been persistant rumors that graphite can offer excellent performance as a vibration management tool.Looking around I didn't see mainstream audio companies selling it. Research time. The first thing you'll discover is that there are many, many grades of graphite. There are porous, sooty, low density forms (extruded), less porous, harder, higher density forms (isomolded) and minimally porous, hard, dense forms (compression molded).
I ordered two slabs of the medium porosity/density isomolded graphite plate from graphitestore.com . These may go under my speakers.
The package arrives. Inside is filthy from carbon dust. Two plates are carefully removed. The graphite is a fairly light material that feels about as dense as a heavy hardwood like ebony or lignum vitae, maybe a little heavier. This grade in 1/2 inch thickness has a soft ring to it when tapped. Somewhere between a wood tone and an ceramic tone, a sweet sound. The material is obviously fragile, and exceedingly dirty to handle. Two reasons it may not have passed the mass market test.
To control the dirtyness I place each slab on three soft gum artist erasers, the cube shaped natural rubber ones you buy at artists stores, and paint them with a heavy coat of thinned C37 laquer that I had no other use for at the moment.
The grapite has a powerful capillary action. It could draw the equivalent of about three normal coats of laquer completely into the slabs so there was no visible laquer coat. Carbon has this weird ability to absorb stuff that I haven't seen in anything else. It was unusual that a thick fluid like the C37, like honey even when lightly thinned, could be drawn through the pores so none remained on the surface.
After 24 hours the C37 has reached a "soft dry" as shown by the spilled laquer (or varnish is closer to the truth) near the slabs. Once sealed with the C37 the graphite is completely clean to the touch.
So far the sealing has made the tone of the slab softer and broader as a quiet "bong" sound when rapped with a knuckle. Another unusual property of the graphite is that when the slab is stood on end and tapped, there is no sound at all. Only a quiet thud of being tapped. It seems that graphite changes its nature substantially when constrained. It clearly isn't like other materials in use at present.
The other mentions I have heard about graphite are that it makes things sound dynamic, alive, involving, palpable, and other adjectives. No specification of which type of graphite, what shape, thickness, etc has been given though. The experiment continues.
Follow Ups:
I use cabon quite a bit in various hobbies and if you sand or machine this material you need to wear a resperator. Not those cloth or paper masks as they are next to useless.The dust is very persistant and difficult to remove from your working enviroment so try to do any sanding etc. outside if possible.
Use a fine particulate filter reperator.
Tony D.
There are specialty graphite companies that can do intense 3D machining. If you can give them specs, they can cut it , turn it, whatever you need. My first step was to seal the graphite with varnish to lock the particles. It now handles like a clean material. Raw graphite is dirty as all get out. If I were planning to work it with a power tool I would use a HEPA grade respirator, the ones with the pleated dust filters. The common hardware store dust masks are passable for drywall sanding and coarse sawdust, barely. But grind graphite at home ? Yow..... you'de never get the soot off.
Could you describe that in more detail? :-)I'm eager to hear your listening impressions.
As for finishing, perhaps an epoxy would be more appropriate than the lacquer? I haven't used or seen the C37. I'm thinking the epoxy that's meant for table tops might work well, although, it takes upwards of 72 hours to fully cure.
I wonder if a thin sheet of the graphite would enhance the performance of a Symposium clone platform? I'm guessing yes.
-Pete
Pete: I noticed on this week's special at Take5Audio a Black Diamond shelf, looks like it is carbon on top. Could not find any info about it though....
that if you're gonna use a shelf, carbon fiber would be the most ideal material since it is essentially the lightest, stiffest material available, in addition to being highly non-resonant. It is, however, cost prohibitive for most people.-Pete
the purpose of the carbon fiber is that it makes stiff composites when embedded in a plastic matrix. Pure graphite has a distinctly different behavior as the graphite acts as an amorphous solid. Black Diamond is a dead sounding product. Some have complained that it is so good at vibration damping that it can take the life out of sound. I have also used cryo treated maple that is lively. When I put it between the Black Diamond and the electronics, the sound takes on a higher presence. Sometimes too much presence in a narrow bandwidth. Graphite sounds like it has an ring tone, although this is GM10 graphite (after double checking , an 8% void, not 4% as I had thought) but it has also been described as vivid, juicy, dynamic, etc.... almost the opposite of the Black Diamond... we'll see,,,
Enjoy the adventure, sounds like a fun one!
something else. Just reminiscing about the old college days. Never mind.
Some of the best times I'll never remember.....-Pete
Ihen the graphite plate is supported on three points by the gum rubber erasers and tapped in the center it has a soft tone. The big question in my mind is how this tone is a result of the porosity. There is a large variation in porosity depending on the grade. Porous graphite could be around 15% void and pressure molded could be as low as 1%. The stuff I have is about 4% void I think. The strange thing is when it is constained somehow, like sitting in on one edge, how much more damped it seems. On the subject of epoxy, I've never liked the sound of raw epoxies. They sound hard plastic. I got around this by mixing my epoxy resins with superfine (15 micron) industrial diamond powder. The result is absolutely awesome. Lightning fast, no blurring, in some applications it can redefine the concept of "smeared", and tough as all get out. Diamond has a Young's modulus four times greater than Beryllium, so there is just no stored energy hangover. I can't remember the exact ratios I used on my last project, I believe it was 50 carats of 15 micron (1000 mesh) for 4 of the double syringe things of 2 ton epoxy. For crossovers and live circuits you have to use low emission electronic grade epoxy.All in all, carbon is wild stuff. I think we're only scratching the surface. I'm toying with the idea of combining ultrfine(1 micron) diamond with C37 for a paint on coating for chips. Diamond has excellent thermal conduction too.
I've had good results combining silica sand with epoxy in the past - very hard and non-resonant. I've also mixed brass powder (very fine filings) in with epoxy so that I could drill holes in it after curing (I don't have the right tools to drill into the silica/epoxy mix - it's not just hard, it's ultra-abrasive).The diamond powder is an interesting option - how much does it cost and where do you get it?
-Pete
Is totally non-conductive and chemically non-reactive. Be careful of metal fillers in epoxies because they might result in electrically conductive epoxy. I buy my diamond from SMG in Berkeley, CA. They have various grades from about 50 cents to 2.50 a carat. Now that I think about it, I used 100 carats, not 50, in my diamond/epoxy mix.... maybe... it was a while back. I assure you though, it is a quantum leap ahead of any other filled epoxy in terms of absolute physical stability. Around my speaker terminals everything locked in so tight it sounded as if the pre epoxy speakers were fuzzy blurred things....Another cautionary note you must take seriously. Industrial diamond is an inhalation hazard. Although the particles are small, they are engineered to be as sharp as possible. They will do some damage to your lungs if you breathe a cloud of diamond powder. Super fine powders aren't too common in daily life. A one micron dust is essentially the fineness of smoke particles. If you dump it out of the bottle, it will cloud like smoke too. You must use a fine dust mast and very, very carefully nudge the powder out or spoon it out slowly. DON'T just plop it into a bowl like you might do with a carbide grit. It would be like breathing a cloud of microscopic knives.
I see also that fullerenes are now in production. Haven't bought my first bottle of buckyballs yet but it sure is interesting as a concept. Buckyball filled epoxy ?
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