Subject: [alfa] Carbon fibre body panels

[RonHorowitz <RonHorowitz@xxxxxxxxxxxxxx>]

Howdy, Folks,

FWIW, I've worked with both carbon and fiberglass. I don't particularly
like either one, or better make that I dislike both, but whatever. I
thought I'd throw in my .02:

Yes, pre-preg is stupid expensive. The way I see it, the biggest advantage
of pre-preg is that you don't have to worry about wetting out all the
fibers or getting too much resin, etc. IMHO, what you gain with prepreg is
mostly process control. There may be other advantages in aerospace, or
whatever, but for the hood of an Alfa, especially one that's going to get
painted, I don't think prepreg has enough advantage over a "properly" laid
up part done wet. Of course, there's the rub, because "properly" isn't
always achieved using $8/hour flunkies, and the work is so labor intensive,
you can't afford to have it done by rocket scientists. In Formula One or
Aerospace or whatever, people are willing to spend a little bit of money to
get things done to the highest possible standard. In my experience, most of
the guys who own old Alfas are motivated instead by the lowest possible
price. (OK, here's where you guys are supposed to get offended, make
mountains out of the exceptions, and generally generate a flurry of
cognitive disonant clatter.)

As far as the carbon fiber stuff for the sports compact market made in
China, some of it is awful, some of it is quite good. You can get _almost_
anything you want made in China to about as good a standard as you're
willing to pay for, _if_ you're willing to invest the time and effort
developing your vendors. Few people bother. The fact is, almost everything
is being made in China.

As far as the vacuum bagging and autoclaving, I did some work for a fellow
named Udo Gietl who built parts of his sailboat out of carbon fiber. He
used plastic bags and heat lamps, and he's got "the fastest sailboat on the
west coast." Of course, he's also run racing teams for Honda and BMW, so
he's pretty good at what he does, but the point is that it's possible if
you know what you're doing.

>
>the hoods being offered at the prices quoted are not genuine carbon fibre
but
>imitations largely with a glass fibre core and made to look like CF.
>

A lot of carbon fiber part are laid up just like normal fiberglass. In
fact, it's common for structural carbon fiber parts to have a layer of
carbon on the outside, a layer on the inside, and a core of fiberglass on
the inside, sort of like an Oreo cookie. As long as the filler holds the
skins in place, the skins are what matters.

Regardless, if you're interested in fixing the dents in your hood (as
opposed to scoring max cool points,) I hate to be a wet blanket, but where
I you, I'd just fix the dents. For one thing, when / if it gets dented
again, steel gets fixed with a hammer and dolly, while fiber gets "fixed"
by cutting patching, slopping, gooing, curing, gel coating, sanding,
whatever.  I'd rather work with steel than fiber-anything, but YMMV.

RON
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