I have been looking everywhere for information on making marble at home and cant find a thing… does any one here have a any good resources or how-to’s on making marble carbon?
I’m not sure what happened to my post because its not visible anymore… Like it was erased. Any way… I’ve been looking everywhere to find a proper method in making marble carbon… But found very little… Can anyone here share some techniques and/or resources in making marble carbon?
sorry could you post a pic or explanation, I have never heard of this. I can’t offer any advice but curious what you are talking about and its application.
What is marble carbon fiber? Picture?
carbon veil?
This is what it looks like… it is also referred to as composite forging
thats compression molded carbon fiber.
Tencate and Hexcel are some of the companies that make the stuff. its chopped prepreg put into a mold and compressed.
Search SMC, sheet moulding compound. Hexmc is one of the names. compression moulded in heated moulds with cycle times of minutes.
The Hexmc stuff comes in prepreg sheets, going off their website picture.
Is it only suitable for compression moulding or could it be used with vacuum bagging?
Compression molding, usually with pretty high cycle temps.
I’ve seen examples of people making this stuff at home using chopped strand carbon. I’m kinda surprised some haven’t heard of it…
Ya, for a home done solution (as opposed to buying the hexcel stuff which is meant for aerospace molds and starts at like 2000gsm or something insanely heavy) just get some 1/4 chopped tow and use a base of that as your visual layer. Then back it with normal wovens or unis as an actual structure. The marbled look is cool, Lambo has been using it quite a bit recently.
if youre using it in a mold, whats the point of backing it with cloth instead of the whole part made from chopped tow?
Probably getting an even backing so that part is strong everywhere
Yes, like CarbonCDM mentioned, the part will have very little strength to it if it’s made entirely of chopped strand carbon. It would be similar to making a part from fiberglass chopped strand mat, except that the carbon strands would be even shorter (I’ve only ever seen chopped carbon available in 1/4" [6.35mm] lengths, which is much shorter than the strands on fg csm.)
On top of all that, if you have any curvature to a mold and are making anything more than a flat part, if you don’t have it bonded to some sort of stabilized backing when you’re laying it up, you’ll end up with a pool of dry chopped carbon at the bottom of your mold :p.
I’ve never done it before but it’d be interesting to take a woven backing layer and spray it with, say, 3m 77, and then sprinkle some chopped carbon on top of it. That way you could lay it in as a sheet. Something of the same concept behind textreme.
interesting. are the problems you mention (strength and proper infusion) only with wet hand layup or infusion on dry chopped tow? i thought the chopped prepregs like hexcel and tencate were great for replacing complex aluminum parts and stronger then them as well.
yes, but the chopped prepregs, smc, needs quite some pressure to get it flowing in the mould cavities. Its not laminated, you place a charge in a mould, then press it. pressure and heat will cause the material to flow through the mould, forming it to a solid part
What Susho said, plus, the ‘chop length’ of the fiber tows in, say, the hexcel mold making prepreg, are a lot longer than a quarter inch. And again, they’re meant for making molds, not structural parts - a uni or woven carbon part with the same cross sectional thickness (and, obliviously, proper fiber orientation and bias) will be much stronger than a part made from the tooling prepregs that use chopped carbon tows. If I remember correctly the ‘lightest’ areal weight that the hexcel one comes in is like 2000 gsm (which is like 60 oz/sqyd); they’re incredibly heavy and bulky materials.
Also many of the products are not using an epoxy matrix. I know that they use PEEK and other engineering plastics as the matrix which are considerably stronger than epoxy
There is HexTool and HexMC, different intended usage. HexMC is for parts and compression molding, HexTool as a tool material and autoclave cured. Hex MC is interesting where you need an isoptropic replacement or as a replacement as a die cast part or Investment casting.
They´re specific strength/ modulus is interesting in that kind of enviroment.
I used it in a project combinded with UD prepreg in a pressed part. Worked really good, and saved tons of kitting/ Placement costs.