[alfa] Carbon fibre body panels

["John Fielding" <johnf@xxxxxxxxxxxxxxx>]

Hi All,

I see this thread growing about new bonnets/hoods for Spiders etc.

A little while back I was attending a race meeting at Kyalami race track near Johannesburg
and I was introduced to a guy who makes the carbon fibre components for the top slaoon car
teams.  What he told me was very interesting!

True carbon fibre material is normally supplied in a version known as "pre-preg"
(pre-impregnated) meaning it is already saturated in the special resin that is used for
bonding.  This pre-preg material is shipped in an insulated styro-foam cool box and
carried in refrigerated cargo vehicles, the same type as used for hauling meat carcasses.
In store it needs to be kept at below -10C or it goes off after a few days.  The major
supplier is based in Germany and ships all over the world.  The shipping costs of a roll
about 1m long is very high because of the special refrigeration airplanes needed.  The
cost of a square foot of one layer of pre-preg would buy a good quality tyre!

To form a body component the layers of pre-preg are cut to size and laid criss-cross
fashion into a mould and heated to around room temperature so that the resin oozes out and
into the next layer.  Then it is placed in a special vacuum bag and pumped down to press
the layers together hard.  Then it goes into an autoclave oven to cure it at high
temperature.  The result is a very light but strong thin wall component.  The company I
used to work for made avionics for missiles nose cones and they bought in carbon fibre
nacelles because of the very temperatures experienced by a missile travelling at
supersonic speed.  Fibreglass crazes and burns at this air speed.

He told me the vast majority of components on the market today which sell at speed shops
aren't carbon fibre at all.  They use a dummy outer layer of special glass fibre made to
look like carbon fibre.  He showed me some of the spare body panels he was delivering to a
top team for the V8 class.  One front wing/fender cost about the price of a small saloon
car!

So I guess 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.

Just thought you would like to know!

John
Durban
South Africa
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