Hi John,
Ive been keeping a weather (snow) eye open and so far Ive seen nothing in
Meribel
to make me want to rush out. Im hoping the snow will arrive later in February
or early March when the days are longer.
Can you clarify what you mean by vent? Are you planning a NACA style inlet or
something
like a moulded duct? (i.e. something that opens into the cowling rather
than projecting out into the airstream).
Either way, for a splash moulding you need a good release system so that the
tooling
wont inadvertently bod to the cowl. Use Meguires No. 8 wax (about six coats
lightly polishing after drying) and PVA release agent lightly sprayed or
applied by hand with a lint free cloth. (See Easy Composites for consumables).
For the splash moulding you can use polyester resin rather than epoxy its much
cheaper and cures faster so you can crack on.
If you have it you can use Chopped Strand Mat (CSM) rather than woven glass
cloth
its cheaper and easier to build up the thickness though it doesnt look so
neat. (If you dont have any you can always use woven glass cloth).
Once cured and before you crack it off - drill two position reference holes
through
the splash moulding and the cowl this will enable you to secure it in exactly
the same spot using Clecos or small screws once you start using it to laminate
the new vent. (The holes in the cowl can be filled later).
Once the splash mould has cured, you can mark out and cut the required aperture
in the cowl.
>From this point on, I need to know exactly what shape duct/vent/hole you wish
to construct. Generally speaking, the best way to create a one-off vent is to
shape some blue foam into the required profile, carefully stick self-adhesive
aluminium tape (used for joining house building insulation block together) over
the surface of the foam model to form a good surface and allow it to release
after cure. Use the release agents above to coat the new foam model and the
splash
moulding, secure it in place (using the locating holes you drilled earlier
and pop-rivets, Clecos or screws.
Then you can laminate the new vent from inside the cowl, having first thoroughly
de-greased and rough-sanded the surrounding bond area.
The original Europa cowl was laminated using a temperature resistant polyester
resin so that it could withstand the high engine bay temperatures. The normal
epoxu laminating resin used in the construction of the Europa (Gurit SP20/21)
will not tolerate high temperatures and will rapidly age harden and scorch.
The resin I have use for this is the polyester tooling resin called Optimould
it cures to a white colour and will withstand the sort of temperatures found
under
the hood.
That should give you something to think about and get you started.
ATB
Nigel
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